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A survey of prototype and experiment for UAV communications

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Science China(Information Sciences) 2021年第4期64卷 5-25页

作者： Qingheng SONG Yong ZENG jie XU Shi JIN College of Electrical and Information Engineeing Huaihua University Key Laboratory of Intelligent Control Technology for Wuling-Mountain Ecological Agriculture in Hunan Province National Mobile Communications Research Laboratory Southeast University Future Network of Intelligence Institute (FNii) and School of Science and Engineering The Chinese University of Hong Kong (Shenzhen)

Unmanned aerial vehicle(UAV) communications have attracted significant attention from both academia and industry. To facilitate the large-scale usage of UAVs for various applications in practice,we provide a comprehensive survey on the prototype and experiment for UAV communications. To this end, we first provide an overview on the general architecture of the prototype and experiment for UAV communications, and then present experimental verification for air-to-ground channel models and UAV energy consumption models. Next, we discuss measurement experiments on two promising paradigms of UAV communications, namely cellular-connected UAVs and UAV-enabled aerial communication platforms. For the former, we focus on the feasibility study and address the interference mitigation issue. For UAV-enabled aerial communication platforms, we present three scenarios, namely UAV-enabled aerial base stations, UAVenabled aerial relays and UAV-enabled aerial data collection/dissemination. Finally, we point out some promising future directions for prototype and experimental measurements of UAV communications.

关键词： UAV communications prototype development channel model energy efficiency UAV-enabled communications platforms cellular-connected UAVs

Sub-nanometer structured silicon-carbon composite nanolayers armoring on graphite for fast-charging and high-energy-density lithium-ion batteries

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Rare Metals 2023年第11期42卷 3692-3704页

作者： Zhen-Wei Li Mei-Sheng Han jie Yu Songshan Lake Materials Laboratory Dongguan523808China Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic Systems Shenzhen Engineering Lab for Supercapacitor MaterialsSchool of Material Science and EngineeringHarbin Institute of TechnologyShenzhenShenzhen 518055China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen518055China

Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent ***,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their ***,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume *** a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode *** addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.

关键词： Si/C anode Sub-nanometer Si Fast-charging capability Lithium-ion batteries(LIBs)

A novel 3D frequency domain SAGE algorithm with applications to parameter estimation in mm Wave massive MIMO indoor channels

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Science China(Information Sciences) 2017年第8期60卷 58-69页

作者： Rui FENG jie HUANG Jian SUN Cheng-Xiang WANG Shandong Provincial Key Laboratory of Wireless Communication Technologies Shandong University State Key Laboratory of Millimeter Waves Southeast University Institute of Sensors Signals and Systems School of Engineering & Physical Sciences Heriot-Watt University

Millimeter wave(mm Wave) and massive multiple-input multiple-output(MIMO) wireless communication channels show some new characteristics different from conventional channels. In order to have an in-depth understanding of mm Wave massive MIMO channels, we conduct channel measurements at 16, 28, and 38 GHz frequency bands using virtual large horizontal planar arrays in an indoor office environment. First, a three dimensional(3D) frequency domain(FD) parameter estimation algorithm extended from the space alternating generalized expectation-maximization(SAGE) algorithm is proposed and used to process the measurement ***, by dividing the large array into several sub-arrays and calculating power delay profiles(PDPs), power azimuth angle profiles(PAAPs), and power elevation angle profiles(PEAPs), we analyze the changes of delay,azimuth angle of arrival(AAo A), and elevation Ao A(EAo A) over the large array. We find that the spatial cross-correlation functions(SCCFs) calculated along different directions of the planar array exhibit significant variations. Third, the comparison of the averaged PDPs(APDPs) at three different frequency bands shows that the attenuation increases when mm Wave channels move to high frequency bands. Furthermore, SCCFs of channels at three frequency bands are also compared for two uniform linear arrays(ULAs). We draw conclusion that the correlation coefficients can be affected by not only measurement environments, but also the relative angle between transmitter(Tx) pointing direction and receiver(Rx) large array, and the operating frequency bands.

