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Impact pressure of waves generated by landslides on bank slopes

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Journal of mountain science 2024年第3期21卷 918-931页

作者： CAO Ting WANG Pingyi QIU Zhenfeng LIU Jie Key Laboratory of Hydraulic and Waterway Engineering of ministry of Education Chongqing Jiaotong UniversityChongqing 400074China Engineering Research Center of Diagnosis Technology and Instruments of Hydro-Construction Chongqing Jiaotong UniversityChongqing 400074China

Impulse waves that are generated by landslides in narrow reservoir areas threaten the stability of buildings and bank *** discuss the action process and evolution law of the wave pressure on bank slopes,a three-dimensional physical model test that considers impulse waves generated by landslides was performed,and factors including landslide width,thickness,slope angles of the sliding surface,and bank slope angle were *** on wave forms on the bank slopes,wave pressure curve characteristics,and peak value,the action process of wave pressure could be divided into the following stages:maximum pulsating pressure stage,wave impact stage(when waves break),and stationary pulsation *** was found that wave breaking is dependent on the value of the surf similarity parameterξ.The distribution pattern of impact pressure decays linearly on both sides of the maximum impact pressure point,and the attenuation degree decreases when it attains 40%of the maximum ***,it is proposed that the prediction formula for the maximum effective impact pressure of the bank slope be related to the reciprocal of wave steepness,relative water depth,and slope *** prediction formula provides strong theoretical support for early safety warning and for predicting the bank slope under impulse waves generated by landslides.

关键词： model test Impact pressure Action stage Breaking discrimination Distribution model

A Hybrid and Inexact Algorithm for Nonconvex and Nonsmooth Optimization

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Journal of Systems science & Complexity 2024年

作者： WANG Yiyang SONG Xiaoliang College of Artificial Intelligence Dalian Maritime University School of mathematical sciences Dalian University of Technology

The problem of nonconvex and nonsmooth optimization (NNO) has been extensively studied in the machine learning community,leading to the development of numerous fast and convergent numerical *** algorithms typically employ unified iteration schemes and require explicit solutions to subproblems for ensuring ***,these inflexible iteration schemes overlook task-specific details and may encounter difficulties in providing explicit solutions to *** contrast,there is evidence suggesting that practical applications can benefit from approximately solving subproblems;however,many existing works fail to establish the theoretical validity of such *** this paper,the authors propose a hybrid inexact proximal alternating method (hiPAm),which addresses a general NNO problem with coupled terms while overcoming all aforementioned *** proposed hiPAm algorithm offers a flexible yet highly efficient approach by seamlessly integrating any efficient methods for approximate subproblem solving that cater to ***,the authors have devised a simple yet implementable stopping criterion that generates a Cauchy sequence and ultimately converges to a critical point of the original NNO *** proposed numerical experiments using both simulated and real data have demonstrated that hiPAm represents an exceedingly efficient and robust approach to NNO problems.

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Biomimetic natural biomaterials for tissue engineering and regenerative medicine:new biosynthesis methods,recent advances,and emerging applications

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military medical Research 2024年第1期11卷 50-79页

作者： Shuai Liu Jiang-ming Yu Yan-Chang Gan Xiao-Zhong Qiu Zhe-Chen Gao Huan Wang Shi-Xuan Chen Yuan Xiong Guo-Hui Liu Si-En Lin Alec mcCarthy Johnson V.John Dai-Xu Wei Hong-Hao Hou Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering the Fifth Affiliated HospitalSchool of Basic Medical ScienceSouthern Medical UniversityGuangzhou 510900China Department of Orthopedics Tongren HospitalShanghai Jiao Tong UniversityShanghai 200336China The Eighth Affiliated Hospital Sun Yat-Sen UniversityShenzhen 518033GuangdongChina Engineering Research Center of Clinical Functional materials and Diagnosis&Treatment Devices of Zhejiang Province Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325011ZhejiangChina Department of Orthopedics Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China Department of Orthopaedics and Traumatology Faculty of Medicinethe Chinese University of Hong KongHong Kong SAR 999077China Department of Functional materials Terasaki Institute for Biomedical InnovationLos AngelesCA 90064USA mary&Dick Holland Regenerative medicine Program College of MedicineUniversity of Nebraska Medical CenterOmahaNE 68130USA Zigong Affiliated Hospital of Southwest medical University Zigong Psychiatric Research CenterZigong Institute of Brain ScienceZigong 643002SichuanChina Key Laboratory of Resource Biology and Biotechnology in Western china Ministry of EducationSchool of MedicineDepartment of Life Sciences and MedicineNorthwest UniversityXi’an 710127China

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative *** contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECm).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative *** paper provides an overview for recent progress of biomimetic natural biomaterials(BNBms),including advances in their preparation,functionality,potential applications and future *** highlight recent advances in the fabrication of BNBms and outline general strategies for functionalizing and tailoring the BNBms with various biological and physicochemical characteristics of native ***,we offer an overview of recent key advances in the functionalization and applications of versatile BNBms for TE ***,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.

