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High-speed imaging observation on molten bridges of AgNi10 electrical contact material

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Rare Metals 2023年第1期42卷 336-345页

作者： jing-hong chen Song chen Ming Xie Jie-Qiong Hu Sai-Bei Wang State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metal Kunming Institute of Precious MetalsKunming650106China

The electrical contact-high-speed imaging experimental system was developed to investigate the molten bridge phenomena of AgNi10 electrical contact *** dimension of molten bridges was measured along with the measurement of waveforms in the contact voltage under the load of direct current(DC) 6 V(8-20 A)and breaking speed of 50.0 mm·s^(-1).A part of the observed results was presented as well as surface morphology of the contacts after electrical contact behavior,which shows some interesting and new *** bridges and arc could exist *** stable molten bridge looks like cylindrical shape and then becomes needle tip at its rupture,the diameter and length of molten bridges both increase with the increase in current and the growth gradient of the diameter is larger than that of the *** morphology and elemental distribution of the contact surface are changed by the behavior of electrical contact.

关键词： Molten bridge High-speed imaging Arc AgNi10 electrical contact material

Mars exploration——In situ K-Ar dating of jarosite

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Science China Earth Sciences 2024年第3期67卷 641-656页

作者： jing YANG Dewen ZHENG Ying WU hong chen Li YANG Bin ZHANG Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Institute of Earth Sciences China University of GeosciencesBeijing 100083China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029Chin

To accurately determine the chronological framework of climatic variations recorded by various Martian terrains, the absolute ages of Martian events and cratering rate need to be constrained by either in situ dating or returned samples. In situ K-Ar dating is currently a more plausible dating technique as compared with sample return. Jarosite(KFe_(3)[SO_(4)]_(2)[OH]_(6)) is the only confirmed K sulfate mineral that is widely present on Mars, as indicated by in situ detection, orbital remote sensing, and meteorite studies. Jarosite can be used for precise K-Ar and (40)Ar/(39)Ar dating. The preservation of jarosite on Mars provides information about the nature and duration of aqueous processes on the Martian surface. Different ages of Martian jarosite represent the key to constraining the transition from Martian surface water activity to arid climatic conditions. This paper summarizes recent advances in our knowledge of the spatial distribution of Martian jarosite, its mineralogical properties and stability on Mars, the Ar diffusion kinetics of jarosite, and the current status of in situ K-Ar dating. Moreover, we examine the key scientific issues to be addressed for in situ K-Ar dating of jarosite and Martian sample return missions, and discuss future research directions.

关键词： Mars Jarosite In situ K-Ar dating Ar diffusion Stability

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Noise-Tolerant ZNN-Based Data-Driven Iterative Learning Control for Discrete Nonaffine Nonlinear MIMO Repetitive Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 344-361页

作者： Yunfeng Hu Chong Zhang Bo Wang jing Zhao Xun Gong Jinwu Gao hong chen State Key Laboratory of Automotive Simulation and Control Jilin UniversityJilin UniversityChangchun 130025China College of Communication Engineering Jilin UniversityJilin UniversityChangchun 130025China Department of Electromechanical Engineering University of MacaoMacao 999078China School of Artificial Intelligence Jilin UniversityChangchun 130012China IEEE College of Electronics and Information Engineering Tongji UniversityShanghai 200092China

Aiming at the tracking problem of a class of discrete nonaffine nonlinear multi-input multi-output(MIMO) repetitive systems subjected to separable and nonseparable disturbances, a novel data-driven iterative learning control(ILC) scheme based on the zeroing neural networks(ZNNs) is proposed. First, the equivalent dynamic linearization data model is obtained by means of dynamic linearization technology, which exists theoretically in the iteration domain. Then, the iterative extended state observer(IESO) is developed to estimate the disturbance and the coupling between systems, and the decoupled dynamic linearization model is obtained for the purpose of controller synthesis. To solve the zero-seeking tracking problem with inherent tolerance of noise,an ILC based on noise-tolerant modified ZNN is proposed. The strict assumptions imposed on the initialization conditions of each iteration in the existing ILC methods can be absolutely removed with our method. In addition, theoretical analysis indicates that the modified ZNN can converge to the exact solution of the zero-seeking tracking problem. Finally, a generalized example and an application-oriented example are presented to verify the effectiveness and superiority of the proposed process.

