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Metal-organic framework-derived Co nanoparticles and single atoms as efficient electrocatalyst for pH universal hydrogen evolution reaction

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Nano Research 2022年第9期15卷 7917-7924页

作者： Rui jiang qian li Xue Zheng Weizhe Wang Shuangbao Wang Zhimou Xu Jiabin Wu School of Optical and Electronic Information Huazhong University of Science and Technology(HUST)Wuhan 430074China Department of Chemistry Tsinghua UniversityBeijing 100084China

Hydrogen release through water splitting is essential for reducing carbon emissions and promoting the hydrogen *** of the crucial challenges for industrial applications of water electrolysis is the manufacture of electrocatalysts which can reduce the kinetic energy barrier of the hydrogen evolution reaction(HER).Loading transition metal(TM)nanoparticles(NPs)or single atoms(SAs)into heteroatom-doped carbon materials(HCMs)is an effective method to improve electrochemical activity and *** this end,we synthesized N-doped porous carbon(NC)encapsulated Co NPs and isolated Co SA nanocatalysts(denoted as Co NPs@SAs-NC)using metal-organic frameworks(MOFs)as sacrificial *** Co NPs@SAs-NC nanocatalysts displayed outstanding HER activity with a 110 mV overpotential in 1 M KOH,47 mV overpotential in 0.5 M H2SO4 and 171 mV in 0.5 M phosphate-buffered saline(PBS)to reach a current density of 10 mA·cm^(−2).In addition,the mechanism of the synergistic effect of Co NPs,Co SAs and N species was investigated in-depth using in situ shielding experiments and density functional theory(DFT)calculations.

关键词： metal-organic frameworks hydrogen evolution reaction nanocatalysts single atoms pH universal

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基于MEMS传感器的振动测量电路设计

山西电子技术 2024年第1期 58-59,79页

作者：李仑升张浩骞恒源闫稳航空工业西安航空计算技术研究所陕西西安710065

针对机载设备所处的振动环境,基于MEMS三轴加速度传感器,设计了一种振动测量电路以及振动信号采集、处理方法,检测环境中的振动情况,通过通信模块上传振动信息,实现对机载设备的振动监测功能。

关键词：振动采集数据处理振动监测

基于人居环境适应性的徽州传统聚落空间量化研究——以祁门磻村为例

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西安文理学院学报(自然科学版) 2024年第2期27卷 64-71页

作者：侯琪玮李茜马鑫全赵怡君安徽工程大学建筑工程学院

传统聚落人居环境与聚落现代化建设要求和村民对美好生活的向往有着密切的联系.公共活动空间作为村民的日常活动聚集点，对人居环境的提升也有着不可或缺的作用.通过对徽州传统村落祁门磻村人居环境的心理感受提取出评价因子，并以此拟... 详细信息

传统聚落人居环境与聚落现代化建设要求和村民对美好生活的向往有着密切的联系.公共活动空间作为村民的日常活动聚集点，对人居环境的提升也有着不可或缺的作用.通过对徽州传统村落祁门磻村人居环境的心理感受提取出评价因子，并以此拟定问卷，使用SPSS工具对问卷数据进行相关性分析得出定量结论；结合实地情况以及整理资料，使用黏菌算法(Physarealm)分别对磻村公共活动空间以及内部道路进行模拟，通过对比分析得出定性结论；形成了定量为主，定性为辅的分析方法.根据分析所得结论，总结出磻村现存公共活动空间在空间尺度、建筑设施、布局结构等方面存在的问题，提出相应建设建议以及空间设计策略.