关键词： Biomimic Scaffold Biosynthesis Natural biomaterial Tissue engineering

Theoretical Performance Analysis of an Ejector Enhanced High-Temperature Heat Pump with Dual-Pressure Condensation and Evaporation

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Journal of Thermal science 2022年第5期31卷 1367-1379页

作者： BAI Tao LIU Ye YAN Gang YU Jianlin Department of Refrigeration and Cryogenic Engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an710049China

In this paper,an ejector enhanced high-temperature heat pump with dual-pressure condensation and evaporation is proposed to improve the system *** analyses of the system operation characteristics are conducted using energetic and exergetic *** performance comparisons among the basic cycle,parallel compression cycle,and ejector enhanced cycle are conducted with six different refrigerants,including R245fa,R600a,R1234ze(Z),R1336mzz(Z),R1224yd(Z),and R1233zd(E).The results demonstrate that environmentally-friendly refrigerant R1234ze(Z)would be a promising alternative *** with the basic cycle and parallel compression cycle at selected operation conditions,29.5%and 12.6%improvements in COP,and 16.7%and 11.1%higher system exergy efficiency are achieved in the ejector enhanced cycle on *** volumetric heating capacity of the ejector enhanced cycle is increased by 15.7%–21.7%.The ejector enhanced cycle outperforms the other two cycles in high-temperature heat pump applications at the large temperature lift and temperature rise in the heat *** assessment offers an option to improve the energy utilization efficiency of the high-temperature heat pumps.

关键词： thermodynamics exergy high-temperature heat pump ejector dual-temperature condensation/evaporation

Algebraic Verification of Finite Group-Based Potential Games with Vector Payoffs

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Journal of Systems science & Complexity 2022年第6期35卷 2131-2144页

作者： WANG Yuanhua LI Haitao Business School Shandong Normal UniversityJi'nan 250014China School of mathematics and Statistics Shandong Normal UniversityJi'nan 250014China

This paper studies a class of strategic games,where players often collaborate with other players to form a group when making decisions,and the payoff functions of players in such games are presented as vector ***,using the semi-tensor product(STP)method,it is proved that a finite game with vector payoffs is potential if and only if its potential equation has *** adding a suitable weight vector to the vector payoffs of each player,a finite game with vector payoffs that is not potential can be converted into a potential ***,as a natural generalization,the authors consider the verification problem of the group-based potential games with vector *** solving a linear potential equation,a simple formula is obtained to calculate the corresponding potential ***,some examples are presented and discussed in detail to illustrate the theoretical results.

关键词： Group-based potential games potential equation semi-tensor product of matrices vector payoffs

Fast least-squares prestack time migration via accelerating the explicit calculation of Hessian matrix with dip-angle Fresnel zone

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Petroleum science 2022年第3期19卷 1031-1047页

作者： Bo-Wu Jiang Jiang-Jie Zhang Hao Zhang Wen-Kai Lu College of mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing100029China The Institute for Artificial Intelligence(THUAI) Beijing100084China State Key Laboratory of Intelligent Technology and Systems Beijing100084China Beijing National Research Center for Information science and Technology(BNRist) Beijing100084China The Department of Automation Tsinghua UniversityBeijing100084China Key Laboratory of Petroleum Resource Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China

Amplitude versus offset analysis is a fundamental tool for determining the physical properties of reservoirs but generally hampered by the blurred common image gathers(CIGs).The blurring can be optimally corrected using the blockwise least-squares prestack time migration(BLS-PSTm),where common-offset migrated sections are divided into a series of blocks related to the explicit offsetdependent Hessian matrix and the following inverse filtering is iteratively applied to invert the corresponding ***,calculating the Hessian matrix is *** present a fast BLS-PSTm via accelerating Hessian calculation with dip-angle Fresnel zone(DFZ).DFZ is closely related to optimal migration aperture,which significantly attenuates migration swings and reduces the computational cost of ***,our fast BLS-PSTm is implemented as a two-stage ***,we limit the aperture for any imaging point with an approximated the projected Fresnel zone before calculating the Hessian ***,we determine whether a seismic trace contributes to the imaging point via DFZ during calculating the Hessian *** tests on synthetic and field data validate the distinct speedup with higher-quality CIGs compared to BLS-PSTm.

