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| 1 | Dynamic design of a nonlinear energy sink with NiTiNOL-steel wire ropes based on nonlinear output frequency response functions显示文摘A novel vibration isolation device called the nonlinear energy sink(NES)with NiTiNOL-steel wire ropes(NiTi-ST)is applied to a whole-spacecraft system.The NiTi-ST is used to describe the damping of the NES,which is coupled with the modified Bouc-Wen model of hysteresis.The NES with NiTi-ST vibration reduction principle uses the irreversibility of targeted energy transfer(TET)to concentrate the energy locally on the nonlinear oscillator,and then dissipates it through damping in the NES with NiTi-ST.The generalized vibration transmissibility,obtained by the root mean square treatment of the harmonic response of the nonlinear output frequency response functions(NOFRFs),is first used as the evaluation index to analyze the whole-spacecraft system in the future.An optimization analysis of the impact of system responses is performed using different parameters of NES with NiTi-ST based on the transmissibility of NOFRFs.Finally,the effects of vibration suppression by varying the parameters of NiTi-ST are analyzed from the perspective of energy absorption.The results indicate that NES with NiTi-ST can reduce excessive vibration of the whole-spacecraft system,without changing its natural frequency.Moreover,the NES with NiTi-ST can be directly used in practical engineering applications. | Yewei ZHANG Kefan XU Jian ZANG Zhiyu NI Yunpeng ZHU Liqun CHEN | 2019 | Applied Mathematics and Mechanics(English Edition)2019，40，12： | 4 |
| 2 | Accelerating an FPGA-Based SAT Solver by Software and Hardware Co-design显示文摘The Boolean Satisfiability (SAT) problem is the key problem in computer theory and application. Field-programmable gate array (FPGA) has been ad-dressed frequently to accelerate the SAT solving process in the last few years owing to its parallelism and flexibility. We have proposed a novel SAT solver based on an improved local search algorithm on the reconfigurable hardware platform. The new software preprocessing procedure and hardware architecture are involved to solve large-scale SAT problems instances. As compared with the past solvers, the proposed solver has the following advantages:the preprocessing technology can strongly improve the efficiency of solver;the strategy of strengthening the variable selection can avoid the same variable flipped continuously and repeatedly. It reduces the possibility of search falling into local minima. The experimental results indicate that the solver can solve problems of up to 32K variables/128K clauses without off-chip memory banks, and has better performance than previous works. | MA Kefan XIAO Liquan ZHANG Jianmin LI Tiejun | 2019 | Chinese Journal of Electronics2019，28，5： | 3 |
| 3 | Dynamics Analysis of Active Variable Stiffness Vibration Isolator for Whole-Spacecraft Systems Based on Nonlinear Output Frequency Response Functions显示文摘In order to improve the harsh dynamic environment experienced by heavy rockets during different external excitations,this study presents a novel active variable stiffness vibration isolator(AVS-VI)used as the vibration isolation device to reduce excessive vibration of the whole-spacecraft isolation system.The AVS-VI is composed of horizontal stiffness spring,positive stiffness spring,parallelogram linkage mechanism,piezoelectric actuator,acceleration sensor,viscoelastic damping,and PID active controller.Based on the AVS-VI,the generalized vibration transmissibility determined by the nonlinear output frequency response functions and the energy absorption rate is applied to analyze the isolation performance of the whole-spacecraft system with AVS-VI.The AVS-VI can conduct adaptive vibration suppression with variable stiffness to the whole-spacecraft system,and the analysis results indicate that the AVS-VI is efTective in reducing the extravagant vibration of the whole-spacecraft system,where the vibration isolation is decreased up to above 65%under different acceleration excitations.Finally,different parameters of AVS-VI are considered to optimize the whole-spacecraft system based on the generalized vibration transmissibility and the energy absorption rate. | Kefan Xu Yewei Zhang Yunpeng Zhu Jian Zang Liqun Chen | 2020 | Acta Mechanica Solida Sinica2020，33，6： | 1 |
