2018 REPORTER 1

JULY 2018

Recent advances in development of noble metal-free electrocatalysts for water splitting

Page 10

Rechargeable metallic lithium batteries

Page 23

3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystalsThermoelectric (TE) technology, which converts heat into electricity, provides a promising route to environmentally friendly power generation through harvesting industrial waste heat. The conversion efficiency of thermoelectric materials is determined by the dimensionless figure of merit, ZT = (S2σ/к)T, where S, σ, к, and T are the Seebeck coefficient, electrical conductivity, thermal conductivity and absolute temperature, respectively.

2 REPORTER 2018

Beihang University REPORTER

CONTENTS//

Talent Attraction and Smart Participation: the 4th Vision Forum Held at Beihang University

Professor Wenfei Fan Elected as Fellow of the Royal SocietyNEWSp1

A review of the new provisions for sanctioning mentally disordered offenders in China, in a broader historical context

High-energy strong-field terahertz sources

Ti-Al-Si-N nanocomposite coatings deposited by high power impulse magnetron sputtering (HiPIMS) technique

Recent advances in development of noble metal-free electrocatalysts for water splitting

Distributed guidance for intercepting multiple UAVs

RESEARCH highlights

p6

Progress in neuroimaging analysis for aging and Alzheimer’s disease

Spatiotemporal crowdsourcing: a novel computing paradigm for the sharing economy

Rechargeable metallic lithium batteries

FEATURE focus

p17

COVER story

p14

3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystals

Thermoelectric (TE) technology, which converts heat into electricity, provides a promising route to environmentally friendly power generation through harvesting industrial waste heat. The conversion efficiency of thermoelectric materials is determined by the dimensionless figure of merit, ZT = (S2σ/к)T, where S, σ, к, and T are the Seebeck coefficient, electrical conductivity, thermal conductivity and absolute temperature, respectively.

2018 REPORTER 1

Talent Attraction and Smart Participation: the 4th Vision Forum Held at Beihang University

The 4th Beihang University Vision Forum for International

Young Scholars, sponsored by Beihang University and

organized by the Human Resource Depar tment , the

Internat ional Research Inst i tute for Mult id iscipl inar y

Science, and the Institute for Medicine and Engineering

Interdisciplinary Innovation, opened in the Vision International

Cultural Exchange Center on May 7, 2018. The Forum gathers

over 100 young scholars from world-class universities and

research institutions including Harvard University, Yale

University, Stanford University, Columbia University, Johns

Hopkins University and National University of Singapore. The

opening session, hosted by Vice President, Professor Wang

Yunpeng, had speakers including Professor Cheng Jiwei,

Deputy Secretary of the CPC Beihang University Committee,

Academician Fang Jiancheng, Vice President and member

of the Chinese Academy of Sciences, Academician Zheng

Beihang University REPORTER NEWS

Zhiming, member of the Chinese Academy of Sciences,

Professor Yang Lijun, Dean of the School of Astronautics and

Changjiang Scholar, and Professor Liu Zhiqi, scholar of Global

Youth 1000 Talent Program. The session also had scientists

and scholars with titles of honor, as well as Deans and

Secretaries of the University’s Schools.

On behalf of the University, Deputy Secretary Cheng

Jiwei gave his welcome speech. He congratulated on the

opening of the 4th Vision Forum and extended greetings to

the young scholars from around the globe. He pointed out

that Beihang has started the journey towards becoming a

world-class university and that members of the Beihang

University community, with “Beihang dreams” in their hearts,

are untiring in their efforts to pursue the original aspiration

and goals, believing that the very beginning mind itself is the

most accomplished mind of true enlightenment. Ever since

2 REPORTER 2018

is exposed”. He laid out the principles of an integrated

strategic plan aimed at strengthening engineering education,

enhancing science education, expanding cooperation with

medical institutions, and accelerating strategic layout for the

two campuses. The University is advancing the initiatives of

the Kunpeng Program and is making great efforts through

coordination of resources to provide greater opportunities for

talents based on improved systems and mechanisms, policies

and measures, and support and services. He sincerely

welcomes talented young people to join the faculty of Beihang

University and build the future together.

In the second half of the session, the talk of “Big Data

– from Newton's Scientific Way of Thinking”, presented by

Academician Zheng Zhiming, looked back at the Newtonian

theory and methodology, the Newtonian system of the

Beihang University REPORTER

its founding, Beihang has been recognized for its pioneering

work, advancement of ideas, and giant leaps in development.

It has made numerous achievements that are to be written

into the history. “Beihang model” exerts everlasting influence,

and “reliance”, “inclusion”, “harmony” and “platform” are

the four key words he gave for the reason why Beihang

deserves to be chosen. The University attracts talents with

platforms and mechanisms, increases group cohesion with

common career pursuits and responsibilities, and unites

efforts with reform and development. He sincerely welcomes

young scholars with academic accomplishment to return to

homeland and make dreams come true at Beihang.

Aligned with the objectives of the “Double First-Class”

plan and to provide better services for faculty to concentrate

on teaching and research, the proposal for the establishment

of the Talent Management Center and the Faculty Service

Center was approved by the University. During the opening

ceremony, Deputy Secretary Cheng Jiwei and Vice President

Fang Jiancheng unveiled the names to officially inaugurate the

Centers, and the University’s integrated talent management

system was formed.

“Knowledge is power, and talents are the future”.

Vice President Fang Jiancheng awarded the ‘Certificate of

Honor’ to the representatives of young scholars, expressing

his appreciation for the excellence in their respective field

of research, and hoping they would take this opportunity to

exchange ideas and learn from each other and to stimulate

vitality of scientific research and technological innovation to

achieve greater success.

In his keynote speech, Vice President Fang Jiancheng

presented the path taken by Beihang to innovation – a

path leading to a world-class university, and told the story

of the spirit, the heart of patriotism, and the dreams of the

pioneers, who, in over 60 years of time and through hard

working, have made significant achievements in the research

and development of unmanned aerial systems, aero engines,

and inertial navigation systems. In retrospect, he showed a

path of scientific and technological innovation by serving the

strategic needs of the country with decades of persistence,

perseverance, and endeavor — till “the edge of the sword

2018 REPORTER 3

world, scientific experiments in the late 19th and early

20th centuries, development and practice of science and

engineering in the mid 20th century, and scientific computing

and the era of big data since the 21st century, showed the

evolution of science and technology in modern times and

reminded the young scholars of the importance of scientific

method and scientific way of thinking in research. The

inspirational talk was followed by Professor Yang Lijun’s report

of “Challenges in High Thrust Liquid Rocket Engine Research”.

Professor Liu Zhiqi’s presentation was on “Electric-Field-

Controlled Memory Devices”. The reports were given in an

active and pleasant atmosphere with applauses from time to

time, giving the audience a great deal of inspiration.

During the two-day forum, the Schools comprehensively

introduced their research strengths, academic environment,

NEWS

and plans for talent team building, discussing the possibility

of future cooperation with outstanding young scholars. The

Human Resource Department, on the other hand, conducted

a talent review meeting for the “Zhuoyue 100” talent

recruitment and management program, implementing the

University’s strategies of talent team construction through

selection of outstanding young scholars.

The Forum, planned to be held twice a year, aims at

advancing the frontier of sciences and promoting scientific

research across disciplines as well as success of young scholars.

The Forum creates a platform and a network of academic

exchanges for outstanding young scholars worldwide on the

basis of the University’s strategies of becoming a world-class

university rooted in the homeland of China.

(Text by Wang Rui)

4 REPORTER 2018

Beihang University REPORTER

Professor Wenfei Fan Elected as Fellow of the Royal Society

Professor Wenfei Fan, chief scientist of Beijing Advanced

Innovation Center for Big Data and Brain Computing at Beihang

University, was elected as a Fellow of the Royal Society

among fifty other eminent scientists in May 2018, due to his

"outstanding achievements as a researcher".

Professor Fan is a computer scientist who has made

fundamental contributions to both theory and practice of data

management. He has both formalized the problems of querying

big data and has developed radically new techniques that

overcome the limits associated with conventional database

systems. In addition, he has made seminal contributions to data

quality, in which he devised new techniques for data cleaning

that have found wide commercial adoption. He has also

contributed to our understanding of semi-structured data.

Professor Fan is one of the top“all-around” database

researchers in the world. He is a recipient of the Best Paper Award

for ACM SIGMOD Conference on Management of Data (2017),

the Alberto O. Mendelzon Test-of-Time Award of ACM Symposium

on Principles of Database Systems (PODS) for papers with the

highest impact over 10 years (2015 and 2010), the Best Paper

Award for International Conference on Very Large Data Bases

(VLDB, 2010), and the Best Paper Award

of IEEE International Conference on Data

Engineering (ICDE, 2007). He is the Chair

Professor of Web Data Management at

the University of Edinburgh, a Fellow of the

Royal Society of Edinburgh (UK), a Member

of Academia Europaea (the Academy of

Europe), and a Fellow of the ACM (USA).

Founded in 1660, the Royal Society

is the national scientific institution with

the longest history in the world. The

society is the United Kingdom's and

Commonwealth of Nations' Academy of

Sciences and fulfils a number of roles,

to recognize, promote, and support

excellence in science and to encourage the development and

use of science for the benefit of humanity. Each year the Royal

Society elects up to 52 new fellows who join a cohort of the

around 1,600 of the world's most eminent scientists.

“Our Fellows are key to the Royal Society’s fundamental

purpose of using science for the benefit of humanity. From

Norwich to Melbourne to Ethiopia, this year’s newly elected

Fellows and Foreign Members of the Royal Society are testament

that science is a global endeavour and excellent ideas transcend

borders. We also recognise the cutting edge innovation

taking place across industry, with many of this year’s Fellows

coming from the thriving tech industry. For their outstanding

contributions to research and innovation, both now and in the

future, it gives me great pleasure to welcome the world’s best

scientists into the ranks of the Royal Society”, as put by Sir Venki

Ramakrishnan, the President of the Royal Society.

References

ht tps ://www.ed.ac .uk/ in format ics/news-events/

stories/2018/wenfei-fan-elected-fellow-the-royal-society

http://iriglobal.buaa.edu.cn/newsroom/events/102493.htm

2018 REPORTER 5

NEWS

Professor Wenfei Fan Elected as Fellow of the Royal Society

The story of the Royal Society is the story of modern science.

