检索结果-内蒙古大学图书馆

Wear Characteristics of the Nuclear Control Rod Drive Mechanism(CRDM)Movable Latch Serviced in High Temperature Water

引用

Chinese Journal of Mechanical Engineering 2022年第2期35卷 111-120页

作者： Tianda Yu Guozhong Fu Yanqing Yu Liting Zhu Maofu Liu Wei Li Qiang Deng Zhenbing Cai The State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 4000442China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China Sichuan Huadu Nuclear Equipment Manufacturing Co. LtdDujiangyan 611830China

The current research of nuclear control rod drive mechanism(CRDM)movable latch only makes a simple measurement of wear *** wear volume and difference in various claw surfaces are ignored and the degradation mechanism of each claw surface is not *** this paper,a detailed degradation analysis was carried out on each claw surface of movable latch combined with wear result and worn *** indicate that the boundary of carbide is preferred for corrosion because carbide presents a nobler Volta potential compared to the metal matrix or boundary *** to the oscillation of drive shaft between the claw surfaces of movable latch,the dominant wear mechanism on the upper surface of claw(USC)and lower surface of claw(LSC)is plastic deformation caused by impact *** impact wear will cause the fragmentation of carbides because of the high hardness and low ductility of *** promotes the broken carbides to fall off from the metal *** generated fine carbides(abrasive particles)cause extra abrasive wear on USC when the movable brings the drive shaft upward or *** a result,USC has a higher wear volume than *** research proposes a method to evaluate the wear on the whole movable latches using a 3D full-size scanner.

关键词： CRDM Movable latch Degradation analysis Wear characteristics Carbide

来源：评论

学校读者我要写书评

暂无评论

Bioinspired smart dual-layer hydrogels system with synchronous solar and thermal radiation modulation for energy-saving all-season temperature regulation

引用

Journal of Energy Chemistry 2025年第2期101卷 175-190,I0005页

作者： Meng-Chen Huang Chao-Hua Xue Zhongxue Bai Jun Cheng Yong-Gang Wu Chao-Qun Ma Li Wan Long Xie Hui-Di Wang Bing-Ying Liu Xiao-Jing Guo College of Bioresources Chemical and Materials Engineering Shaanxi University of Science&TechnologyXi'an 710021ShaanxiChina Schoolof Manufacture Science and Engineering Key Laboratory of Testing Technology for Manufacturing ProcessMinistry of EducationSouthwest University of Science and TechnologyMianyang 621010SichuanChina School of Life Science and Engineering Southwest University of Science and TechnologyMianyang 621010SichuanChina Northwest Institute for Nonferrous Metal Research Shaanxi Key Laboratory of Biomedical Metal MaterialsXi'an 710016ShanxiChina

All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating ***,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature ***,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design *** PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating ***,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,***,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and *** novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.

关键词： Thermochromic hydrogel Self-adaptive thermal management Radiative cooling Spectral modulation Energy-saving

来源：评论

学校读者我要写书评

暂无评论

Extinction Chains Reveal Intermediate Phases Between the Safety and Collapse in Mutualistic Ecosystems

引用

Engineering 2024年第12期43卷 89-98页

作者： Guangwei Wang Xueming Liu Ying Xiao Ye Yuan Linqiang Pan Xiaohong Guan Jianxi Gao Hai-Tao Zhang The MOE Engineering Research Center of Autonomous Intelligent Unmanned Systems State Key Laboratory of Digital Manufacturing Equipment and TechnologySchool of Artificial Intelligence and AutomationHuazhong University of Science and TechnologyWuhan 430074China Guangdong HUST Industrial Technology Research Institute Huazhong University of Science and TechnologyDongguan 523808China Guangdong Provincial Engineering Technology Center of Autonomous Unmanned Vessels Dongguan 523808China MOE Key Laboratory of Intelligent Networks and Network Security&State Key Laboratory of Manufacturing Systems Xi’an Jiaotong UniversityXi’an 710049China Tsinghua National Laboratory of Information Science and Technology Department of AutomationTsinghua UniversityBeijing 100084China Department of Computer Science Rensselaer Polytechnic InstituteTroyNY 12180USA

