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Collaborative Spectrum Sensing for Illegal Drone Detection: A Deep Learning-Based Image Classification Perspective

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China Communications 2020年第2期17卷 81-92页

作者： Huichao Chen zheng wang Linyuan Zhang College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of communications engineering Army Engineering UniversityNanjing 210007China

Drones,also known as mini-unmanned aerial vehicles(UAVs),are enjoying great popularity in recent years due to their advantages of low cost,easy to pilot and small size,which also makes them hard to *** can provide real time situational awareness information by live videos or high deﬁnition pictures and pose serious threats to public *** this article,we combine collaborative spectrum sensing with deep learning to effectively detect potential illegal drones with states of high ***,we formulate the detection of potential illegal drones under illegitimate access and rogue power emission as a quaternary hypothesis test ***,we propose an algorithm of image classiﬁcation based on convolutional neural network which converts the cooperative spectrum sensing data at a sensing slot into one ***,to exploit more information and improve the detection performance,we develop a trajectory classiﬁcation algorithm which converts theﬂight process of the drones in consecutive multiple sensing slots into trajectory *** addition,simulations are provided to verify the proposed methods’performance under various parameter conﬁgurations.

关键词： illegal drones detection deep learning collaborative spectrum sensing

Ad hoc distributed mutual exclusion algorithm based on token-asking

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Journal of Systems Engineering and Electronics 2007年第2期18卷 398-406页

作者： wang zheng Liu Xin'song Li Mei'an School of Economic Information Engineering Southwestern Univ. of Finance and Economics Chengdu 610074 P.R.China 8010 R&D Computer Science and Engineering College Univ. of Electronic Science and Technology Chengdu 610054 P.R.China

The solution of distributed mutual exclusion is difficult in Ad hoc networks owing to dynamic topologies and mobility. Based on the analysis of the properties of Ad hoc networks and the disadvantages of the traditional algorithms, an improved Ad hoc system model was given and a novel algorithm was presented as AHDME （Ad Hoc Distributed Mutual Exclusion）; it was based on the token-asking algorithms. It utilized broadcast to search for the token and to decrease the message complexity of multi-hop Ad hoc networks. Lamport＇s timestamp was improved to ensure the time sequence and to prevent nodes from starvation. When compared to traditional algorithms, AHDME does not require the fixed size of request queues and the global system information, which adapts itself to the frequent arrival/departures and the limited computing capability of nodes in Ad hoc networks. Performance analysis and simulation results show that the AHDME algorithm has low message complexity, small space complexity, and short response delay.

关键词： Ad hoc Distributed mutual exclusion Token-asking Logical timestamp.

Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China Earth Sciences 2024年第5期67卷 1436-1458页

作者： Qing GONG Ming-Xing LING wang zheng State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)***,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic *** stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic *** date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the ***,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of *** a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

Can the Prior Cathodic Polarisation Treatment Remove the Air-Formed Surface Film and Is It Necessary for the Potentiodynamic Polarisation Test?

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Acta Metallurgica Sinica(English Letters) 2020年第6期33卷 839-845页

作者： zheng-Rong Ye Zhi-Chao Qiu zheng-Bin wang Yu-Gui zheng Ran Yi Xiang Zhou Research Institute of Petroleum Exploration and Development PetroChinaBeijing 100083China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

This paper clarifies two issues related to the prior cathodic polarisation treatment(PCPT) for the potentiodynamic polarisation test: whether PCPT can(1) remove the air-formed surface film and(2) affect the polarisation test results. X-ray photoelectron spectroscopy analyses of fluoride ion-labelled samples show that PCPT cannot remove the surface film completely due to the low reaction rate. Potentiodynamic polarisation tests demonstrate that PCPT with proper operating parameters,-1.0 V SCE for 5 min with subsequent open circuit potential(OCP) stabilisation in this study, is necessary because it can improve the test reproducibility without affecting the corrosion parameters by unifying the initial surface state. However, PCPT with lower potentials, longer time or no OCP stabilisation has significant effects on the electrochemical corrosion parameters due to the hydrogen absorption under the conditions of this study.

关键词： Stainless steel Prior cathodic polarisation treatment Surface film Potentiodynamic polarisation

Estimation of provincial forest carbon sink capacities in Chinese mainland

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Chinese Science Bulletin 2011年第9期56卷 883-889页

作者： MA XiaoZhe wang zheng ECNU Key Laboratory of Geographic Information ScienceMinistry of EducationEast China Normal UniversityShanghai 200062China Institute of Policy and Management Chinese Academy of SciencesBeijing 100190China Institute of Geographical Science Henan Academy of SciencesZhengzhou 450052China

Estimation of the capacity of provincial forest carbon sinks in Chinese mainland using the CO2FIX model provides data support for the effective management of provincial regions. According to China’s Sixth National Forest Inventory, we estimate the capacities of original and new afforestation carbon sinks under the assumption of using the country’s non-forest land for afforestation and reforestation to achieve a new forested area of 57323200 ha. The carbon absorption capacity of China’s forest ecosystems estimated from 2005 to 2050 reaches 8.4 GtC. The absorption capacities of original forest and new afforestation respectively are 4.9 and 3.5 GtC. The annual capacity of all forest carbon sinks has a roughly decreasing trend. Inner Mongolia Autonomous Region, Yunnan, Sichuan and Heilongjiang provinces make major contributions to the carbon sink capacity.