关键词： Adaptive control control system synthesis data-driven iterative learning control neurocontroller nonlinear discrete time systems

MADRL-based UAV swarm non-cooperative game under incomplete information

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Chinese Journal of Aeronautics 2024年第6期37卷 293-306页

作者： Ershen WANG Fan LIU chen hong jing GUO Lin ZHAO Jian XUE Ning HE School of Electronic and Information Engineering Shenyang Aerospace UniversityShenyang 110136China College of Robotics Beijing Union UniversityBeijing 100101China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China College of Smart City Beijing Union UniversityBeijing 100101China

Unmanned Aerial Vehicles(UAVs)play increasing important role in modern *** this paper,considering the incomplete observation information of individual UAV in complex combat environment,we put forward an UAV swarm non-cooperative game model based on Multi-Agent Deep Reinforcement Learning(MADRL),where the state space and action space are constructed to adapt the real features of UAV swarm air-to-air *** multi-agent particle environment is employed to generate an UAV combat scene with continuous observation *** recently popular MADRL methods are compared extensively in the UAV swarm noncooperative game model,the results indicate that the performance of Multi-Agent Soft Actor-Critic(MASAC)is better than that of other MADRL methods by a large *** swarm employing MASAC can learn more effective policies,and obtain much higher hit rate and win *** under different swarm sizes and UAV physical parameters are also performed,which implies that MASAC owns a well generalization ***,the practicability and convergence of MASAC are addressed by investigating the loss value of Q-value networks with respect to individual UAV,the results demonstrate that MASAC is of good practicability and the Nash equilibrium of the UAV swarm non-cooperative game under incomplete information can be reached.

关键词： UAV swarm Reinforcement learning Deep learning Multi-agent Non-cooperative game Nash equilibrium

Kerr black hole shadows cast by extraordinary light rays with Weyl corrections

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 18-26页

作者： Songbai chen Jiliang jing Department of Physics Institute of Interdisciplinary StudiesKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China

We investigate the equation of motion for photons with Weyl corrections in a Kerr black hole spacetime in a small coupling *** results show that Weyl corrections yield phenomena of *** light rays propagating in the spacetime are separated into the ordinary rays and the extraordinary rays,and the propagation of the latter depends on the *** probe the effects of Weyl corrections on the Kerr black hole shadows casted by the extraordinary rays and find that such corrections result in a weak stretching or squeezing in the vertical direction for the black hole ***,we also study the change of the length of the Near-Horizon Extremal Kerr line(NHEK line)with Weyl *** features could help us to understand the electrodynamics with Weyl corrections from black hole shadows.

关键词： correction light stretching

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Performance Characterization of CR/PU Asphalt for Potential Application in Assembled Fast-Repairing Engineering

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1063-1074页

作者： hong Pang Ao Lu Ming Xiong chen chen Xian Cao Xiong Xu jing Wang Hubei Regional Management Headquarters CCCC Asset Management Co.Ltd.Beijing101399China School of Civil Engineering and Architecture Wuhan Institute of TechnologyWuhan430073China Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures Wuhan Institute of TechnologyWuhan430073China

Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically *** address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized ***,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking *** test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved ***,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.

关键词： Composite modified asphalt crumb rubber polyurethane assembled fast-repairing asphalt concrete maintenance engineering

Exploration of cyclooxygenase-2 inhibitory peptides from walnut dreg proteins based on in silico and in vitro analysis

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Food Science and Human Wellness 2024年第3期13卷 1636-1644页

作者： Zishan hong jing Xie Liang Tao jing-jing Dai Tingting Li Li Zhang Yuying Bai Xia Hu Jinlian chen Jun Sheng Yang Tian College of Food Science and Technology Yunnan Agricultural UniversityKunming 650201China Yunnan Provincial Key Laboratory of Precision Nutrition and Personalized Food Manufacturing Yunnan Agricultural UniversityKunming 650201China Engineering Research Center of Development and Utilization of Food and Drug Homologous Resources Ministry of EducationYunnan Agricultural UniversityKunming 650201China School of Tea and Coffee Pu’er UniversityPu’er 665000China Yunnan Provincial Engineering Research Center for Edible and Medicinal Homologous Functional Food Yunnan Agricultural UniversityKunming 650201China Key Laboratory of Pu-er Tea Science Ministry of EducationYunnan Agricultural UniversityKunming 650201China

Walnut dreg protein hydrolysates(WDPHs)exhibit a variety of biological activities,however,the cyclooxygenase-2(COX-2)inhibitory peptide of WDPHs remain *** aim of this study was to rapidly screen for such peptides in WDPHs through a combination of in silico and in vitro *** total,1262 peptide sequences were observed by nano liquid chromatography/tandem mass spectrometry(nano LC-MS/MS)and 4 novel COX-2 inhibitory peptides(AGFP,FPGA,LFPD,and VGFP)were *** kinetic data indicated that AGFP,FPGA,and LFPD displayed mixed-type COX-2 inhibition,whereas VGFP was a non-competitive *** is mainly because the peptides form hydrogen bonds and hydrophobic interactions with residues in the COX-2 active *** results demonstrate that computer analysis combined with in vitro evaluation allows for rapid screening of COX-2 inhibitory peptides in walnut protein dregs.

