检索结果-内蒙古大学图书馆

SSRN 2024年

作者： Wu, Zhiguang Lu, Liang Bai, Shuang Shi, Jiaqi Zhang, Zhuotao Pan, Yunlu Wang, Wei Wu, Wenfeng Sun, Shoubin Li, Xu Hou, Gang Huang, Tianyun Jia, Yuxin Zuo, Kaiwen Granovsky, Alexander Wu, He Nikolai, Perov School of Medicine and Health Harbin Institute of Technology Harbin China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China The First Affiliated Hospital of Harbin Medical University Harbin China National Center for Respiratory Medicine State Key Laboratory of Respiratory Health and Multimorbidity National Clinical Research Center for Respiratory Diseases Institute of Respiratory Medicine Chinese Academy of Medical Sciences Department of Pulmonary and Critical Care Medicine Center of Respiratory Medicine China-Japan Friendship Hospital Beijing China College of Science Sichuan Agricultural University Chengdu China The Fourth Affiliated Hospital of Harbin Medical University Harbin China Department of Ophthalmology The Second Hospital Jilin University Changchun China Department of Advanced Manufacturing and Robotics College of Engineering State Key Laboratory for Turbulence and Complex Systems Peking University Beijing China Department of Mathematics Imperial College London United Kingdom Department of Computer Science University of Warwick Coventry United Kingdom Magnetism Department Faculty of Physics Lomonosov Moscow State University Moscow Russia Harbin Medical University China

Learning from natural bacteria flagellum, we demonstrate a magnetic polymer multilayer conical microrobot that bestow the controllable propulsion upon external rotating magnetic field with uniform intensity. The magnetic microrobots were constructed by template-assisted Layer-by-Layer technique technique and subsequent functionalization of magnetic particle onto the big opening of the microrobots. Geometric variables of the polymer microrobots, such as the diameter and wall thickness, can be controlled by selection of porous template and layers of assembly. The microrobots perform controllable propulsion through the manipulation of magnetic field. The comparative analysis of the movement behavior reveals that the deformation of microrobots may attributed to the propulsion upon rotating magnetic field, which is similar as that of natural bacteria. The influence of actuation frequencies and frequencies on the velocity of the microrobots is studied. Such use of polymer polymer multilayer tubular micro/nanoarchitectures results in significant savings in the processing costs and provides a simple and cost-effective fabrication route for the mass production of magnetic polymer microrobots. © 2024, The Authors. All rights reserved.

关键词： Bacteria

来源：评论

学校读者我要写书评

暂无评论

Influences of Weaving Parameters on Dynamic Characteristics and Stability Control of the Droplet Transfer in Arc-Weaving P-GMAW Process

Research Square

引用

Research Square 2021年

作者： Wu, Di Chen, Yuxi Chen, Huabin Chen, Shanben School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200240 China Shanghai Collaborative Innovation Center of Laser Advanced Manufacturing Technology Shanghai University of Engineering Science Shanghai200240 China Shanghai Fanuc Robotics Co. Ltd. Shanghai201206 China

The dynamic characteristics of droplet transfer is extremely complicated with the combined effects of gravity force and weaving motion during the weaving vertical-up welding on thick plate. In this paper, we firstly observed the droplet transfer behavior under various weaving parameters with high-speed photography and electrical signals during pulsed gas metal arc welding (P-GMAW). Then we investigated the influences of different weaving parameters on the arc shape and molten pool as well as droplet characteristics. By establishing a novel weaving-force model based on static-force balance theory (SFBT), we further revealed the drop transfer mechanism in weaving P-GMAW process. Extensive experimental results demonstrated that the suitable weaving parameters could effectively improve the droplet transfer stability and suppress welding defects including incomplete root penetration and lack of sidewall fusion. The findings of this paper will provide a basis for enhancing the welding process stability and obtaining a high-quality weld joint. © 2021, CC BY.