It started from a 1660 ‘invisible college’ of natural philosophers and physicians. Today it is the UK’s

national science academy and a Fellowship of some 1,600 of the world’s most eminent scientists.

Nullius in verba

The very first ‘learned society’ meeting on 28 November 1660 followed a lecture at Gresham

College by Christopher Wren. Joined by other leading polymaths including Robert Boyle and John

Wilkins, the group soon received royal approval, and from 1663 it would be known as 'The Royal

Society of London for Improving Natural Knowledge'.

The Royal Society's motto 'Nullius in verba' is taken to mean 'take nobody's word for it'. It is an

expression of the determination of Fellows to withstand the domination of authority and to verify all

statements by an appeal to facts determined by experiment.

Advancements and adventure

The early years of the Society saw revolutionary advancements in the conduct and communication

of science. Hooke’s Micrographia and the first issue of Philosophical Transactions were published in 1665

alone. Philosophical Transactions, which established the important concepts of scientific priority and peer

review, is now the oldest continuously-published science journal in the world.

It published Isaac Newton’s Principia Mathematica, and Benjamin Franklin’s kite experiment

demonstrating the electrical nature of lightning. It backed James Cook’s journey to Tahiti, reaching Australia

and New Zealand, to track the Transit of Venus. It published the first report in English of inoculation against

disease, approved Charles Babbage’s Difference Engine, documented the eruption of Krakatoa and published

Chadwick’s detection of the neutron that would lead to the unleashing of the atom.

The leading scientific lights of the past four centuries can all be found among the 8,000

Fellows elected to the Society to date. From Newton to Darwin to Einstein and beyond, pioneers

and paragons in their fields are elected by their peers. Current Fellows include Jocelyn Bell Burnell,

Richard Dawkins, Stephen Hawking and Tim Berners-Lee.

Independence

Over time, the criteria for, and transparency of election to the Fellowship became stricter, and

Fellows were elected solely on the merit of their scientific work. The first female Fellows were elected in

1945 – Dorothy Hodgkin, elected in 1947, remains Britain’s only female Nobel Prize-winning scientist.

In the 19th century, a Parliamentary Grant system was introduced, allowing the Society to aid

scientific development while remaining an independent body. The Society now allocates nearly £42

million each year from government grants and donations and legacies from organizations and individuals.

Peter Collins, Emeritus Director at the Royal Society, has written about the history of the

Society’s postwar activities in The Royal Society and the promotion of science since 1960 (published

by Cambridge University Press in 2015).

Through its policy work, journals, scientific meetings, events, worldwide partnerships and grants

and awards, the Royal Society works to support excellence in science, building a home and future for

science in the UK.

Source: https://royalsociety.org/about-us/history/

History of the Royal Society

6 REPORTER 2018

A review of the new provisions for sanctioning mentally disordered offenders in China, in a broader historical context

Reforms of the criminal justice system in China in recent

years have included the 2012 Code of Criminal Procedure

(CCP), which resulted in new disposals for mentally disordered

offenders. The 2012 CCP introduces the power of mental health

commitment by the judiciary for those found non-responsible for

an offense because of a mental disorder. As offending behavior

arising from a mental disorder is both an eternal and universal

problem, this paper takes a historical comparative approach

to comment on legislation that cannot yet be fully evaluated in

practice due to both its recent enactment and the difficulties in

accessing empirical data concerning the practice of criminal law

in China.

Taking a historical perspective, our research reveals that

in the East, as much as in the West, there is a ‘moral tradition’

of not punishing mentally disordered offenders who are not

considered responsible for their acts. The Western moral

tradition is usually traced back to the earliest recordings of

Hebrew Law, and the Chinese tradition can actually be traced

back to around the West Zhou Dynasty. Differences are more

obvious when it comes to the possible measures that can be

taken after an acquittal for being ‘not guilty by reason of insanity’.

Whereas Western jurisdictions have offered (criminal) courts

the opportunity for commitment in (forensic) mental hospitals

from the early 19th century, in China, disposal has remained,

until the recent changes, the responsibility of the administration

(mainly the police) or the family of the offender. A few high profile

cases brought to light the inadequacy of these arrangements

and the general disregard of obvious mental health issues when

sentencing offenders. There was a lack of clarity regarding who

would take responsibility for treatment and issues of future

public protection arising from a mental disorder.

Against such background, the most prominent reform

concerning this issue in the 2012 CCP is that the criminal court

itself can now decide on commitment to a psychiatric hospital

upon an acquittal on the basis of non-responsibility due to a

mental disorder. It is a vital approach to restrict the decision-

maker’s discretion, and, as a consequence, it is expected to

avoid arbitrariness of the government.

However, the praise must be mitigated, especially because

of the absence of a procedure for periodical judicial review, the

remaining procedural power of the ‘procuratorate’ in selecting

cases or challenging verdicts, the absence in the criterion for

dangerousness, and a related inequality of arms. In practice, also

the independence of the judiciary and psychiatric evaluators,

the quality of the legal aid and the quality of the treatment in

psychiatric hospitals increase concerns. Similar to provisions

in Western jurisdictions there remain human rights concerns

regarding aspects of the 2012 CCP and the role of ‘preventive

detention’ for mentally disordered offenders on indeterminate

secure mental health detention.

This study shows many similarities with Western frameworks

of preventive detention. As these frameworks are thoroughly

debated in liberal democracies as well, and they are concerned

with a similarly marginalized subset of people for which

basic human rights are not given but have to be struggled for

continuously, it is not an issue on which the West can easily

take the moral high ground as it can in commenting on other

aspects of criminal justice. Criminal justice concerning mentally

disordered offenders is a good starting point for legal reform,

because they are among the most vulnerable and in the greatest

need of effective defense.

Wei Pei, associate professor, school of law, Beihang University,

E-mail: peiwei@buaa.edu.cn

Michiel van der Wolf, assistant professor, Erasmus Law School,

Erasmus University, E-mail: vanderwolf@law.eur.nl

Reference

Pei, W.*, and van der Wolf, M. (2016). A review of the new provisions for sanctioning

mentally disordered offenders in China, in a broader historical context. International journal of

law and psychiatry, 49, 31-39.

Beihang University REPORTER

2018 REPORTER 7

High-energy strong-field terahertz sources

Terahertz wave (0.1-30THz), also named as submillimeter

wave and life-ray is located between microwave and far infrared

light in the electromagnetic spectrum. This frequency range has

not yet been fully studied and explored, but it has important

academic value and significant applications. The collective

vibrational modes of large molecules like DNA and proteins

correspond to terahertz frequency. The timescale of hydrogen

network dynamics of water is in the picosecond time with the

corresponding frequency of terahertz. However, when people

were trying to extend the electronic and optical technologies

into this special frequency range, they met lots of difficulties

and challenges, with “fertile ground” left in the electromagnetic

spectrum.

The bottleneck that hinders the development of terahertz

science and technology lies in the lack of highly efficient

terahertz sources, highly sensitive detectors, versatile functional

device, and a fully understanding of the mechanism of terahertz-

matter interaction. The lack of highly efficient terahertz sources

is significantly critical. Terahertz source based on ultrafast

laser technology is currently one of the best ways to obtain

high-efficiency, ultrabroadband, cost effective strong terahertz

sources. Among them, tilted pulse front technology is one of

the best choices for generation of low-frequency, high-energy

terahertz radiation.

RESEARCH highlights

Fig 1. The position of terahertz wave in the electromagnetic spectrum

8 REPORTER 2018

The tilted pulse front technique was first proposed by

Professor Hebling in 2002[1]. By tilting the pump laser

intensity front before the lithium niobate crystals, the best

phase matching and longer coherent interaction distance in

the lithium niobate crystal can be achieved, and the energy

conversion efficiency of the terahertz radiation can be scaled

up several orders of magnitude. However, the acquisition of

ultrafast super-strong terahertz sources requires higher-energy

femtosecond lasers as the pump source, and such laser pulse

durations are less than 50 fs. Such a narrow pulse duration

is unsuitable for the tilted pulse front technique. Therefore,

the use of high-energy ultrashort laser pulses with Joule-

level single pulse energy for milli-Joule terahertz generation

has been recognized internationally as a major scientific and

technical problem.

Recent ly, Beihang Univers i ty Associate Professor

Xiaojun Wu’s team cooperated with the Institute of Physics

of the Chinese Academy of Sciences, and overcame the

aforementioned problems. Employing 20TW high energy

ultrashort Ti:sapphire laser pulse, the researchers achieved

0.2mJ, 4 MV/cm strong-field terahertz pulses[2]. At the

9th International Symposium on Ultrafast Phenomena and

Terahertz Waves on April 23-26, 2018, Professor Hebling,

inventor of the tilted pulse front technique, listed this work as

the latest world record obtained using this technology, which

was presented in his thematic report.

Extreme terahertz science and technology have become the

second wave of research in the field of ultrafast optics and the

terahertz research fields[3]. Extreme terahertz science calls for

the emergence of ultrafast super-strong terahertz sources with

single-pulse energy >milli-Joule, peak power >GW, peak electric

field >10 MV/cm, and peak magnetic field >3Tesla. Under

extreme experimental conditions, the ultra-strong terahertz

sources can be used in various disciplines such as physics,

chemistry, materials, biology, and medicine. It is expected to

realize extensive cross-convergence with related research, thus

opening up wider application prospects.

Xiaojun Wu, associate professor, school of electronics and

information engineering, Beihang University, E-mail: xiaojunwu@buaa.

edu.cn

References

[1]J. Hebling, G. Almási, I. Kozma, and J. Kuhl, Velocity matching by pulse front tilting

for large area THz-pulse generation, Opt. Express 10(21), 1161–1166 (2002).

[2]Xiao-jun Wu, Jing-long Ma, Bao-long Zhang, Shu-su Chai, Zhao-ji Fang, Chen-Yi

Xia, De-yin Kong, Jin-guang Wang, Hao Liu, Chang-Qing Zhu, Xuan Wang, Cun-Jun Ruan,

and Yu-Tong Li, Highly efficient generation of 0.2 mJ terahertz pulses in lithium niobate at

room temperature with sub-50 fs chirped Ti:sapphire laser pulses, Optics Express, 2018, 26 (6),

7107-7116.

[3]Xi Cheng Zhang, Alexander Shkurinov and Yan Zhang, Extreme terahertz science,

Nat. Photon. 11, 16 (2017).

