检索结果-内蒙古大学图书馆

Dynamic Modeling and Experimental Verification of an RPR Type Compliant Paralle Mechanism with Low Orders

Chinese Journal of Mechanical engineering 2024年第3期37卷 83-94页

作者： Shuang Zhang Jingfang Liu Huafeng Ding Yanbin Zhang School of Mechatronics Engineering Henan University of Science and TechnologyLuoyangHenanChina Faculty of Materials and Manufacturing College of Mechanical Engineering and Applied Electronics TechnologyBeijing University of TechnologyBeijingChina Key laboratory of advanced manufacturing technology Beijing University of TechnologyBeijingChina School of Mechanical Engineering and Electronic Information China University of Geosciences(Wuhan)WuhanChina Center of Machinery Equipment Advanced Manufacturing of Henan Province LuoyangChina

Efficiency of calculating a dynamic response is an important point of the compliant mechanism for posture *** modeling with low orders of a 2R1T compliant parallel mechanism is studied in the *** mechanism with two out-of-plane rotational and one lifting degrees of freedom(DoFs)plays an important role in posture *** on elastic beam theory,the stiffness matrix and mass matrix of the beam element are established where the moment of inertia is *** improve solving efficiency,a dynamic model with low orders of the mechanism is established based on a modified modal synthesis ***,each branch of the RPR type mechanism is divided into a ***,a set of hypothetical modes of each substructure is obtained based on the C-B ***,dynamic equation of the whole mechanism is established by the substructure assembly.A dynamic experiment is conducted to verify the dynamic characteristics of the compliant mechanism.

关键词： Compliant parallel mechanism Dynamic model Modal synthesis method Dynamic experiment

来源：评论

学校读者我要写书评

暂无评论

Ultrasensitive SERF atomic magnetometer with a miniaturized hybrid vapor cell

引用

Microsystems & Nanoengineering 2024年第4期10卷 367-376页

作者： Yintao Ma Yao Chen Mingzhi Yu Yanbin Wang Shun Lu Ju Guo Guoxi Luo Libo Zhao Ping Yang Qijing Lin Zhuangde Jiang State Key Laboratory for Manufacturing Systems Engineering International Joint Laboratory for Micro/Nano Manufacturing and Measurement TechnologiesXi’an Jiaotong University(Yantai)Research Institute for Intelligent Sensing Technology and SystemsXi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Instrument Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing YantaiYantai 265503China

The chip-scale hybrid optical pumping spin-exchange relaxation-free(SERF)atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features,including ultrahigh sensitivity,an enhanced signal-to-noise ratio,homogeneous spin polarization and a much simpler optical configuration than other *** this work,a miniaturized single-beam hybrid optical pumping SERF atomic magnetometer based on a microfabricated atomic vapor cell is *** the optically thin Cs atoms are spinpolarized,the dense Rb atoms determine the experimental *** enhanced signal strength and narrowed resonance linewidth are experimentally proven,which shows the superiority of the proposed magnetometer *** using a differential detection scheme,we effectively suppress optical noise with an approximate five-fold ***,the cell temperature markedly affects the performance of the *** systematically investigate the effects of temperature on the magnetometer *** theoretical basis for these effects is explained in *** developed miniaturized magnetometer has an optimal magnetic sensitivity of 20 fT/Hz^(1/2).The presented work provides a foundation for the chip-scale integration of ultrahighly sensitive quantum magnetometers that can be used for forward-looking magnetocardiography(MCG)and magnetoencephalography(MEG)applications.

关键词： pumping polarization magnetometer

来源：评论

学校读者我要写书评

暂无评论

Temperature-modulated crystallographic orientation and electrical properties of BiFeO_(3) thick films sputtered on LaNiO_(3)/Pt/Ti/SiO_(2)/Si for piezo-MEMS applications

引用

Journal of Advanced Ceramics 2024年第12期13卷 1943-1954页

作者： Hongyu Luo Miaomiao Niu Hanfei Zhu Li Li Hongbo Cheng Chao Liu Jianting Li Yuyao Zhao Chenxi Zhang Xiaojie Cao Isaku Kanno Qingguo Chi Jun Ouyang School of Chemistry and Chemical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China Key Laboratory of Engineering Dielectrics and Its Application(Ministry of Education) Harbin University of Science and TechnologyHarbin 150080China School of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Laboratory of Metal Matrix Composites School of Material Sciences and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering Kobe UniversityKobe 657-8501Japan Key Laboratory of Key Film Materials&Application for Equipments(Hunan Province) Hunan Provincial Key Laboratory of Thin Film Materials and DevicesSchool of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China