关键词： High speed photography

来源：评论

学校读者我要写书评

暂无评论

FFPA-Net: Efficient Feature Fusion with Projection Awareness for 3D Object Detection

arXiv

引用

arXiv 2022年

作者： Jiang, Chaokang Wang, Guangming Wu, Jinxing Miao, Yanzi Wang, Hesheng Engineering Research Center of Intelligent Control for Underground Space Ministry of Education School of Information and Control Engineering Advanced Robotics Research Center China University of Mining and Technology Xuzhou221116 China Department of Automation Key Laboratory of System Control and Information Processing of Ministry of Education Key Laboratory of Marine Intelligent Equipment and System of Ministry of Education Shanghai Engineering Research Center of Intelligent Control and Management Shanghai Jiao Tong University Shanghai200240 China The Department of Engineering Mechanics Shanghai Jiao Tong University Shanghai200240 China

Promising complementarity exists between the texture features of color images and the geometric information of LiDAR point clouds. However, there still present many challenges for efficient and robust feature fusion in the field of 3D object detection. In this paper, first, unstructured 3D point clouds are filled in the 2D plane and 3D point cloud features are extracted faster using projection-aware convolution layers. Further, the corresponding indexes between different sensor signals are established in advance in the data preprocessing, which enables faster cross-modal feature fusion. To address LiDAR points and image pixels misalignment problems, two new plug- and-play fusion modules, LiCamFuse and BiLiCamFuse, are proposed. In LiCamFuse, soft query weights with perceiving the Euclidean distance of bimodal features are proposed. In BiLiCamFuse, the fusion module with dual attention is proposed to deeply correlate the geometric and textural features of the scene. The quantitative results on the KITTI dataset demonstrate that the proposed method achieves better feature-level fusion. In addition, the proposed network shows a shorter running time compared to existing methods. Copyright © 2022, The Authors. All rights reserved.

关键词： Object detection

来源：评论

学校读者我要写书评

暂无评论

Surface state induced velocity transition for layered carbon nanotube films under transverse penetration loading

引用

Composite Structures 2025年 369卷

作者： Pengfei Wang Wenshuai Wang Jie Tian Zhenhua Song Songlin Xu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China Hefei 230027 China Engineering and Materials Science Experiment Center University of Science and Technology of China Hefei 230027 China Department of Aeronautics and Astronautics College of Intelligent Robotics and Advanced Manufacturing Fudan University Shanghai 200433 China

Carbon nanotube (CNT) films, consisting of entangled two-dimensional networks, exhibit prominent surface-dependent characteristics. Lubricants have been recognized as an effective strategy for reducing interfacial friction. However, experimental evidence indicates that lubricants unexpectedly increased the interfacial friction, demonstrating a counterintuitive velocity-dependent behavior. To elucidate the anomalous interfacial dynamics, experimental and computational methodologies were employed to systematically investigate the transverse penetrating behaviors of CNT films with different interface states and loading velocities. Experimental results indicate that the lubricant exhibits a decreasing trend at lower relative velocities, but transitions from decreasing to strengthening behavior as penetration velocity increases. The proposed equation reveals that the strengthening mechanism is not solely velocity-dependent but is jointly governed by the load magnitude and surface conditions. The high specific surface area of CNT films induces enhanced interface states and pronounced velocity-dependent characteristics, which collectively govern the fracture pattern observed in films subjected to distinct surface stress conditions. Deciphering the lubricant-induced velocity-transition mechanisms in CNT films yields new theoretical insights into interface-governed penetration behavior, while establishing material design principles for engineering impact-resistant membranes with tunable energy dissipation pathways.

关键词： Carbon films

来源：评论

学校读者我要写书评

暂无评论

Design and Mathematical Model for Bending Pneumatic Soft Actuators with Asymmetric Cavity

Design and Mathematical Model for Bending Pneumatic Soft Act...

引用

IEEE/RAS-EMBS International Conference on Biomedical robotics and Biomechatronics (BioRob)

作者： Pihsaia S. Sun Yuwen Lu Jingeng Mai Qining Wang Department of Advanced Manufacturing and Robotics Peking University Beijing China Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT) Peking University China Beijing Engineering Research Center of Intelligent Rehabilitation Engineering Beijing China

ISBN: (数字)9781728159072

ISBN: (纸本)9781728159089

Pneumatic bending soft actuators have been used in various innovative applications. However, there is a need for efficient design principles and methods that can improve the control accuracy of soft robots. In this paper, we present a mathematical model of soft bending actuators based on optimization and design a cylindrical soft actuator with asymmetric inner cavity that will perform bending motion upon pressurization. We introduce neutral plane as a reference layer with constant length instead of using a strain-limiting layer on the soft actuator. Preliminary experimental results verify the modelling approach and demonstrate the effectiveness of the proposed method.