关键词：人居环境适应性公共空间黏菌算法量化分析

Analysis of temporal and spatial distribution characteristics of ammonium chloride smoke particles in confined spaces

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Defence Technology（防务技术） 2022年第7期18卷 1269-1280页

作者： Chen-youshi Xu Bing-ting Zha Jia-qian Bao He Zhang Hong-xia li ZNDY of Ministerial Key Laboratory Nanjing University of Science and TechnologyJiangsuNanjing210094China

In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke *** particle size distribution,composition,and mass flow distribution of the smoke were *** on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined *** temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was *** with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread ***,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and *** the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m *** concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short ***,this system was suitable for conducting experimental research on laser fuzes in a smoke *** to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke ***,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky envir

关键词： Laser fuze Smoke environment Temporal distribution Spatial distribution Confined space Smoke agent

High-Risk LEO Satellite Network Path Detection Based on Spatial and Temporal Delay Anomaly Analysis

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China Communications 2023年第7期20卷 57-71页

作者： Tianyu Zhang Hewu li Jun liu Lu Lu qian Wu Shaowen Zheng Zeqi Lai Yuanjie li Institute for Network Sciences and Cyberspace Tsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology Beijing 100084China China Mobile Research Institute Beijing 100053China

The gradual deployment of Low-Earth Orbit(LEO)mega constellations with inter-satellite links(ISLs)promises ubiquitous,low-latency,and high-throughput satellite network ***,networked LEO satellites with ISLs are also at risk of routing attacks such as *** defenses against route hijacking in terrestrial networks can hardly work for the LEO satellite network due to its high spatiotemporal *** deal with it,we propose RPD,a high-risk routing path detection method for LEO mega-constellation *** detects abnormal high-risk LEO network paths by checking the consistency between the path delay and the geographical *** is efficiently achieved by combining in-band measurements and out-of-band statistical processing to detect the anomaly of the clustering feature in the reference delay *** avoids the recalculation of the header cryptographic marks when the handover occurs,thus greatly reducing the cost and improving the performance of highrisk path *** showed that the proposed RPD mechanism achieves an average detection accuracy of 91.64%under normal network conditions,and maintain about 89%even when congestion occurs in multiple areas of the network and measurement noise is *** addition,RPD does not require any cryptographic operation on the intermediate node,only minimal communication cost with excellent scalability and deployability.

关键词： LEO satellite networks route hijacking path verification risky path detection

网络视听节目平台视频技术质量评测方法及结果分析

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广播与电视技术 2024年第2期51卷 27-30页

作者：李厦张乾汪芮刘汉源国家广播电视总局广播电视规划院北京100866

随着网络视听节目快速增长,越来越多的人通过互联网观看视频节目。但是网络视听节目的视频质量良莠不齐,针对视频技术质量的评测手段也没有统一标尺,各平台的评测结果无从知晓。本文提出一种针对网络视听节目平台进行视频技术质量评测... 详细信息

随着网络视听节目快速增长,越来越多的人通过互联网观看视频节目。但是网络视听节目的视频质量良莠不齐,针对视频技术质量的评测手段也没有统一标尺,各平台的评测结果无从知晓。本文提出一种针对网络视听节目平台进行视频技术质量评测的方法,并运用该方法,对8家网络视听平台的视频质量进行了测评。

关键词：网络视听视频质量节目评测

A combined finite element and deep learning network for structural dynamic response estimation on concrete gravity dam subjected to blast loads

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Defence Technology（防务技术） 2023年第6期24卷 298-313页

作者： Xin Fang Heng li She-rong Zhang Xiao-hua Wang Chao Wang Xiao-chun Luo State Key Laboratory of Hydraulic Engineering Simulation and Safety&School of Civil Engineering Tianjin UniversityTianjin300072China Department of Building and Real Estate Hong Kong Polytechnic UniversityKowloonHong KongChina

Social infrastructures such as dams are likely to be exposed to high risk of terrorist and military attacks,leading to increasing attentions on their vulnerability and catastrophic consequences under such *** paper tries to develop advanced deep learning approaches for structural dynamic response prediction and dam health *** first,the improved long short-term memory(LSTM)networks are proposed for data-driven structural dynamic response analysis with the data generated by a single degree of freedom(SDOF)and the finite numerical simulation,due to the unavailability of abundant practical structural response data of concrete gravity dam under blast *** kinds of LSTM-based models are discussed with the various cases of noise-contaminated signals,and the results prove that LSTM-based models have the potential for quick structural response estimation under blast ***,the damage indicators(i.e.,peak vibration velocity and domain frequency)are extracted from the predicted velocity histories,and their relationship with the dam damage status from the numerical simulation is *** study provides a deep-learning based structural health monitoring(SHM)framework for quick assessment of dam experienced underwater explosions through blastinduced monitoring data.

