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Bioinspired hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers

National science Review 2020年第1期7卷 73-83页

作者： Huai-Ling Gao Ran Zhao Chen Cui Yin-Bo Zhu Si-Ming Chen Zhao Pan Yu-Feng Meng Shao-Meng Wen Chuang Liu Heng-An Wu Shu-Hong Yu Division of Nanomaterials & Chemistry Hefei National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in Nanoscience Hefei Science Center of CAS Department of Chemistry University of Science and Technology of China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China

Bio-sourced nanocellulosic materials are promising candidates for spinning high-performance sustainable macrofibers for advanced applications. Various strategies have been pursued to gain nanocellulose-based macrofibers with improved strength. However, nearly all of them have been achieved at the expense of their elongation and toughness. Inspired by the widely existed hierarchical helical and nanocomposite structural features in biosynthesized fibers exhibiting exceptional combinations of strength and toughness, we report a design strategy to make nanocellulose-based macrofibers with similar characteristics. By combining a facile wet-spinning process with a subsequent multiple wet-twisting procedure, we successfully obtain biomimetic hierarchical helical nanocomposite macrofibers based on bacterial cellulose nanofibers, realizing impressive improvement in their tensile strength, elongation and toughness simultaneously. The achievement certifies the validity of the bioinspired hierarchical helical and nanocomposite structural design proposed here. This bioinspired design strategy provides a potential platform for further optimizing or creating many more strong and tough nanocomposite fiber materials for diverse applications.

关键词： bioinspired nanocomposite hierarchical helical macrofibers strength and toughness bacterial cellulose

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Building Energy Efficiency Assessment Base on Predict-Center Criterion Under Diversified Conditions

SSRN

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SSRN 2023年

作者： Liao, Xuechao Zheng, Xiujuan Ping, Zouwei Zhao, Haoyi Wang, Ning Zhang, Yong School of Computer Science and Technology Wuhan University of Science and Technology Wuhan430080 China Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System Wuhan430080 China School of Information Science and Engineering Wuhan University of Science and Technology Wuhan430080 China National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Wuhan430030 China WISDRI City Construction Engineering &Research Incorporation Ltd. Wuhan430030 China Changjiang Institute of Survey Planning Design and Research Wuhan430010 China

With the rapid expanding of urban economy and population, how to reduce the energy consumption and improve energy efficiency of public buildings has become a key issue for energy conservation and urban development. However, due to the diversity of building employing condition, energy consumption data often has problems with nonlinearity, outliers, and diversity, which will greatly reduce the accuracy of energy consumption prediction and energy conservation assessment. To overcome the above drawbacks, a regression prediction model of building energy consumption is designed, which cluster the same type of data characteristics to form a subset of equipment through Gaussian mixture clustering, and design the specific normalized adaptive loss function to determine the optimal control parameters of regression model. Furthermore, a novel predict-center energy efficiency evaluation criterion is proposed, and the cumulative distribution pattern is further statistically analyzed. Finally, the energy benchmark evaluation framework is proposed to determine the energy efficiency evaluation grade. Through comparative experimental analysis, it can be seen that the proposed prediction model can adapt to different types of building data, and have better prediction accuracy and convergence speed. The consistency and robustness of the benchmark evaluation framework and method are optimal. © 2023, The Authors. All rights reserved.

关键词： Energy utilization

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Orthogonal Geometry of Magneto-Optical Kerr Effect Enabled by Magnetization Multipole of Berry Curvature

arXiv

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arXiv 2024年

作者： Pan, Haolin Li, Han Huang, Jixiang Liu, Zheng Fang, Mingyue Yuan, Yanan Liu, Daxiang Hu, Xintong Peng, Wenzhi Liang, Zhenguo Chang, Xiao Sheng, Zhigao Chen, Xianzhe Wang, Lingfei Li, Qian Li, Peng Niu, Qian Gao, Yang Yang, Qinghui Hou, Dazhi International Center for Quantum Design of Functional Materials Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of China Hefei230026 China School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu611731 China School of Microelectronics University of Science and Technology of China Hefei230026 China Department of Physics University of Science and Technology of China Hefei230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei230026 China High Magnetic Field Laboratory Chinese Academy of Sciences Hefei230031 China Frontier Institute of Chip and System Fudan University Shanghai200000 China