In this work,thick BiFeO_(3)films(~1μm)were prepared on LaNiO_(3)-buffered(111)Pt/Ti/SiO_(2)/(100)Si substrates via radio-frequency magnetron sputtering without post-growth *** effects of the substrate temperature on the film’s crystallinity,defect chemistry,and associated electrical properties were *** contrast to the poorly crystallized BiFeO_(3)film deposited at 300℃and the randomly-oriented and(111)-textured films deposited at 500 and 650℃,respectively,a(001)-preferred orientation was achieved in the BiFeO_(3)film deposited at 350℃.This film not only showed a dense,fine-grained morphology but also displayed enhanced electrical properties due to the(001)texture and improved defect *** properties include a reduced leakage current(J≈2.4×10^(−5)A/cm^(2)@200 kV/cm),a small dielectric constant(ε_(r)≈243–217)with a low loss(tanδ≤0.086)measured from 100 Hz to 1 MHz,and a nearly intrinsic remnant polarization(Pr)of~60μC/cm^(2).A detailed TEM analysis confirmed the R3c symmetry of the BFO films and hence ensured good stability of their electrical *** particular,single-beam cantilevers fabricated from BiFeO_(3)/LaNiO_(3)/Pt/Ti/SiO_(2)/Si heterostructures showed excellent electromechanical performance,including a large transverse piezoelectric coefficient(e_(31,f))of~−2.8 C/m^(2),a high figure of merit(FOM)parameter of~4.0 GPa,and a large signal-to-noise ratio of~1.5 C/m^(2).An in-depth analysis revealed the intrinsic nature of the e_(31,f)piezoelectric coefficient,which is well fitted along a straight line of e_(31,f)ratio=(ε_(r)P_(r))ratio with the reported representative *** high-quality lead-free piezoelectric films processed with a reduced thermal budget can open many possibilities for the integration of piezoelectricity into Si-based microelectro–mechanical systems(MEMSs).

关键词： BiFeO_(3) film ferroelectric piezoelectric micro-electro-mechanical system(piezo-MEMS) low thermal budget crystallographic orientation magnetron sputtering

来源：评论

学校读者我要写书评

暂无评论

Laser ranging and reflectance discrimination based on stretched noise-like pulse

Laser ranging and reflectance discrimination based on stretc...

引用

2024 Asia Communications and Photonics Conference, ACP 2024 and International Conference on information Photonics and Optical Communications, IPOC 2024

作者： Yao, Yao Sun, Yixiang Liu, Haoguang Lu, Long An, Yu Luo, Yiyang Sun, Qizhen Shum, Ping Perry Key Laboratory of Optoelectronic Technology and Systems Ministry of Education Chongqing University Chongqing China School of Optics and Electronic Information Huazhong University of Science and Technology Wuhan China Department of Electronic and Electrical Engineering Southern University of Science and Technology Shenzhen China

ISBN: (纸本)9798350379266

We propose a chaotic ultrafast laser-based ranging scheme. Employing the noise-like pulse stretched by the time-stretch dispersive Fourier transform technique, the distance and surface reflectance information can be obtained through a cross-correlation operation. It is demonstrated that this approach has a range resolution of 6 mm and can identify the relative reflectance information of the target. © 2024 IEEE.

关键词： laser ranging noise-like pulse reflectance discrimination

来源：评论

学校读者我要写书评

暂无评论

Effect of contact materials on the transient characteristics of vacuum arc plasma and anode erosion

引用

Plasma science and technology 2024年第11期26卷 170-180页

作者： Ze YANG Dongsheng CAI Qi HUANG Lijun WANG College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059People’s Republic of China Postdoctoral Mobile Station in Nuclear Science and Technology Chengdu University of TechnologyChengdu 610059People’s Republic of China School of Information Engineering Southwest University of Science and TechnologyMianyang 621010People’s Republic of China State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China

In this study, the mechanisms of the anode phenomena and anode erosion with various contact materials were investigated. Arc parameters were calculated, and the anode temperature was predicted with a transient self-consistent model. The simulation results predicted a constricted arc column and obvious anode phenomena in Cu–Cr alloy contacts than in W–Cu alloy *** observation could be the reason for the concentrated anode erosion in Cu–Cr alloys. For the contacts made by pure tungsten(W) and W–Cu alloy, the anode temperature increased rapidly because of the low specific heat of W. However, the maximum energy flux from the arc column to the anode surface was lower than in other cases. The simulation results were compared with experimental results.