关键词：森林资源连续清查吸收能力中国大陆碳估算森林生态系统内蒙古自治区 ities

Effect of removing Al and Ti elements on peak flow stress of nickel-based heat-resistant alloy 617

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Journal of Iron and Steel Research International 2023年第2期30卷 384-391页

作者： Chen Dong zheng-zong Chen zheng-dong Liu Han-sheng Bao Zhen Liu zheng-jun wang Faculty of Mechanical and Material Engineering Huaiyin Institute of TechnologyHuaian223003JiangsuChina Jiangsu Key Laboratory of Advanced Manufacturing Technology Huaiyin Institute of TechnologyHuaian223003JiangsuChina Institute for Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing100081China

The hot deformation behavior and the microstructure characteristics of alloy 617 and alloy C-HRA-2 were compared and *** removal of Al and Ti elements has a significant change in the hot deformation of the alloy,and there are two opposite effects on the flow stress before and after *** results show that the removal of Al and Ti elements increases the flow stress of the alloy under high temperature or low strain rate deformation *** is mainly due to the increase in the stacking fault energy of the alloy so that the alloy contains a higher twin boundary fraction after dynamic recrystallization(DRX).However,before DRX occurs,that is,at low temperature and high strain rate,the flow stress of this alloy is relatively *** is due to the reduction in Peierls-Nabarro stress,making the alloy more prone to dislocation slip.

关键词： Peak flow stress Nickel-based heat-resistant alloy Slip band Stacking fault energy

Diffusion tensor imaging of the hippocampus reflects the severity of hippocampal injury induced by global cerebral ischemia/reperfusion injury

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Neural Regeneration Research 2022年第4期17卷 838-844页

作者： Wen-Zhu wang Xu Liu zheng-Yi Yang Yi-zheng wang Hai-Tao Lu China Rehabilitation Science Institute School of Rehabilitation MedicineCapital Medical UniversityBeijing Bo’ai HospitalChina Rehabilitation Research CenterBeijingChina Beijing Key Laboratory of Neural Injury and Rehabilitation BeijingChina Department of Rehabilitation Medicine Beijing Friendship HospitalCapital Medical UniversityBeijingChina Brainnetome Center Institute of AutomationChinese Academy of SciencesBeijingChina

At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical *** such an injury,clinical indicators that can directly reflect neurological dysfunction are *** change in hippocampal microstructure is the key to memory formation and *** tensor imaging is a highly sensitive tool for visualizing injury to hippocampal *** hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains *** address this issue,we established rat models of GCI/RI using the four-vessel occlusion *** tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity *** results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional *** findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/*** study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval ***-2015-139)on November 9,2015.

关键词： brain-derived neurotrophic factor diffusion tensor imaging fractional anisotropy value global cerebral ischemia/reperfusion injury hippocampus Trk B

Macroscopic Quantum Coherence in an Antiferromagnetic Spin Chain with Biaxial Anisotropy

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Communications in Theoretical Physics 2009年第8期52卷 365-368页

作者： ZHAO Qun-Chao zheng Gong-Ping wang zheng Department of Physics Henan Normal University Xinxiang 453007 China Department of Physics and Information Engineering Shangqiu Normal Univeristy Shangqiu 476000 China

Instanton configurations of （1＋1）-dimensions in an antiferromagnetic biaxial-anisotropy-spin-chain are obtained explicitly in the strong anisotropy limit, which interpolate between degenerate equilibrium orientations of the Neel vector along easy axis and are seen to be responsible for quantum tunneling. Macroscopic quantum coherence of the domain walls is demonstrated in terms of the instantons.

关键词： macroscopic quantum coherence antiferromagnetic spin chain

Study on Interaction Between Two Parallel Plates with Iteration Method in Functional Theory

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Chinese Journal of Chemical Physics 2008年第2期21卷 131-135页

作者： Ming Zhou zheng-wu wang Zu-min Xu Department of Food Science and Technology School of Agriculture and Biology Shanghai Jiao Tong University Shanghai 200240 China School of Chemical and Material Engineering Jiangnan University Wuxi 214122 China

By introducing the functional theory into the calculation of electric double layer （EDL） interaction, the interaction energies of two parallel plates were calculated respectively at low, moderate, and high potentials. Compared with the results of two existing methods, Debye-Hückel and Langmuir methods, which are applicable just to the critical potentials and perform poorly in the intermediate potential, the functional approach not only has much simpler expression of the EDL interaction energy, but also performs well in the entire range of potentials.

关键词： Interaction energy Functional theory Electric double layer Parallel plate