Beihang University REPORTER

Fig 2. (a)Highly efficient terahertz generation with chirped pump laser pulses; (b)Extracted terahertz energy and its corresponding efficiency as a function of the pump energy

2018 REPORTER 9

Ti-Al-Si-N nanocomposite coatings deposited by high power impulse magnetron sputtering (HiPIMS) technique

and grain size, as well as improved hardness and coating-substrate

adhesion strength. Moreover, by increasing the bias voltage, the

discharge current has been increased during the coating deposition,

which in turn further reduced the surface roughness and grain size

and improved hardness of the coatings.

This study provides new insight for optimizing HiPIMS

technique and improving the quality of Ti-Al-Si-N coatings. The

work has been published in the journal Applied Surface Science.

Ye Xu, professor, school of mechanical engineering and automation,

Beihang University, E-mail: ye.xu@buaa.edu.cn

Liuhe Li, professor, school of mechanical engineering and

automation, Beihang University, E-mail: liliuhe@buaa.edu.cn

Reference

Quansheng Ma, Liuhe Li*, Ye Xu*, Jiabin Gu, Lei Wang, and Ye Xu; Effect of bias voltage

on TiAlSiN nanocomposite coatings deposited by HiPIMS; Applied Surface Science 392, 826-

833 (2017). (*corresponding authors)

Depositing a hard coating on the surface is a common

technique for protecting materials and is widely used in

application, including high-speeding cutting tools and aero-

engine blades. One typical hard coating material is Titanium

Nitride (TiN). With the increasing demand of higher surface

hardness and wear resistance, researchers have developed

superhard nanocomposite coatings by alloying other elements,

such as Si and Al, into the TiN in order to improve the properties

of nitride protective coatings. Among other coating materials, Ti-

Al-Si-N has emerged as a promising candidate for high speed

cutting tools, thanks to its high hardness, low friction coefficient,

good adhesion, and better high-temperature oxidation resistance.

Nitride coatings including Ti-Al-Si-N are usually prepared

using direct current magnetron sputtering (DCMS) technique.

However, it suffers from its drawback of low ionization degree,

often resulting in coatings with low quality. Recently, high power

impulse magnetron sputtering (HiPIMS) technique capable of

increasing the ionization of target materials has been developed,

which makes it possible to deposit coatings with increased

density, reduced roughness, and improved crystallinity. Other

processing parameters that determine the quality of coatings

include flow rate of nitrogen, pressure, target power, temperature

and bias voltage. Investigating and optimizing those parameters

are crucial in preparing high quality Ti-Al-Si-N coatings.

A research team led by Beihang’s Professor Liuhe Li and

Professor Ye Xu from the School of Mechanical Engineering

and Automation studied how HiPIMS technique and the bias

voltage applied at the substrate during the process affected the

microstructure and properties of the deposited Ti-Al-Si-N coatings.

By using home-made vacuum deposition system and HiPIMS power

supply, Ti-Al-Si-N coatings were deposited on cemented carbide

substrates using both DCMS and HiPIMS and also under various

bias voltages. After careful characterization, the results show that,

comparing to those deposited using DCMS, Ti-Al-Si-N coatings

deposited with HiPIMS technique show reduced surface roughness

Fig. (A)Scheme of Ti-Al-Si-N deposition system; (B)Cross-section of Ti-Al-Si-N coatings deposited under different processing conditions

RESEARCH highlights

10 REPORTER 2018

Recent advances in development of noble metal-free electrocatalysts for water splitting

Beihang University REPORTER

Electrochemical water splitting

for hydrogen production is often

cons idered to be in tegrated

into existing renewable power

generat ing systems because

hydrogen can work as a versatile

energy carrier, and can overcome

t h e i n te r m i t te n c y o f t y p i c a l

renewable energy resources, such

as wind and solar energy. One

of the grand challenges facing

this scenario is to develop highly

efficient, low-cost electrocatalysts

for the react ions involved in

water splitting. To date, noble

metal Pt-based materials are

Fig 1. Schematic illustration of the synthesis of Ni-Fe-OH@Ni3S2/NF by quickly immersing Ni3S2/NF in a preheated aqueous solution with Fe3+ ions at 100 °C for only 5s

Fig 2. Schematic illustration of the synthesis of Cu@CoSx/CF by a low-temperature synthetic route involving the growth of CoSx film on CF, along with the interdiffusion of copper species from CF into the CoSx film

the electrocatalysts with the highest intrinsic activity for the

hydrogen evolution reaction (HER), and noble metal-based IrO2 is

highly active for the oxygen evolution reaction (OER). However, it

remains a challenge to make such noble metal catalytic couple-

based electrolyzers find a wide range of applications, because

of the high cost and scarcity, as well as the instability, of the

catalysts involved in them. Thus, a major step forward in water

splitting lies in the development of game-changing, non-noble

metal-based HER and OER electrocatalysts that have good

catalytic activity to reduce the overpotentials as well as with high

durability for long operational life.

Recently, Professor Yu Zhang of Beihang University,

Associate Professor Xiaoxin Zou of Jilin University, and their

coworkers have made important advances in the development

of noble metal-free electrocatalysts for water splitting. The

research, combining novel material preparation method, careful

catalyst characterization and theoretical computation, not only

provides some highly efficient, low-cost electrocatalysts based

on transition metals such as cobalt, nickel, iron, etc., but also

discusses in-depth the relationship between hydrogen adsorption

on catalyst surface and the water splitting process. The results

help better understand their catalytic mechanism and pave the

way towards the development of high-efficiency water splitting

electrochemical devices. The work has been published in Adv.

Mater. and Chem (a new journal of Cell Press).

Developing nonprecious electrocatalysts that can work

well at large current densities is vitally important in a viable

water-splitting technology. The researchers reported a facile

2018 REPORTER 11

RESEARCH highlights

CoSx is mainly responsible for Cu@CoSx/CF’s excellent catalytic

activity in the water splitting reaction. Besides CoSx’s intrinsic

catalytic activity, copper clusters strongly induce the charge

redistribution at the interface region of Cu@CoSx and significantly

promote the water dissociation step, further facilitating the surface

water-splitting reaction kinetics.

Furthermore, the researchers reported the synthesis of

mackinawite FeS nanosheets grown on iron foam, which can

serve as an efficient pre-electrocatalyst for both HER and OER

in alkaline media. During electrochemical HER testing, core@

shell iron@iron oxysulfide nanoparticles as the catalytically

active phase are generated in situ on FeS nanosheets. During

electrochemical OER testing, FeS nanosheets totally transform

into porous amorphous FeOx film that can mediate the OER

efficiently. The resulting materials can function effectively as both

the anode and cathode of a single alkaline electrolyzer, whose

output is found to be comparable with the one obtained from an

electrolyzer based on the Pt/C-IrO2 catalytic couple.

ultrafast (5s) synthetic approach that produces a novel, efficient,

non-noble metal oxygen-evolution nano-electrocatalyst that

is composed of amorphous Ni-Fe bimetallic hydroxide film-

coated, nickel foam (NF)-supported, Ni3S2 nanosheet arrays.

The composite nanomaterial (Ni-Fe-OH@Ni3S2/NF) shows highly

efficient electrocatalytic activity toward oxygen evolution reaction

(OER) at large current densities, even in the order of 1000 mA

cm−2. Further experimental results indicate that the effective

integration of high catalytic reactivity, high structural stability,

and high electronic conductivity into a single material system

gives Ni-Fe-OH@Ni3S2/NF a remarkable catalytic ability for OER at

large current densities.

Making highly efficient catalysts for overall water splitting

reaction remains a significant challenge. The researchers reported

an efficient, bifunctional HER and OER electrocatalyst composed of

a copper foam (CF)-supported, copper cluster-coupled amorphous

cobalt sulfide (Cu@CoSx/CF). Experimental results and theoretical

calculations show that the synergy between copper clusters and

Fig 3. Schematic illustration of FeS/IF as a pre-catalyst for generating active electrocatalysts for both HER and OER

Yu Zhang, research professor, Key

Laboratory of Bio-Inspired Smart Interfacial

Science and Technology of Ministry of

Education, school of chemistry, Beihang

University, E-mail: jade@buaa.edu.cn

Xiaoxin Zou, associate professor, State

Key Laboratory of Inorganic Synthesis and

Preparative Chemistry, College of Chemistry,

Jilin University, E-mail: xxzou@jlu.edu.cn

References

[1]Xu Zou, Yipu Liu, Guo-Dong Li, Yuanyuan

Wu, Da-Peng Liu, Wang Li, Hai-Wen Li, Dejun Wang,

Yu Zhang* and Xiaoxin Zou*, Ultrafast formation of

amorphous bimetallic hydroxide films on 3D conductive

sulfide nanoarrays for large-current-density oxygen

evolution electrocatalysis, Adv. Mater. 29, 1700404 (2017).

[2]Yipu Liu, Qiuju Li, Rui Si, Guo-Dong Li, Wang

Li, Da-Peng Liu, Dejun Wang, Lei Sun, Yu Zhang* and

Xiaoxin Zou*, Coupling Sub-Nanometric Copper Clusters

with Quasi-Amorphous Cobalt Sulfide Yields Efficient and

Robust Electrocatalysts for the Water Splitting Reaction,

Adv. Mater. 29, 1606200 (2017).

[3]Xiaoxin Zou, Yuanyuan Wu, Yipu Liu, Dapeng

Liu, Wang Li, Lin Gu, Huan Liu, Pengwei Wang, Lei

Sun and Yu Zhang*, In-Situ Generation of Bifunctional,

Efficient Fe-Based Catalysts from Mackinawite Iron

Sulf ide for Water Splitt ing, Chem DOI: 10.1016/

j.chempr.2018.02.023 (2018).

12 REPORTER 2018

Distributed guidance for intercepting multiple UAVs

the intruders, implying that multi-UAV guidance is required. In

existing research on multi-UAV guidance, however, the scenarios

are often multiple interceptors versus one target; the results on

guidance laws to intercept multiple targets are rather limited.

In multi-UAV guidance, the issues of collision avoidance and

mis-interception avoidance must be considered. By “collision

avoidance”, it means that the interceptors should not collide with

each other; and by “mis-interception avoidance”, it indicates that

The rotary-wing unmanned aerial vehicle (UAV) has proved

its applicability in various areas. However, it is often annoying

if unidentified UAVs intrude into non-flight areas. There

exist urgent necessities to design strategies and devices to

intercept intruding UAVs. Using weapons (missiles or laser

devices) to destroy the intruding UAV is among the possible

solutions, but it may result in noise, air pollution, or direct

human injuries. An alternative solution is to employ UAV to

intercept the intruding UAV so that less environmental side

effects would occur. A key issue for UAV interception is to

design the guidance law. Rotary-wing UAV guidance is different

from missile guidance in that it is free from non-holonomic

constraints, and can be implemented in full degree-of-

freedom. Control techniques can be applied to improve the

performance of guidance.

