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Journal of Computer Science & Technology 2020年第4期35卷 825-842页

作者： Zachary P.Languell Qijun Gu Department of Computer Science Texas State UniversitySan MarcosTX 78666USA

The Automatic dependent Surveillance-Broadcast(ADS-B)protocol is being adopted for use in unmanned aerial vehicles(UAVs)as the primary source of information for emerging multi-UAV collision avoidance *** lack of security features in ADS-B leaves any processes dependent upon the information vulnerable to a variety of threats from compromised and dishonest *** could result in substantial losses or damage to *** research proposes a new distance-bounding scheme for verifying the distance and flight trajectory in the ADS-B broadcast data from surrounding *** proposed scheme enables UAVs or ground stations to identify fraudulent UAVs and avoid *** scheme was implemented and tested in the ArduPilot SITL(Software In The Loop)simulator to verify its ability to detect fraudulent *** experiments showed that the scheme achieved the desired accuracy in both flight trajectory measurement and attack detection.

关键词： automatic dependent surveillance-broadcast (ADS-B) unmanned aerial vehicle (UAV) distance bounding collision airspace safety

Diameter dependent doping in horizontally aligned high-density N-doped SWNT arrays

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Nano Research 2019年第8期12卷 1845-1850页

作者： Pan Li Yiming Li Xiao Zhang Jun Chen Yingwen Cheng Yi Li Yanwen Ma Jie Liu Key Laboratory for Organic Electronics and Information Displays Jiangsu Key Laboratory for BiosensorsInstitute of Advanced Materials (LAM)Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM)Nanjing University of Posts & Telecommunications9 Wenyuan RoadNanjing 210023China Department of Chemistry Duke UniversityDurhamNorth Carolina 27708USA Department of Chemistry and Biochemistry Northern Illinois UniversityDeKalbIllinois 60115USA

We reported the growth of horizontally aligned nitrogen-doped single-walled carbon nanotubes (SWNTs) on quartz substrates. The synthesized SWNTs were comprehensively characterized at the single nanotube level. Owing to the highly aligned nature of the nanotubes, we were able to investigate the diameter dependent doping mechanism through systematic resonant Raman spectroscopy studies. Other than the formerly found narrowing effect by N-doping, we proposed that the nanotube diameter affects the introduction of N atoms into the carbon lattice in an elaborate way. The obtained doping level increased along with the nanotube diameter but lost the increasing trend when the diameter became larger and experienced a slight decrease after reaching the local peak value. These insights about the heteroatom doping into the carbon nanotubes could benefit the development of the carbon nanotube based functional materials and extend their application in a broad range of areas.

关键词： single-walled carbon nanotube (SWNT) array chemical vapor deposition (CVD) N-doping diameter dependent doping Raman spectroscopy

Time-dependent Ginzburg–Landau equations for multi-gap superconductors

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Chinese Physics B 2020年第3期29卷 385-388页

作者： Minsi Li Jiahong Gu Long Du Hongwei Zhong Lijuan Zhou Qinghua Chen School of Science Guangxi University of Science and TechnologyLiuzhou 545006China

We numerically solve the time-dependent Ginzburg–Landau equations for two-gap superconductors using the finite-element technique. The real-time simulation shows that at low magnetic field, the vortices in small-size samples tend to form clusters or other disorder structures. When the sample size is large, stripes appear in the pattern. These results are in good agreement with the previous experimental observations of the intriguing anomalous vortex pattern, providing a reliable theoretical basis for the future applications of multi-gap superconductors.

关键词： vortex multi-gap superconductivity time dependent finite element technique

Quantum dynamics of dissociative adsorption of H_2 and D_2:The time-dependent wave packet method

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Science China Chemistry 1998年第4期41卷 403-409页

作者：关大任华东明张庆刚丁世良 1. Institute of Theoretical Chemistry Shandong University 250100 Ji’nan China 2. Institute of Atomic and Molecular Physics Shandong Normal University 250014 Ji’nan China

A time dependent quantum wave packet method was used to study the dynamics of dissociative adsorption of H 2 and D 2 on a flat and static surface. The molecule surface interaction is described using a modified London Eyring Polanyi Sato (LEPS) type potential for the H 2/Ni(100) system. The three dimensional (3 D) dissociation probabilities were calculated for different initial rovibrational states as a function of initial incident energies. Our results show that the dissociation of the diatomic rotational states whose quantum numbers satisfy j+m =odd is forbidden at low energies for the homonuclear H 2 and D 2 due to the selection rule. The effect of the rotational orientation of diatoms on adsorption predicts that the in plane rotation (m=j) is more favorable for dissociation than the out of plane rotation (m=0) . Enhanced dissociation for vibrationally excited molecules and the significant enhancement of the dissociation probability of H 2 when compared to D 2 were explained reasonably in terms of quantum mechanical zero point energies, the tunneling effect and the reflection from an activation barrier.

