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Research on the Relationship Between Environmental and Economic Coupling Systems in Bohai Bay Area Based on a Vector Autoregression(VAR)Model

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Journal of Ocean University of China 2024年第2期23卷 557-566页

作者： CAO huimin WANG Ping ZHANG Surong XU Dongpo TIAN Weijun Key Laboratory of Marine Environment and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China Business School Qingdao UniversityQingdao 266100China

This study analyzed the impact of land-based contaminants and tertiary industrial structure on economic development in the selected Bohai Bay area,*** on panel data spanning 2011-2020,a vector autoregressive(VAR)model is used to analyze and forecast the short-run and long-run relationships between three industrial structures,pollutant discharge,and economic *** results showed that the environmental index had a long-term cointegration relationship with the industrial structure economic *** capital chemical oxygen demand(PCOD)and per capita ammonia nitrogen(PNH_(3)N)had a positive impact on delta per capita GDP(dPGDP),while per capita solid waste(PSW),the secondary industry rate(SIR)and delta tertiary industry(dTIR)had a negative impact on *** VAR model under this coupling system had stability and *** impulse response results showed that the short-term effect of the coupling system on dPGDP was basically consistent with the Granger causality test *** addition,variance decomposition was used in this study to predict the long-term impact of the coupling system in the next ten periods(i.e.,ten years).It was found that dTIR had a great impact on dPGDP,with a contribution rate as high as 74.35%in the tenth period,followed by the contribution rate of PCOD up to 3.94%,while the long-term contribution rates of PSW,SIR and PNH3N were all less than 1%.The results show that the government should support the development of the tertiary industry to maintain the vitality of economic development and prevent environmental deterioration.

关键词： Bohai Bay area environmental pollution industrial structure cointegration theory VAR model impulse response

Tribological Behaviors of Electroless Nickel-Boron Coating on Titanium Alloy Surface

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 309-320页

作者： Yao Jia Jianping Lai Jiaxin Yu huimin Qi Yafeng Zhang Hongtu He Key Laboratory of Testing Technology for Manufacturing Process in Ministry of Education State Key Laboratory of Environment-Friendly Energy MaterialsSouthwest University of Science and TechnologyMianyang 621010China

Titanium alloys are excellent structural materials in engineering fields,but their poor tribological properties limit their further *** plating is an effective method to enhance the tribological performance of alloys,but it is difficult to efficiently apply to titanium alloys,due to titanium alloy’s strong chemical *** this work,the electroless Nickel-Boron(Ni-B)coating was successfully deposited on the surface of titanium alloy(Ti-6AL-4V)via a new pre-treatment ***,linearly reciprocating sliding wear tests were performed to evaluate the tribological behaviors of titanium alloy and its electroless Ni-B *** was found that the Ni-B coatings can decrease the wear rate of the titanium alloy from 19.89×10^(−3)mm^(3)to 0.41×10^(−3)mm^(3),which attributes to the much higher hardness of Ni-B *** heat treatment,the hardness of Ni-B coating further increases corresponding to coating crystallization and hard phase ***,heat treatment does not improve the tribological performance of Ni-B coating,due to the fact that higher brittleness and more severe oxidative wear exacerbate the damage of heat-treated ***,the Ni-B coatings heat-treated both in air and nitrogen almost present the same tribological *** finding of this work on electroless coating would further extend the practical applications of titanium alloys in the engineering fields.

关键词： Electroless coating Titanium alloy Tribology Wear Heat treatment Nanoindentation

An analytical transient coal permeability model:Sorption non-equilibrium index-based swelling switch

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1175-1191页

作者： Xingxing Liu Jishan Liu Liang Chen Jinchang Sheng huimin Wang College of Civil and Transportation Engineering Hohai UniversityNanjing210098China School of Engineering The University of Western Australia35 Stirling HighwayCrawleyWA6009Australia College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China

Long-term permeability experiments have indicated that sorption-induced swelling can switch from internal to bulk depending on the evolutive sorption ***,this sorption swelling switch mechanism has not been considered in current analytical permeability *** study introduces a normalized sorption non-equilibrium index(SNEI)to characterize the sorption status,quantify the dynamical variations of matrix swelling accumulation and internal swelling partition,and formulate the sorption swelling switch *** incorporation of this index into the extended total effective stress concept leads to an analytical transient coal permeability *** results show that the sorption swelling switch itself results in the permeability switch under stress-constrained conditions,while the confined bulk swelling suppresses the permeability recovery to the continuous reduction under displacement-constrained *** verifications show that current experimental observations correspond to the early stages of the transient process,and they could be extended to the whole process with these *** study demonstrates the importance of the sorption swelling switch in determining permeability evolution using simple boundary *** provides new insights into experimentally revealing the sorption swelling switch in the future,and underscores the requirement of a rigorous model for complex coupled processes in large-scale coal seams.