关键词： Walnut dreg proteins Cyclooxygenase-2 inhibitory peptide Identification Virtual screening Molecular docking

Calcitonin gene-related peptide inhibits neuronal apoptosis in heatstroke rats via PKA/p-CREB pathway

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Chinese Journal of Traumatology 2024年第1期27卷 18-26页

作者： Jie Zhu Ya-hong chen jing-jing Ji cheng-Xiang Lu Zhi-Feng Liu Department of Pediatric General Hospital of Southern Theater Command of PLAGuangzhou510010China Department of Medical Intensive Care Unit General Hospital of Southern Theater Command of PLAGuangzhou510010China Department of Intensive Care Unit Zhongshan Hospital Xiamen UniversityXiamenFujian province361004China

Purpose:The incidence of heatstroke(HS)is not particularly high;however,once it occurs,the consequences are *** is reported that calcitonin gene-related peptide(CGRP)is protective against brain injury in HS rats,but detailed molecular mechanisms need to be further *** this study,we further explored whether CGRP inhibited neuronal apoptosis in HS rats via protein kinase A(PKA)/p-cAMP response element-binding protein(p-CREB)***:We established a HS rat model in a pre-warmed artificial climate chamber with a temperature of(35.5±0.5)℃and a relative humidity of 60%±5%.Heatstress was stopped once core body temperature reaches above 41℃.A total of 25 rats were randomly divided into 5 groups with 5 animals each:control group,HS group,HS+CGRP group,HS+CGRP antagonist(CGRP8-37)group,and HS+CGRP+PKA/p-CREB pathway blocker(H89)group.A bolus injection of CGRP was administered to each rat in HS+CGRP group,CGRP8-37(antagonist of CGRP)in HS+CGRP8-37 group,and CGRP with H89 in HS+CGRP+H89 *** were recorded and the serum concentration of S100B,neuron-specific enolase(NSE),neuron apoptosis,activated caspase-3 and CGRP expression,as well as pathological morphology of brain tissue were detected at 2 h,6 h,and 24 h after HSin *** expression of PKA,p-CREB,and Bcl-2 in rat neurons were also detected at 2 h after HSin *** CGRP,CGRP8-37,or H89 were used to determine whether CGRP plays a protective role in brain injury via PKA/p-CREB *** unpairedt-test was used between the 2 samples,and the mean±SD was used for multiple ***-tailedp<0.05 was considered statistically ***:Electroencephalogram showed significant alteration ofθ(54.50±11.51vs.31.30±8.71,F=6.790,p=0.005)andαwave(16.60±3.21vs.35.40±11.28,F=4.549,p=0.020)in HS group compared to the control group 2 h after *** results of triphosphate gap terminal labeling(TUNEL)showed that the neuronal apoptosis of HS rats was increased in the c

关键词： Heatstroke Calcitonin gene-related peptide Brain injury Apoptosis

B and Fe co-doped Co_(2)P hollow nanocubes for nitrate electroreduction to ammonia

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Chinese Chemical Letters 2024年第2期35卷 278-282页

作者： jing Miao Qingling hong Liping Liang Guomin Li Zhihong Liu Shibin Yin Yu chen School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China School of Materials Science and Engineering Shaanxi Normal UniversityXi'an 710062China School of Chemistry and Chemical Engineering Shaanxi Normal UniversityXi'an 710062China Guangxi Key Laboratory of Electrochemical Energy Materials School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China

Nitrate(NO_(3)^(−))electroreduction reaction(NO_(3)^(−)RR)provides an attractive and sustainable route for NO_(3)^(−)pollution mitigation or energy-saved ammonia(NH3)*** this work,high-quality B and Fe co-doped Co_(2) P hollow nanocubes(B/Fe-Co_(2) P HNCs)are successfully synthesized though simultaneous boronation-phosphorization treatment,which reveal outstanding selectivity,activity,stability for the NO_(3)^(−)to NH_(3) conversion in neutral electrolyte because of big surface area,fast mass transport,superhydrophilic surface,and optimized electronic structure.B/Fe-Co_(2) P HNCs can achieve the high NH3 yield rate(22.67 mg h^(−1) mg_(cat)^(−1))as well as Faradaic efficiency(97.54%)for NO_(3)^(−)RR,greatly outperforming most of non-precious metal based NO_(3)^(−)RR electrocatalysts.

关键词： Nitrate electroreduction reaction Ammonia synthesis Transition metal phosphides Hollow nanocubes