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Coulomb stress changes due to the 2021 MS7.4 Maduo Earthquake and expected seismicity rate changes in the surroundings

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Science China Earth Sciences 2022年第4期65卷 675-686页

作者： Yashan FENG xiong xiong Bin SHAN Chengli liu School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China

On May 22 nd,2021,an MS7.4 earthquake occurred near the Maduo county of the Qinghai Province,China,within the Bayan Har *** activities have been intense in this block,thus whether the Maduo Earthquake will bring subsequent seismic hazards to its surrounding regions raises wide *** this paper,we first calculated the Coulomb failure stress changes caused by the Maduo Earthquake on nearby faults,and estimated how much these faults are brought closer or further from their next failures based on their stressing ***,we combined the Coulomb failure stress changes with the rate-state frictional law to estimate the seismicity rate in the study region in the next decade.A declustered catalogue before the Maduo Earthquake was adopted to calculate background seismicity rate,and rate-state parameters are constrained by fault slip *** results show that the Maduo Earthquake increases stress accumulations in the northwestern portion of the Qingshuihe fault(0.02 MPa at maximum),the two ends of the Kunlun Mountain Pass-Jiangcuo fault(0.01 MPa at maximum),and the northwestern portion of the Maduo-Gande fault(on average~0.09 MPa),and seismicity rates are expected to increase near these *** is especially worth noting is the seismic hazard in the region extending from the eastern end of the Kunlun Mountain Pass-Jiangcuo fault to the Maqin-Maqu seismic gap on the Eastern Kunlun fault,which is calculated to have experienced a maximum stress increase of 0.67 MPa after the Maduo *** the other hand,stress accumulations are reduced in the southern end of the Elashan fault,the Eastern Kunlun fault segment to the west of Maduo,and the northwestern portion of the Dari *** hazards are expected to be low in these *** the study region as a whole,the probability of an M≥6 earthquake taking place in the next decade is estimated to be 59%,about twice the value calculated for the time period before the Maduo Earthquake.

关键词： Maduo Earthquake Coulomb stress change Fault slip rate Seismicity rate Rate-state frictional law

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Support vector regression-based operational effectiveness evaluation approach to reconnaissance satellite system

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1626-1644页

作者： HAN Chi xiong Wei xiong Minghui liu Zhen College of Aerospace Information Space Engineering UniversityBeijing 101400China Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering UniversityBeijing 101400China

As one of the most important part of weapon system of systems(WSoS),quantitative evaluation of reconnaissance satellite system(RSS)is indispensable during its construction and *** at the problem of nonlinear effectiveness evaluation under small sample conditions,we propose an evaluation method based on support vector regression(SVR)to effectively address the defects of traditional *** the performance of SVR is influenced by the penalty factor,kernel type,and other parameters deeply,the improved grey wolf optimizer(IGWO)is employed for parameter *** the proposed IGWO algorithm,the opposition-based learning strategy is adopted to increase the probability of avoiding the local optima,the mutation operator is used to escape from premature convergence and differential convergence factors are applied to increase the rate of *** experiments of 14 test functions validate the applicability of IGWO algorithm dealing with global *** index system and evaluation method are constructed based on the characteristics of *** validate the proposed IGWO-SVR evaluation method,eight benchmark data sets and combat simulation are employed to estimate the evaluation accuracy,convergence performance and computational *** to the experimental results,the proposed method outperforms several prediction based evaluation methods,verifies the superiority and effectiveness in RSS operational effectiveness evaluation.

关键词： reconnaissance satellite system(RSS) support vector regression(SVR) gray wolf optimizer opposition-based learning parameter optimization effectiveness evaluation

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A comparative study on ApEn,SampEn and their fuzzy counterparts in a multiscale framework for feature extraction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第4期11卷 270-279页

作者： Guo-liang xiong Long ZHANG He-sheng liu Hui-jun ZOU Wei-zhong GUO School of Mechatronie Engineering East China Jiaotong University Nanchang 330013 China School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China Department of Physics Shangrao Normal University Shangrao 334001 China

Feature extraction from vibration signals has been investigated extensively over the past decades as a key issue in machine condition monitoring and fault *** existing methods,however,assume a linear model of the underlying *** this study,the feasibility of devoting nonlinear dynamic parameters to characterizing bearing vibrations is ***,fuzzy sample entropy (FSampEn) is formulated by defining a fuzzy membership function with clear physical ***,inspired by the multiscale sample entropy (multiscale SampEn) which is originally proposed to quantify the complexity of physiological time series,we placed approximate entropy (ApEn),fuzzy approximate entropy (FApEn) and the proposed FSampEn into the same multiscale *** led to the developments of multiscale ApEn,multiscale FApEn and multiscale ***,all four multiscale entropies along with their single-scale counterparts were employed to extract discriminating features from bearing vibration signals,and their classification performance was evaluated using support vector machines (SVMs).Experimental results demonstrated that all four multiscale entropies outperformed single-scale ones,whilst multiscale FSampEn was superior to other multiscale methods,especially when analyzed signals were contaminated by heavy *** with statistical features in time domain also support the use of multiscale FSampEn.

