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Coalbursts in China: Theory, practice and management

Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 1-25页

作者： Yishan Pan yimin song Hao Luo Yonghui Xiao Institute of Disaster Rock Mechanics Liaoning UniversityShenyang110036China School of Civil Engineering North China University of TechnologyBeijing100144China College of Computer Science Liaoning UniversityShenyang110036China School of Physics Liaoning UniversityShenyang110036China

Coalburst is one of the most serious disasters that threaten the safe production of coal mines, and this disaster is particularly serious in China. This paper presents an overview of coalbursts in China since 1980s. From the "stress and energy" and "regional and local" perspectives, the achievements in the theory, practice and management of coalbursts in China are systematically summarized. A theoretical system of coalbursts has been formed to reveal the deformational behavior of coalbursts and explain the mechanism of coalbursts. The occurrence conditions of coalbursts are put forward and the critical stress is obtained. The stress index method for risk evaluation of coalbursts before mining is proposed, and the deformation localization prediction method of coalbursts is put forward. The relationship between energy release and absorption in the process of coalbursts is found, and the prevention and control methods of coalbursts, including the regional method, the local method and support, are presented. The safety evaluation index of coalburst prevention and control is put forward. The integrated prevention and control method for coal and gas outbursts is proposed. The prevention and control technology and equipment of coalbursts have also been developed. Amongst them, the distribution law of the critical stress in China coalburst mines is discovered. The technology and equipment for monitoring, prevention and control of coalbursts, as well as for integrated prevention and control of combined coalbursts and other disasters, have been developed. The energy-absorbing and coalburst-preventing support technology for roadways is invented, and key engineering parameters of coalburst prevention and control are pointed out. In China, coalburst prevention and control laws and standards have been developed. Technical standards for coalbursts are formulated, statute and regulations for coal mines are established, and regulatory documents are promoted.

关键词： Coalbursts Rockbursts Dynamic disaster Energy-absorbing support Monitoring and early warning

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Multi-locomotion transition of tensegrity mobile robot under different terrains

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Science China(Technological Sciences) 2024年第2期67卷 536-557页

作者： YANG Qi LIU XinYu WANG PanFeng song yimin SUN Tao Key Laboratory of Mechanism Theory and Equipment Design(Tianjin University) Ministry of EducationTianjin UniversityTianjin 300350China

Knowing how to make a multi-locomotion robot achieve locomotion transition under different terrains is a challenging problem,especially for tensegrity robots with multi-locomotion *** this study,a motion planning method for the transition of a multi-locomotion tensegrity robot(hereafter TJUBot)under different terrains is *** robot can achieve four locomotion modes:earthworm-like,inchworm-like,tumbling,and sliding locomotion with only two *** models of the four locomotion modes under five typical terrains,including flat ground,confined space,obstacle,gap,and descending slope,are established using the energy ***,the kinematic characteristics(driving law and initial position)of the robot under these terrains are *** this basis,motion planning for the locomotion transition of TJUBot is conducted,which includes a perception strategy based on three laser sensors and a transition strategy under different *** driving laws of the two motors that can ensure the effective locomotion transition of TJUBot under different terrains are naturally ***,experiments are *** demonstrate that the robot can achieve effective locomotion transition when the motion planning method is used.

关键词： multi-locomotion robot tensegrity kinematic modeling locomotion transition

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Digs and Dreams

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China Weekly 2024年第3期 56-59页

作者： song yimin 不详

How Chinese archaeologists took back control over ancient sites from foreign adventurers,Aone time,archaeology was not a place for *** in recent years,it has capturedthepublicimagination in China with movie blockbusters about tomb raiding like The Lost Tomb and the mysterious new findings at the Sanxingdui excavations near Chengdu in Southwest *** is even a popular toy set that lets children imagine they are an archaeologist through play.

关键词： China. outside finding

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Amazing Graze

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China Weekly 2024年第1期 57-59页

作者： song yimin 不详

A masterpiece created nearly a millennium ago holds the distinction of being the inaugural piece to undergo expert appraisal following the reestablishment of the Chinese Ancient Art Appraisal Group.

关键词： holds appraisal piece

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Music Interesting Chimes

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China Weekly 2024年第7期 53-55页

作者： song yimin Wang Zhiwei 不详

A set of bronze chimes from more than 2,400 years ago reveals new aspects of ancient Chinese music,unexpectedly retuning our understanding of global music history.

关键词： tuning bronze Music

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Elegant Reminders

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China Weekly 2024年第9期 56-59页

作者： song yimin Wang Zhiwei 不详

A testament to his political achievements,Han Qi's stone stele embodies literary and artistic *** in his personal study,the monument has evolved into an inspiring sanctuary for future generations of literati Thesecond... 详细信息

关键词： significance. literary political

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基于结构相似性的并联机构拓扑与尺寸同步设计方法

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农业机械学报 2024年第4期55卷 431-439页

作者：王猛林文琦崔青春宋轶民孙涛西北机电工程研究所咸阳712099 天津大学机械工程学院天津300350

随着并联机构从单一尺寸设计和拓扑设计向两者融合方向不断发展,基于拓扑叠加-再惩罚和全变量正交设计-再拓扑的同步设计方法得到广泛应用,但两者存在设计效率低等不足。为解决上述问题,本文提出了一种基于结构相似性的并联机构拓扑与... 详细信息

