检索结果-内蒙古大学图书馆

Effect of annealing temperature on microstructure and mechanical properties of Mg-Zn-Zr-Nd alloy with large final rolling deformation

引用

Journal of Central South University 2024年第6期31卷 1774-1789页

作者： ZHANG Jin-hai NIE Kai-bo ZHANG Jin-hua DENG Kun-kun LIU Zhi-long College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of High-end Compressor and System Technology Hefei 230031China

In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was *** rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both *** mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening *** annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the ***,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.

关键词： Mg-Zn-Zr-Nd alloy large final rolling deformation annealing temperatures microstructures mechanical properties

来源：评论

学校读者我要写书评

暂无评论

A Secure and Cost-Effective Training Framework Atop Serverless Computing for Object Detection in Blasting

引用

Computer Modeling in Engineering & Sciences 2024年第5期139卷 2139-2154页

作者： Tianming Zhang Zebin Chen Haonan Guo Bojun Ren Quanmin Xie Mengke Tian Yong Wang Department of Computer and Science Shanghai Jiaotong UniversityShanghai200240China Aerospace System Engineering Shanghai Shanghai200240China State Key Laboratory of Precision Blasting Jianghan UniversityWuhan430056China Beijing Microelectronics Technology Institute Beijing100076China

The data analysis of blasting sites has always been the research goal of relevant *** rise of mobile blasting robots has aroused many researchers’interest in machine learning methods for target detection in the field of *** Computing can provide a variety of computing services for people without hardware foundations and rich software development experience,which has aroused people’s interest in how to use it in the field ofmachine *** this paper,we design a distributedmachine learning training application based on the AWS Lambda *** on data parallelism,the data aggregation and training synchronization in Function as a Service(FaaS)are effectively *** also encrypts the data set,effectively reducing the risk of data *** rent a cloud server and a Lambda,and then we conduct experiments to evaluate our *** results indicate the effectiveness,rapidity,and economy of distributed training on FaaS.

关键词： Serverless computing object detection blasting

来源：评论

学校读者我要写书评

暂无评论

Study on Clamping Type DC Circuit Breaker with Short Fault Isolation Time and Low Energy Dissipation

引用

CSEE Journal of Power and Energy systems 2023年第5期9卷 1743-1752页

作者： Xibei Zhao Gen Li Jianzhong Xu Jinsha Yuan the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China the Electric Energy Group Department of Engineering TechnologyTechnical University of Denmark(DTU)2750 BallerupDenmark

The development of DC grids faces challenges from DC fault *** conventional DC circuit breaker(DCCB)employs metal-oxide varistor(MOV)to isolate the faulted line,in which the fault isolation process is coupled with the energy dissipation *** this study,a clamping type DCCB(CTCB)using internal capacitors to clamp the converter voltage is *** to the proposed configuration,fault isolation and energy dissipation are decoupled,resulting in a fast fault isolation and low energy dissipation compared to the conventional *** working principle of the proposed CTCB is presented and verified in a DC grid simulation model.A comparison is made with the traditional *** fault isolation time can be reduced by 34.5%.The dissipated energy can be reduced by 17.4%.The energy dissipation power can be reduced by 76.2%.

关键词： DC circuit breaker DC fault DC protection,HVDC grid MMC

来源：评论

学校读者我要写书评

暂无评论

Design and Control for WLR-3P:A Hydraulic Wheel-Legged Robot

引用

Cyborg and Bionic systems 2023年第1期4卷 243-259页

作者： Xu Li Haoyang Yu Haibo Feng Songyuan Zhang Yili Fu State Key Laboratory of Robotics and System College of Mechatronics EngineeringHarbin Institute of TechnologyHarbin 150001China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China Intelligent Robot Research Center Zhejiang LaboratoryHangzhou 311100China

The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex *** hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydraulic wheel-legged robot)has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough *** this paper,3 design requirements are proposed to improve the mobility and environmental adaptability of the *** meet these 3 requirements,2 design principles for each requirement are put ***,for light weight and low inertia with high stiffness,3-dimensional printing technology and lightweight material are ***,the integrated hydraulically driven unit is used for high power density and fast response ***,the microhydraulic power unit achieves power autonomy,adopting the hoseless design to strengthen the reliability of the hydraulic *** is more,the control system including hierarchical distributed electrical system and control strategy is *** mobility and adaptability of WLR-3P are demonstrated with a series of ***,the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.