Sometimes there exist multiple intruders, and the

interceptions cannot be completed by a single interceptor UAV.

An intuitive strategy is to employ multiple UAVs to intercept

Fig 1. Experimental UAV platform and its working procedure

Beihang University REPORTER

2018 REPORTER 13

RESEARCH highlights

each interceptor can only be assigned one target, and it cannot

intercept the target assigned to other interceptors. Another

issue to be considered in multi-UAV guidance is to prove that the

interceptions can be completed within finite time with nonzero

hitting velocity.

In our research, a new distributed guidance law is

proposed for the multi-UAV system to intercept multiple

targets. It is proved strictly that, with the proposed multi-

UAV guidance law, multiple targets can be intercepted by

the multi-UAV system within finite interception time and with

nonzero hitting velocities. The strategy of collision avoidance

and mis-interception avoidance is direction-based (Most of

the current collision avoidance schemes are position-based

or distance-based.), and it is embedded in the guidance law.

The direction-based strategy ensures that the interceptors are

capable of performing maneuvers to avoid collisions or mis-

interceptions in advance, far earlier than possible collisions or

mis-interceptions would ever happen.

As shown in Fig 1, the UAV platform in the experiment is a

custom-built quadrotor with a motor-to-motor span of 45cm and

1.7kg gross weight. Attitude and altitude control are managed by

a 3DR Pixhawk flight controller unit running customized firmware.

The proposed guidance law is implemented on an onboard

Beaglebone Black computer using Robot Operating System

(ROS). To emulate a radar system, the interceptor UAV receives

the position and velocity of the target via a pair of XBee 2.4GHz

modules. Position and velocity of the interceptor UAV itself are

estimated online with IMU and GPS data. Position estimates are

subject to measurement errors and time-delay.

A 2-D semi-physical experiment was conducted to

demonstrate the theoretical results. Two pairs of targets and

interceptors were employed in the semi-physical experiment, as

can be seen from Fig 2. In Pair 1, the target and the interceptor

were real; in Pair 2, the target and the interceptor were virtual.

Interceptor 1 was capable of intercepting its target within finite

time and with nonzero hitting velocity. To explain the behavior of

interceptor 2, we divide its trajectory into several segments. In

segment 1–2, interceptor 2 was trying to avoid possible collision

with interceptor 1, since they were close to each other at this

moment. In segment 2–3, interceptor 2 was trying to avoid target

1, since target 1 happened to appear on its sight. In segment

3–4, no possible collisions existed, and interceptor 2 was

capable of capturing target 2.

This research serves as a concrete successful step in

our project supported by the National Science Foundation of

China. Extensions of the proposed results to further research

on multi-UAV interceptions are still progressing. Some future

topics include: 1) dynamic task allocation for optimal time-

efficiency and energy-efficiency, and 2) distributed guidance

to intercept multiple targets with uncertain or stochastic

maneuvering.

Bing Zhu, associate professor, school of automation science and

electrical engineering, Beihang University, E-mail: zhubing@buaa.edu.cn

Reference

B. Zhu*, A.H.B. Zaini, and L. Xie “Distributed Guidance for Interception by Using

Multiple Rotary-Wing Unmanned Aerial Vehicles”, IEEE Transactions on Industrial

Electronics, Vol. 64, No. 7, 5648-5656, 2017.

East (m)-10 -5 0 5 10

Nort

h (

m)

-5

0

5

10

15

20

25

30

35

Target 1→

Target 2→

Interceptor 1→

Interceptor 2→1

42

3

Fig 2. The 2-D semi-physical experiment with one real pair of interceptor-target and another virtual pair of interceptor-target

14 REPORTER 2018

Beihang University REPORTER

3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystals

Fig 1. (A)ZT values for p-type SnSe and n-type SnSe. Inset images show the SnSe crystal structure with the investigated out-of-plane direction. The typical sample cleaved along the (100) plane and the diagram show how the crystals are cut for measurements (from left to right). (B)Schematic out-of-plane charge and phonon transports in n-type and p-type SnSe. The colorful dots represent the charge densities. The gray blocks represent the two-atom-thick SnSe slabs along the out-of-plane direction (a-axis) of SnSe.

much more complex behaviors due to a temperature-dependent

continuous phase transition from Pnma to Cmcm, which leads

to an outstanding temperature-independent power factor and a

record high maximum ZT (ZTmax) of ~2.8 at 773K along the out-

of-plane direction.

The achieved high performance of n-type SnSe can be

explained by two unique cumulative features. First, density functional

theory (DFT) calculations and scanning tunneling microscopy (STM)

observations indicate that delocalized Sn p and Se p electrons near

the conduction band minimum (CBM) contribute to a larger charge

density (carriers distribution). When the carrier concentration is fixed

at ~ 1.2 × 1019 cm-3, in contrast to p-type SnSe, the charge density

of n-type SnSe is larger and overlaps to fill the crystal structure

interlayers. The overlapped charge density can facilitate electron

transport through the interfaces, resulting in an expected ZTmax ~2.1

at 773K for n-type SnSe. In contrast, the ZTmax is ~ 0.5 at 773K for

p-type SnSe (Fig 1A). Second, in situ high-temperature synchrotron

radiation X-ray diffraction (SR-XRD) indicates a continuous phase

transition from Pnma to Cmcm starting at ~ 600K before the critical

temperature (800K) in SnSe. This apparently continuous phase

transition in n-type SnSe leads to an increased symmetry in the

Thermoelectric (TE) technology, which

converts heat into electricity, provides a

promising route to environmentally friendly

power generation through harvesting

industrial waste heat. The conversion

efficiency of thermoelectric materials is

determined by the dimensionless figure

of merit, ZT = (S2σ/к)T, where S, σ, к, and

T are the Seebeck coefficient, electrical

conductivity, thermal conductivity and

absolute temperature, respectively.

However, the complex inter-relationships

among thermoelectr ic parameters

prevent us from maximizing the ZT value

and conversion efficiency.

Over the past decade, bulk crystals with two-dimensional

(2D) layered structures have been studied due to their strongly

anisotropic transport features. High thermoelectric performance

along the in-plane direction was primarily achieved via the

sufficient charge carrier mobility; however, the out-of-plane

properties have garnered less attention because this directional

electrical transport is always impeded by the 2D interface.

Considering out-of-plane thermal conductivities in 2D layered

materials are sufficiently low to approach the amorphous limit, we

expect to realize high out-of-plane thermoelectric performance by

enhancing these directional electrical transport properties.

Recent findings of high thermoelectric performance along

the in-plane direction of p-type SnSe crystals with a 2D layered

structure have surprised the scientific community. The strong

anharmonic and anisotropic bonding in a binary compound,

leading to very low thermal conductivity, is remarkable. After hole

doping, SnSe shows an exceptionally high power factor enabled

by its multiple valence bands. We note that SnSe exhibits even

lower thermal conductivity along the out-of-plane direction,

which motivates us to investigate its power factor. In this work,

we found that the conduction bands of n-type SnSe elucidate

2018 REPORTER 15

COVER story

crystal structure, which is further confirmed by in situ spherical

aberration-corrected transmission electron microscopy (Cs-corrected

TEM). This phase transition also results in the divergence of two

converged conduction bands at ~ 600K. The changes in both the

crystal and band structures due to the continuous phase transition

further increase ZTmax from 2.1 to 2.8 at 773K (Fig 1A). Collectively,

our findings show that the out-of-plane electrical transport

properties in n-type SnSe are comparable to that along the in-plane

direction (3D charge transport), which has rarely been observed in

bulk materials with a two-dimensional (2D) structure. The unique 3D

charge- and 2D phonon-transport properties in n-type SnSe crystals

along the out-of-plane direction are schematically shown in Fig 1B.

The higher out-of-plane electrical transport (as compared

to the p-type control sample) in n-type SnSe originates from the

higher carrier mobility, which indicates that electron transport

is facilitated through the interlayers. To provide insight into

the origins of the higher carrier mobility in n-type SnSe, we

investigated the charge density for both types of SnSe. DFT

calculations indicate the distinct overlaps of the electron

orbitals in the out-of-plane direction of n-type SnSe, which form

electrical conduction pathways (Fig 2A). However, the charge

densities mainly distribute along the in-plane direction in p-type

SnSe (Fig 2B). The charge density distribution in the bc plane

is further confirmed by the contrast STM image and dI/dV

mapping (Fig 2C-F).

The dynamic structural behavior of SnSe at 800K involves

a reversible phase transition from Pnma to Cmcm, and the

highly symmetric Cmcm phase can enhance carrier mobility and

preserve the high power factor of SnSe. To directly capture the

structural evolution of SnSe as a function of temperature, we

conducted in situ Cs-corrected TEM heating experiments for both

n-type and p-type SnSe. The parameters D and d are defined as

the interlayer and intralayer distances of the Se atomic column,

respectively. The d/D ratio is used to describe the symmetry

change of the crystal structure as a function of temperature (Fig

3B). After heating, in n-type SnSe, the d/D ratio increases with

an increasing temperature, which indicates an increase in the

crystal structure symmetry (Fig 3C). This behavior is particularly

obvious above ~ 600K for n-type SnSe. The same phenomenon

is further confirmed through in situ high-temperature synchrotron

radiation (SR-XRD).

To clarify the Seebeck coefficient enhancements above

~600K in n-type SnSe, we performed DFT calculations based

on the temperature-dependent crystal structures determined

by SR-XRD. The DFT calculations indicate that the lowest CBM

lies in the Γ-Y direction (CBM1, Fig 4A), while the second CBM is

Fig 2. Calculated charge densities of (A) n-type and (B) p-type SnSe in the ab plane and bc plane. STM images and corresponding dI/dV mapping for the (C-D) n-type and (E-F) p-type SnSe crystals in the bc plane.

Fig 3. (A)Images of n-type and p-type SnSe at elevated temperatures viewed along the b axis. (B)Atomic model of SnSe viewed along the b axis. (C)The d/D ratio of the n-type and p-type SnSe crystals with rising temperature.