The Magneto-Optical Kerr Effect (MOKE) is a fundamental tool in magnetometry, pivotal for advancing research in optics, magnetism, and spintronics as a direct probe of magnetization. Traditional MOKE measurements primarily detect the magnetization components parallel to the Poynting vector, which can only access the magnitude but not the direction of the orthogonal component. In this study, we introduce an orthogonal MOKE geometry in which the Kerr signal detects both the magnitude and direction of the magnetization component perpendicular to the Poynting vector. We demonstrate the broad applicability of this orthogonal geometry through the MOKE measurements in cubic ferromagnets and van der Waals ferromagnet. We theoretically show that the orthogonal MOKE geometry is enabled by the multipolar structure of Berry curvature in the magnetization space, which generally induces a Voigt vector orthogonal to the magnetization, thereby accounting for the unique magnetization angle dependence distinct from conventional MOKE. The establishment of the orthogonal MOKE geometry not only introduces a new paradigm for magneto-optical measurements but also provides a framework for exploring the magnetization multipoles of Berry curvature across the electromagnetic spectrum. Copyright © 2024, The Authors. All rights reserved.

关键词： Van der Waals forces

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Air-Ground Collaborative Control for Angle-Specified Heterogeneous Formations

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-13页

作者： Chen, Liangming Xiao, Jiaping Teo, Clarence Wei Rui Li, Jianqing Feroskhan, Mir School of System Design and Intelligent Manufacturing and Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology Shenzhen China school of Mechanical and Aerospace Engineering Nanyang Technological University Singapore Singapore College of Communication Engineering Hangzhou Dianzi University Hangzhou China

The need for better search and rescue capabilities has led to the increased demand for collaborative aerial-ground multi-robot deployments. However, most existing solutions require high communication bandwidth or bulky sensor equipment that is not suitable especially for aerial robots. To make the execution of these tasks more efficient, this paper proposes an angle-specified heterogeneous leader-follower formation framework consisting of unmanned aerial vehicles (UAVs) flying in a 3D space and ground robots moving in a 2D plane. The UAVs are controlled to maintain a desired angle-specified formation with the first three UAVs as the leaders forming a triangular shape and the remaining UAVs as the followers. The follower UAVs only need direction measurements to track the leader UAVs. For the ground robots, two leader robots track the UAV group and determine the orientation and scale of the ground formation, while the follower robots track the leader robots using only direction measurements. The proposed heterogeneous formation framework is energy-efficient as most robots only require low-cost and lightweight direction measurements. The stability of the proposed formation control algorithms is proved and validated through various physical application experiments. IEEE

关键词： Multi agent systems

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Adaptive terminal sliding mode control for flexible air-breathing hypersonic vehicle

Adaptive terminal sliding mode control for flexible air-brea...

引用

AIAA science and technology Forum and Exposition, AIAA SciTech Forum 2021

作者： Qin, Decong Chen, Haibing Lin, Wei Tang, Peng Ma, Tielin Xu, Cheng School of Transportation Science and Engineering Beihang University Beijing China Aircraft/Engine Integrated System Safety Beijing Key Laboratory Beijing China Beijing System Design Institute of the Electro-mechanic Engineering Beijing China Institute of Unmanned System Beihang University Beijing China Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China

ISBN: (纸本)9781624106095

Flexible air-breathing hypersonic vehicles show significant and complex aerodynamic, scramjet propulsion system, flight dynamic and elastic coupling characteristics, which usually are highly nonlinear. These result in huge uncertainties, parameter perturbation and internal disturbance, which can no longer be ignored, and therefore, extreme difficulties for flight control design. A unique parameter adaptive non-singular terminal sliding mode method is proposed for longitudinal control law design of a flexible coupling air-breathing hypersonic vehicle. This method uses adaptive reaching law gain instead of additional adaptive compensation term to handle the uncertainty to improve robustness. The stability of the close loop system is proved via a Lyapunov way. The longitudinal tracking control law for velocity and angle of attack is designed based on a rigid dynamic model of a flexible air-breathing hypersonic vehicle. A strong coupling model of the same vehicle, considering aerodynamic-scramjet engine-flight dynamic-elastic couplings, is established as the verification platform of control law designed. Simulation results obtained based on the coupling model demonstrate that the control law designed has good performance and acceptable robustness. © 2021, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Hypersonic vehicles

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Learning Pre-Grasp Manipulation of Flat Objects in Cluttered Environments using Sliding Primitives

Learning Pre-Grasp Manipulation of Flat Objects in Cluttered...

