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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1642-1653页

作者： Zhi geng Minxiao Han Changjiang xia Longze Kou School of Electrical and Electronic Engineering North China Electric Power University(NCEPU)Beijing 102206China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research InstituteBeijing 102209China

Due to the large number of submodules(SMs),and modular multilevel converters(MMCs)in high-voltage applications,they are usually regulated by the nearest level modulation(NLM).Moreover,the large number of SMs causes a challenge for the fault diagnosis strategy(FDS).This paper proposes a currentless FDS for MMC with *** FDS,the voltage sensor is relocated to measure the output voltage of the *** acquire the capacitor voltage and avoid increasing extra sensors,a capacitor voltage calculation method is *** on the measurement of output voltages,the faults can be detected and the number of different-type switch open-circuit faults can be confirmed from the numerous SMs in an arm,which narrows the scope of fault ***,the faulty SMs and faulty switches in these SMs are further located without arm current according to the sorting of capacitor voltages in the voltage balancing *** FDS is independent of the arm current,which can reduce the communication cost in the hierarchical control system of ***,the proposed FDS not only simplifies the identification of switch open-circuit faults by confirming the scope of faults,but also detects and locates multiple different-type faults in an *** effectiveness of the proposed strategy is verified by the simulation results.

关键词： Fault diagnosis high voltage direct current(HVDC) modular multilevel converter(MMC) nearest level modulation(NLM) switch open-circuit fault

Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

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China Ocean Engineering 2024年第3期38卷 453-466页

作者： ZHANG Guo-xing xia Xin-lu GUO Jin-wei School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling capture mechanism with strong adaptability and high retraction rate has been proposed for the launch and recovery of torpedo-shaped AUVs with different morphological ***,the principle of capturing motion retraction is described based on the appearance characteristics of torpedo-shaped AUVs,and the configuration synthesis of the capture mechanism is carried out using the method of constrained chain ***,the screw theory is employed to analyze the degree of freedom(DoF)of the capture ***,the 3D model of the capture mechanism is established,and the kinematics and dynamics simulations are carried *** with the capture orientation requirements of the capture mechanism,the statics and vibration characteristics analyses are carried ***,considering the capture process and the underwater working environment,the motion characteristics and hydraulics characteristics of the capture mechanism are ***,a principle prototype is developed and the torpedo-shaped AUVs capture experiment is *** work provides technical reserves for the research and development of AUV capture special equipment.

关键词： capture mechanism torpedo-shaped AUVs configuration synthesis launch and recovery grasping performance analysis

Deployment optimization for target perpetual coverage in energy harvesting wireless sensor network

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Digital Communications and Networks 2024年第2期10卷 498-508页

作者： Zhenkun Jin Yixuan geng Chenlu Zhu Yunzhi xia xianjun Deng Lingzhi Yi xianlan Wang Wuhan Business University 430056China Wuhan Research Institute of Post and Telecommunication Wuhan430074China Hubei Key Laboratory of Distributed System Security Hubei Engineering Research Center on Big Data SecuritySchool of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Hubei Chutian Expressway Digital Technology Co.Ltd Wuhan430074China School of Information and Safety Engineering Zhongnan University of Economics and LawWuhan430073China

Energy limitation of traditional Wireless Sensor Networks(WSNs)greatly confines the network lifetime due to generating and processing massive sensing data with a limited *** energy harvesting WSN is a novel network architecture to address the limitation of traditional ***,existing coverage and deployment schemes neglect the environmental correlation of sensor nodes and external energy with respect to physical *** considering the spatial correlation of the environment and the uneven distribution of energy in energy harvesting WSN,we investigate how to deploy a collection of sensor nodes to save the deployment cost while ensuring the target perpetual *** Confident Information Coverage(CIC)model is adopted to formulate the CIC Minimum Deployment Cost Target Perpetual Coverage(CICMTP)problem to minimize the deployed sensor *** the CICMTP is NP-hard,we devise two approximation algorithms named Local Greedy Threshold Algorithm based on CIC(LGTA-CIC)and Overall Greedy Search Algorithm based on CIC(OGSA-CIC).The LGTA-CIC has a low time complexity and the OGSA-CIC has a better approximation *** simulation results demonstrate that the OGSA-CIC is able to achieve lower deployment cost and the performance of the proposed algorithms outperforms GRNP,TPNP and EENP algorithms.