Fig 4. (A)Electronic band structures. (B)The changing energy gap between CBM1 and CBM2 at elevated temperature. Inset diagram indicates the two conduction bands experience convergence and then divergence with rising temperature.

16 REPORTER 2018

COVER storyBeihang University REPORTER

located at point Γ (CBM2, Fig 4A). The energy offset for these two

conduction bands is ~0.10 eV at room temperature, and as the

temperature increases, the energy offset narrows and reaches

a minimum value of ~0.04 eV at approximately 600K. Above

this temperature, the energy gap sharply rises and returns to

~0.10 eV again at 773K (Fig 4B). These results indicate that the

conduction bands of n-type SnSe experience band convergence

and divergence. The thermoelectric performance can be

enhanced by converging band structures. Band convergence

can enhance the effective mass via introducing additional

band degeneracy (Nv) from heavy band contributions. However,

increasing the effective mass usually deteriorates the carrier

mobility. Therefore, unique band structures that can balance

the effective mass and carrier mobility are highly desired. In

this study, we found that the conduction bands of n-type SnSe

experience energy convergence and divergence within 0.10 eV

as the temperature increases. The conduction band divergence

is expected to improve the carrier mobility by reducing Nv.

Indeed, the unique conduction band structures in n-type SnSe

lead to optimizations of both the Seebeck coefficient and carrier

mobility, which are critical to preserving a higher power factor.

In summary, utilizing the ultralow thermal conductivity of

out-of-plane SnSe along with an outstanding power factor, we

realized a record high ZTmax ~ 2.8 at 773K in out-of-plane n-type

SnSe crystals. Our results open prospects for exploring new 2D

layered materials that are expected to realize unprecedented

thermoelectric performance for energy conversion applications.

Summing-up: The thermoelectric efficiency is evaluated

by the material thermoelectric figure of merit (ZT), which can

be usually improved by enhancing the electrical transport

properties and/or reducing the thermal conductivity. The ultralow

thermal conductivity in layered SnSe crystals along the out-

of-plane direction, which is caused by two-dimensional (2D)

interface scattering, motivated us to enhance the corresponding

electrical transport properties. Here, we report that, in n-type

SnSe crystals, the overlapped interlayer charge density due to

delocalized Se p and Sn p electrons near the conduction band

minimum facilitates electron transport through the interfaces,

resulting in high electrical conductivity. Moreover, a continuous Science 360,778-783 (2018)

phase transition from Pnma to Cmcm, starting from ~600K

before the critical temperature of 800K, leads to increased

symmetry of the crystal structure and divergence of the two

converging conduction bands. Both of these factors enhance

the out-of-plane electrical transport properties similar to 3D

charge transport, i.e., a simultaneous enhancement of the

carrier mobility and preservation of a large Seebeck coefficient,

thus yielding an improved out-of-plane power factor in n-type

SnSe crystals. The combination of 3D charge and 2D phonon

transports eventually leads to a record high ZT of ~2.8 ± 0.5 at

773K in n-type SnSe crystals along the out-of-plane direction.

Our findings can be applied in other 2D layered materials and

shed light on their thermoelectric performance improvement.

Corresponding author: Lidong Zhao, professor, school of materials

science and engineering, Beihang University, E-mail: zhaolidong@buaa.

edu.cn

First author: Cheng Chang, doctoral student

References

[1]L. -D. Zhao et al., Ultralow thermal conductivity and high thermoelectric figure of

merit in SnSe crystals. Nature 508, 373-377 (2014).

[2]L. -D. Zhao et al., Ultrahigh power factor and thermoelectric performance in hole-

doped single-crystal SnSe. Science 351, 141-144 (2016).

[3]L. -D. Zhao, C Chang et al., SnSe: a remarkable new thermoelectric material. Energy

Environ. Sci. 9, 3044-3060 (2016).

[4]C. Chang, L. -D. Zhao et al., 3D charge and 2D phonon transports leading to high

out-of-plane ZT in n-type SnSe crystals, Science 360, 778-783 (2018).

2018 REPORTER 17

Science 360,778-783 (2018)

Progress in neuroimaging analysis for aging and Alzheimer’s disease

Fig 1. The eight sulci for which fold opening and sulcal depth were calculated: superior frontal sulcus (A), central sulcus (B), Sylvian fissure (C), superior temporal sulcus (D), intraparietal sulcus (E), subparietal sulcus (F), posterior cingulate sulcus (G), anterior cingulate sulcus (H).

Fig 2. The dynamics of the biomarkers can aid in tracking the progression of cognitive impairment.

With the overwhelming aging around the world, the number

of people with dementia diseases is growing dramatically. The

structural and functional abnormalities of brain can be caused by

both normal aging and dementia that comes with aging. Recently,

a large body of research has been published on neuroimaging-

based studies of normal aging and Alzheimer’s disease (AD).

However, there’s still a lack of the golden standards to evaluate the

quantification of brain aging and the early diagnosis of dementia

diseases. Given the paths carved by the powerful neuroimaging,

promising future of further understanding the mechanisms of brain

is expected by leveraging neuroimaging indices.

Recently, in collaboration with University of New South

Wales, University of Sydney, Beijing Tian Tan Hospital, and

Capital Medical University, a study on aging was performed by

Beihang’s Associate Professor Tao Liu and his research group.

The sulcal morphological changes in normal aging of the elderly

were investigated. They examined the fold opening and sulcal

depth of sixteen (eight on each hemisphere) prominent sulci (Fig

1) based on T1-weighted MRI. The trajectory of each individual

sulcus with respect to age was examined separately by linear

mixed models. Fold opening was best modelled by cubic fits in

five sulci, by quadratic models in six sulci and by linear models in

five sulci, indicating an accelerated widening of a number of sulci

in older age. Sulcal depth showed significant linear decline in

three sulci and quadratic trend in one sulcus. In addition, turning

points of non-linear trajectories towards accelerated widening of

the fold were found to be around the age between 75 and 80.

This important discovery indicates that an accelerated atrophy

of brain cortex starts in the age of late 70s. The findings provide

a reference for the studies of neurocognitive disorders, including

neurodegenerative diseases, in the elderly. This study has been

published in the journal Neuroimage, an authoritative journal

ranking first in the JCR category of Neuroimaging (Shen et al.,

2017, IF 5.8).

The research group has also gained ground in utilizing

machine learning for neuroimaging analysis. They conducted a

study of early diagnosis of AD by using classifiers trained with

morphological features like sucal width, cortical volume, cortical

thickness and subcortical volume. The performances of three

different classifiers (Naïve Bayes, Logistic Regression, and

Beihang University REPORTER FEATURE focus

18 REPORTER 2018

Beihang University REPORTER

Fig 3. Flowchart of WMH segmentation pipeline

be useful neuroanatomical markers for detecting early-stage

AD. The findings of this study put forward new thoughts for

early diagnosis of AD (Cai et al., 2017). On the other hand, for

the targeted treatments and therapeutic interventions, the

research group used machine learning for the classification of

different subtypes of mild cognitive impairment (MCI, seen as a

prodromal stage of dementia). They classified the MCI subjects

into amnestic MCI (aMCI) and non-amnestic MCI (naMCI) with

structural magnetic resonance imaging. Cortical surface based

measurements were computed from longitudinal and cross-

sectional scans. By introducing a feature selection algorithm,

they identified a set of discriminative features. The best results

for differentiating aMCI from naMCI were achieved with baseline

features. Hippocampus, amygdala and frontal pole were found to

be the most discriminative features for classifying MCI subtypes.

Further investigation of the temporal patterns of those selected

features indicated the dynamics of several MRI biomarkers (Fig

2). Learning the dynamics of atrophy may aid in the development

of better biomarkers, as it may track the progression of cognitive

impairment. This study has been published in Frontiers in Aging

Neuroscience, a leading journal in the field of age-related neural

diseases (Guan et al., 2017, IF 4.5).

Leukoaraiosis (LA), sometimes referred to as white matter

hyperintensity (WMH), is closely related to various pathological

processes, including stroke and dementia. Most available WMH

segmentation toolboxes have neither been designed as fully

automated nor evaluated comprehensively. Tao Liu’s group

worked together with researchers from University of New South

Wales to develop a cluster-based, fully automated pipeline for

extracting WMH (Fig 3). They validated the performance of this

innovative toolbox by showing a high segmentation (similarity

index (SI) = 0.848) and volumetric (intraclass correlation

coefficient (ICC) = 0.985) agreement with the manually traced

WMH performed by clinicians. The study provides a reliable,

efficient and fully automated WMH segmentation pipeline for the

neuroimaging-based analysis of aging related diseases, and has

been published in Neuroimage (Jiang et al., 2018, IF 5.8).

In summary, these discoveries may shed new light on brain

aging and early diagnosis of neurocognitive disorders.

Tao Liu, associate professor, school of biological science and

medical engineering, Beihang University, E-mail: tao.liu@buaa.edu.cn

This article was drafted by Hao Guan and Qiongge Li.

References

[1]Shen, X., Liu, T.*, Tao, D., Fan, Y., Zhang, J., Li, S., Jiang, J., Zhu, W., Wang, Y., Wang,

Y., Brodaty, H., Sachdev, P., Wen, W., 2018. Variation in longitudinal trajectories of cortical

sulci in normal elderly. Neuroimage, 166, 1-9.

[2]Jiang, J., Liu, T.*, Zhu, W., Koncz, R., Liu, H., Lee, T., Sachdev, P.S., Wen, W.*,

2018. UBO Detector–A cluster-based, fully automated pipeline for extracting white matter

hyperintensities. Neuroimage, 174, 539-549.

[3]Cai, K., Xu, H., Guan, H., Zhu, W., Jiang, J., Cui, Y., Zhang, J., Liu, T.*, Wen, W.,

2017. Identification of Early-Stage Alzheimer's Disease Using Sulcal Morphology and Other

Common Neuroimaging Indices. PLoS One 12, e0170875.

[4]Guan, H., Liu, T.*, Jiang, J., Tao, D., Zhang, J., Niu, H., Zhu, W., Wang, Y., Cheng,

J., Kochan, N.A., Kochan, N.A., Brodaty, H., Sachdev, P., Wen, W., 2017. Classifying MCI

Subtypes in Community-Dwelling Elderly Using Cross-Sectional and Longitudinal MRI-Based

Biomarkers. Frontiers in Aging Neuroscience, 9, 309.