引用

IEEE International Conference on Robotics and Automation (ICRA)

作者： Jiaxi Wu Haoran Wu Shanlin Zhong Quqin Sun Yinlin Li State Key Laboratory of Turbulence and Complex Systems Intelligent Biomimetic Design Lab College of Engineering Peking University Beijing China Department of Automation University of Science and Technology of China Heifei China State Key Laboratory of Management and Control for Complex System Institute of Automation Chinese Academy of Science Beijing China Science and Technology on Thermal Energy and Power Laboratory Wuhan China

Flat objects with negligible thicknesses like books and disks are challenging to be grasped by the robot because of the width limit of the robot's gripper, especially when they are in cluttered environments. Pre-grasp manipulation is conducive to rearranging objects on the table and moving the flat objects to the table edge, making them graspable. In this paper, we formulate this task as Parameterized Action Markov Decision Process, and a novel method based on deep reinforcement learning is proposed to address this problem by introducing sliding primitives as actions. A weight-sharing policy network is utilized to predict the sliding primitive's parameters for each object, and a Q-network is adopted to select the acted object among all the candidates on the table. Meanwhile, via integrating a curriculum learning scheme, our method can be scaled to cluttered environments with more objects. In both simulation and real-world experiments, our method surpasses the existing methods and achieves pre-grasp manipulation with higher task success rates and fewer action steps. Without fine-tuning, it can be generalized to novel shapes and household objects with more than 85% success rates in the real world. Videos and supplementary materials are available at https://***/view/pre-grasp-sliding.

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Mechanical properties and microstructure evolution of T2 copper in multimodal ultrasonic vibration assisted micro-compression

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材料科学技术（英文版） 2025年第5期208卷 152-163页

作者： Weiqiang Wan Zidong Yin Guangchao Han Ming Yang Jitao Hu Fuchu Liu Linhong Xu Wei Bai Hui Chen School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Graduate School of System Design Tokyo Metropolitan UniversityTokyo 191-0065Japan Graduate School of System Design Tokyo Metropolitan UniversityTokyo 191-0065Japan School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China Shenzhen Research Institute China University of GeosciencesShenzhen 518057China Shenzhen Huazhong University of Science and Technology Research Institute Shenzhen 518000China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

Multimodal ultrasonic vibration(UV)assisted micro-forming has been widely investigated for its advan-tages of further reducing forming loads and improving forming ***,the influence mecha-nism of different UV modes on microstructure evolution and mechanical properties was still ***-timodal UV assisted micro-compression tests on T2 copper with different grains and sample sizes were conducted in this *** microstructure evolution for different UV modes was observed by *** results showed that the true stress reduction caused by UV was increased sequentially with tool ultrasonic vibration(TV),mold ultrasonic vibration(MV)and compound ultrasonic vibration(CV).The region of grain deformation was shifted along the direction of UV,and the MV promoted the uniform distribution of deformation *** grain refinement,fiber streamline density,grain deformation and rotation degree were further enhanced under CV,due to the synergistic effect of TV and ***,a coupled theoretical model considering both acoustic softening effect and size effect was proposed for describing the mechanical *** a physical model of dislocation motion in different UV modes was developed for describing the microstructure *** maximum error between the theoretical and experimental results was only 2.39％.This study provides a theoretical basis for the optimization of UV assisted micro-forming process.

关键词： Multimodal ultrasonic vibration Microstructure evolution Acoustic softening Size effect Coupling mechanism

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A compact fluorescence/circular dichroism dual-modality probe for detection, differentiation, and detoxification of multiple heavy metal ions via bond-cleavage cascade reactions

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Chinese Chemical Letters 2021年第12期32卷 3876-3881页