关键词： Actuators Bending Solids Strain Solid modeling Mathematical model Finite element analysis

来源：评论

学校读者我要写书评

暂无评论

Formation Control with Orientation Alignment and Constrained Input

引用

IFAC-PapersOnLine 2020年第2期53卷 3397-3402页

作者： Yu-Wen Chen Ming-Li Chiang Li-Chen Fu Department of Electrical Engineering National Taiwan University Taipei Taiwan Graduate Institute of Automation Technology National Taipei University of Technology Taipei Taiwan Department of Electrical Engineering and the Center for Artificial Intelligence and Advanced Robotics National Taiwan University Taipei Taiwan

We design a formation controller for Multi Agent Systems such that the agents can form into the desired shape and track a given reference trajectory. The main feature of the proposed design is that not only the orientation of individual agents, but also the orientation of the whole formation is considered and is designed to be aligned with the moving direction of the reference trajectory, which helps the tracking movement to be smoother compared with the common tracking results. Moreover, the control inputs are designed in predefined input ranges to reflect the practical system. System stability is proved based on nonlinear system theory and some simulations are given to validate the proposed results.

关键词： Multi-agent systems Nonlinear adaptive control Coordination of multiple vehicle systems

来源：评论

学校读者我要写书评

暂无评论

Giant radiative thermal rectification using an intrinsic semiconductor film

arXiv

引用

arXiv 2021年

作者： Li, Qizhang Chen, Qun Song, Bai Beijing Innovation Center for Engineering Science and Advanced Technology Peking University Beijing100871 China Key Laboratory for Thermal Science and Power Engineering Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing100084 China Department of Energy and Resources Engineering Peking University Beijing100871 China Department of Advanced Manufacturing and Robotics Peking University Beijing100871 China

Rectification of heat flow via a thermal diode is not only of fundamental interest, but can also enable a range of novel applications in thermal management and energy conversion. However, despite decades of extensive research, large rectification ratios of practical importance have yet to be demonstrated. Here, we theoretically achieve giant rectification ratios (3 to almost 5 orders of magnitude) by leveraging near-field radiative thermal transport between two parallel planes. Guided by a rational design approach centering on the electromagnetic local density of states (LDOS), we employ a thin film of an intrinsic semiconductor-such as silicon-as one terminal of our radiative thermal diodes, which provides the necessary nonlinearity and a substantial LDOS contrast as the temperature bias is flipped. For the other terminal, we explore two kinds of materials which either serve as a narrowband or a broadband filter, both capable of converting the large LDOS contrast into giant thermal rectification. We further consider representative multilayer configurations in order to block backside radiation and improve mechanical stability. All the diodes perform well over a wide range of film thicknesses, gap sizes, and temperatures. Our work offers an opportunity for realizing thermal diodes with unprecedented rectification ratios. Copyright © 2021, The Authors. All rights reserved.

关键词： Thin films

来源：评论

学校读者我要写书评

暂无评论

Radiative thermal diode via hyperbolic metamaterials

arXiv

引用

arXiv 2021年

作者： Li, Qizhang He, Haiyu Chen, Qun Song, Bai Beijing Innovation Center for Engineering Science and Advanced Technology Peking University Beijing100871 China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing100084 China Department of Energy and Resources Engineering Peking University Beijing100871 China Department of Advanced Manufacturing and Robotics Peking University Beijing100871 China