Support Vector Machine) were

compared. The results indicated

that the classification results

were accounted for by features

rather than by classifiers: no

significant differences between

t h e t h r e e c l a s s i f i e r s w e r e

found; sulcal features were

either superior than or equal

to the other features used for

classification; the g-SI and the

width of the Sy lv ian f issure

were two of the most sensitive

sulcal features, which could

2018 REPORTER 19

FEATURE focus

Spatiotemporal crowdsourcing: a novel computing paradigm for the sharing economy

Fig 2. Spatial, weather and POI distribution of taxi orders in Beijing

internet and internet of

things have transformed

c row d s o u rc i n g f ro m

the conventional online

Web p la t fo rm based

m o d e [ 1 ] i n to a n ew

comput ing paradigm

called spatiotemporal

c r o w d s o u r c i n g

( a l s o k n o w n a s

spatial crowdsourcing and mobile crowdsourcing). In brief,

spatiotemporal crowdsourcing is a novel crowdsourcing paradigm

which, through spatiotemporal data management platforms,

assigns tasks with spatiotemporal characteristics to an

unspecified crowd of participants, and requires the participants

to actively or passively complete the tasks under spatiotempral

constraints.

Spatiotemporal crowdsourcing is also viewed as a novel

computing paradigm for the sharing economy. Sharing economy

prevails in recent years, but dates back to 1978, when Marcus

Felson, a professor of sociology from the Texas State University

and Joe L. Spaeth, a professor of sociology from the University of

Illinois initiated the concept. Its main feature is that individuals

exchange idle items, share their knowledge and experience,

or raise funds for companies and innovative projects via Web

platforms. Spatiotemporal crowdsourcing is ideal to organize

T h e c o n c e p t o f

c row d s o u rc i n g wa s

first proposed by Jeff

Howe in 2006. It refers

t o t h e d i s t r i b u t e d

problem-solving model

of assigning tasks to

an unspecified crowd

of participants through

public Web platforms.

The most famous application of crowdsourcing is the reCAPTCHA

system proposed by Lui von Ahn, a professor of Carnegie Mellon

University, USA. It gathers the wisdom of billions of netizens

through the form of the verification codes in network to digitalize

the printouts of New York Times automatically. With the success

of reCAPTCHA, various crowdsourcing platforms have sprung

up, including the early question-answering systems such as

Baidu Knows, and the more recent online job recruitment and

task subcontracting management platforms such as Amazon

Mechanical Turks (AMT), CrowdFlower and oDesk. These

platforms not only bring new technical revolution but also

create huge market economic value. Therefore, crowdsourcing

holds great potential to revolutionize the era of the Internet. As

commented by the People’s Daily in 2014, “Crowdsourcing is the

trend of the times”.

The recent emergence and the rapid development of mobile

Fig 1. Spatiotemporal crowdsourcing applications

20 REPORTER 2018

Fig 3. Taxi demand prediction system

Beihang University REPORTER

offline participants through the Web platform to complete

various spatiotemporal tasks that cover almost every aspect

in daily life and make social and economic benefits. Popular

and successful spatiotemporal crowdsourcing applications

in the sharing economy include real-time taxi-calling services

such as Didi Chuxing, and logistics delivery services such as

Baidu Takeaway. This is only one example of spatiotemporal

crowdsourcing applications that penetrate people’s everyday life

and have brought influential social and economic benefits (see

Fig 1 for more examples). The wide adoption of spatiotemporal

crowdsourcing has also triggered extensive research in the

academia. The main focus of spatiotemporal crowdsourcing

research includes real-time task assignment and dynamic

incentive mechanism design. These two issues study the global

optimization, management and mechanisms for large-scale,

sustainable spatiotemporal crowdsourcing platforms, and are

thus considered core in spatiotemporal crowdsourcing research.

1. Real-time task assignment

Real-time task assignment studies the problem of assigning

participants to proper tasks based on their spatial, temporal and

other factors, when both participants and tasks arrive on the

crowdsourcing platform dynamically. The problem is challenging

because the spatiotemporal distributions of participants and

tasks can be random and are unknown in advance. The lack of

information makes real-time task assignment vulnerable to local

optimum, leading to uneven resource allocation and suboptimal

solution to task assignment.

To tackle the challenges of real-time task assignment in

spatiotemporal crowdsourcing, our team proposes a prediction-

based real-time assignment scheme. It first predicts the number

of participants and tasks and dispatches participants before

the arrival of their assigned tasks based on the prediction

result to optimize the assignment. Specifically, we first

designed a participant and task prediction algorithm based on

“simple model+complex features”[2]. The algorithm fusions

heterogenous spatial, temporal, weather, event and POI features.

Fig 2 shows the spatial, POI and weather distributions of taxies

in Beijing, with data provided by Didi Chuxing. Each of these

features affects the distributions of taxi orders differently, and

some features have joint impact on the task distributions. An

example of combined features is that the taxi orders in certain

2018 REPORTER 21

regions will surge during holidays. Based on these observations,

we engineered high-dimensional combinational features from

single features and fed them into a simple linear model for

prediction. Our work adopts features of more than two hundred

million dimensions. Experiments on large-scale taxi order data in

Beijing and Hangzhou show that our method outperforms other

complex prediction models, such as Neural Network and GBDT.

Fig 3 shows an illustrative prediction result of Unit Original Taxi

Demand (UOTD) in Haidian District, Beijing.

On this basis, we propose a prediction-based real-time

assignment algorithm[3]. Fig 4 shows the algorithm framework.

The algorithm makes assignments according to the prediction of

the number of tasks and participants to maximize the number

of completed tasks. It partitions time and space into slots and

regions, and predicts the number of tasks and participants for

each slot and region. Then, a bipartite graph is constructed

based on the predictions, which is used to make assignment to

maximize the number of completed tasks. When a new task or

participant arrives, it can be immediately assigned according

to such pre-calculated assignment. When the actual number

of tasks or participants differs from the predicted one, a new

task will wait, and a new participant will be asked to go to the

designated region. We prove that the algorithm achieves an

approximate ratio of 0.47. Experiments on the data of Didi

Chuxing show that the algorithm can guide the assignment

of tasks more accurately and the number of completed tasks

increases by 40%.

2. Dynamic incentive mechanism

Dynamic pricing mechanism is another important research

topic in spatiotemporal crowdsourcing, as it is the driving

power to attract participants and the enabler for sustainable

spatiotemporal crowdsourcing. Our team proposes a global

dynamic pricing solution[4], which aims to set prices of tasks in

each region dynamically, such that the expected revenue of the

platform is maximized. The framework addresses the following

challenges: (1)unknown demand — Tasks appear dynamically,

and the decisions (accept or reject) of participants are unknown

before the release of prices. This challenge makes it necessary

to estimate the acceptance probability of participants for

different prices. (2)limited supply — Supply of participants can

be limited in many spatiotemporal crowdsourcing applications.

A pricing framework suited for limited-supply in spatiotemporal

crowdsourcing is needed. (3)dependent supply — Different

participants cover different regions and they can intersect.

Participants in a certain region simultaneously influence the

Fig 4. Framework of the prediction-based real-time task assignment algorithm

FEATURE focus

22 REPORTER 2018

crowdsourcing in the past two years. Thanks to the close

cooperation with leading sharing economy companies such as

Didi Chuxing, some of our theoretical achievements have been

applied in real-world applications. As pointed out at the beginning

of this article, spatiotemporal crowdsourcing is a new computing

paradigm in the era of sharing economy. We expect that the

follow-up research in our team will have the opportunity to serve

more applications for people’s everyday life.

Yongxin Tong, associate professor, school of computer science,

Beihang University, E-mail: yxtong@buaa.edu.cn

References

[1]Yongxin Tong, Lei Chen, Zimu Zhou, H. V. Jagadish, Lidan Shou, Weifeng Lv.

SLADE: A Smart Large-Scale Task Decomposer in Crowdsourcing. IEEE Transactions on

Knowledge and Data Engineering (TKDE), 30(8): 1588 - 1601, August 2018.

[2]Yongxin Tong, Yuqiang Chen, Zimu Zhou, Lei Chen, Jie Wang, Qiang Yang,

Jieping Ye, Weifeng Lv. The Simpler the Better: A Unified Approach to Predicting Original

Taxi Demands on Large-Scale Online Platforms. ACM SIGKDD Conference on Knowledge

Discovery and Data Mining (SIGKDD), 2017, 1653-1662.

[3]Yongxin Tong, Libin Wang, Zimu Zhou, Bolin Ding, Lei Chen, Jieping Ye, Ke Xu.

Flexible Dynamic Task Assignment in Real-Time Spatial Data. In International Conference on

Very Large Databases (VLDB), 2017, 1334-1345.

[4]Yongxin Tong, Libin Wang, Zimu Zhou, Lei Chen, Bowen Du, Jieping Ye:

Dynamic Pricing in Spatial Crowdsourcing: A Matching-Based Approach. In ACM SIGMOD

International Conference on Management of Data (SIGMOD), 2018, 773-788.

Fig 5. Prototype system of dynamic pricing

Beihang University REPORTER

supply of other regions reachable by the participants, which

makes the problem even harder.

We propose a two-step framework, “base pricing+dynamic

pricing”, to solve the problem. In the first step of base pricing,

we present a base pricing strategy assuming sufficient supply.

It sets a rough global price of the crowdsourcing market, which

will be used in dynamic pricing. Specifically, the expected

revenue is only related to the local Revenue-Price curve when

the local supply is sufficient. The base pricing strategy models

the curve as a Myerson reserve price curve, and sets the price

that maximizes the revenue. In the second step of dynamic

pricing, where the supply can be limited and dependent

among regions, we adopt a multi-armed bandit model to

estimate the unknown demand for regions, and f inally

get the price for each region that maximizes the expected

revenue with theoretical guarantees. Experiments on both

synthetic and real datasets demonstrate the effectiveness

and efficiency of our proposed framework. Fig 5 illustrates the

prototype of the dynamic pricing system.

Above is the major research outcome in our team on task

assignment and incentive mechanism design for spatiotemporal

2018 REPORTER 23

Fig 1. Reasons for the failure of metallic lithium and corresponding solutions

Rechargeable metallic lithium batteries

concentration on the surface of electrode; (3)inhomogeneous

distribution of lithium ions around electrode. Correspondingly,

three strategies can be explored to avoid the failure of

lithium anodes such as pre-fabricated uniform SEI film, three-

dimensional (3D) conductive host and 3D host with polarized

functional groups or channels. To realize the application of

lithium anodes, our team not only reviewed the new progress of

research of metallic lithium, summarizing the failure reasons of

metallic lithium and corresponding solving strategies, but also

solved the uncontrollable growth of lithium by developing new

efforts such as constructing 3D host and confining nucleation

seeds.