关键词： Coal permeability Sorption swelling switch Sorption non-equilibrium Boundary conditions

Achieving single-cell-resolution lineage tracing in zebrafish by continuous barcoding mutations during embryogenesis

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Journal of Genetics and Genomics 2024年第9期51卷 947-956页

作者： Zhan Liu Hui Zeng huimin Xiang Shanjun Deng Xionglei He State Key Laboratory of Biocontrol School of Life SciencesSun Yat-Sen UniversityGuangzhouGuangdong 510275China

Unraveling the lineage relationships of all descendants from a zygote is fundamental to advancing our understanding of developmental and stem cell ***,existing cell barcoding technologies in zebrafish lack the resolution to capture the majority of cell divisions during embryogenesis.A recently developed method,a substitution mutation-aided lineage-tracing system(SMALT),successfully reconstructed high-resolution cell phylogenetic trees for Drosophila ***,we implement the SMALT system in zebrafish,recording a median of 14 substitution mutations on a one-kilobase-pair barcoding sequence for one-day post-fertilization *** this system,we reconstruct four cell lineage trees for zebrafish fin cells,encompassing both original and regenerated *** tree consists of hundreds of internal nodes with a median bootstrap support of 99%.Analysis of the obtained cell lineage trees reveals that regenerated fin cells mainly originate from cells in the same part of the *** multiple times sampling germ cells from the same individual,we show the stability of the germ cell pool and the early separation of germ cell and somatic cell *** system offers the potential for reconstructing high-quality cell phylogenies across diverse tissues,providing valuable insights into development and disease in zebrafish.

关键词： Lineage tracing Cellular barcoding Zebrafishcell phylogeny Fin regeneration Germcell lineage

A novel matrix topology-based analysis method of thermal circuits for reliability optimization of HSER

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Chinese Journal of Aeronautics 2024年第4期37卷 479-492页

作者： huimin LIANG Bo LI Jiaxin YOU Shan JIANG Mengtong ZHU Aobo WANG Department of Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Nanjing Research Institute of Electronics Technology Nanjing 210008China

Hermetically Sealed Electromagnetic Relay(HSER), used in aviation and aerospace,demands high reliability due to its critical applications. Given its complex operating conditions, efficient thermal analysis is essential for optimizing reliability. The commonly used Finite Element Method(FEM) is often time-consuming and may not be efficient or adaptable for complex multi-dimensional system calculations and design processes. This paper introduces an analysis method for thermal networks based on matrix perspective technology, encompassing matrix transformation, backpropagation of the heat path model, temperature rise calculation, solution comparison, and product implementation. Using the similarity theory of heat circuits, a basic thermal unit is established. Based on the fundamental connection between key components, a thermal network for a typical HSER is designed. An experimental system is set up, and the thermal network model's accuracy is confirmed using test data. Employing the topology analysis method, the topology of the thermal network is analyzed under both coil-energized and de-energized states. Potential thermal paths are identified, leading to optimized solutions for the HSER. Utilizing these solutions, the thermal path matrix topology model is backpropagated to the thermal path for temperature rise calculations. When compared to prototype HSER test data, the efficiency and accuracy of this matrix topology-based analysis method are confirmed.

关键词： Thermal networks HSER(Hermetically Sealed Electromagnetic Relay) Heat-circuit topology model Heat-circuit matrix Optimization design

Current-collapse suppression and leakage-current decrease in AlGaN/GaN HEMT by sputter-TaN gate-dielectric layer

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Journal of Semiconductors 2024年第7期45卷 70-75页

作者： Bosen Liu Guohao Yu huimin Jia Jingyuan Zhu Jiaan Zhou Yu Li Bingliang Zhang Zhongkai du Bohan Guo Lu Wang Qizhi Huang Leifeng Jiang Zhongming Zeng Zhipeng Wei Baoshun Zhang State Key Laboratory of High-Power Semiconductor Laser School of PhysicsChangchun University of Science and TechnologyChangchun 130022China Nanofabrication facility Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China Suzhou Powerhouse Electronics Technology Co. Ltd.Suzhou 215123China