关键词： millimeter wave bands massive MIMO 3D FD-SAGE algorithm planar array statistical properties

Quantum spin Hall effect in inverted InAs/GaSb quantum wells

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Frontiers of physics 2012年第2期7卷 200-207页

作者： Ivan Knez (1) Rui-Rui du (1) 1. Department of Physics and Astronomy Rice University Houston TX 77251-1892 USA

We review the recent experimental progress towards observing quantum spin Hall effect in inverted InAs/GaSb quantum wells （QWs）. Low temperature transport measurements in the hybridization gap show bulk conductivity of a non-trivial origin, while the length and width dependence of con- ductance in this regime show strong evidence for the existence of helical edge modes proposed by Liu et al. [Phys. Rev. Lett., 2008, 100： 236601]. Surprisingly, edge modes persist in spite of compa- rable bulk conduction and show only weak dependence on magnetic field. We elucidate that seeming independence of edge on bulk transport comes due to the disparity in Fermi-wave vectors between the bulk and the edge, leading to a total internal reflection of the edge modes.

关键词： quantum spin Hall effect InAs/GaSb quantum wells topological insulators

Rational Design of Biomolecules/Polymer Hybrids by Reversible Deactivation Radical Polymerization (RDRP) for Biomedical Applications

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Chinese Journal of Polymer Science 2021年第9期39卷 1093-1109页

作者： jie Zhou Xiao-Yuan Zhang Zhi-Qiang Su State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Advanced Functional Polymer CompositesBeijing University of Chemical TechnologyBeijing 100029China

Hybrids,produced by hybridization of proteins,peptides,DNA,and other new biomolecules with polymers,often have unique functional *** properties,such as biocompatibility,stability and specificity,lead to various smart *** review mainly introduces biomolecule polymer hybrid materials by reversible deactivation radical polymerization(RDRP),emphasizing reverse addition-fragmentation chain transfer(RAFT)polymerization,and nitroxide mediated polymerization(NMP).It includes the methods of RDRP to improve the biocompatibility of biomedical materials and organisms by surface *** key to the current synthesis of biomolecule polymer hybrids is to control ***,this review describes several different kinds of biomolecule polymer hybrid materials and their applications in the biomedical *** progresses provide ideas for the investigation of biodegradable and highly bioactive biomedical soft tissue *** research hotspots of nanotechnology in biomedical fields are controlled drug release materials and gene therapy carrier *** showed that RDRP method could improve the therapeutic effect and reduce the dosage and side effects of the ***,by means of RDRP,the original materials can be modified to develop intelligent polymer materials as membrane materials with selective permeability and surface modification.

关键词： Biomolecule-polymer hybrids RDRP Biomedical applications Drug release Nanotechnology

Sphericity and Identity Test for High-dimensional Covariance Matrix Using Random Matrix Theory

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Acta Mathematicae Applicatae Sinica 2021年第2期37卷 214-231页

作者： Shou-cheng YUAN jie ZHOU Jian-xin PAN jie-qiong SHEN College of Mathematics Sichuan UniversityChengdu 610064China School of Mathematics University of ManchesterManchester M139PLUK School of Computer and Data Engineering Zhejiang University Ningbo Institute of TechnologyNingbo 315100China

This paper addresses the issue of testing sphericity and identity of high-dimensional population covariance matrix when the data dimension exceeds the sample *** central limit theorem of the first four moments of eigenvalues of sample covariance matrix is derived using random matrix theory for generally distributed ***,some desirable asymptotic properties of the proposed test statistics are provided under the null hypothesis as data dimension and sample size both tend to *** show that the proposed tests have a greater power than existing methods for the spiked covariance model.