| 4 | Integrated analysis of human influenza A(H1N1)virus infectionrelated genes to construct a suitable diagnostic model显示文摘The genome characteristics and structural functions of coding proteins correlate with the genetic diversity of the H1N1 virus,which aids in the understanding of its underlying pathogenic mechanism.In this study,analyses of the characteristic of the H1N1 virus infection-related genes,their biological functions,and infection-related reversal drugs were performed.Additionally,we used multi-dimensional bioinformatics analysis to identify the key genes and then used these to construct a diagnostic model for the H1N1 virus infection.There was a total of 169 differently expressed genes in the samples between 21 h before infection and 77 h after infection.They were used during the protein-protein interaction(PPI)analysis,and we obtained a total of 1725 interacting genes.Then,we performed a weighted gene co-expression network analysis(WGCNA)on these genes,and we identified three modules that showed significant potential for the diagnosis of the H1N1 virus infection.These modules contained 60 genes,and they were used to construct this diagnostic model,which showed an effective prediction value.Besides,these 60 genes were involved in the biological functions of this infectious virus,like the cellular response to type I interferon and in the negative regulation of the viral life cycle.However,20 genes showed an upregulated expression as the infection progressed.Other 36 upregulated genes were used to examine the relationship between genes,human influenza A virus,and infection-related reversal drugs.This study revealed numerous important reversal drug molecules on the H1N1 virus.They included rimantadine,interferons,and shikimic acid.Our study provided a novel method to analyze the characteristic of different genes and explore their corresponding biological function during the infection caused by the H1N1 virus.This diagnostic model,which comprises 60 genes,shows that a significant predictive value can be the potential biomarker for the diagnosis of the H1N1 virus infection. | WENBIAO CHEN KEFAN BI JINGJING JIANG XUJUN ZHANG HONGYAN DIAO | 2021 | BIOCELL2021，45，4： | 1 |
| 5 | Effects of Organic Fertilizers Made from Distiller's Grains on the Growth and Development of Flue-cured Tobacco显示文摘Pot experiments were conducted to study the effects of different organic fertilizers made from distiller's grains on the physiological characteristics and growth of flue-cured tobacco. The results showed that the agronomic traits and biomass of flue-cured tobacco in the three treatments were higher than that of the control group,and the mixed application of different organic fertilizers made from distiller's grains and compound fertilizer could promote the growth and development of flue-cured tobacco significantly. | Sheng JIANG Miao YANG Fei XIONG Yonghui ZHANG Chun XIA Jiao GUAN Kefan CAI Juntao HE Yuangai ZHANG Fei WANG Fuzhao NIAN | 2018 | Agricultural Biotechnology2018，7，3： | 1 |
| 6 | Valorizing carbon dioxide via electrochemical reduction on gas-diffusion electrodes显示文摘The electrochemical carbon dioxide(CO_(2))reduction provides a means to upgrade CO_(2)into value-added chemicals.When powered by renewable electric-ity,CO_(2)electroreduction holds the promise of chemical manufacturing with carbon neutrality.A commercially relevant CO_(2)electroreduction process should be highly selective and productive toward desired products,energetically efficient for power conversion,and stable for long-term operation.To achieve these goals,designing gas-diffusion catalytic electrodes and prototyping reactors built upon in-depth understandings of the reaction mechanisms are of para-mount importance.In this review,the fundamentals of gas-diffusion electrodes are briefly presented.Then,the most recent advances in developing high-performance CO_(2)reduction using gas-diffusion electrodes are overviewed.Reactor engineering aiming at enhancing productivity,energy efficiency,CO_(2)single-pass utilization,and operating lifetime is further discussed.Challenges in developing CO_(2)electroreduction systems are included.The prospects for advancing CO_(2)electroreduction toward practical applications are also narrated. | Yuqing Luo Kefan Zhang Yanguang Li Yuhang Wang | 2021 | InfoMat2021，3，12： | 1 |