关键词： Prestack time migration Fresnel zone Hessian Least squares migration migrated gather

Compliant Control of Lower Limb Rehabilitation Exoskeleton Robot Based on Flexible Transmission

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Journal of Bionic Engineering 2023年第3期20卷 1021-1035页

作者： Keping Liu Li Li Wanting Li Jian Gu Zhongbo Sun Department of Control science and Engineering Changchun University of TechnologyChangchun130012China Department of Electrical and Information Engineering Jilin Engineering Normal UniversityChangchun130052China

To ensure the safety, comfort, and effectiveness of lower limb rehabilitation exoskeleton robots in the rehabilitation training process, compliance is a prerequisite for human–machine interaction safety. First, under the premise of considering the mechanical structure of the lower limb rehabilitation exoskeleton robot (LLRER), when conducting the dynamic transmission of the exoskeleton knee joint, the soft axis is added to ensure that the rotation motion and torque are flexibly transmitted to any position to achieve flexible force transmission. Second, to realize the active compliance control of LLRER, the sliding mode impedance closed-loop controller is developed based on the kinematics and dynamics model of LLRER, and the stability of the designed control system is verified by Lyapunov method. Then the experiment is designed to track the collected bicycle rehabilitation motion data stably, and the algorithm and dynamic model are verified to satisfy the experimental requirements. Finally, aiming at the transmission efficiency and response performance of the soft shaft in the torque transmission process of the knee joint, the soft shaft transmission performance test is carried out to test the soft shaft transmission performance and realize the compliance of the LLRER, so as to ensure that the rehabilitation training can be carried out in a safe and comfortable interactive environment. Through the design of rehabilitation exercise training, it is verified that the LLRER of flexible transmission under sliding mode impedance control has good adaptability in the actual environment, and can achieve accurate and flexible control. During the experiment, the effectiveness of monitoring rehabilitation training is brought through the respiratory belt.

关键词： Lower limb rehabilitation exoskeleton Flexible control Impedance control Stability

Development and Evaluation of a Wearable Lower Limb Rehabilitation Robot

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Journal of Bionic Engineering 2022年第3期19卷 688-699页

作者： Wanting Li Keping Liu Chunxu Li Zhongbo Sun Shui Liu Jian Gu Department of Control Engineering Changchun University of TechnologyChangchun130012China Centre for Robotics and Neural Systems University of PlymouthPlymouthPL48AAUK School of mechatronical Engineering Changchun University of TechnologyChangchun130012China

This paper introduces a rigid-flexible coupling wearable exoskeleton robot for lower limb,which is designed in light of gait biomechanics and beneficial for low limb movement disorders by implementing gait *** rationality of the proposed mechanism is shown with the implementation of the dynamic simulation through mSC *** the purposes of lightweight,the exoskeleton mechanism is optimized through finite element *** can be concluded from performance evaluation experiment,the mechanism has certain advantages over existing exoskeleton robots,namely,comfortable,lightweight,low cost,which can be utilized for rehabilitation training in medical institutions or as a daily-walking ancillary equipment for patients.

关键词： Wearable rehabilitation robot Biomechanics Robot mechanism design Virtual analysis

Quantum control with Lyapunov function and bang–bang solution in the optomechanics system

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Frontiers of physics 2022年第3期17卷 139-153页

作者： Yu Wang Yi-Hao Kang Chang-Sheng Hu Bi-Hua Huang Jie Song Yan Xia Fujian Key Laboratory of Quantum Information and Quantum Optics(Fuzhou University) Fuzhou 350108China Department of Physics Fuzhou UniversityFuzhou 350108China Department of Physics Harbin Institute of TechnologyHarbin 150001China

We propose a quantum control scheme with the help of Lyapunov control function in the optomechanics system. The principle of the idea is to design suitable control fields to steer the Lyapunov control function to zero as t → ∞ while the quantum system is driven to the target state. Such an evolution makes no limit on the initial state and one needs not manipulate the laser pulses during the evolution. To prove the effectiveness of the scheme, we show two useful applications in the optomechanics system: one is the cooling of nanomechanical resonator and the other is the quantum fluctuation transfer between membranes. Numerical simulation demonstrates that the perfect and fast cooling of nanomechanical resonator and quantum fluctuation transfer between membranes can be rapidly achieved. Besides, some optimizations are made on the traditional Lyapunov control waveform and the optimized bang–bang control fields makes Lyapunov function V decrease faster. The optimized quantum control scheme can achieve the same goal with greater efficiency. Hence, we hope that this work may open a new avenue of the experimental realization of cooling mechanical oscillator, quantum fluctuations transfer between membranes and other quantum optomechanics tasks and become an alternative candidate for quantum manipulation of macroscopic mechanical devices in the near future.

关键词： bang-bang solution quantum control Lyapunov control optomechanics system