基本参数

Using hybrid CSG/Brep representation, the whole solid model is a CSG tree made of leaf nodes with basic Brep, which include triangular mesh, subdivision surface control mesh and basic geometries with parametric representation.

该方法采用混合CSG/Brep表示，实体模型在整体上用CSG树表示，整个模型为基本边界表示的叶节点的组合，叶结点可以是三角网格、细分曲面控制网格或参数表示的基本几何体。

This thesis discusses principal issues of the matrix converter such as prime principle, control strategy, current commutation, parameter selection and its applications etc.

本文研究的目的是对矩阵变换器基本原理、控制策略、开关换流、参数选择、应用范围等基本问题进行了探索性研究工作。

Firstly, this dissertation carries out bionic research on the motion of fish body and caudal fin of Thunmiform swimmers in one-dimensional steady swimming for the purpose of establishing kinematic model of underwater propulsor of Thunmiform. This paper also presents the kinematic parameters which describe the motion of fish body and caudal fin, the fundamental approach to getting the propulsion force and the factors related to the propulsion force and efficiency.

首先，从建立仿鲹科加新月形尾鳍推进模式水下推进器运动学模型的目的出发，对采用鲹科加新月形尾鳍推进模式的鱼类在一维稳态游动情况下的身体以及尾鳍的运动进行了仿生学研究，研究了推进运动的基本特征，给出了身体及尾鳍的运动状态、描述其运动的运动学参数、推进力产生的基本途径以及与推进力和推进效率有关的因素，从而为仿鱼水下推进器运动学建模与仿真提供了仿生学基础。

In respect of real-time radioscopy inspection specified in ASME Code （2004）,some highlights of technology, such as the requirements of system components, calibration,written procedure,parameters quantification and so on,are shown.

凸现 ASME 法规（2004）中有关射线实时成像检测的一些技术亮点，如系统特性、校验测试、工艺规程和参数量化等基本要求，并结合射线成像基本原理和工业生产应用实践，作简要评析。

Firstly, based on the force acting on a single-particle, establish a discriminant formula of the sand threshold, and prove that the sand threshold belongs to the cusp catastrophe. Then establish the basic equation of the cusp catastrophe using coordinate transformation and catastrophe theory. Finally, while particle Reynold number and equivalend diameter are the state variables and Shields parameter is the control variables, we can obtain the model of cusp catastrophe of sand threshold, putting those variables into the basic equations of the cusp catastrophe. The model is derived from the mathematics, which has a certain mathematical theory foundation.

首先从单颗沙粒受力分析出发，建立沙床沙粒起动条件判别公式，进而证明了风沙起动属于尖点型突变；然后通过坐标变换和突变理论建立了尖点突变的基本方程；最后本文选择颗粒雷诺数和等效粒径作为控制变量，希尔兹参数作为状态变量，并把它们代入尖点突变的基本方程，经过拓扑变换得到风沙起动的尖点突变模型，并与前人的公式及实验数据进行比较。

The invention discloses the anti-fake method by using the 3D stereoscopic icon, which can show 3D stereoscopic icons and hide the confidential image information in the 3D stereoscopic icons, comprising the following steps of: obtaining parameters, inputting confidential images and grey images; then using a visual divided storage method to build n visual divided storage images, using a 3D stereograph method to build n 3D stereoscopic images, adjusting the sizes of the n visual divided storage images and the n 3D stereoscopic images and dividing the n visual divided storage images and the n 3D stereoscopic images into a plurality of basic blocks; finally random choosing the basic blocks in the corresponding positions in the visual divided storage images or the 3D stereoscopic images to build n 3D stereoscopic and visual divided storage icons, etc.

为了既能三维立体显示图标，又能在三维显示的图标中隐藏秘密图像信息，本发明公开了利用三维立体图标防伪的方法，包括获取参数，输入秘密图像和灰度图像；然后利用可视分存方法构造n幅可视分存图，利用三维立体画方法构造n幅三维立体图，调整所述n幅可视分存图和所述n幅三维立体图大小并分成多个基本块；最后随机选取可视分存图或三维立体图中相应位置处的基本块，构造n幅三维立体可视分存图标等步骤。

And usually this method will suffice to typify all the rest, and not only can we easily solve the problems of calculating statistics of mathematical statistics in this way, but also a large number of sophisticated data can be avoided in the mathematical statistics teaching.

在方差分析中，无论是单因素还是双因素分析，基本思想方法和基本概念都是很清楚的，学生在经过参数的区间估计、点估计和假设检验的学习之后，对这些概念的掌握应该是顺理成章的事。

3The microcosmic analysis of drill pipes: Through comparison metallographic analysis of drill pipes, this paper finds out the ultimate reason which its" performance are difference, then uses SEM to analyze drill pipes and studies crack and acanthopore, measures local chemistry component and the influence that Shot-peened to performance of drill pipes in it"s inside thickening transitional region, measures microcosmic rigidity of drill pipes.

本文的创新点：(1)提出了钻杆失效的过程和概念模型，即内表面缺陷-解理断裂-裂纹疲劳扩展-过载断裂，为解决钻杆失效分析中存在的困惑(各项基本检测参数基本合格，刺穿和断裂仍有发生)提出了分析方法和手段。

In chapter two, we introduce the theory of SAW, and the basic constructure and operation principle of SAW-IDT.

第二章，介绍了SAW原理及其基本性质；给出了SAW叉指换能器的基本组成与主要参数等。

In chapter Ⅰ, a historial review of structure control is given; In chapter Ⅱ, A discussion of the controllability and observablity of flexible structures is given, Two kinds of controllability and observablity index are defined, and applied to actuator allocation; chapter Ⅲ considers the reduction of high order flexible structure mode; the content of chapter Ⅳ is about the basic problem of distributed parameter control system design. It is proved that a stable controllor in mode space may be unstable in real use in distributed paramater systems, also, by closed loop mode concept, a pole assignment method of flexible structure controllor design is given; chapter Ⅴ is about the low-authority controllor design, it is pointed out by use of high order eigenvalue/eigenvector perturbation, a better controllor can be designed; chapter Ⅳ considers flexible structure reduced order control; chapter Ⅶ disscusses the basic problem of flexible structure computer control, analyses discreate controllablity and observablity and its computing, the sample period and coefficient wordlength; chapter Ⅷ is on the problem of low flexibility compensation; chapter Ⅸ is a design example.

在第一章简要回顾了挠性结构控制的历史，并且指出控制中的一些问题；第二章讨论了挠性结构的能控性与能观性，定义了两类能控性程度和能观性程度指标，还将能控性程度概念应用于执行器位置的确定；第三章论述了高阶模型的降价问题，比较了适于挠性结构模型降阶的方法，指出其适用范围；第四章内容是分布参数系统设计的基本问题，首先证明在模态空间中设计的稳定的控制器在实际分布系统上可能是不稳定的，进而根据闭环模态的概念，获得挠性结构控制器设计的极点配置方法；第五章的内容是关于低权控制器的设计问题，指出利用特征值高价摄动和特征向量的摄动，可以设计出更加完善的低权控制器；第六章讨论挠性结构降阶控制问题；第七章讨论挠性结构计算机控制的基本问题，分析了时间离散化模型的能控性和能观性及其计算问题，讨论了采样周期选择和系数字长问题；第八章讨论低挠性结构的补偿问题；第九章的设计例子用来说明第二章和第四章的结果。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。