关键词： Deep learning Structural health monitoring Dynamic response Concrete gravity dam

Multi-effect anthraquinone-based polyimide enclosed SnO_(2)/reduced graphene oxide composite as high-performance anode for lithium-ion battery

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化学科学与工程前沿:英文版 2023年第9期17卷 1231-1243页

作者： lin Wang Yinjie Kuang qian Cui Junyu Shi liubin Song Qionghua li Tianjian Peng Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation School of Chemistry and Chemical EngineeringChangsha University of Science and TechnologyChangsha410114China Guizhou Dalong Huicheng New Material Co. Ltd.Tongren554000China

The cycling stability of SnO_(2)anode as lithium-ion battery is poor due to volume *** coatings can effectively confine the expansion of SnO_(2).However,linear polyimides are easily dissolved in ester electrolytes and their carbonyls is not fully utilized during charging/discharging ***,the SnO_(2)enclosed with anthraquinone-based polyimide/reduced graphene oxide composite was prepared by *** from the anthraquinone unit provide fully available active sites to react with li^(+),improving the utilization of carbonyl in the *** exposed carbonyl active sites promote the conversion of Sn to SnO_(2)with electrode gradual activation,leading to an increase in reversible capacity during the charge/discharge *** addition,the introduction of reduced graphene oxide cannot only improve the stability of polyimide in the electrolyte,but also build fast ion and electron transport channels for composite *** to the multiple effects of anthraquinone-based polyimide and the synergistic effect of reducing graphene oxide,the composite anode exhibits a maximum reversible capacity of 1266 mAh·g^(−1) at 0.25 A·g^(−1),and maintains an excellent specific capacity of 983 mAh·g^(−1) after 200 *** work provides a new strategy for the synergistic modification of SnO_(2).

关键词： anthraquinone-based polyimide multi-effect tin dioxide reduced graphene oxide lithium-ion battery

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焊前预处理对钛合金厚板焊接残余应力的影响

金属学报 2024年第8期60卷 1064-1078页

作者：周牧王倩王延绪翟梓融何伦华李昺马英杰雷家峰杨锐中国科学技术大学材料科学与工程学院沈阳110016 中国科学院金属研究所师昌绪先进材料创新中心沈阳110016 中国科学院金属研究所沈阳材料科学国家研究中心沈阳110016 上海科技大学智造系统工程中心上海201210 散裂中子源科学中心东莞523803 中国科学院物理研究所北京国家凝聚态物理学实验室北京100190

焊接残余应力是影响焊接成型及焊接部件服役的重要因素。为了优化焊接工艺和焊接接头微观结构,有效地减小焊接残余应力,本工作研究了焊前预处理工艺对电子束焊接钛合金厚板焊接接头组织、性能和残余应力的影响机制。对不同预处理工艺制... 详细信息

焊接残余应力是影响焊接成型及焊接部件服役的重要因素。为了优化焊接工艺和焊接接头微观结构,有效地减小焊接残余应力,本工作研究了焊前预处理工艺对电子束焊接钛合金厚板焊接接头组织、性能和残余应力的影响机制。对不同预处理工艺制备的钛合金焊接接头进行组织形貌表征,发现焊前预热显著增宽了焊接接头的熔合区和热影响区,粗化了两区域内的α片层,提高了焊接接头的强韧性匹配。采用中子衍射法、深孔法和轮廓法检测钛合金厚板电子束焊接头残余应力,对3种方法的检测结果进行对比分析,获得了焊接接头不同区域沿不同方向的残余应力分布。另外,对比了2种预热工艺焊接接头采用深孔法获得的残余应力结果,发现焊前预热可以显著降低焊接接头的残余应力。采用数值模拟计算了不同预热温度下温度场和应力场的变化情况,获得了不同预热温度条件下热应力的动态变化规律,揭示了预热降低残余应力的内在机理。对比2种预处理工艺焊接接头熔合区和热影响区的显微组织、元素分布和晶粒取向,进一步阐明了预热可以通过促进元素扩散和诱发变体选择降低β→α相变产生的应力集中。

关键词：钛合金残余应力中子衍射显微组织力学性能