关键词： Energy harvesting WSN Deployment optimization Confident information coverage(CIC) Target perpetual coverage

An Adaptive Local Grid Nesting-based Genetic Algorithm for Multi-earth Observation Satellites' Area Target Observation

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Journal of Systems Science and Systems Engineering 2024年第2期33卷 232-258页

作者： Ligang xing Wei xia xiaoxuan Hu Waiming Zhu Yi Wu School of Management Hefei University of TechnologyHefei 230009China Key Laboratory of Process Optimization and Inteligent Decision-making Ministry of EducationHefei 230009China Intelligent Interconnected Systems Laboratory of Anhui Province Hefei 230009China

The Scheduling of the Multi-EOSs Area Target Observation(SMEATO)is an EOS resource schedul-ing problem highly coupled with computational *** advances in EOS technology and the ex-pansion of wide-area remote sensing applications have increased the practical significance of *** this paper,an adaptive local grid nesting-based genetic algorithm(ALGN-GA)is proposed for developing SMEATO ***,a local grid nesting(LGN)strategy is designed to discretize the target area into parts,so as to avoid the explosive growth of calculations.A genetic algorithm(GA)framework is then used to share reserve information for the population during iterative evolution,which can generate high-quality solutions with low computational *** this basis,an adaptive technique is introduced to determine whether a local region requires nesting and whether the grid scale is *** effectiveness of the proposed model is assessed experimentally with nine randomly generated tests at different *** results show that the ALGN-GA offers advantages over several conventional algorithms in 88.9%of instances,especially in large-scale *** fully demonstrate the high efficiency and stability of the ALGN-GA.

关键词： Multi-EOSs scheduling area target observation adaptive genetic algorithm local grid nesting

Numerical and experimental study on the falling film flow characteristics with the effect of co-current gas flow in hydrogen liquefaction process

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Petroleum Science 2024年第2期21卷 1369-1384页

作者： Chong-Zheng Sun Yu-xing Li Hui Han xiao-Yi geng xiao Lu College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590ShandongChina College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety China University of PetroleumQingdao 266580ShandongChina

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process(LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2spiral wound heat *** results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

关键词： Hydrogen liquefaction Spiral wound heat exchanger Flow pattern transition Falling film flow

Atomic force microscopy-based nanoscale infrared techniques for liquid environments

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Science Bulletin 2024年第2期69卷 151-153页

作者： Jian Li Jing Liang Mu-Hao Lan xing-Hua xia State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Infrared(IR)light energy matches well with the vibration and rotation of chemical bonds in molecules,hence IR spectroscopy is commonly used for accurate molecular identification[1].Conventional IR analysis involves bulk samples,providing averaged information of the entire *** spatially-resolved investigation of heterogeneous sample properties is constrained by the micrometer-level spatial resolution of optical IR microscopy.

关键词： spatially hence rotation

A Data-Driven Real-Time Trajectory Planning and Control Methodology for UGVs Using LSTMRDNN

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1292-1294页

作者： Kaiyuan Chen Runqi Chai Runda Zhang Zhida xing Yuanqing xia Guoping Liu Vanke School of Public Health Institute for Healthy ChinaTsinghua UniversityBeijing 100084 School of Automation Beijing Institute of TechnologyBeijing 100081 Department of Electronic and Electrical Engineering Southern University of Science and TechnologyShenzhen 518055China

Dear Editor,This letter presents a novel data-driven trajectory planning and control scheme for the unmanned ground vehicles(UGVs).A recent work[1]has demonstrated the effectiveness of approximating the optimal state ... 详细信息

关键词： LSTM UGV neural

High performance photodegradation resistant PVA@TiO_(2)/carboxyl-PES self-healing reactive ultrafiltration membrane

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Chinese Journal of Chemical Engineering 2024年第2期66卷 31-39页

作者： Yu Liang Yuanfang Fan Zhongmin Su Mingxin Huo xia Yang Hongliang Huo Chi Wang Zhi geng College of Environment Engineering Research Center of Low-Carbon Treatment and Green Development of Polluted Water in Northeast ChinaMinistry of EducationNortheast Normal UniversityChangchun 130117China School of Science Hainan UniversityHaikou 570225China

The occurrence of ultrafiltration(UF)membrane fouling frequently hampers the sustainable advancement of UF *** self-cleaning UF membranes can effectively alleviate the problem of membrane ***,the self-cleaning process may accelerate membrane *** these concerns,we present an innovative design concept for composite self-healing materials based on self-cleaning UF *** begin,TiO_(2)nanoparticles were incorporated into the polymer molecular structure via molecular design,resulting in the synthesis of TiO_(2)/carboxyl-polyether sulfone(PES)hybrid ***,the nonsolvent-induced phase inversion technique was employed to prepare a novel of UF ***,a polyvinyl alcohol(PVA)hydrogel coating was applied to the hybrid UF membrane surface to create PVA@TiO_(2)/carboxyl-PES self-healing reactive UF *** establishing a covalent bond,the TiO_(2)nanoparticles were effectively and uniformly dispersed within the UF membrane,leading to exceptional self-cleaning ***,the water-absorbing and swelling properties of PVA hydrogel,along with its capacity to form hydrogen bonds with water molecules,resulted in UF membranes with improved hydrophilicity and active self-healing *** results demonstrated that the water contact angle of PVA@5%TiO_(2)/carboxyl-PES UF membrane was 43.1°.Following a 1-h exposure to simulated solar exposure,the water flux recovery ratio increased from 48.16%to 81.03%.Moreover,even after undergoing five cycles of 12-h simulated sunlight exposure,the UF membranes exhibited a consistent retention rate of over 97%,thus fully demonstrating their exceptional self-cleaning,antifouling,and selfhealing *** anticipate that the self-healing reactive UF membrane system will serve as a pioneering and comprehensive solution for the self-cleaning antifouling challenges encountered in UF membranes while also effectively mitigating the aging effects of reactive