随着并联机构从单一尺寸设计和拓扑设计向两者融合方向不断发展,基于拓扑叠加-再惩罚和全变量正交设计-再拓扑的同步设计方法得到广泛应用,但两者存在设计效率低等不足。为解决上述问题,本文提出了一种基于结构相似性的并联机构拓扑与尺寸同步设计方法,该方法拓扑优化时以相同质量保留此条件下尺寸参数小范围变化对拓扑结构微弱影响为切入点,通过拓扑结构参数化缩放和刚度-质量元模型构建,形成并联机构尺寸-拓扑同步高效设计流程。以典型■RS并联机构为例开展算例验证与对比分析,结果表明,相同质量条件下,所提设计方法比尺寸设计方法得到的各向刚度更高,即拓扑优化使RS连杆的材料分布更加合理。

关键词：并联机构结构相似性尺寸设计拓扑优化同步设计

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巷道防冲吸能钢管混凝土拱架支护性能研究

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煤炭科学技术 2024年第3期52卷 53-62页

作者：许海亮高晗钧宋义敏安栋郑鑫雷北方工业大学土木工程学院北京100144

针对目前巷道支护中钢管混凝土拱架缺乏可缩让压性能的问题,从吸能让位角度设计了一种防冲吸能钢管混凝土拱架结构。通过Abaqus建立新型钢管混凝土拱架与围岩组合模型,在静载与动载两种荷载状态下,对比分析新型拱架对巷道的支护效果与... 详细信息

针对目前巷道支护中钢管混凝土拱架缺乏可缩让压性能的问题,从吸能让位角度设计了一种防冲吸能钢管混凝土拱架结构。通过Abaqus建立新型钢管混凝土拱架与围岩组合模型,在静载与动载两种荷载状态下,对比分析新型拱架对巷道的支护效果与抗冲击能力。结论如下:①根据合理的让位阻力特性设计吸能构件壁厚与尺寸,在拱架上部连接处和底弧段中部设置吸能构件,可避免弯曲过大发生失稳。套管形状依据U型钢拱架卡揽结构设置为折纹型,与拱架摩擦实现缩动让压;②在竖向与侧向冲击下,优化后拱架支护巷道各点位移量呈减少趋势,降低了拱架顶弧段下沉与底弧段上拱,支护效果更强;③静载作用下,优化后拱架与吸能构件接触后,拱架各点处塑性应变不再增加,吸能构件代替拱架发生形变。在受到动载后,吸能构件能快速响应,同时拱架两帮拐角发生弯曲变形,其余部分仍未发生明显变形。吸能构件压溃后,拱架整体塑性应变开始增加,最终优化后拱架各点等效塑性应变竖向与侧向冲击下分别降低了10%~50%和13%~78%。

关键词：钢管混凝土吸能构件防冲设计巷道支护冲击地压

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Rigid-Soft Coupled Robotic Gripper for Adaptable Grasping

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Journal of Bionic Engineering 2023年第6期20卷 2601-2618页

作者： Zhiyuan He Binbin Lian yimin song Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin300350China Department of Mechanical Engineering Tianjin Renai CollegeTianjin301636China

Inspired by the morphology of human fingers,this paper proposes an underactuated rigid-soft coupled robotic gripper whose finger is designed as the combination of a rigid skeleton and a soft *** from the current grippers who have multi-point contact or line contact with the target objects,the proposed robotic gripper enables surface contact and leads to flexible grasping and robust *** actuated mechanism,which is the palm of proposed gripper,is optimized for excellent operability based on a mathematical *** material selection and rigid skeleton structure of fingers are then analyzed through a series of dynamic simulations by RecurDyn and *** above design process including topology analysis,actuated mechanism optimization,soft material selection and rigid skeleton analysis,the rigid-soft coupled robotic gripper is fabricated via 3D ***,the grasping and holding capabilities are validated by experiments testing the stiffness of a single finger and the impact resistance of the *** results show that the proposed rigid-soft coupled robotic gripper can adapt to objects with different properties(shape,size,weight and softness)and hold them *** confirms the feasibility of the design procedure,as well as the compliant and dexterous grasping capabilities of proposed rigid-soft coupled gripper.

关键词： Rigid-soft coupled robotic gripper Parameter optimization Dynamic simulation Adaptive grasping Robust holding

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Geometric error analysis of an over-constrained parallel tracking mechanism using the screw theory

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Chinese Journal of Aeronautics 2019年第6期32卷 1541-1554页

作者： Jiateng ZHANG Binbin LIAN yimin song Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300072China Department of Machine Design KTH Royal Institute of TechnologyStockholm SE-10044Sweden

This paper deals with geometric error modeling and sensitivity analysis of an overconstrained parallel tracking mechanism. The main contribution is the consideration of overconstrained features that are usually ignored in previous research. The reciprocal property between a motion and a force is applied to tackle this problem in the framework of the screw theory. First of all, a nominal kinematic model of the parallel tracking mechanism is formulated. On this basis, the actual twist of the moving platform is computed through the superposition of the joint twist and geometric errors. The actuation and constrained wrenches of each limb are applied to exclude the joint displacement. After eliminating repeated errors brought by the multiplication of wrenches, a geometric error model of the parallel tracking mechanism is built. Furthermore,two sensitivity indices are defined to select essential geometric errors for future kinematic calibration. Finally, the geometric error model with minimum geometric errors is verified by simulation with SolidWorks software. Two typical poses of the parallel tracking mechanism are selected, and the differences between simulation and calculation results are very small. The results confirm the correctness and accuracy of the geometric error modeling method for over-constrained parallel mechanisms.

关键词： Error model simulation Geometric error modeling Over-constrained parallel mechanism Screw theory Sensitivity analysis

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