Ecosystems are undergoing unprecedented persistent deterioration due to unsustainable anthropogenic human activities,such as overfishing and deforestation,and the effects of such damage on ecological stability are *** recent advances in experimental and theoretical studies on regime shifts and tipping points,theoretical tools for understanding the extinction chain,which is the sequence of species extinctions resulting from overexploitation,are still lacking,especially for large-scale nonlinear networked *** this study,we developed a mathematical tool to predict regime shifts and extinction chains in ecosystems under multiple exploitation situations and verified it in 26 real-world mutualistic networks of various sizes and *** discovered five phases during the exploitation process:safe,partial extinction,bistable,tristable,and collapse,which enabled the optimal design of restoration strategies for degraded or collapsed *** validated our approach using a 20-year dataset from an eelgrass restoration ***,we also found a specific region in the diagram spanning exploitation rates and competition intensities,where exploiting more species helps increase *** computational tool provides insights into harvesting,fishing,exploitation,or deforestation plans while conserving or restoring the biodiversity of mutualistic ecosystems.

关键词： Complex system Network science Overexploitation Regime shift Metastability

来源：评论

学校读者我要写书评

暂无评论

Reorientation and obstacle avoidance control of free-floating modular robots using sinusoidal oscillator

引用

Chinese Journal of Aeronautics 2024年第6期37卷 262-275页

作者： Zhiyuan YANG Mingzhu LAI Jian QI Ning ZHAO Xin SUI Jie ZHAO Yanhe ZHU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China

This paper presents that a serpentine curve-based controller can solve locomotion control problems for articulated space robots with extensive flight phases,such as obstacle avoidance during free floating or attitude adjustment before *** proposed algorithm achieves articulated robots to use closed paths in the joint space to accomplish the above *** snakes,which can shuttle through gaps and adjust their landing posture by swinging their body during gliding in jungle environments,inspired the design of two *** first maneuver generates a rotation of the system by varying the moment of inertia between the joints of the robot,with the magnitude of the net rotation depending on the controller *** maneuver can be repeated to allow the robot to reach arbitrary *** second maneuver involves periodic undulations,allowing the robot to avoid collisions when the trajectory of the global Center of Mass(CM)passes through the *** maneuvers are based on the improved serpenoid curve,which can adapt to redundant systems consisting of different numbers of ***,the simulation illustrates that combining the two maneuvers can help a free-floating chain-type robot traverse complex *** proposed algorithm can be used with similar articulated robot models.

关键词： Collision avoidance Modularrobots Reorientation Free-floating space robots Nonholonomic systems Biologically inspired controllers Serpenoid curve

来源：评论

学校读者我要写书评

暂无评论

Dynamic Vision-Based Machinery Fault Diagnosis With Cross-Modality Feature Alignment

引用

IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2068-2081页

作者： Xiang Li Shupeng Yu Yaguo Lei Naipeng Li Bin Yang Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi’an Jiaotong UniversityXi’an 710049China IEEE

Intelligent machinery fault diagnosis methods have been popularly and successfully developed in the past decades,and the vibration acceleration data collected by contact accelerometers have been widely *** many industrial scenarios,contactless sensors are more *** event camera is an emerging bio-inspired technology for vision sensing,which asynchronously records per-pixel brightness change polarity with high temporal resolution and low *** offers a promising tool for contactless machine vibration sensing and fault ***,the dynamic vision-based methods suffer from variations of practical factors such as camera position,machine operating condition,***,as a new sensing technology,the labeled dynamic vision data are limited,which generally cannot cover a wide range of machine fault *** at these challenges,a novel dynamic vision-based machinery fault diagnosis method is proposed in this *** is motivated to explore the abundant vibration acceleration data for enhancing the dynamic vision-based model performance.A crossmodality feature alignment method is thus proposed with deep adversarial neural networks to achieve fault diagnosis knowledge *** event erasing method is further proposed for improving model robustness against *** proposed method can effectively identify unseen fault mode with dynamic vision *** on two rotating machine monitoring datasets are carried out for validations,and the results suggest the proposed method is promising for generalized contactless machinery fault diagnosis.