To address these issues of lithium, we first proposed

a conductive host to decrease the local current density of

lithium deposition. Based on the ductility of metallic lithium

and super lubricity of 2D materials, flexible Ti3C2 MXene-lithium

composite with lamellar structure was fabricated via a roll to

roll approach. It is found that a few Ti-Li bonds are generated

in Ti3C2 nanosheets by X-ray photoelectron spectroscopy

Metallic lithium has been regarded as the “ultimate”

choice for anodes of rechargeable batteries due to its high

theoretical capacity (3860 mA h g−1), low potential (−3.04 V

vs Standard Hydrogen Electrode) and low density (0.534 g

cm−3). Though metallic lithium has great potential in the field

of electrochemical energy storage, its practical application in

rechargeable batteries has been plugged by the formation of

dendrites and dead lithium which originated from the repetitive

deposition/dissolve process, leading to rapid fading of the

reversible capacity of batteries, and even inducing internal short

circuit. These problems were related to the formation of uneven

solid electrolyte interphase (SEI) film owing to the reaction

of high activity of lithium with organic electrolyte, resulting in

the inhomogeneous transmitting of lithium ions in SEI film.

In addition, heterogeneous morphologies of lithium were

inevitable, generating nonuniform distribution of lithium ions

and charge concentration. Therefore, the reasons that cause the

failure of lithium anodes can be ascribed to three aspects (as

shown in Fig 1): (1)naturally formed uneven SEI film; (2)charge

FEATURE focus

24 REPORTER 2018

(XPS) tests, acting as nucleation seeds to guide facile lithium

nucleation. Furthermore, it is confirmed that lithium prefers to

nucleate inside the gaps between Ti3C2 nanosheets by in-situ

transmission electron microscope characterizations. As the Ti3C2

MXene-lithium composite is applied for an anode, rechargeable

property of lithium anode is successfully obtained, and a cycle

stability of over 200 cycles is achieved at 1 mA cm-2 (Fig 2).

When current density is increased to 5 mA cm-2, this composite

anode is still stable. These can be attributed to the conductive

Ti3C2 nanosheets that not only decrease the current density of

lithium deposition, but also act as nucleation seeds to guide

lithium deposition, and accommodate the volume change of

lithium.

Further studies have confirmed that the lithium deposition

process is highly influenced by the nucleation. The metal-organic

frameworks (MOFs) materials naturally contain tunable structure

and metal ions, which can be transformed to conductive porous

carbon with homogenously distributed nucleation seeds via

simple heating treatment. Therefore, porous C-Zn nanomaterials

are developed as hosts for metallic lithium via heating Zn-based

MOFs, and further achieve a carbonized MOFs-lithium (cMOFs-

Li) composite via molten lithium infusion approach. In this

matrix, Zn (ZnO) clusters, which not only enhance the lithium

affinity of carbonized MOFs, but also behave like pre-planted

nucleation seeds to guide Li deposition inside the matrix and

confine the growth of lithium, are homogeneously dispersed

inside (Fig 3). At the same time, the 3D conductive porous

structure dramatically homogenizes the distributions of electric

field and Li ion flux, accelerating the uniform deposition of

lithium and greatly enhancing cycle stability of cMOFs-Li anodes.

This provides a new manner to achieve a series of stable

metallic lithium anodes based on the large family of MOFs with

tunable metal species.

The severe growth of lithium dendrites during lithium

deposition may puncture the separator, resulting in inside short

circuit and even safety hazards, and it is an essential strategy to

explore high-strength separators to ensure the safety of lithium

anodes. We developed a high-strength separator consisting of

sandwich-like Go-silicon nanosheets (G-SiO2). This separator

processes a thickness of only 20 μm and superior high shear

modulus, efficiently restraining the growth of lithium dendrites

and preventing the separator from being pierced. Moreover,

Fig 2. The top: the symmetric cell with numerous transfer channels for lithium ions in the hybrid, avoiding the formation and growth of lithium dendrites; the bottom: cycle performance of lamellar structured Ti3C2 MXene-Li films electrodes, indicating superior stability

Beihang University REPORTER

2018 REPORTER 25

Fig 3. The top: schematic representat ion exhibi t s the fabrication process of lithium-carbonized metal-organic frameworks. The uniformly distributed zinc clusters act as the nucleation seeds to guide uniform li thium deposit ion; the bottom: cycle stability of symmetr ica l ce l l s wi th lithium-carbonized metal-o r g a n i c f r a m e w o r k s (red) and bare Li (black) electrodes, indicating the greatly enhanced stability of lithium-carbonized metal-organic frameworks anodes

mesoporous with diameters around 2.8 nm and the big pore

volume of G-SiO2 enable fast lithium ion transportation. Based

on the simple fabrication method with tunable pore structure

and thickness, this separator consisting of G-SiO2 offers new

insights for other kinds of separators.

In summary, we have accumulated abundant theoretical

and practical experiences in rechargeable metallic lithium-

based batteries, and have provided different methods to

solve the problems of metallic lithium from the aspects

of host construction, pre-planted nucleation seeds and

enhanced separators, laying solid experimental foundations

for the application of metallic lithium. On this basis, we

fur ther propose new insights to address the intr insic

problems of lithium metal anodes: 1)further identify the

deposition behaviors of metallic lithium using advanced

characterizations such as in-situ tests and cryo-electron

microscopy, establ ishing a regular model for l i th ium

deposition and proposing the primary cause of growth of

lithium dendrites; 2)fabricate lithium-based composite by

harnessing new processes to achieve nanocrystallization of

lithium and efficient control of lithium deposition, solving

the uncontrollable growth of lithium; 3)explore nondendritic

lithium anodes, such as liquid lithium contained anodes.

Shubin Yang, professor, school of materials science and

engineering, Beihang University, E-mail: yangshubin@buaa.edu.cn

References

[1]Bin Li, Ying Wang, Shubin Yang*. A material perspective of rechargeable metallic

lithium anodes. Advanced Energy Materials 2018, 1702296.

[2]Mengqi Zhu, Bin Li, Songmei Li, Zhiguo Du, Yongji Gong, Shubin Yang. Dendrite-

free metallic lithium in lithiophilic carbonized metal–organic frameworks. Advanced Energy

Materials 2018, 1703505.

[3]Bin Li, Di Zhang, Yue Liu, Yuyou Xin, Songmei Li, Shubin Yang*. Flexible Ti3C2

MXene-lithium film with lamellar structure for ultrastable metallic lithium anodes. Nano

Energy 39, 2017, 654-661.

[4]Nan Zhang, Bin Li, Songmei Li, Shubin Yang. Mesoporous hybrid electrolyte

for simultaneously inhibiting lithium dendrites and polysulfide shuttle in Li–S Batteries.

Advanced Energy Materials 2018,170312.

FEATURE focus

26 REPORTER 2018

WELCOME new starters

Xiaoliang ZhangYouth 1000 Talent Program

Optoelectronic materials; solar cells

xiaoliang.zhang@buaa.edu.cn

Wei ChenAssociate Professor of Zhuoyue Program

Complex networks and data science

（percolation in complex networks,

data mining of social networks and

biological networks）

chwei@buaa.edu.cn

Shuanhu QiAssociate Research Professor of

Zhuoyue Program

Polymer theory and simulation

schemes

qishuanhu@buaa.edu.cn

Xiantong ZhenAssociate Research Professor of

Zhuoyue Program

Computer vision, machine learning,

artificial intelligence, medical image

analysis

zhenxt@buaa.edu.cn

Fengjun YanYouth 1000 Talent Program

Automotive powertrain system

control

yanfengjun@buaa.edu.cn

Jingnan ChenAssociate Research Professor of

Zhuoyue Program

Operations research and management

science, financial engineering

jchen@buaa.edu.cn

Shoushu GongResearch Professor of Zhuoyue Program

Condensed matter theory (strongly

correlated materials, computational

condensed matter physics)

shoushu.gong@buaa.edu.cn

Wang KangAssociate Research Professor of

Zhuoyue Program

Spintronics and its related devices,

circuits, and architectures

wang.kang@buaa.edu.cn

Pu WangYouth 1000 Talent Program

Biophotonics

10318@buaa.edu.cn

Teng WangYouth 1000 Talent Program

Organic synthetic methodology

tengwang@buaa.edu.cn

Xiang YuYouth 1000 Talent Program

Fault-tolerant control, guidance,

navigation, and control of flight

vehicles

xiangyu_buaa@buaa.edu.cn

Cheng QianAssociate Research Professor of

Zhuoyue Program

Physics of failure, system reliability

d e s i g n , r e l i a b i l i t y a n d l i f e t i m e

assessment, accelerated test methods

cqian@buaa.edu.cn

Dexiang WuAssociate Research Professor of

Zhuoyue Program

Decision support system （optimization

and decomposition algorithm design, risk

analysis and performance evaluation）

dexter@buaa.edu.cn

Linyun LiangYouth 1000 Talent Program

Development of mesoscale theories and models to study the behaviors of the irradiation-induced microstructural evolution in nuclear materials for the advanced nuclear energy system

lyliang@buaa.edu.cn

Yihan LiAssociate Research Professor of

Zhuoyue Program

Microwave photonics, ultrafast

optics, high-frequency broadband

micro- and millimeter-wave

yihanli@buaa.edu.cn

Ying WangAssociate Research Professor of

Zhuoyue Program

Neural engineering and biomaterials:

using biomaterials and new technology

to solve neural science problems

ywang527@buaa.edu.cn

Peipei ZhangAssociate Research Professor of

Zhuoyue Program

Advanced manufacturing techniques

for biomedical applications

pzhang@buaa.edu.cn

Defeng WangYouth 1000 Talent Program

Medical imaging, medical image

analys is , s tat is t ica l learn ing,

computational life science

dfwang@buaa.edu.cn

Hua ZhongAssociate Research Professor of

Zhuoyue Program

Environmental and resource economics;

environmental policy and welfare;

applied general equilibrium model

hzhong@buaa.edu.cn

Liang DaiYouth 1000 Talent Program

Theoretical and computational soft

matter physics, polymer physics,

biophysics

dailiang@buaa.edu.cn

2018 REPORTER 27

Beihang University Calls for Global Talents

2018 REPORTER 27

1. About the University

Founded in 1952, Beihang University (BUAA) is the first higher education institution featuring aeronautics and

astronautics established after the founding of the People’s Republic of China in 1949. As one of the top research

universities in China, Beihang University is under the supervision of the Ministry of Industry and Information

Technology. Ever since its founding, Beihang has been the university given priority for development, one of the first

16 National Key Universities, and one of the 22 universities to establish graduate schools since degree system

was reintroduced in the 1980s. It was one of the first universities to be funded by China’s government initiated

“Project 211” and became a member of “Project 985” in 2001. In 2013, Beihang University became one of the

first National Collaborative Innovation Centers in “Program 2011”. In 2017, Beihang was chosen as “Class A

University” in the “Double First-Class” plan, which includes major support from the Chinese Ministry of Education

and other government departments to build a world-class university with first-class subject areas.

