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Relationship Between Individuals’Epidemic Risk Perception Within Living Space and Subjective Well-Being:Empirical Evidence from China after the First Wave of COVID-19

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Chinese Geographical Science 2024年第2期34卷 369-382页

作者： SONG Jiangyu ZHOU Suhong KWAN Mei-Po zheng zhong School of Geography and Planning Sun Yat-sen UniversityGuangzhou 510006China Guangdong Provincial Engineering Research Center for Public Security and Disaster Guangzhou 510275China Institute of Space and Earth Information Science the Chinese University of Hong KongHong Kong 999077China Department of Geography and Resource Management the Chinese University of Hong KongHong Kong 999077China Institute of Future Cities the Chinese University of Hong KongHong Kong 999077China Center for Territorial Spatial Planning and Real Estate Studies Beijing Normal UniversityZhuhai 519000China

It is common to observe the epidemic risk perception(ERP)and a decline in subjective well-being(SWB)in the context of public health events,such as Corona Virus Disease 2019(COVID-19).However,there have been few studies exploring the impact of individuals’ERP within living space on their SWB,especially from a geographical and daily activity perspective after the resumption of work and other activities following a wave of the pandemic.In this paper,we conducted a study with 789 participants in urban China,measuring their ERP within living space and examining its influence on their SWB using path analysis.The results indicated that individuals’ERP within their living space had a significant negative effect on their SWB.The density of certain types of facilities within their living space,such as bus stops,subway stations,restaurants,fast food shops,convenience shops,hospitals,and public toilets,had a significantly negative impact on their SWB,mediated by their ERP within living space.Additionally,participation in out-of-home work and other activities not only increased individuals’ERP within living space,but also strengthened its negative effect on their SWB.

关键词： subjective well-being epidemic risk perception living space the density of facilities out-of-home activities

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Resource Allocation in Multi-User Cellular Networks:A Transformer-Based Deep Reinforcement Learning Approach

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China Communications 2024年第5期21卷 77-96页

作者： Zhao Di zheng zhong Qin Pengfei Qin Hao Song Bin State Key Laboratory of Integrated Services Networks Xidian University710071China China Academy of Space Technology Beijing 100081China

To meet the communication services with diverse requirements,dynamic resource allocation has shown increasing importance.In this paper,we consider the multi-slot and multi-user resource allocation(MSMU-RA)in a downlink cellular scenario with the aim of maximizing system spectral efficiency while guaranteeing user fairness.We first model the MSMURA problem as a dual-sequence decision-making process,and then solve it by a novel Transformerbased deep reinforcement learning(TDRL)approach.Specifically,the proposed TDRL approach can be achieved based on two aspects:1)To adapt to the dynamic wireless environment,the proximal policy optimization(PPO)algorithm is used to optimize the multi-slot RA strategy.2)To avoid co-channel interference,the Transformer-based PPO algorithm is presented to obtain the optimal multi-user RA scheme by exploring the mapping between user sequence and resource sequence.Experimental results show that:i)the proposed approach outperforms both the traditional and DRL methods in spectral efficiency and user fairness,ii)the proposed algorithm is superior to DRL approaches in terms of convergence speed and generalization performance.

关键词： dynamic resource allocation multi-user cellular network spectrum efficiency user fairness

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Numerical multi-physical optimization of operating condition and current collecting setup for large-area solid oxide fuel cells

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Frontiers in Energy 2024年第3期18卷 356-368页

作者： Chengrong YU Zehua PAN Hongying ZHANG Bin CHEN Wanbing GUAN Bin MIAO Siew Hwa CHAN zheng zhong Yexin ZHOU School of Science Harbin Institute of TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyShenzhen UniversityShenzhen 518060China Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province Ningbo Institute of Materials Technology and Engineering of the Chinese Academy of SciencesNingbo 315201China Energy Research Institute at NTU(ERIAN) Nanyang Technological UniversitySingapore 639798Singapore

Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the world.Solid oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high efficiency.To further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective route.However,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal performance.In this work,a multi-physical model is built to study the effect of the effective area on the cell performance.The distribution of different physical fields is systematically analyzed.Optimization of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection setup.An improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current collection.In the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.

关键词： solid oxide fuel cell(SOFC) large effective area flow rate discharge performance current collection

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Production of Functional Materials Derived from Regenerated Silk Fibroin by Utilizing 3D Printing and Biomimetic Enzyme-induced Mineralization

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Chinese Journal of Polymer Science 2024年第3期42卷 299-310,I0005页