作者： Junwei Chen Na Wang Hongjuan Tong Chao Song Huijuan Ma Yajun Zhang Feng Gao Huan Xu Wei Wang Kaiyan Lou State Key Laboratory of Bioengineering Reactor.Shanghai Key Laboratory of New Drug Design and Shanghai Key Laboratory of Chemical BiologySchool of PharmacyEast China University of Science & TechnologyShanghai 200237China School of Pharmacy Collaborative Innovation Center of Green Manufacturing Technology for Traditional Chinese Medicine in Shaanxi ProvinceShaanxi Institute of International Trade&CommerceXi'an 712046China Department of Pharmacology and Toxicology and BIO5 Institute University of ArizonaTucson AZ 85721-0207United States

Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions(Ag^(+), Hg^(2+), Cu^(2+)). The probe shows divergent fluorescence(FL)/circular dichroism(CD) responses via divergent bond-cleavage cascade reactions(metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+(no hydrolysis), FL “turn-on” and CD “turn-off” for Hg^(+)(imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu^(2+)(lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D-penicillamine heavy metal ion complexes for potential detoxification treatments.

关键词： Fluorescent probe Circular dichroism Heavy metal ions Dual-modality Detoxification Cascade reaction Divergent responses

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Effect of the Graphene Oxide Incorporation on the Morphology, Corrosion Resistance And Fatigue Performance Of Micro-Arc Oxidation Coating on Mg Alloy

SSRN

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SSRN 2024年

作者： Tan, Yansong Liu, Xin Sun, Xiaohao Gao, Lilan Liu, Debao Zhang, Chunqiu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Cont rol School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineerin g Education Tianjin University of Technology Tianjin300384 China School of Materials Science and Engineering Tianjin University of Technology Tianjin300384 China

Mg alloy has great potential in biomedical applications, but the rapid corrosion rate which mismatches with bone reconstruction rate limits its clinical use. A protective oxide coating layer can be generated on the surface of Mg alloy by micro-arc oxidation (MAO) technique, aiming to improve the corrosion performance and long-term structural integrity of Mg alloy. In this study, the MAO coating layer of Mg alloy was improved by adding appropriate content of graphene oxide (GO) into electrolyte solution. GO has excellent adsorption property and plays a role in the MAO process, reducing the intermolecular gap, thereby improving the densification and obturation of the coating surface. With the increase of GO content, the surface morphology of the MAO coating initially has improved, then later deteriorated, and the best surface morphology has achieved at a GO content of 0.4 g/L. When the GO content increases from 0 g/L to 0.4 g/L, the corrosion current density reduces to 5.226 μA/cm2, with a reduction two orders in magnitude;in addition, at a stress amplitude of 140 MPa and a frequency of 4 Hz, the fatigue life increases from 9261 cycles to 13887 cycles without corrosion, and from 2042 cycles to 2759 cycles after pre-corrosion. This study provided a promising approach to ameliorate the morphology, corrosion resistance and fatigue performance of MAO coating on Mg alloy by elaborately configuring the electrolyte solution and customizing the process parameters. © 2024, The Authors. All rights reserved.

关键词： Corrosion resistance

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Effect of the Graphene Oxide Incorporation on the Morphology, Corrosion Resistance and Fatigue Performance of Micro-Arc Oxidation Coating on Magnesium Alloy

SSRN

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SSRN 2024年

Magnesium (Mg) alloy has great potential in biomedical applications, but the rapid corrosion rate which mismatches with bone reconstruction rate limits its clinical use. In this study, the graphene oxides (GO) were added into alkaline electrolyte solution during micro-arc oxidation (MAO) process, aiming to form a corrosion resistant surface coating on Mg alloy. By changing the concentration of GO, the coatings' morphology, composition, corrosion resistance, and fatigue property were compared to reveal the strengthening mechanism and find out the optimal graphene concentration. The results show that the MAO coating is composed of MgO, Mg2SiO4, Mg3(PO4)2 and GO. The added GO exhibits excellent adsorption property in the MAO process, reducing the intermolecular gap, thereby improving densification and obturation of the MAO coating. The surface morphology of MAO coating initially improves with increasing GO content, but then deteriorates, reaching its best quality at 0.4 g/L. Compared to MAO samples without GO, the samples with 0.4g/L GO not only have lower corrosion current density of 5.226 μA/cm2, but also show higher fatigue lives both before and after pre-corrosion. This study offers a promising approach to enhance the corrosion resistance and fatigue performance of Mg alloy by applying a GO-strengthened MAO coating onto its surface. © 2024, The Authors. All rights reserved.

关键词： Magnesium alloys

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