轴定理

Firstly,using the method of concentrate mass this paper establish a non-linear dynamics model of a two-stage gear train with backlashe between the gear pair,and through analysed the dynamics model,the torsional motion differential equations are got , on this basis,then calculate the torsional motion differential equations using Runge—Kutta method ,and discuss how to influence the dynamics characteristic of system when these parameters chage such as mesh frequentcies、 stiffness of the intermediate shaft、the ration of mesh frequentcies.and discuss when the chaos will happen under the change of these parameters.

首先用集中质量法建立系统的含间隙的非线性动力学模型，并根据牛顿力学定理，得到系统的运动微分方程。然后对所建立的运动微分方程运用四阶变步长Runge—Kutta方法进行了求解，并对计算结果进行分析，研究了齿轮啮合频率、中间联接轴的刚度，一、二级齿轮的啮合频率比等参数变化时，对系统非线性动力学特性的影响规律，并讨论了当参数如何变化时会导致系统的混沌响应的出现。

By using holographic theory,hologram sampling theorem and separation condition of frequency spectrum,the maximum spatial frequency of off-axis Fresnel was analyzed,and recording conditions were studied.

根据全息理论，通过分析全息图光栅结构的极值频率，利用抽样定理以及频谱分离条件，分析了离轴菲涅耳全息的记录条件，得到了不同于以往文献的最小记录距离及参考光源设置表达式，并做了计算机模拟验证。

Based on its exact kinematic analysis and by applying the power equation of kinetic energy theorem,its balance analysis is given,and the exact analytical expression for computing crank axle torque is obtained.

在对摆杆型游梁式抽油机进行详细运动分析的基础上，应用动能定理的功率方程对其进行了平衡分析，得到了曲柄输出轴扭矩的解析表达式。

This paper describes and compares 4 streamtube models (single-disk single-streamtube, double-disk single-streamtube, single-disk multi-streamtube and double-disk multi-streamtube models) based on the momentum theory for the hydrodynamic performance prediction of the vertical-axis variable-pitch turbine that may be employed to tap tidal stream energy resources, especially for the prediction of the overall turbine power coefficient.

以潮流发电水轮机的设计为研究背景，分析和总结了基于动量定理方法的四种流管模型(单盘面-单流管模型、双盘面-单流管模型、单盘面-多流管模型和双盘面-多流管模型)在竖轴变攻角水轮机的水动力性能计算中的应用，特别是能量利用率预报方面的应用。

In order to reduce the effect of probe errors in near-field antenna measurement, the solutions are proposed as follows: On the one hand, theoretical formula of probe-compensated is derived; on the other hand, drop-shaped probe is designed and near-zone gain, far-field patterns, axial ratio, main lobe width, input impedance, voltage standing-wave ratio, electromagnetic field and current distribution of probe are obtained through the computer simulation.

针对近场测量中的重要误差源之一&探头&的影响，本文提出解决方法：一方面用探头补偿的方法，根据洛仑兹互易定理和微波网络理论对补偿的解析式进行详细推导；另一方面用两种不同的仿真软件求解终端开口矩形波导探头的近场增益、远场方向图、轴比、主瓣宽度、输入阻抗、电压驻波比、电场分布、磁场分布、表面电流分布等特性参数，可实现探头增益的修正。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。