关键词： robot Robot terrain

来源：评论

学校读者我要写书评

暂无评论

Investigation of Short-Circuit Failure Mechanism in 1.2kV SiC MOSFET 2

Investigation of Short-Circuit Failure Mechanism in 1.2kV Si...

引用

2nd IEEE International Power Electronics and Application Symposium, PEAS 2023

作者： Luo, Houcai Wu, Huan Zhang, Jingping Zheng, Bofeng Chen, Xianping Chongqing University Key Laboratory of Optoelectronic Technology and Systems Chongqing400044 China System Security and New Technology Chongqing University Key Laboratory of Optoelectronic Technology and Systems Education Ministry of China State Key Laboratory of Power Transmission Equipment Chongqing400044 China

ISBN: (纸本)9798350313765

The reliability and failure mechanism of SiC MOSFET under short-circuit was investigated using experiment and physical simulation in this paper. A short-circuit test platform was constructed, and a physical simulated model was calibrated. A commercial 1.2kV SiC MOSFET operated under different voltages including 200V, 400V, 600V with series short-circuit time was studied. The results showed that the thermal dissipation played a critical role during short-circuit operation, which is one of the most impacting factor to gate voltage and current tails. Two failed mechanisms including gate oxide degradation and parasitic BJT conduction failure were verified during short-circuit. This study may be helpful to the application engineering of SiC MOSFET. © 2023 IEEE.

关键词： experiment and physical simulation failure mechanism short-circuit SiC MOSFET

来源：评论

学校读者我要写书评

暂无评论

Assistive robots for Beijing Winter Paralympic torch relay: Accessible technologies to restore human functionality

引用

The Innovation 2024年第1期5卷 19-20页

作者： Bi Zhang Mei Shuai Bicheng Han Shuo Li Lianqing Liu Xingang Zhao State Key Laboratory of Robotics Shenyang Institute of AutomationCASShenyang 110016China Institutes for Robotics and Intelligent Manufacturing CASShenyang 110169China Department of Biomedical Engineering Beihang UniversityBeijing 100191China Beijing AI-Robotics Technology Co. Ltd.Beijing 100176China Zhejiang BrainCo Technology Co. Ltd.Hangzhou 311121China

The success of the Beijing Winter Olympics and Paralympics epitomized the vision of a community with a shared future for *** robots and artificial intelligence technologies were used in various games and events,such as assisting in parades,logistics,and security *** integration of unmanned robotic systems into torch relays was one of the highlights of the Winter Olympics.

关键词： Winter Access artificial

来源：评论

学校读者我要写书评

暂无评论

DORM: Distance-based opportunistic routing and medium access protocol for multi-AUV monitoring system 23

DORM: Distance-based opportunistic routing and medium access...

引用

2nd International Conference on Networks, Communications and Information technology, CNCIT 2023

作者： Qiu, Tianyou Li, Yiping Feng, Xisheng School of Information Science and Technology University of Science and Technology of China Anhui230026 China State Key Laboratory of Robotics Shenyang Institute of Automation Chinese Academy of Sciences Shenyang110016 China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences Shenyang110169 China Key Laboratory of Marine Robotics Liaoning Province Shenyang110169 China

ISBN: (纸本)9798400700620

In a multi-AUV (autonomous underwater vehicle) monitoring system, each vehicle uploads sensor data to the surface central control platform through underwater acoustic communication, and the control platform sends commands or task files to AUVs. For a multi-AUV system with many vehicles and a large-scale underwater network, it is a challenge to design protocols to achieve reliable, low-latency, and energy-efficient communication due to the unique characteristics of underwater acoustic channels. We propose a distance-based opportunistic routing-MAC protocol (DORM), which combines opportunistic routing and CSMA, using distance and hop counts information to determine backoff time and forwarding priority. We conducted simulation experiments to analyze the performance of DORM and compared it with P-AUV and Probabilistic Broadcast (PB). The results show that DORM ensures reliable transmission and has apparent advantages in latency and energy efficiency. © 2023 Owner/Author.

关键词： Routing protocols

来源：评论

学校读者我要写书评

暂无评论

Inverse Kinematics of a Reconfigurable Space Manipulator Based on the Closed-Loop Algorithm

Inverse Kinematics of a Reconfigurable Space Manipulator Bas...