关键词： vacuum arc MHD model anode erosion contact materials

来源：评论

学校读者我要写书评

暂无评论

Light-Mediated Spatiotemporally Dynamic Assembly of DNA Nanostructures in Living Cells Regulates Autophagy

引用

CCS Chemistry 2024年第6期6卷 1557-1570页

作者： Rui Zhang Pin Hu Yuwei Xu Ziqing Wang Dayong Yang Chi Yao Frontiers Science Center for Synthetic Biology Key Laboratory of Systems Bioengineering(MOE)School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350 Department of Chemistry State Key Laboratory of Molecular Engineering of PolymersShanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsCollege of Chemistry and MaterialsFudan UniversityShanghai 200438

The assembly of exogenous artificial architectures inside cells can regulate a series of biological events,which heavily relies on the development of spatiotemporally controlled molecular assembly *** herein report a designer deoxyribonucleic acid(DNA)nanostructure that enables light-mediated spatiotemporally dynamic assembly in living cells and consequently achieves efficient regulation of cell *** DNA nanostructure was constructed from i-motif moiety-containing branched DNA,photocleavable bond-containing linker,and tumor cell-targeting *** cellular uptake mediated by aptamers,under the spatiotemporal control of both UV light and late endosomal/lysosomal acidic environments,disassembly/reassembly of DNA nanostructure occurred via two rationally designed routes,generating microsized DNA *** a result,autophagy was significantly enhanced with the increase of DNA assembly *** enhanced autophagy showed an impact on related biological *** system is expected to be a powerful tool for the regulation of intracellular events and cellular behaviors.

关键词： DNA nanotechnology DNA hydrogel self-assembly autophagy i-motif

来源：评论

学校读者我要写书评

暂无评论

Research on automatic switching of hydraulic feed dual process in honing processing 4

Research on automatic switching of hydraulic feed dual proce...

引用

2024 4th International Conference on Mechatronics, Automation and Intelligent Control, MAIC 2024

作者： Lu, Yong Pei, Hailong Li, Guang Deng, Haijun Key Laboratory of Autonomous Systems and Networked Control Ministry of Education Guangdong Engineering Technology Research Center of Unmanned Aerial Vehicle Systems School of Automation Science and Engineering South China University of Technology Guangzhou510640 China School of Information Guangdong Polytechnic of Science and Trade Guangzhou510440 China

Honing is a finishing process used for the inner cylindrical surfaces of engine blocks or liners. The process involves abrasive particles bonded to the surface of a honing head, which come into contact with the inner bore surface, performing an oscillating and rotational motion. These motions follow a specific pattern, allowing for the creation of crosshatch patterns on the inner bore surface, thereby improving dimensional accuracy, form accuracy and reducing surface roughness. Common honing processes are divided into four distinct phases: material removal, crosshatching, finish honing, and plateau honing. Each phase corresponds to specific tasks such as material removal from the bore, creating crosshatch patterns, honing the peaks in the crosshatch, and final surface finishing. In computer numerical control (CNC)-based honing machine, individual control commands are typically used to manage each of these phases separately. The commands are combined according to process requirements to achieve the desired honing results. To enhance the efficiency of the honing process, this study focuses on the hydraulic feed of the abrasive strips on the honing head, specifically examining the automatic continuous switching between finish honing and plateau honing. The research analyzes the honing principles, develops a control algorithm for dual-process automatic switching, and validates the process through machining tests. Compared to single-process control, the proposed algorithm significantly improves processing efficiency. Additionally, this algorithm can be applied to other dual-process automatic switching controls, providing valuable insights for the design of CNC honing systems. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Honing machines

来源：评论

学校读者我要写书评

暂无评论

Iron oxide/CNT-based artificial nacre for electromagnetic interference shielding

引用

Nano Research 2024年第7期17卷 6560-6566页

作者： Cheng-Xin Yu Yu-Feng Meng Bo Yang Jun Pang Xiang-Sen Meng Zi-Ye Zhao Qing-Yue Wang Li-Bo Mao Zhi-Kun Wu Shu-Hong Yu Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China Department of Chemistry New Cornerstone Science LaboratoryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China