Hyperbolic metamaterials (HMMs) support propagating waves with arbitrarily large wavevectors over broad spectral ranges, and are uniquely valuable for engineering radiative thermal transport in the near field. Here, by employing a rational design approach based on the electromagnetic local density of states, we demonstrate the ability of HMMs to substantially rectify radiative heat flow. Our idea is to establish a forward-biased scenario where the two HMM-based terminals of a thermal diode feature overlapped hyperbolic bands which result in a large heat current, and suppress the reverse heat flow by creating spectrally mismatched density of states as the temperature bias is flipped. As an example, we present a few high-performance thermal diodes by pairing HMMs made of polar dielectrics and metal-to-insulator transition (MIT) materials in the form of periodic nanowire arrays, and considering three representative kinds of substrates. Upon optimization, we theoretically achieve a rectification ratio of 324 at a 100 nm gap, which remains greater than 148 for larger gap sizes up to 1 µm over a wide temperature range. The maximum rectification represents an almost 1000-fold increase compared to a bulk diode using the same materials, and is twice that of state-of-the-art designs. Our work highlights the potential of HMMs for rectifying radiative heat flow, and may find applications in advanced thermal management and energy conversion systems. Copyright © 2021, The Authors. All rights reserved.

关键词： Metamaterials

来源：评论

学校读者我要写书评

暂无评论

Thin-film radiative thermal diode with large rectification

arXiv

引用

arXiv 2021年

作者： Li, Qizhang He, Haiyu Chen, Qun Song, Bai Beijing Innovation Center for Engineering Science and Advanced Technology Peking University Beijing100871 China Key Laboratory for Thermal Science and Power Engineering Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing100084 China Department of Energy and Resources Engineering Peking University Beijing100871 China Department of Advanced Manufacturing and Robotics Peking University Beijing100871 China

We propose a mechanism to substantially rectify radiative heat flow by matching thin films of metal-to-insulator transition materials and polar dielectrics in the electromagnetic near field. By leveraging the distinct scaling behaviors of the local density of states with film thickness for metals and insulators, we theoretically achieve rectification ratios over 140—a 10-fold improvement over the state of the art—with nanofilms of vanadium dioxide and cubic boron nitride in the parallel-plane geometry at experimentally feasible gap sizes (~100 nm). Our rational design offers relative ease of fabrication, flexible choice of materials, and robustness against deviations from optimal film thicknesses. We expect this work to facilitate the application of thermal diodes in solid-state thermal circuits and energy conversion devices. Copyright © 2021, The Authors. All rights reserved.

关键词： Film thickness

来源：评论

学校读者我要写书评

暂无评论

Characterization of exploratory patterns and hippocampal–prefrontal network oscillations during the emergence of free exploration

引用

Science Bulletin 2021年第21期66卷 2238-2250,M0004页

作者： Wenxiu Dong Hongbiao Chen Timothy Sit Yechao Han Fei Song Alexei L.Vyssotski Cornelius T.Gross Bailu Si Yang Zhan Guangdong Provincial Key Laboratory of Brain Connectome and Behavior CAS Key Laboratory of Brain Connectome and Manipulationthe Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Key Laboratory of Translational Research for Brain DiseasesShenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research InstitutionsShenzhen 518055China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169 University of Chinese Academy of Sciences Beijing 100049China Institute of Neuroinformatics the University of Zürich and Swiss Federal Institute of Technology(ETH)Zurich CH-8057Switzerland European Molecular Biology Laboratory(EMBL) Monterotondo 00015Italy School of Systems Science Beijing Normal UniversityBeijing 100875China

During free exploration,the emergence of patterned and sequential behavioral responses to an unknown environment reflects exploration traits and ***,the behavioral dynamics and neural substrates underlying the exploratory behavior remain poorly *** developed computational tools to quantify the exploratory behavior and performed in vivo electrophysiological recordings in a large arena in which mice made sequential excursions into unknown *** entropy was calculated to characterize the cumulative and moment-to-moment behavioral dynamics in explored and unexplored *** field potential analysis revealed that the theta activity in the dorsal hippocampus(d HPC)was highly correlated with the occupancy *** d HPC and prefrontal cortex(PFC)oscillatory activities could classify various aspects of free *** of exploration was accompanied by a coordinated decrease and increase in theta activity in PFC and d HPC,*** results indicate that d HPC and PFC work synergistically in shaping free exploration by modulating exploratory traits during emergence and visits to an unknown environment.

关键词： Exploration Prefrontal cortex Hippocampus Neural oscillations Entropy

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：