In this paper, we explore the electrical characteristics of high-electron-mobility transistors(HEMTs) using a TaN/AlGaN/GaN metal insulating semiconductor(MIS) structure. The high-resistance tantalum nitride(TaN) film prepared by magnetron sputtering as the gate dielectric layer of the device achieved an effective reduction of electronic states at the TaN/AlGaN interface, and reducing the gate leakage current of the MIS HEMT, its performance was enhanced. The HEMT exhibited a low gate leakage current of 2.15 × 10^(-7) mA/mm and a breakdown voltage of 1180 V. Furthermore, the MIS HEMT displayed exceptional operational stability during dynamic tests, with dynamic resistance remaining only 1.39 times even under 400 V stress.

关键词： AlGaN/GaN MIS HEMTs gate dielectric layer depletion-mode gate reliability I_(on)/I_(off)ratio

Selenium-oxidizing Agrobacterium sp.T3F4 decreases arsenic uptake by Brassica rapa *** a native polluted soil

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Journal of Environmental Sciences 2024年第4期138卷 506-515页

作者： Lijin An Chunzhi Zhou Lipeng Zhao Ao Wei Yiting Wang huimin Cui Shixue Zheng State Key Laboratory of Agricultural Microbiology College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China

Toxic arsenic(As)and trace element selenium(Se)are transformed by microorganisms but their complex interactions in soil-plant systems have not been fully *** Asand Se-oxidizing bacterium,Agrobacterium sp.T3F4,was applied to a native seleniferous As-polluted soil to investigate As/Se uptake by the vegetable Brassica rapa *** As-Se interaction as mediated by strain *** Se content in the aboveground plants was significantly enhanced by 34.1%,but the As content was significantly decreased by 20.5% in the T3F4-inoculated pot culture compared to the control(Pduced by increasing Se(IV)*** 50% growth inhibition concentration(IC50)values for As in plants were increased about one-fold and two-fold under co-exposure with 5 and 10μmol/L Se(IV),*** conclusion,strain T3F4 improves Se uptake but decreases As uptake by plants via oxidation of As and Se,resulting in decrease of soil As bioavailability and As/Se competitive absorption by *** provides a potential bioremediation strategy for Se biofortification and As immobilization in As-polluted soil.

关键词： Selenium oxidation Selenium biofortification Arsenite-oxidizing bacteria Arsenic immobilization Brassica rapa L

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卷积神经网络混合截断量化

计算机辅助设计与图形学学报 2021年第4期33卷 553-559页

作者：黄钲喆杜慧敏常立博西安邮电大学电子工程学院西安710121

量化是压缩卷积神经网络、加速卷积神经网络推理的主要方法.现有的量化方法大多将所有层量化至相同的位宽,混合精度量化则可以在相同的压缩比下获得更高的准确率,但寻找混合精度量化策略是很困难的.为解决这种问题,提出了一种基于强化... 详细信息

量化是压缩卷积神经网络、加速卷积神经网络推理的主要方法.现有的量化方法大多将所有层量化至相同的位宽,混合精度量化则可以在相同的压缩比下获得更高的准确率,但寻找混合精度量化策略是很困难的.为解决这种问题,提出了一种基于强化学习的卷积神经网络混合截断量化方法,使用强化学习的方法搜索混合精度量化策略,并根据搜索得到的量化策略混合截断权重数据后再进行量化,进一步提高了量化后网络的准确率.在ImageNet数据集上测试了ResNet18/50以及MobileNet-V2使用此方法量化前后的Top-1准确率,在COCO数据集上测试了YOLOV3网络量化前后的mAP.与HAQ, ZeroQ相比, MobileNet-V2网络量化至4位的Top-1准确率分别提高了2.7%和0.3%;与分层量化相比, YOLOV3网络量化至6位的mAP提高了2.6%.

关键词：卷积神经网络混合精度量化强化学习混合截断

Asymmetrical Fault Current Calculation Method and Influencing Factors Analysis of Droop-Controlled Inverters

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 562-573页

作者： huimin Zhao Zhikang Shuai Jun Ge An Luo Weimin Wu Z.John Shen College of Electrical and Information Engineering Hunan UniversityChangsha 410006China Electrical Engineering Department Shanghai Maritime UniversityShanghai 201306China Department of Electrical and Computer Engineering Ilinois Institute of TechnologyChicagoIL 60616 USA

Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.

关键词： Asymmetrical fault analysis droop control fault current calculation method limiter transient fault characteristics