关键词： time dependent wave packet method dissociative adsorption quantum dynamics optical potential.

DKP Equation with Energy dependent Potentials

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Communications in Theoretical Physics 2019年第9期71卷 1069-1074页

作者： O.Langueur M.Merad B.Hamil Departement des sciences de la matiere Faculte des Sciences ExactesUniversitede Oum El Bouaghi04000Oum El BouaghiAlgeria Departement de TC de SNV Universite Hassiba BenboualiChlefAlgeria

In this work, we study the DKP equation subjected to the action of combined vector plus scalar energy depend on potentials in(1+1) dimensions space-time. The conditions of normalisation and continuity equation are calculated. The eigenfunctions and the corresponding eigenvalues are then determined. A numerical study is presented and the energy graphs for some values of the energy parameter are plotted.

关键词： DKP equation energy dependent potentials biconfluent Heun function

Temperature trends and elevation dependent warming during 1965-2014 in headwaters of Yangtze River, Qinghai Tibetan Plateau

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Journal of Mountain Science 2020年第3期17卷 556-571页

作者： Naveed AHMED WANG Gen-xu Adeyeri OLUWAFEMI Sarfraz MUNIR HU Zhao-yong Aamir SHAKOOR Muhammad Ali IMRAN Key Laboratory of Mountain Surface Process and Ecological Regulations Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Institute for Meteorology and Climate Research Atmospheric Environmental Research Karlsruhe Institute of TechnologyCampus Alpine82467Germany Water Resources Engineering University of Kurdistan Hewler 30 Meter Avenue ErbilKurdistan44001Iraq Department of Agricultural Engineering Bahauddin Zakariya UniversityMultan66000Pakistan Beijing Key Laboratory of Water Resources and Environmental Engineering China University of GeosciencesBeijing 100083China

The understanding of temperature trends in high elevation mountain areas is an integral part of climate change research and it is critical for assessing the impacts of climate change on water resources including glacier melt, degradation of soils, and active layer thickness. In this study, climate changes were analyzed based on trends in air temperature variables(Tmax, Tmin, Tmean), and Diurnal Temperature Range(DTR) as well as elevation-dependent warming at annual and seasonal scales in the Headwaters of Yangtze River(HWYZ), Qinghai Tibetan Plateau. The Base Period(1965-2014) was split into two subperiods;Period-Ⅰ(1965-1989) and Period-Ⅱ(1990-2014) and the analysis was constrained over two subbasins;Zhimenda and Tuotuohe. Increasing trends were found in absolute changes in temperature variables during Period-Ⅱ as compared to Period-Ⅰ.Tmax, Tmin, and Tmean had significant increasing trends for both sub-basins. The highest significant trends in annual time scale were observed in Tmin(1.15℃ decade-1) in Tuotuohe and 0.98℃ decade-1 in Zhimenda sub-basins. In Period-Ⅱ, only the winter season had the highest magnitudes of Tmax and Tmin0.58℃ decade-1 and 1.26℃ decade-1 in Tuotuohe subbasin, respectively. Elevation dependent warming analysis revealed that Tmax, Tmin and Tmean trend magnitudes increase with the increase of elevations in the middle reaches(4000 m to 4400 m) of the HWYZ during Period-Ⅱ annually. The increasing trend magnitude during Period-Ⅱ, for Tmax, is 1.77, 0.92, and 1.31℃ decade-1, for Tmin 1.20, 1.32 and 1.59℃ decade-1,for Tmean 1.51, 1.10 and 1.51℃ decade-1 at elevations of4066 m, 4175 m and 4415 m respectively in the winter season. Tmean increases during the spring season for> 3681 m elevations during Period-Ⅱ, with no particular relation with elevation dependency for other variables. During the summer season in Period Ⅱ, Tmax, Tmin, Tmean increases with the increase of elevations(3681 m to 4415 m) in the middle reaches of HWYZ. Elevation dependent wa

关键词： Climate change Elevation dependent warming Mann Kendall Temperature trends Yangtze River Qinghai Tibetan Plateau

Influence of DCM dye doping on the magnetic field dependent electroluminescence in organic light emitting diodes

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Science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 24-29页

作者： CHEN Ping, LEI YanLian, LIU Rong, ZHANG QiaoMing, ZHANG Yong & XIONG ZuHong School of Physical Science and Technology, MOE Key Laboratory on Luminescence and Real-Time Analysis, Southwest University, Chongqing 400715, China 1. School of Physical Science and Technology MOE Key Laboratory on Luminescence and Real-Time Analysis Southwest University Chongqing 400715 China