关键词： Fault diagnosis Bearing Multiscale entropy Feature extraction Support vector machines (SVMs)

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Security Enhancement of Arbiter-Based Physical Unclonable Function on FPGA

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Wuhan University Journal of Natural Sciences 2017年第2期22卷 127-133页

作者： WANG jun liu Shubo xiong Xingxing LIANG Cai Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education Wuhan University Wuhan 430072 Hubei China School of Computer Wuhan University Wuhan 430072Hubei China

In order to reduce physical unclonable fixnction （PUF） response instability and imbalance caused by the metastability and the bias of arbiter, this paper uses an improved balanced D flip-plop （DFF） based on the unbalanced DFF to reduce the bias in response output and enhances the security of PUF by adopting two balanced DFFs in series. The experimental results show that two cascaded balanced DFFs improve the stability of the DFF, and the output of two balanced DFFs is more reliable. The entropy of output is fixed at 98.7%.

关键词： physical unclonable function metastability balanced D flip-flop field programmable gate arrays (FPGA) security

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One-dimensional PT-symmetric acoustic heterostructure

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Chinese Physics B 2022年第12期31卷 289-294页

作者： Hai-Xiao Zhang Wei xiong Ying Cheng Xiao-jun liu Department of Physics MOE Key Laboratory of Modern AcousticsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of Electrical and Information Engineering Changzhou Institute of TechnologyChangzhou 213032China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

The explorations of parity-time(PT)-symmetric acoustics have resided at the frontier in physics,and the pre-existing accessing of exceptional points typically depends on Fabry-Perot resonances of the coupling interlayer sandwiched between balanced gain and loss ***,the concise PT-symmetric acoustic heterostructure,eliminating extra interactions caused by the interlayer,has not been researched in *** we derive the generalized unitary relation for one-dimensional(1D)PT-symmetric heterostructure of arbitrary complexity,and demonstrate four disparate patterns of anisotropic transmission resonances(ATRs)accompanied by corresponding spontaneous phase *** a special case of ATR,the occasional bidirectional transmission resonance reconsolidates the ATR frequencies that split when waves incident from opposite directions,whose spatial profiles distinguish from a unitary *** derived theoretical relation can serve as a predominant signature for the presence of PT symmetry and PT-symmetry-breaking transition,which may provide substantial support for the development of prototype devices with asymmetric acoustic responses.

关键词： acoustic PT-symmetric heterostructure anisotropic transmission resonance occasional bidirectional transmission resonance

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基于自适应续流比的混合式步进电机转矩脉动抑制方法

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陕西科技大学学报 2025年第1期43卷 142-151,202页

作者：王焜刘宝泉刘艺张浩铭刘俊陕西科技大学电气与控制工程学院陕西西安710021 西安西电高压开关有限责任公司陕西西安710018

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前... 详细信息

混合式步进电机细分驱动存在较大的电流纹波,导致转矩脉动明显.通过分析H桥驱动电路的续流过程,提出一种基于自适应续流比的混合式步进电机转矩脉动抑制方法.该方法利用环型分配器产生的细分指令电流i ref与实际电流i相比较,以区分当前时刻所需的续流模式.在快速续流模式下,实时监测电流指令与实际电流的差值Δi ref,通过自适应系数k动态调节续流时间,直至电机相电流快速下降至给定电流i ref后切换至缓慢续流模式.对续流时长与快速续流占总续流时间的比例自适应调节以适应不同工况下步进电机的平稳运行,有效降低了转矩脉动.最后,搭建MATLAB/Simulink仿真平台并进行实验验证,结果表明,与传统混合续流控制相比,所提方法能够有效减小步进电机的转矩脉动.

关键词：混合式步进电机自适应续流比电流纹波转矩脉动

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Atomic Layer Deposition-Assisted Construction of Binder-Free Ni@N-Doped Carbon Nanospheres Films as Advanced Host for Sulfur Cathode

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Nano-Micro Letters 2019年第4期11卷 147-160页

作者： jun liu Aixiang Wei Guoxiang Pan Qinqin xiong Fang Chen Shenghui Shen Xinhui Xia Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter School of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006People’s Republic of China Department of Information Science Xinhua College of Sun Yat-sen UniversityGuangzhou 510520People’s Republic of China Department of Materials Chemistry Huzhou UniversityHuzhou 313000People’s Republic of China College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018People’s Republic of China Department of Chemistry Zhejiang UniversityHangzhou 310027People’s Republic of China State Key Laboratory of Silicon Materials Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Provinceand Department of Materials Science and EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071People’s Republic of China