关键词： Condition monitoring domain generalization eventbased camera fault diagnosis machine vision

来源：评论

学校读者我要写书评

暂无评论

Computational fluid dynamics simulations of spray tests in a multicompartment construction with an Eulerian–Lagrangian approach

引用

Frontiers in Energy Research 2024年 12卷

作者： Lu, Yazhe Ran, Xu Wei, Zonglan Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

This paper is an investigation of the gas mixing and depressurization effects of containment spray on hydrogen risk during a typical severe accident in a light water reactor (LWR). Two spray tests (ST3_0 and ST3_1) were simulated using the OECD/SETH-2 project frame;the tests were performed with different preconditions in two interconnected vessels of the PANDA facility by focusing on the breaking-up of the stratified helium-rich layer and helium transport between the interconnected vessels with and without heat and mass transfer. The computational fluid dynamics simulations were performed using an Eulerian–Lagrangian approach, in which the dispersed droplets were tracked with a Lagrangian framework and the heat and mass transfer model between the droplets and gas were developed through user-defined functions. The simulation results are in reasonable agreement with the test data and reproduce the main phenomena of the spray tests. Although the proposed approach is adequate for addressing similar problems, some discrepancies still exist in the simulations. Based on these discrepancies, some recommendations are suggested to improve the accuracy of the proposed approach. Copyright © 2024 Lu, Ran and Wei.

关键词： Light water reactors

来源：评论

学校读者我要写书评

暂无评论

OpSecureCam: optically enhanced secure camera via an engineering point spread function

引用

Optics Express 2025年第10期33卷 20880-20893页

作者： Luo, Haoqi Zhang, Junyu Liu, Ye Sun, Weibing Wu, Yunlong Ye, Qing Hu, Yihua State Key Laboratory of Pulsed Power Laser Technology National University of Defense Technology Hefei230037 China Advanced Laser Technology Laboratory of Anhui Province Anhui Hefei230026 China

Photoelectric imaging systems usually pursue a small-sized point spread function (PSF) to acquire high-quality images, but it also poses safety hazards for the camera in certain scenarios. For instance, ultrahigh intensity light focused on the sensor may cause irreversible damage when the camera is subjected to unexpected laser irradiation. Furthermore, clear images captured are vulnerable to privacy breaches during online transmission. In this paper, we report a concept of the OpSecureCam with protection capability versus both laser damage and privacy breaches via PSF engineering. The design recipe of the PSF with simultaneous enhancements in energy spread ratio and information flux is derived. An end-to-end framework is developed under theoretical guidance to jointly optimize the PSF and the decoding network, maximizing both protection capability and imaging quality of the OpSecureCam. A wavefront coding system is built to realize the concept, wherein the pupil phase distribution is obtained through a hybrid phase retrieval method based on Gerchberg-Saxton and stochastic gradient descent algorithms. Experiment results demonstrate that the OpSecureCam reduces the peak intensity of the jamming laser on its sensor by 99.73%, while the encoded images are robust against various blind deblurring methods. After being decoded by the matched network, the intricate structures of the image are restored with high quality for target identification or information extraction, including text, QR code, and human face. Our work offers a compact and efficient solution to enhance the adaptability of imaging systems, which holds potential for applications in autonomous driving and security monitoring. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Optical transfer function

来源：评论

学校读者我要写书评

暂无评论

Nonstationary channel model of reentry plasma sheath for spacecraft: Overview, parameter estimation, and perspective

引用

Chinese Journal of Aeronautics 2024年第10期37卷 26-49页

作者： Lei SHI Zongyuan LIU Weimin BAO Bo YAO Yifan WANG Xiaoping LI Yanming LIU Fangyan LI School of Aerospace Science and Technology Xidian UniversityXi’an 710126China Key Laboratory of Equipment Efficiency in Extreme Environment Ministry of EducationXi’an 710126China China Aerospace Science and Technology Corporation Beijing 100048China

The Tracking,Telemetering,and Command(TT&C)communication of spacecraft faces severe limitations during *** Electromagnetic(EM)propagation channel is influenced by changes in the flight state and fluid *** addition to the high-speed spatial channel,the Plasma Sheath Channel(PSC),which covers the surface of spacecraft,exhibits unique nonstationary and highly dynamic time-varying *** absence of a channel model for the reentry process of spacecraft negatively impacts the quality evaluation and system design of TT&C *** paper summarizes the methods for nonstationary PSC modeling,involving calculation methods for attenuation and phase shift in the channel,as well as a multistate nonstationary channel statistical model based on a hidden Markov ***,the correlation between amplitude variation and phase variation with electron density is *** paper also provides statistical characteristics of the channel and channel parameters at typical frequencies in the S/C/X/Ka *** findings serve as a reference for the design and evaluation of TT&C communication systems for reentry ***,the paper discusses the prospects of various aspects related to the channel characteristics and modeling of spacecraft PSCs in the shortwave and terahertz/laser bands,as well as the potential challenges in cross-domain spacecraft channel sensing and prediction.