Biological structural materials,despite consisting of limited kinds of compounds,display multifunctionalities due to their complex hierarchical *** some biomimetic strategies have been applied in artificial materials to enhance their mechanical stability,the simultaneous optimization of other functions along with the mechanical properties via biomimetic designs has not been thoroughly ***,iron oxide/carbon nanotube(CNT)-based artificial nacre with both improved mechanical and electromagnetic interference(EMI)shielding performance is fabricated via the mineralization of Fe_(3)O_(4)onto a CNTincorporated *** micro-and nano-structures of the artificial nacre are similar to those of natural nacre,which in turn improves its mechanical *** alternating electromagnetic wave-reflective CNT layers and the wave-absorptive iron oxide layers can improve the multiple reflections of the waves on the surfaces of the reflection layers,which then allows sufficient interactions between the waves and the absorption ***,compared with the reflection-dependent EMI-shielding of the non-structured material,the artificial nacre exhibits strong absorption-dependent shielding behavior even with a very low content of wave-absorptive *** to the high mechanical stability,the shielding effectiveness of the artificial nacre that deeply cut by a blade is still maintained at approximately 70%−96%depending on the incident wave *** present work provides a new way for designing structural materials with concurrently enhanced mechanical and functional properties,and a path to combine structural design and intrinsic properties of specific materials via a biomimetic strategy.

关键词： artificial nacre electromagnetic interference shielding biomineralization biomimetic material hierarchical structure

来源：评论

学校读者我要写书评

暂无评论

A universal charge-compensating strategy for high-energy-density pseudocapacitors

引用

Journal of Energy Chemistry 2023年第3期78卷 333-339,I0010页

作者： Baoyi Yin Jiaqi Zhang Yuanhui Su Yu Huan Liang Hao Chen Wang Xun Hu Tao Wei School of Material Science and Engineering University of Jinan336 Nanxinzhuang West RoadJinan 250022ShandongChina School of Microelectronics Dalian University of TechnologyDalian 116024LiaoningChina Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of ASIC and Systems School of MicroelectronicsFudan UniversityShanghai 200433China

For pseudocapacitive electrode materials(PseEMs),despite much progress having been made in achieving both high power density and high energy density,a general strategy to guide the enhancement of intrinsic capacitive properties of PseEMs remains ***,we demonstrate a universal chargecompensating strategy to improve the charge-storage capability of PseEMs intrinsically:ⅰ) in the electrolyte with anion as charge carriers(such as OH-),reducing the multivalent cations of PseEMs into lower valences could create more reversible low-to-high valence redox cou ples to promote the intercalation of the anions;ⅱ) in the electrolytes with cation as charge carriers(such as H^(+),Li^(+),Na^(+)),oxidizing the multivalent cations of PseEMs into higher valences could introduce more reversible high-to-low valence redox couples to promote the intercalation of the *** we demonstrated that the improved intrinsic charge-storage capability for PseEMs originates from the increased Faradaic charge storage sites.

关键词： Supercapacitors Universal charge-compensating strategy Changed valence state Increased Faradaic charge storage sites

来源：评论

学校读者我要写书评

暂无评论

Adversarial Stress Test for Autonomous Vehicle Via Series Reinforcement Learning Tasks With Reward Shaping

IEEE Transactions on Intelligent Vehicles

引用

IEEE Transactions on Intelligent Vehicles 2024年 1-16页

作者： Cai, Xuan Bai, Xuesong Cui, Zhiyong Hang, Peng Yu, Haiyang Ren, Yilong Research Institute for Frontier Science Beihang University Beijing China State Key Laboratory of Intelligent Transportation Systems School of Transportation Science and Technology Beihang University Beijing China Department of Traffic Engineering Tongji University Shanghai China

Testing is a pivotal phase for uncovering potential vulnerabilities in autonomous vehicles (AVs) to develop a secure autonomy system. However, existing methods often lack consideration for efficiently exploring multiple vulnerability-revealing cases, particularly under adversarial game scenarios. We introduce an evolving series reinforcement learning (RL) framework for adversarial policy training, integrating Responsibility Sensitive Safety (RSS) and Dynamic Time Warping (DTW) theories to shape the reward function to steer the evolving direction of the subsequent series agents for exploring vulnerability-revealing attack scenarios uncharted in the refined buffered repository. Our method undertakes adversarial stress tests for both black-box and white-box AV systems under test in driving tasks that engage in games with traffic vehicles and pedestrians. The results indicate that our approach expedites the exploration of additional scenarios blamed for the AV, outperforming the baselines in the vulnerability-revealing accident and scenario diversity. Furthermore, the causality of the collisions is qualitatively analyzed to provide insights for AV system vulnerability repair. Code is available at https://***/caixxuan/AST-SRL. IEEE

关键词： Accidents

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：