Rational design of hybrid carbon host with high electrical conductivity and strong adsorption toward soluble lithium polysulfides is the main challenge for achieving high-performance lithium-sulfur batteries(LSBs).Herein,novel binder-free Ni@N-doped carbon nanospheres(N-CNSs)films as sulfur host are firstly synthesized via a facile combined hydrothermal-atomic layer deposition *** cross-linked multilayer N-CNSs films can effectively enhance the electrical conductivity of electrode and provide physical blocking“dams”toward the soluble long-chain ***,the doped N heteroatoms and superficial NiO layer on Ni layer can work synergistically to suppress the shuttle of lithium polysulfides by effective chemical interaction/*** virtue of the unique composite architecture and reinforced dual physical and chemical adsorption to the soluble polysulfides,the obtained Ni@N-CNSs/S electrode is demonstrated with enhanced rate performance(816 mAh g?1 at 2 C)and excellent long cycling life(87%after 200 cycles at 0.1 C),much better than N-CNSs/S electrode and other carbon/S *** proposed design strategy offers a promising prospect for construction of advanced sulfur cathodes for applications in LSBs and other energy storage systems.

关键词： Atomic layer deposition Nickel N-doped carbon nanospheres Sulfur cathode Lithium-sulfur batteries

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Ridge-Forward Quadratic Discriminant Analysis in High-Dimensional Situations

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Journal of Systems Science & Complexity 2016年第6期29卷 1703-1715页

作者： xiong Cui ZHANG jun LUO Xinchao School of Statistics East China Normal University College of Mathematics and Statistics Institute of Statistical SciencesShen Zhen-Hong Kong Joint Research Centre for Applied Statistical SciencesShenzhen University

Quadratic discriminant analysis is a classical and popular classification tool,but it fails to work in high-dimensional situations where the dimension p is larger than the sample size *** address this issue,the authors propose a ridge-forward quadratic discriminant(RFQD) analysis method via screening relevant predictors in a successive manner to reduce misclassification *** authors use extended Bayesian information criterion to determine the final model and prove that RFQD is selection *** Carlo simulations are conducted to examine its performance.

关键词： Extended BIC quadratic discriminant analysis ridge-forward selection consistency.

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CO selective methanation in hydrogen-rich gas mixtures over carbon nanotube supported Ru-based catalysts

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Journal of Natural Gas Chemistry 2012年第4期21卷 445-451页

作者： jun xiong Xinfa Dong Lingling Li School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640GuangdongChina

Series of carbon nanotube supported Ru-based catalysts were prepared by impregnation method and applied successfully for complete removal of CO by CO selective methanation from H2-rich gas stream conducted in a fixed-bed quartz tubular reactor at ambient pressure. It was found that the metal promoter, reduction temperature and metal loading affected the catalytic properties significantly. The most excellent performance was presented by 30 wt% Ru-Zr/CNTs catalyst reduced at 350 ℃. Since it decreased CO concentration to below 10 ppm from 12000 ppm by CO selective methanation at the temperature range of 180-240 ℃, and kept CO selectivity higher than 85% at the temperature below 200 ℃. Characterization using XRD, TEM, H2-TPR and XPS suggests that Zr modification of Ru/CNTs results in the weakening of the interaction between Ru and CNTs, a higher Ru dispersion and the oxidization of surface Ru. Amorphous and high dispersed Ru particles with small size were obtained for 30 wt% Ru-Zr/CNTs catalyst reduced at 350 ℃, leading to excellent catalytic performance in CO selective methanation.

关键词： CO selective methanation Ru-based/CNTs catalyst hydrogen-rich gases CNTs hydrogen energy

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Unveiling the superior hydrogen evolution reaction activity of 1T-2H MoS_(2)heterointerface by on-chip microdevices

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Nano Research 2025年第1期18卷 149-156页

作者： Bowen liu junjie xiong Shuaishuai Xu Xinying Luo Wenyan Yao Shigang liu Yuting Du Qinghua Zhang Yang Gao Bin Wang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology(NCNST)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

The identification and clarification of active sites of MoS_(2)have long been the focus of research efforts in hydrogen evolution reaction(HER).In this study,we constructed phase transition-induced 1T-2H MoS_(2)heterojunction via lithium intercalation and evaluated the HER activity using on-chip electrocatalytic microdevices(OCEMs).The heterojunction achieved an overpotential of only 226 mV at a cathodic current density of 10 mA/cm^(2),outperforming the basal planes of 1T and 2H MoS_(2).Furthermore,density functional theory(DFT)calculations demonstrated that the charge redistribution occurs at the 1T-2H MoS_(2)interface with electrons transferring from 1T to 2H MoS_(2),and the interfacial S atom at the top site of 1T MoS_(2)presents the smallest overpotential of 0.37 ***,the interference from highly active edge sites was avoided by precisely exposing specific active areas,quantitatively revealing the catalytic activity order of different types of in-plane MoS_(2)active *** work enables a systematic investigation of the HER activity of various active sites in MoS_(2),laying the foundation for quantitative analysis of activity in other lowdimensional materials.

关键词： on-chip microdevice phase transition heterojunction MoS_(2) hydrogen evolution reaction(HER)

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