The DCM dye doped organic electroluminescence devices with structure of ITO/NPB/Alq 3 : DCM/Alq 3 /LiF/Al were fabricated. From 15 K to room temperature, the magnetic field dependent of electroluminescence (MEL) of devices was investigated. Our observations indicated that the MEL is composed of two effects in different regimes: a low field (0≤B≤40 mT) effect and a high field (B > 40 mT) effect. For undoped devices, the low field effect exhibits a rapid rising with the increasing field, and the high field effect shows a slow increase and gradually saturates at room temperature. For doped devices, the low field rapid increase is also present, whereas the high field effect displays a decrease with the increasing field. The larger the injection current is, the more apparent the high field decrease is. In addition, the doped device demonstrates less temperature dependence of the high field effect than undoped device, although the undoped devices also present high field decrease of electroluminescence at low temperatures (T≤150 K). Based on the energy level trapping effect due to dye doping and magnetic field modulated triplet exciton annihilation, the experimental results are carefully explained.

关键词： dye doping magnetic field dependent of electroluminescence energy level traps triplet exciton annihilation

In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes

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InfoMat 2023年第1期5卷 161-171页

作者： Ran Cai Lixia Bao Wenqi Zhang Weiwei Xia Chunhao Sun Weikang Dong Xiaoxue Chang Ze Hua Ruiwen Shao Toshio Fukuda Zhefei Sun Haodong Liu Qiaobao Zhang Feng Xu Lixin Dong Beijing Advanced Innovation Center for Intelligent Robots and Systems School of Medical TechnologyBeijing Institute of TechnologyBeijingPeople's Republic of China Analysis&Testing Center Beijing Institute of TechnologyBeijingPeople's Republic of China Department of Biomedical Engineering City University of Hong KongHong KongPeople's Republic of China Shaanxi Materials Analysis and Research Center School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'anPeople's Republic of China School of Environmental and Safety Engineering North University of ChinaTaiyuanPeople's Republic of China Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamenFujianPeople's Republic of China Department of Nanoengineering University of California San DiegoLa JollaCaliforniaUSA SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjingPeople's Republic of China

Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant *** addition,the reaction mecha-nisms and origins of enhanced performance remain ***,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron *** found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is *** expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized *** significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element *** the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon *** particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural *** article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation ***,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.

关键词： elucidated by geometric phase analysis and finite-element analysis. Despite the different intercalation behaviors the formed products of Fe and K 2 Se after full potassiation can be converted back into the original FeSe phase upon depotassiation. In particular small-sized nanoflakes exhibit better cycling perfor- mance with well-maintained structural integrity. This article presents the first successful demonstration of atomic-scale visualization that can reveal size- dependent potassiation dynamics. Moreover it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. KEYWOR DS in situ transmission electron microscopy potassium-ion batteries potassium-ion storage mechanism size-dependent effects tetragonal FeSe

Complete f-moment Convergence for Widely Orthant dependent Random Variables and Its Application in Nonparametric Models

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Acta Mathematica Sinica,English Series 2019年第12期35卷 1917-1936页

作者： Chao LU Zhuang CHEN Xue Jun WANG School of Mathematical Sciences Anhui University

In this paper,we study the complete f-moment convergence for widely orthant dependent(WOD,for short)random variables.A general result on complete f-moment convergence for arrays of rowwise WOD random variables is *** applications,we present some new results on complete f-moment convergence for WOD random *** also give an application to nonparametric regression models based onWOD errors by using the complete convergence that we ***,the choice of the fixed design points and the weight functions for the nearest neighbor estimator are proposed,and a numerical simulation is provided to verify the validity of the theoretical result.

关键词： Widely orthant dependent random variables complete f-moment convergence complete convergence complete consistency

Rate dependent rheological stress-strain behavior of porous nanocrystalline materials

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Journal of Central South University 2008年第S1期15卷 21-24页

作者：李慧周剑秋 School of Mechanical and Power Engineering Nanjing University of Technology

To completely understand the rate-dependent stress-strain behavior of the porous nanocrystalline materials,it is necessary to formulate a constitutive model that can reflect the complicated experimentally observed stress-strain relations of nanocrystalline *** nanocrystalline materials consisting grain interior and grain boundary are considered as viscoplastic and porous materials for the reasons that their mechanical deformation is commonly governed by both dislocation glide and diffusion,and pores commonly exist in the nanocrystalline materials.A constitutive law of the unified theory reflecting the stress-strain relations was established and verified by experimental data of bulk nanocrystalline Ni prepared by hydrogen direct current arc plasma evaporation method and hot *** effect of the evolution of porosity on stress-strain relations was taken into account to make that the predicted results can keep good agreements with the corresponding experimental results.

关键词： stress-strain porous nanocrystalline materials rate dependent porosity