Beihang University is committed to providing high-level education and research to better foster innovation

and creativity in order to cultivate leaders who contribute to the development of the nation and the world. At

Beihang, academic prosperity and distinctiveness are created in a wide range of subject areas including sciences,

engineering, economics, management, humanities, law, philosophy, education, medicine and art. Engineering,

material science, physics, computer science, and chemistry rank top 1% in the Essential Science Indicator

database, with engineering ranking top 1‰, which marks its competitiveness in building world-class subject

areas. There are 8 degree programs for priority development (tied for seventh in the nation), 8 fields of study

(second level disciplines) for priority development in the nation, 9 programs of study for priority development in

Beijing, and 10 programs of study for priority development related to national defense. There are 7 national first-

class programs of study (tied for sixteenth in the nation) including aerospace science and technology, materials

science and engineering, mechanics, instrument science and technology, software engineering, computer science

and technology, and control science and engineering. According to results of the fourth round of assessment of

programs of study nationwide released in December 2017, Beihang University has 14 programs of study listed in

Class A. Aerospace science and technology, instrument science and technology, materials science and engineering,

and software engineering are listed as A+ (the number of A+ programs tied for eleventh in the nation).

A large number of renowned scientists and professors including many young and promising scholars with

profound attainment are contributing their wisdom and intelligence to the development of the University. Among

them are 3 Nobel laureates, 24 academicians of the Chinese Academy of Sciences or the Chinese Academy of

Engineering, 27 Global Talent 1000 national experts, 31 “Program 973” chief scientists, 75 Changjiang Scholars,

48 recipients of “National Science Fund for Distinguished Young Scholars”, 3 awardees of National Excellence

in Teaching, 56 Global Youth Talent 1000 scholars, and 38 recipients of “National Science Fund for Outstanding

Young Scholars”. Significant contributions have been made by Beihang University faculty members. A number of

outstanding faculty members have been awarded First Prizes of national level science and technology awards or

become prominent scientists and chief engineers.

28 REPORTER 2018

The innovative capacity that meets the national strategic needs is a high priority for Beihang University, which

enhances basic, forward-looking, and strategic high-tech research, gathers together key elements to innovation

to break technology bottleneck, and, at the intersection of industry, academia, research and application, builds

top innovation platforms and research groups. The total amount of scientific research activities is increasing.

The per capita amounts of research expenditure rank number 1 among higher education institutions in the

country. It has 9 State Key Laboratories, 4 National Engineering Research Centers, 66 provincial or ministerial-

level key laboratories, 6 Innovative Research Groups of the Natural Science Foundation of China, 12 Innovative

Research Groups of the Ministry of Education, 6 Innovative Research Groups of National Defense Science and

Technology, and 7 Innovative Research Groups of the Ministry of Science and Technology’s Key Research Areas

of the Innovative Talents Promotion Plan. Since the “10th five-year plan” period, Beihang has been awarded more

than 60 prizes from the three major science and technology awards at national level, including 12 national First

Prizes, and 3 Second Prizes of National Natural Science Award in 13 years, which sets the record for a university

receiving the highest level of national science and technology awards in consecutive years and affirms the success

of the “Beihang model” for scientific innovation. Beihang remains committed to strengthening basic research

and enhancing innovative capacity. Breakthroughs have been made in both the quality and quantity of papers

published in top international journals including Science and Nature.

“We have started the journey toward the sky and clouds high and far, our world lit up with achievements

like the bright stars”. Standing at a new historic starting point, while adhering to its traditions, principles

and philosophy, Beihang University will further broaden its horizon in planning for the future, making new

breakthroughs in promoting cross disciplinary innovation, fostering creative mind with elite education, constructing

top talent teams, setting the trend for science and technology development, as well as expanding international

cooperation. With one heart and one mind, and to forge ahead with determination, the University will quicken its

pace in building a world-class university rooted in the homeland of China, with Beihang Dream a major force in

realizing the Chinese Dream of the great rejuvenation of the Chinese nation. We sincerely welcome outstanding

scholars worldwide to join us in this process.

2. Subject Areas for Recruitment

Materials science and engineering, information and communications technology, electronic science and

technology, electrical engineering, control science and engineering, power engineering and thermal physics

and engineering, aerospace science and technology, mechanics, computer science and technology, software

engineering, mechanical engineering, management science and engineering, mathematics, systems science,

biological and medical engineering, transportation engineering, civil engineering, reliability engineering,

instrument science and technology, optoelectronics engineering, physics, nuclear science and technology,

chemistry, environmental science and engineering, geophysics, interdisciplinary medicine-engineering, and other

cutting-edge, cross-disciplinary or emerging research areas.

3. Qualifications and Benefits

(1)Qualifications

a. All candidates are expected to comply with laws, rules and regulations of the People’s Republic of China,

with academic integrity and high ethical standards.

b. Candidates, who should be under the age of 40 (see official program announcement for further details),

should be doing research in the field of natural sciences, engineering, or technology.

c. Candidates, at the time of filing the application, must have more than 36 consecutive months of overseas

research or work experience (full time), and must have received the PhD degree. Those who keep an employment

relationship with domestic institutions and receive salaries while working overseas are not eligible. Applicants

2018 REPORTER 29

with doctoral degree conferred in China shall not exceed the requirement for 3 years mentioned above; applicants

whose doctoral degree has been conferred overseas may exceed the requirement for 3 years, only if they have

obtained outstanding results in research or have significant achievements. In this case, the employer should

attach a statement to the application explaining why the applicant is qualified.

d. At the time of filing the application, the applicant must have a full-time teaching and/or research

appointment at a world renowned university, research institution or well-known corporate R & D lab abroad. For

those who have been working in China, the time since returning/coming to China should be less than one year.

e. After being admitted to the program, scholars should work in China for over three years.

f. The applicant should stand out among his/her peers in the field or have the potential to become leading

talent in his/her field of research.

g. Before the application deadline, students, senior visiting scholars, postdoctoral researchers, and others

who have been approved of national scholarship funding and/or whose overseas study and/or research has been

funded by the state, are not eligible if they are not complying with scholarship rules and regulations; those who

have terminated the funding agreement with relevant parties should provide documentation as justification for

eligibility in their application.

(2)Benefits

Beihang University will provide competitive salary, benefits, and research funding to Global Youth Talent 1000

scholars.

a. Salary is based at ¥400,000 per annum (pretax), with potential earnings of up to ¥600,000 (pretax).

b. Housing: apartment for faculty (subject to University policy) or ¥1,000,000 one-time housing allowance

(pretax)

c. Research funding: In addition to the national funding of ¥500,000 supplement plus ¥1,000,000 to

¥3,000,000 research funding, the candidate may apply for the University’s faculty start-up funds of ¥1,000,000 to

¥3,000,000.

d. Professional titles: ‘Distinguished’ Research Professor, PhD advisor

e. Resources and support: adequate number of doctoral students and “Zhuoyue” postdoctoral researchers

under supervision; office and lab space

f. Family support (subject to national and local policies): high quality “k through twelve” education for children;

assistance with spouse’s employment and Beijing permanent residence permit (hukou)

30 REPORTER 2018

4. Contact

We welcome eminent scholars, both domestic and international, to join us. Individuals should contact relevant

Schools to send application materials.

Queries related to policy should be directed to the Human Resource Department.Tel: 86-10-82317776 or 86-10-82317779E-mail: rsc@buaa.edu.cn

Other queries should be directed to the appropriate school.School of Materials Science and EngineeringTel: 86-10-82317134E-mail: lyjun@buaa.edu.cn

School of Electronic Information EngineeringTel: 86-10-82317235E-mail: 07434@buaa.edu.cn

School of Automation Science and Electrical EngineeringTel: 86-10-82317333E-mail: zhaoyuxia@buaa.edu.cn

School of Energy and Power EngineeringTel: 86-10-82339512E-mail: zhangxueqin@buaa.edu.cn

School of Aeronautic Science and EngineeringTel: 86-10-82317535E-mail: xuyani@buaa.edu.cn

School of Computer ScienceTel: 86-10-82317632E-mail: koko@buaa.edu.cn

School of Mechanical Engineering and AutomationTel: 86-10-82317730E-mail: smearenshi@buaa.edu.cn

School of Economics and ManagementTel: 86-10-82317837E-mail: linyaohu@buaa.edu.cn

School of Mathematics and Systems ScienceTel: 86-10-82317933E-mail: dingqin@buaa.edu.cn

School of Biological Science and Medical EngineeringTel: 86-10-82339280E-mail: lingwang@buaa.edu.cn

School of Transportation Science and EngineeringTel: 86-10-82339923E-mail: shaolin@buaa.edu.cn

School of Reliability and Systems EngineeringTel: 86-10-82316431E-mail: zlx@buaa.edu.cn

School of AstronauticsTel: 86-10-82316530E-mail: chengying@buaa.edu.cn

School of Instrument Science and Optoelectronic Engineering Tel: 86-10-82338319E-mail: hongye@buaa.edu.cn

School of Physics and Nuclear EngineeringTel: 86-10-82317241E-mail: caihy@buaa.edu.cn

Sino-French Engineer School Tel: 86-10-82339307E-mail: zhangli@buaa.edu.cn

School of ChemistryTel: 86-10-82317615E-mail: zhujingchao@buaa.edu.cn

School of Space and EnvironmentSpace Science:Tel: 86-10-82317921E-mail: anan@buaa.edu.cnEnvironmental Science:Tel: 86-10-82339539E-mail: environment@buaa.edu.cn