| 7 | An Early Warning Model of Telecommunication Network Fraud Based on User Portrait显示文摘With the frequent occurrence of telecommunications and networkfraud crimes in recent years, new frauds have emerged one after another whichhas caused huge losses to the people. However, due to the lack of an effectivepreventive mechanism, the police are often in a passive position. Usingtechnologies such as web crawlers, feature engineering, deep learning, andartificial intelligence, this paper proposes a user portrait fraudwarning schemebased on Weibo public data. First, we perform preliminary screening andcleaning based on the keyword “defrauded” to obtain valid fraudulent userIdentity Documents (IDs). The basic information and account information ofthese users is user-labeled to achieve the purpose of distinguishing the typesof fraud. Secondly, through feature engineering technologies such as avatarrecognition, Artificial Intelligence (AI) sentiment analysis, data screening,and follower blogger type analysis, these pictures and texts will be abstractedinto user preferences and personality characteristics which integrate multidimensionalinformation to build user portraits. Third, deep neural networktraining is performed on the cube. 80% percent of the data is predicted basedon the N-way K-shot problem and used to train the model, and the remaining20% is used for model accuracy evaluation. Experiments have shown thatFew-short learning has higher accuracy compared with Long Short TermMemory (LSTM), Recurrent Neural Networks (RNN) and ConvolutionalNeural Network (CNN). On this basis, this paper develops a WeChat smallprogram for early warning of telecommunications network fraud based onuser portraits. When the user enters some personal information on the frontend, the back-end database can perform correlation analysis by itself, so as tomatch the most likely fraud types and give relevant early warning information.The fraud warning model is highly scaleable. The data of other Applications(APPs) can be extended to further improve the efficiency of anti-fraud whichhas extremely high public welfare value. | Wen Deng Guangjun Liang Chenfei Yu Kefan Yao Chengrui Wang Xuan Zhang | 2023 | Computers, Materials & Continua2023，，4： | 0 |
| 8 | An active high-static-low-dynamic-stiffness vibration isolator with adjustable buckling beams:theory and experiment显示文摘High-static-low-dynamic-stiffness(HSLDS)vibration isolators with buckling beams have been widely used to isolate external vibrations.An active adjustable device composed of proportion integration(PI)active controllers and piezoelectric actuators is proposed for improving the negative stiffness stroke of buckling beams.A nonlinear output frequency response function is used to analyze the effect of the vibration reduction.The prototype of the active HSLDS device is built,and the verification experiment is conducted.The results show that compared with the traditional HSLDS vibration isolator,the active HSLDS device can broaden the isolation frequency bandwidth,and effectively reduce the resonant amplitude by adjusting the active control parameters.The maximum vibration reduction rate of the active HSLDS vibration isolator can attain 89.9%,and the resonant frequency can be reduced from 31.08 Hz to 13.28 Hz.Therefore,this paper devotes to providing a new design scheme for enhanced HSLDS vibration isolators. | Kefan XU Muqing NIU Yewei ZHANG Liqun CHEN | 2024 | Applied Mathematics and Mechanics(English Edition)2024，45，3： | 0 |