关键词： sphericity test identity test high-dimensional covariance matrix spiked model spectral distribution

Mediation Effects of Placental Inflammatory Transcriptional Biomarkers on the Sex-Dependent Associations between Maternal Phthalate Exposure and Infant Allergic Rhinitis: A Population-Based Cohort Study

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Biomedical and Environmental Sciences 2022年第8期35卷 711-721页

作者： WANG Jian Qing LI Zhi Juan GAO Hui SHENG jie LIANG Chun Mei HU Ya Bin XIA Xun HUANG Kun WANG Su Fang ZHU Peng hao Jia Hu TAO Fang Biao Department of Maiernal Child and Adolescent HealthSchool of Public HealthAnhui Medical UniversityHefei 230032AnhuiChina MOE Key Laboratory of Popularion Health across Life Cycle Hefei 230032AnhuiChina NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract Hefei 230032AnhuiChina Anhui Provincial Key Laboratory of Population Health and Aristogenics Anhui Medical UniversityHefei 230032AnhuiChina The Fourth Affiliated Hospital Anhui Medical UniversiyHefei 230022AnhuiChina Department of Pediatrics First Afiliated Hospital of Anhui Medical UniversityHefei 230022AnhuiChina

Objective Prenatal phthalate exposure has been associated with placental inflammatory factors and infant allergic rhinitis(AR).However,the results are *** designed a population-based cohort study to examine the effects of placental inflammatory biomarkers on the sex-dependent associations between maternal phthalate exposure and infant *** A total of 2,348 pregnant women from Ma’anshan,Anhui Province,China,who were screened before antenatal visits and met the inclusion criteria,were included in the present *** assessed AR in their offspring aged 36 months with a *** PCR was performed to measure placental inflammatory factor m *** independent samples t-test and multivariable logistic regression were used to determine the associations between infant AR and maternal *** Childhood AR may be related to education and family monthly income(P = 0.01).The phthalate metabolites,mono(2-ethylhexyl) phthalate(MEHP),mono(2-ethyl-5-hydroxyl) phthalate(MEHHP),in pregnant women were associated with a significantly increased risk for infant AR in males[P duced disease risk in children.

关键词： Phthalate Infants Allergic rhinitis Inflammation Sex difference

Some results on the algebraic immunity of Boolean functions

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The Journal of China Universities of Posts and Telecommunications 2011年第2期18卷 102-105页

作者： XU Li-qing CHEN hao Software Engineering Institute East Normal University Shanghai 200062 China

From the motivation of algebraic attacks on stream and block ciphers,the concept of algebraic immunity（AI） of a Boolean function was introduced and studied *** algebraic immunity is a necessary condition for resisting algebraic *** this paper,we give some lower bounds on the algebraic immunity of Boolean *** results are applied to give lower bounds on the AI of symmetric Boolean functions and rotation symmetric Boolean *** balanced rotation symmetric Boolean functions with their AI near the maximum possible value「n/2」are constructed.

关键词： algebraic attack Boolean function AI symmetric Boolean function rotation symmetric Boolean function

Coherent change detection of fine traces based on multi-angle SAR observations

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Journal of Systems Engineering and Electronics 2023年第1期34卷 1-8页

作者： KOU Xiuli WANG Guanyong LI Jun CHEN jie School of Electronics and Information Engineering Beihang UniversityBeijing 100191China Beijing Institute of Radio Measurement Beijing 100854China

Coherent change detection(CCD) is an effective method to detect subtle scene changes that occur between temporal synthetic aperture radar(SAR) observations. Most coherence estimators are obtained from a Hermitian product based on local statistics. Increasing the number of samples in the local window can improve the estimation bias, but cause the loss of the estimated images spatial resolution. The limitations of these estimators lead to unclear contour of the disturbed region, and even the omission of fine change targets. In this paper, a CCD approach is proposed to detect fine scene changes from multi-temporal and multi-angle SAR image pairs. Multi-angle CCD estimator can improve the contrast between the change target and the background clutter by jointly accumulating singleangle alternative estimator results without further loss of image resolution. The sensitivity of detection performance to image quantity and angle interval is analyzed. Theoretical analysis and experimental results verify the performance of the proposed algorithm.

关键词： coherent change detection(CCD) multi-angle synthetic aperture radar(SAR)