引用

IEEE International Conference on Mechatronics and Automation

作者： Zhiyuan Zhao Xiaohang Yang Zichun Xu Yuntao Li Zhonglai Tian Jingdong Zhao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin Heilongjiang Province China

This paper investigates a reconfigurable space manipulator’s inverse kinematics (IK) with two lockable passive telescopic links (LPTLs). Depending on these LPTLs’ locking state, the manipulator includes free-space and reconfiguration operation modes. Firstly, we introduce a new ball joint-based solution for the reconfigurable operation mode. Then, we propose an IK simplified method capable of significantly reducing the computational load of the complex inverse differential kinematic (IDK) equations corresponding to the two operation modes. Next, to solve the resulting simplified IDK equations efficiently, we present an IK solution method based on the closed-loop algorithm. This method is developed to resolve the redundancy at the velocity level and can generate highly accurate and smooth trajectory IK solutions that satisfy the joint limit constraints. Finally, we design two typical case studies corresponding to working scenarios of the manipulator during two operation modes. Their simulation results validate the proposed methods’ effectiveness.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Research on Motion Mode Conversion Control of Wheel-legged Biped Robot 20

Research on Motion Mode Conversion Control of Wheel-legged B...

引用

20th IEEE International Conference on Mechatronics and Automation, ICMA 2023

作者： Fu, Yili Li, Xu Dong, Xinyu Intelligent Robot Research Center Zhejiang Laboratory Hangzhou China Harbin Institute of Technology State Kay Laboratory of Robotics and System Heilongjiang Province Harbin China Harbin Institute of Technology Heilongjiang Province Harbin China

ISBN: (纸本)9798350320831

The bipedal wheel-legged robot with auxiliary legs studied in this paper has two motion modes, two wheels and four wheels, and can transform motion modes according to operation requirements. This paper focuses on how to realize motion mode transformation control under stable equilibrium. Firstly, kinematics analysis and dynamics modeling of the robot are carried out to complete the motion description and dynamics description of the robot in Cartesian space. Then the robot is simplified into a wheeled inverted pendulum model, and the driving wheel and other parts are decoupled to analyze its dynamic characteristics. In this paper, LQR controller will be used to ensure the robot is always in a balanced state, and then priority task space control (PTSC) based on quadratic programming (QP) will be adopted to track the robot trajectory. Finally, the smooth transformation of the robot under two motion modes of two wheels and four wheels is completed by experiments, which verifies the effectiveness of the control algorithm designed in this paper. © 2023 IEEE.

关键词： Quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Boosting spring runoff into the sea by reservoir regulation and its potential for estuarine fishery recovery

引用

Science China Earth Sciences 2024年第5期67卷 1591-1603页

作者： Xiao WU Houjie WANG Yongyong FAN Naishuang BI Chiyuan MIAO Jingping XU Zuosheng YANG College of Marine Geosciences Key Laboratory of Submarine Geosciences and Prospecting Technologyand Frontiers Science Center for Deep Ocean Multispheres and Earth SystemOcean University of ChinaQingdao 266100China Laoshan National Laboratory Qingdao 266061China Institute of the Yellow River Estuary and Coast Science Dongying 257000China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Department of Ocean Science&Engineering Southern University of Science and TechnologyShenzhen 518055China

With global surge in reservoir construction over the past decades,river systems worldwide have been profoundly ***,flow manipulation by reservoirs has altered the natural hydrological processes,resulting in extensive modifications of fluvial-marine *** the adverse ecological consequences of reservoirs has become a global concern and has garnered increasing *** Yellow River,as one of the most extensively manipulated river systems globally,has experienced substantial changes in the amount and timing of water discharge due to the presence of numerous reservoirs scattered throughout its catchment *** alterations have caused physicochemical changes in the estuary and subsequent modifications to the estuarine *** recent years,the Yellow River Conservancy Committee initiated the release of water through the Xiaolangdi Dam during the major spawning period of fisheries,specifically in the spring,with the aim of improving the estuarine ecological *** 2011 to 2020,a total of 84.05 km^(3)of water was discharged from the Xiaolangdi Reservoir during spring seasons,of which 40%(33.16 km^(3))constituted water impounded within the reservoir during preceding ***,the spring water discharge from the Yellow River to the sea increased significantly from 1.50 km^(3)/yr to 3.46 km^(3)/yr in the past decade,leading to a decrease in estuarine salinity by 1.6 *** estuarine fishery resources,such as fish eggs in the Yellow River estuary,have demonstrated evident *** reservoir regulation in the Yellow River,which has successfully enhanced spring water discharge and subsequently restored estuarine fishery resources,presents an effective attempt for mitigating the adverse ecological effects associated with reservoirs.

关键词： Reservoir regulation Water release Spring runoff Estuarine ecosystem Yellow River

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

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：