| 9 | 北暖温带地区油松人工林天然发育恢复过程中的植被群落动态显示文摘本研究旨在揭示人工林在天然发育的恢复过程中其植物群落结构、多样性、种间关系和稳定性的变化特征。这种人工林的恢复过程依靠其与天然树种的交互作用实现,而不依赖于人为管理措施。在本研究中,依据油松(Pinus tabulaeformis)种群盖度占样方内乔木层盖度的比例,将八仙山国家级自然保护区的人工林天然发育序列划分为油松林、混交林和近自然3个典型阶段,并选择地域性天然次生林作为对照。以乔木层每木检尺数据为依据,重点关注群落的动态变化,包括群落结构、多样性、稳定性等方面。研究结果表明,在油松人工林天然发育的恢复过程中:(i)从混交林阶段开始形成稳定的优势种群组成,α多样性提高。(ii)乔木层径级结构由钟型向倒‘J’型转变,表明种群更新、发育状态良好。(iii)优势种群中胡桃楸(Juglans mandshurica)、蒙古栎(Quercus mongolica)、栓皮栎(Quercus variabilis)及紫椴(Tilia amurensis)的生态位宽度增加,但槲树(Quercus dentata)种群的生态位宽度在其发挥了先锋树种的作用之后下降。(iv)负关联和高生态位重叠(Levins生态位重叠指数>0.5)种群对比例下降。总之,保护区内的油松人工林在与天然树种交互作用的群落发育过程中促进了种群的更新和发育以及人工林群落的健康恢复,同时群落内的种间关系也在积极调整。本研究结论可以为揭示人工林群落天然发育过程中的动态变化特征提供有价值的参考。 | Zhenlu Qiu Mei Zhang Kefan Wang Fuchen Shi | 2023 | Journal of Plant Ecology2023，16，4： | 0 |
| 10 | Influence of Participating Radiation on Measuring Thermal Conductivity of Translucent Thermal Insulation Materials with Hot Strip Method显示文摘The hot strip method,as one typical transient method,is widely used to measure the effective thermal conductivity of thermal insulation materials at various temperatures.Since the test theory is based on solving the energy equation via heat conduction,the test result will be questionable when measuring thermal insulation materials,such as silica aerogel and photovoltaic glazing,in which the participating thermal radiation is a dominant heat transfer mode at high temperature.In this study,numerical investigation is employed to reveal the measurement reliability of hot strip method when applied to translucent thermal insulation materials.By reproducing the dynamic conduction-radiation coupled heat transfer process within the translucent materials numerically,the effective thermal conductivity of translucent materials with varying extinction coefficients are obtained at various temperatures.Comparisons are made for the effective thermal conductivity of translucent materials determined by the hot strip method,one-dimensional steady state method,transient plane source method and Rosseland model.Large discrepancies are found among the effective thermal conductivity determined by different methods for translucent materials with low extinction coefficient.The thermal conductivity obtained from the hot strip method is overestimated at elevated temperature when compared with that from one-dimensional steady state method.In order to measure the effective thermal conductivity of translucent materials accurately,the effect of thermal radiation should be considered for different transient methods. | ZHANG Hu WU Kefan TANG Guihua | 2022 | Journal of Thermal Science2022，31，4： | 0 |
| 11 | An Parallel FPGA SAT Solver Based on Multi-Thread and Pipeline显示文摘The Boolean Satisfiability(SAT) problem is the key problem in computer theory and application. A parallel multi-thread SAT solver named pprob SAT+ on a configurable hardware is proposed. In the algorithm,multithreads are executed simultaneously to hide the circuit stagnate. In order to improve the working frequency and throughput of the SAT solver, the deep pipeline strategy is adopted. When all data stored in block random access memory of the field programmable gate array, the solver can achieve maximum performance. If partial data are stored in the external memory, the size of the problem instances the SAT solver can be greatly improved. The experimental results show that the speedup of three-thread SAT solver is approximately 2.4 times with single thread,and shows that the pprob SAT+ have achieved substantial improvement while a solution is found. | LI Tiejun MA Kefan ZHANG Jianmin | 2021 | Chinese Journal of Electronics2021，30，6： | 0 |
| 12 | Reduced-search guessing random additive noise decoding of polar codes显示文摘Guessing random additive noise decoding(GRAND) has attracted researchers since its introduction in [1]. For an additive noise channel with hard decision output, the algorithm checks all error patterns, and it schedules its search in descending likelihood order. | Kefan WANG Yuejun WEI Zhenyuan CHEN Huarui YIN Liping LI Wenyi ZHANG | 2023 | Science China(Information Sciences)2023，66，2： | 0 |
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