作者： Ni Chen Fei-Yu Luo Gong-Wen Yang Jin-Rong Yao Xin Chen zheng-zhong Shao State Key Laboratory of Molecular Engineering of Polymers Laboratory of Advanced Materials and Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Critical-sized bone defects, commonly encountered in clinical orthopedic surgery, present a significant challenge. One of the promising solutions is to prepare synthetic bone substitute materials with precise structural control, mechanical compatibility, and enhanced osteogenic induction performance, nevertheless the successful preparation of such materials remains difficult. In this study, a two-step technique,integrating an extrusion-based printing process with biomimetic mineralization induced by alkaline phosphatase(ALP), was developed. Initially,a pre-cured hydrogel of regenerated silk fibroin(RSF) with a small quantity of hydroxypropyl cellulose(HPC) and ALP was prepared through heating the mixed aqueous solution. This pre-cured hydrogel demonstrated thixotropic property and could be directly extruded into predetermined structures through a 3D-printer. Subsequently, the 3D-printed RSF-based materials with ALP underwent biomimetic in situ mineralization in calcium glycerophosphate(Ca-GP) mineralizing solution, utilizing the polymer chains of RSF as templates and ALP as a trigger for cleaving phosphate bonds of Ca-GP. The resulting 3D-printed RSF-mineral composites including hydrogel and sponge possessed adjustable compression modulus of megapascal grade and variable hydroxyapatite content, which could be controlled by manipulating the duration of the mineralization process.Moreover, these 3D-printed RSF-mineral composites demonstrated non-cytotoxicity towards rat bone marrow mesenchymal stem cells. Therefore, they may hold great potential for applications involving the replacement of tissues characterized by osteoinductivity and intricate structures.

关键词： Silk protein Alkaline phosphatase Extrusion-based printing Biomineralization

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Intelligent overheating fault diagnosis for overhead transmission line using semantic segmentation

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High Voltage 2024年第2期9卷 309-318页

作者： Xiangyu Yang Youping Tu Zhikang Yuan zhong zheng Geng Chen Cong Wang Yan Xu Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijingChina College of Electronic and Information Engineering Tongji UniversityShanghaiChina

The strain clamps and leading wires are important components that connect conductors on overhead transmission lines and conduct current.During operation,poor contact between these components can cause abnormal overheating,leading to electric failures and threatening power system reliability.Recently,the use of unmanned aerial vehicles equipped with infrared thermal imagers for strain clamp and leading wire maintenance has become increasingly popular.Deep learning-based image recognition shows promising prospects for intelligent fault diagnosis of overheating faults.A pre-treatment method is proposed based on dynamic histogram equalisation to enhance the contrast of infrared images.The DeepLab v3+network,loss function,and existing networks with different backbones are compared.The DeepLab v3+network with ResNet101 and convolutional block attention module added,and the Focal Loss function achieved the highest performance with an average pixel accuracy of 0.614,an average intersection over union(AIoU)of 0.567,an F1 score of 0.644,and a frequency weighted intersection over union of 0.594 on the test set.The optimised Atrous rates has increased the AIoU by 12.91%.Moreover,an intelligent diagnosis scheme for evaluating the defect state of the strain clamps and leading wires is proposed and which achieves a diagnostic accuracy of 91.0%.

关键词： union fault diagnosis

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Human-cyber-physical system for production and operation decision optimization in smart steel plants

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Science China(Technological Sciences) 2022年第2期65卷 247-260页

作者： zheng zhong ZHANG KaiTian GAO XiaoQiang College of Materials Science and Engineering Chongqing UniversityChongqing 400045China College of Economics and Business Administration Chongqing UniversityChongqing 400045China

Based on the core developmental demands of smart steel manufacturing plants, this review analyzes the essential characteristics of the steel manufacturing process and its implications for production and operation decision optimization(PODO). A discussion on the potential application of technologies, including the Industrial Internet, big data, cloud computing, and 5 G, in the PODO of smart steel plants based on the Industry 4.0 intelligent manufacturing and human-cyber-physical system(HCPS) is also presented. An adaptive update conception for a new dual-level cyber system(for management control and unit operation) of a flatstructured HCPS for steel plants is proposed to eliminate issues such as the hierarchical structure of the cyber system, the occurrence of data islands, and weak intelligence in PODO ability. Additionally, the review provided an in-depth analysis of the closed-loop decision logic of a dual-level HCPS. The critical technologies required for developing the HCPS model include data platforms and their associated application technologies, intelligent modeling, human-machine collaboration, and platform-based integration. Finally, suggestions are proposed to develop smart steel plants, including concept renewal, technological integration,and talent training.

关键词： HCPS smart steel plants PODO management control unit operation

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Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

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Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia Li Yang Tian Yuan-Yuan Liu Ke Jia zhong-zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan Li zheng-Cao Li Sha-Sha Lv College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China Department of Engineering Physics Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy resolution.The surface passivation of HPGe has become crucial for achieving an extremely low energy threshold.In this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface passivation.Theoretical calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface state.Based on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio structure.The microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state density.The mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

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A novel design scheme for acoustic cloaking of complex shape based on region partitioning and multi-origin coordinate transformation

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Applied Mathematics and Mechanics(English Edition) 2022年第11期43卷 1641-1656页

作者： Pengfei LI Fan YANG Peng WANG Jinfeng ZHAO zheng zhong School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