关键词： Spacecraft Plasma sheaths Electromagnetic wave transmission Communication channels Channel estimation

来源：评论

学校读者我要写书评

暂无评论

Performance Evaluation and Transmitter Optimization for AN-Aided FH Communication Against Time Misalignment

引用

china Communications 2025年第3期22卷 86-103页

作者： Song Changqing Lin Lang Qin Lizhi Xiao Fei Zhao Hongzhi Shao Shihai National Key Laboratory of Wireless Communications University of Electronic Science and Technology of ChinaChengdu 611731China The Laboratory of Electromagnetic Space Cognition and Intelligent Control Beijing 100089China The Thirtieth Research Institude of China Electronic Science and Technology Group Corporation Chengdu 610093China

To guarantee secure communication against eavesdropping and malicious attack,an artificial noise(AN)-aided frequency-hopping(FH)architecture is adopted in this *** the inevitable time misalignment between the received signal and locally reconstructed AN will deteriorate the AN cancellation performance,yielding significant secrecy degradation at the FH *** view of this,first,the AN cancellation performance under time misalignment is evaluated via signal to AN-plus-noise ratio,and the system secrecy is analyzed via secrecy ***,to mitigate the performance degradation raised by time misalignment,the transmitting power allocation scheme for AN and confidential signal(CS)is optimized,and the optimal hopping period is ***,the obtained conclusions in both the performance evaluation and transmitter optimization sections hold no matter whether the eavesdropper can realize FH synchronization or *** verify that time misalignment will raise non-negligible performance ***,the power ratio of AN to CS should decrease as time misalignment increases,and for perfect time synchronization,the transmitting power of AN and CS should be *** addition,a longer hopping period is preferred for secrecy enhancement when time misalignment gets exacerbated.

关键词： artificial noise(AN)cancellation hopping period design power allocation time misalignment

来源：评论

学校读者我要写书评

暂无评论

Investigation on the temperature-dependent diffusion growth of intermetallic compounds in the Mg-Al-Zn system:Experiment and modeling

引用

Journal of Magnesium and Alloys 2024年第8期12卷 3394-3408页

作者： Kaiming Cheng Yan Zheng Jiaxing Sun Yafei Zhao Jin Wang Huan Yu Dongqing Zhao Hang Li Jixue Zhou Zhenyu Ma Junmin Wang Cuiping Guo Xitao Wang Lijun Zhang Yong Du Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan250014China Laboratory of Materials Phase Equilibria and New Materials Design School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Technology R&D Center Shandong Qiangang Metal Technology Co.LtdJining272000China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

With the rapid development of Mg alloys,deeper understanding to the thermodynamic and diffusional kinetic behavior of intermetallic compounds(IMCs)is important for studying the effect of alloying elements to the microstructure ***,a systematic quantitative investigation on the diffusional growth of IMCs is of great ***,the works studying the elemental diffusion behaviors of multiple-element IMCs are rare in magnesium alloy *** current work takes the ternary Mg-Al-Zn system as research target,and combines the diffusion couple technique,phase stability diagrams,in-situ observation technique and numerical inverse method to investigate the temperature-dependent kinetic *** parabolic growth constant(PGC)and interdiffusion coefficients for Mg solid-solution phase andγ-Mg_(17)Al_(12),β-Mg_(2)Al_(3),ε-Mg_(23)Al_(30),MgZn_(2),Mg_(2)Zn_(3),τ-Mg_(32)(Zn,Al)49 andφ-Mg_(5)Zn_(2)Al_(2) IMCs in the Mg-Al-Zn alloy system are *** comparing the current experimental with calculation results,the rate-controlling factor of the temperature-dependent diffusion growth ofφ,τandεternary IMCs in the Mg-Al-Zn system is further discussed in detail.

关键词： Diffusion couple Phase stability diagram Numerical inverse method(NIM) Interface migration High-temperature laser-scanning confocal microscopy(HTLSCM)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：