刚体力学

In the view of biomechanics and biomathematics, we build the simple model with pivot and 4-rigid model, and make further analysis.

本文是在前人已有工作的基础上，对已有的模型进行了改进，运用运动生物力学和运动生物数学分别建立了带有支点的简单模型和四刚体模型，并对模型进行了更进一步的讨论和分析。

Assuming that linear elastic continuums will deform following the elastic rules of Hook and taking the transformation of linear elastic organs in medical images as that of continuity, Finite element method is used to perform motion analysis, which is non-rigid algorithm based motion.

我们采用基于非刚体的有限元方法对超声心动图像进行运动分析，其中涉及到弹性力学的引入、有限元理论的介绍、单元网格的划分、单元的集成、位移边界条件以及对实验结果的分析。

The ideas and methods of modern differential geometry have found wide application in classical mechanics, in the theory of multibody system dynamics, and in the Lagrangian and Hamiltonian formalisms of mechanics.

微分几何动力学建模理论已经广泛应用于经典力学，多刚体动力学理论和Lagrange和Hamilton动力学建模理论当中。

Character 2:The algebraic sum of the moments of the forces of a couple about any point in its plane of action is independent of the location of that point and is equal to the moment of the couple.

Statics 静力学性质2：力偶对其所在平面内任一点的矩恒等于力偶矩，而与矩心的位置无关，因此力偶对刚体的效应用力偶矩度量。

Central-force Motion, Dynamics of a System of Particles, Dynamics of Rigid Body, Coupled Oscillations, Nonlinear Oscillations, Motion in a Noninertial Reference Frame, Continuous Systems.

力学 (0，3)/应用力学（0，3）中心力下的运动、多粒子系统动力学、刚体动力学、耦合振动、非线性振动、非惯性参考座标系中的运动、连续系统。

By the analysis of wave mechanics of typical percussive drilling system of rock, characteristic parameter a, which describes wave dynamics and structure of the percussive drill system, has been presented.

通过对冲击凿岩典型系统的波动力学分析，提出了反映冲击凿岩机具波动力学和结构特征的参数α，继而确定冲击凿岩机具的动力学特征参数α和运动学特征参数τ，实现了活塞弹性动力学与刚体运动学的融合，为冲击凿岩机具的概念设计提供了较完整的方法。

The control of system can be converted to the motion planning problem for a driftless system.

首先导出由两个对称刚体组成的力学模型的非完整姿态运动方程。

Topics covered include oscillations, Keplerian orbits, two-body scattering, rotating frames of reference, rotation of rigid bodies in three dimensions, Lagrangian mechanics, Hamiltonian mechanics, and coupled oscillations.

内容包括振荡，开普勒轨道，两体散射，旋转参考坐标系，在三个方面，拉格朗日力学，哈密顿力学刚体转动，和耦合振荡。

A cusp catastrophe model is presented to describe the behavior of sliding along one deep incompetent structural plane of a gravity dam foundation, and the sufficient conditions leading to instability are discussed. It is found that the instability of sliding relies mainly on the stiffness ratio k, the homogeneity index of the medium m and the geometry-mechanic parameter ξ and that the reliability of the traditional limit analysis method is deficient.

通过建立的模型分析，发现坝基滑动失稳主要取决于软弱面上复杂弹脆性介质和应变软化介质在应变软化拐点处的刚度比k、材料的均匀性指标m及几何－力学参数ξ；并给出了发生突变失稳的充分力学判据，指出传统的刚体极限平衡分析法存在一定的缺陷。

In the second part of the paper, the sport techniques of the flight elements was analysised in-depth theoretically by the movement technical structure:①the giant swing was first analysised in mechanics by applying the Kane's method, the dynamic equation of 5-link multi-body model was established, and the computer simulation software of the giant swing on the high bar was developed.

其次，作为单杠上飞行动作系统性研究的另一主要方面，本论文对飞行动作一般技术结构中的各技术环节进行了深入的理论分析：①着重对飞行动作准备阶段的回环运动技术进行了动力学分析，主要采用了多体力学理论中的Kane方法，建立了5环节人体回环运动的动力学方程，并应用计算机数值仿真技术研制开发了用于回环运动动力学分析的数值仿真软件，进而以动作实例对回环运动进行了数值仿真与误差分析，其所得到的数值仿真结果能够满足对人体回环运动的动力学分析和仿真要求；②对于飞行动作的撒手技术环节，本论文从人体环节相对运动角度，来分析撒手时人体质心的运动以及撒手时角动量参数，并列举了几种飞行动作撒手技术的基本力学指标；③关于飞行动作的空中技术，论文在总结了空翻转体动力学机理的研究成果基础上，对人体空中运动定量化问题进行了一般性描述，并进一步应用刚体动力学理论，着重建立起了描述空翻与转体技术之间定量化的关系，讨论了空翻转体运动的稳定性及其运动模式的转换问题，它对于定量地评定空翻转体技术以及今后对空翻转体动作进行数值仿真都具有理论上和实践上的重要意义；④关于飞行动作再握技术环节，本论文避免了以再握瞬时性的力学参数指标来描述再握技术特征的简单化途径，提出以再握下摆与回环下摆相对比的方法来研究再握技术，并以飞行动作再握技术的具体实例进行了对比分析，表明再握下摆技术相比回环下摆技术有着相当的困难性和复杂性，运动员对再握下摆过程中各环节的相对运动实施有效的控制，是连接高难动作以及顺利流畅地完成成套动作的关键。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