Acoustic cloaking is an important application of acoustic metamaterials.This article proposes a novel design scheme for acoustic cloaking based on the region partitioning and multi-origin coordinate transformation.The cloaked region is partitioned into multiple narrow strips.For each strip,a local coordinate system is established with the local origin located at the strip center,and a coordinate transformation in the local coordinate system is conducted to squeeze the material along the strip length direction to form the cloaked region.To facilitate the implementation of the acoustic cloak,the multilayer effective medium is used to approximate the non-uniform anisotropic material parameters.The effectiveness of the proposed coordinate transformation method is verified by comparing the results from our method with those in the literature.Firstly,the results of a circular acoustic cloak in the literature are reproduced by using our finite element(FE)simulations for validation.Then,a comparison is made between the traditional coordinate transformation scheme and our new scheme for simulating an elliptical acoustic cloak.The results indicate that the proposed multi-origin coordinate transformation method has a better cloaking effect on the incident wave along the ellipse minor axis direction than the traditional method.This means that for the same object,an appropriate transformation scheme can be selected for different incident wave directions to achieve the optimal control effect.The validated scheme is further used to design an arch-shaped cloak composed of an upper semicircular area and a lower rectangular area,by combining the traditional single-centered coordinate transformation method for the semicircular area and the proposed multi-origin method for the rectangular area.The results show that the designed cloak can effectively control the wave propagation with significantly reduced acoustic pressure level.This work provides a flexible acoustic cloak design method applicable for arbitrary shapes and different w

关键词： metamaterial acoustic cloak transformation acoustic region partitioning finite element(FE)simulation

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Basic Survey Scheduling for the Wide Field Survey Telescope(WFST)

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Research in Astronomy and Astrophysics 2024年第1期24卷 59-69页

作者： Yan-Peng Chen Ji-An Jiang Wen-Tao Luo Xian-zhong zheng Min Fang Chao Yang Yuan-Yu Hong Zong-Fei Lü Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Department of Astronomy University of Science and Technology of ChinaHefei 230026China National Astronomical Observatory of Japan National Institutes of Natural Sciences2-21-1 OsawaMitakaTokyo 181-8588Japan Institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230026China

Aiming at improving the survey efficiency of the Wide Field Survey Telescope, we have developed a basic scheduling strategy that takes into account the telescope characteristics, observing conditions, and weather conditions at the Lenghu site. The sky area is divided into rectangular regions, referred to as “tiles,” with a size of2°. 577 × 2°. 634 slightly smaller than the focal area of the mosaic CCDs. These tiles are continuously filled in annulars parallel to the equator. The brightness of the sky background, which varies with the moon phase and distance from the moon, plays a significant role in determining the accessible survey fields. Approximately 50connected tiles are grouped into one block for observation. To optimize the survey schedule, we perform simulations by taking into account the length of exposures, data readout, telescope slewing, and all relevant observing conditions. We utilize the Greedy Algorithm for scheduling optimization. Additionally, we propose a dedicated dithering pattern to cover the gaps between CCDs and the four corners of the mosaic CCD array, which are located outside of the 3° field of view. This dithering pattern helps to achieve relatively uniform exposure maps for the final survey outputs.

关键词： telescopes surveys Moon

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Study on the influence mechanism of ambient humidity on the temperature rise of decay-like composite insulators

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High Voltage 2022年第5期7卷 916-924页

作者： zheng zhong Yuan Chen Yunpeng Liu Sizu Hou Jianghai Geng Hebei Key Laboratory of Power Transmission Equipment Security Defense North China Electric Power UniversityBaodingChina High Voltage Technology Institute North China Electric Power Research InstituteBeijingChina Hebei Key Laboratory of Power Internet of Things Technology North China Electric Power UniversityBaodingChina

At present,observing the temperature rise of composite insulators is an effective method for the detection of decay-like defects.However,ambient humidity will affect the temperature rise of composite insulators,which will cause problems in screening the decaylike composite insulators.Therefore,it is urgent to study the temperature rise principle of decay-like insulators and find out the influence mechanism of humidity on temperature rise.In this study,a four-electrode system is designed to measure the surface current,volume current and interface current of the decay-like short sample and the intact short sample under different humidity.Then the equivalent circuit models of short samples and the 500 kV full-size decay-like composite insulator are built to analyse the contribution rates of leakage conductance loss and polarisation loss to temperature rise.The results show that the contribution rates of the polarisation loss to the temperature rise of two samples are 35.8%and 23.6%in low humidity,while they are 98.3%and 64.4%in high humidity.For the full-size decay-like composite insulator,the contribution rates of polarisation loss to its temperature rise in high or low humidity are more than 99%.In addition,the proportion of polarisation loss increases at first and then decreases with the increase of the length of the decay-like section.The conclusions of this study provide a theoretical basis for further understanding the corresponding relationship between decaylike defects and temperature rise and improve the detection rate of decay-like insulators.

关键词： composite ambient humidity

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