关键词： Ultrafiltration membrane Self-cleaning Self-healing Poly(aryl ether sulfone)

Effects of potassium lactate on sensory attributes,bacterial community succession and biogenic amines formation in Rugao ham

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Food Science and Human Wellness 2024年第1期13卷 198-210页

作者： Renyong Liao Ying Wang Qiang xia Changyu Zhou Fang geng Daodong Pan Jinxuan Cao State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products Key Laboratory of Animal Protein Food Processing Technology of Zhejiang ProvinceNingbo UniversityNingbo 315211China Meat Processing Key Laboratory of Sichuan Province School of Food and Biological EngineeringChengdu UniversityChengdu 610106China School of Food and Health Beijing Technology and Business UniversityBeijing 100048China

To deepen the understanding in the effect of potassium lactate on the sensory quality and safety of Rugao ham,sensory attributes,physicochemical parameters,total volatile basic nitrogen(TVBN),microorganism community and biogenic amines of Rugao ham manufactured with different potassium lactate levels(0%,0.5%,1%,2%)were investigated;the relationship between microbial community and the formation of TVBN and biogenic amines was further *** the increase of potassium lactate from 0%to 2%,the increased sensory scores and the decreased total aerobic bacterial count and TVBN were observed;the abundance of Staphylococcus increased,while the content of Halomonas *** effect size(LEf Se)and correlations analysis showed that Staphylococcus equorum and Lactobacillus fermentum could be the key species to improve sensory scores and decrease biogenic amines and *** pathway analysis further showed that amino acids metabolism and nitrogen metabolism were mainly involved in decreasing TVBN and biogenic amines in the treatment of 2%potassium lactate.

关键词： Rugao ham Potassium lactate Biogenic amines Microbial community Metabolic pathways

In-situ embedded ultrafine Bi_(12)O_(17)Br_(2)nanotubes in MOF-derived hierarchical porous carbon for enhanced photocatalytic CO_(2)conversion to CO

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Journal of Materials Science & Technology 2024年第4期171卷 47-53页

作者： xing Sun Mengxia Ji Yi Zhang Qingzeng xing Zihan Liu Nianhua Liu Emmanuel Nkudede Huaming Li Sheng Yin Jiexiang xia School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013China Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources Qinghai Provincial Key Laboratory of Resources Chemistry of Salt LakesQinghai Institute of Salt LakesChinese Academy of SciencesXining 81008China

Increasing the utilization efficiency of photogenerated electrons is highly recognized as one of the ef-ficient approaches to boost the photocatalytic CO_(2)conversion ***,ZIF-67-derived porous carbon(PC)material was employed for the construction of PC@ultrafine Bi_(12)O_(17)Br_(2)nanotubes(PC@BOB NTs)composites through a facile solvothermal synthesis in order to optimize the use of excited elec-trons in the BOB *** characterization results revealed that the introduction of PC material achieved a faster charge separation rate in the PC@BOB composites,ensuring more photogener-ated electrons participate in the CO_(2)adsorption and activation ***,the pore structures of ZIF-67-derived PC material provided abundant confined spaces for the enrichment of CO_(2)***-ter 5 h of Xenon lamp irradiation,PC@BOB composites exhibited obviously increased photocatalytic CO_(2)reduction activity in the pure *** the addition amount of PC was 5 wt%,the PC@BOB-2 com-posite showed the highest CO evolution rate of 359.70μmol/g,which was 2.95 times higher than that of the pure BOB *** work provides some independent insights into the applications of Metal-Organic Framework(MOF)-derived hierarchical porous structures to strengthen the CO_(2)enrichment,as well as the excited charge utilization efficiency,thus achieving a high solar-to-fuel conversion efficiency.

关键词： Bi_(12)O_(17)Br_(2)nanotubes Hierarchical porous structure CO_(2)enrichment Charge separation CO_(2)photoreduction