基本参数

First it concludes elementary methods for product modeling such as feature recognition, feature-based design and feature mapping. Then it probes into the mechanism of constraint-based feature parametric modeling, representation of feature parametric model and methods for solving constraint in details. At the end it proposes a feature-based modeling system that makes good use of resources and synthesizes many feature modeling methods, and analyses the development of prototype system oriented to actual application.

首先全面归纳了基本的基于特征的产品建模方法，包括特征识别、基于特征设计和特征映射方法，然后对基于约束的特征参数化建模、特征参数化模型的表达和定义方法以及约束求解方法进行了深入研究，最后提出了一个充分利用现有资源，特征识别、基于特征设计和特征映射共用的特征建模系统，并探讨了面向实际应用的原型系统的开发技术。

RESULTS Master graduate has grasped the theory of health statistics preferably.The abso-lute majority,namely97.9%of the total students,have used the basic statistic method in their thesis,75.7percent could use statistic method correctly.The main problem arising in using parametric test is that they hadn't judged the applying condition,while in non-parametric test is that the conclusion is wrong.

结果 论文中采用单因素设计者占94.0%，多因素设计占6.0%，应用正确率为96.6%；论文中使用经典基本数理统计方法为97.9%，统计学方法的正确应用率为75.7%；应用参数统计时出现的主要问题是未进行适用条件判断，而应用非参数统计时出现的主要问题则是推断结论有误。

By using the basic method of virtual design and motion simulation of mechanical system based on Solid Works, virtual design of the robot of excavating tree stump was completed by synthetically using parametric and variable modeling technology and top-down design method. In case of the carrier was changed, the COSMOSMotion2006 was used to perform the motion simulation and optimized the parameter of the interface and the mechanical arm, by this way the useable of the new frameworks was confirmed, and in favor of reduce the exploiting cycle and exploiting cost.

通过使用SolidWorks软件的机械系统虚拟设计和运动仿真的基本方法，综合运用SolidWorks的参数化、变量化建模技术以及自上向下的设计思路，完成伐根清理机器人及其行走底盘的虚拟建模，并对由于行走底盘的改变而重新设计的接口和机械臂采用最新的COSMOSMotion2006软件进行了运动仿真和参数优化，以确定其机构可用性，有利于缩短产品的开发周期和减少开发费用。

To acquire the inherent topology properties and characteristics of the topology graph at AS-level, we introduce basic network model (Scale-free network and Small-world network) and evaluating parameters (such as cluster coefficient, average path length, degree distribution, Pearson correlation coefficient) in this thesis. Through thorough analysis of the topology of the generating topology at AS-level, we can see some apparent properties with the evaluating parameters and the inherent power-law distribution property of the derived topology. Besides, we discuss the perspective of the evolution of the networks topology based on these analyses.

为了研究Internet自治系统级拓扑的内在拓扑特性和规律，利用了复杂网络的基本网络模型(无标度网络和小世界网络)和度量参数(簇系数、平均路径长度、节点度分布、皮尔森系数等)，对生成的自治系统级拓扑进行了大量的分析，从中可以看出度量参数具有一些明显的特性，拓扑中具有一些幂律分布特性，并对网络拓扑的演化发展的趋势进行了探讨。

The basic process of three-dimensional parameterized design for the piercer guide board series has been described in this article as well as its necessity and superiority with CAD.

介绍了穿孔机导板系列三维参数化设计的基本过程，及运用计算机进行导板三维参数化设计的必要性和优越性。

In the first part of this paper, we give some basic concepts of regular Sturm-Liouville problems and some Sturm-Liouville problems with eigenparameter in the boundary conditions and the definition and properties of the Krein space. Using the Krein space, we describe a class of Sturm-Liouville problems with eigenparameter in two boundary conditions and prove that it can generate a self-adjoint operator in Krein space with only point spectrum.

第一部分我们介绍了一些基本概念如正则Sturm-Liouville问题、边界条件含参数的问题、Krein空间等，并利用Krein空间的定义和性质描述了一类参数边界条件的Sturm-Liouville问题，证明它可构造一Krein空间上的自伴算子，并且谱全为点谱。

Several essential problems about the mechanism, such as the relations between cam angles and geometric parameters, the allowable values of some angular parameters, the equations of cam prole and the return motion of rocker AC, are solved.

关于这种机构的几个基本问题得到解决，如凸轮角度和几何参数的关系，一些角参数的允许值，凸轮的轮廓线和摇杆的回行运动的方程。

The basic steps of this method are as follows.The firststep is to derive a necessary condition such that the families of quasipolynomials withone parameter,corresponding to the edges of the polytope,have pure imaginary rootsby using the Dixon's resultant for polynomials.Then to check that the casescorresponding to the parameters obtained in the first step are in fact impossible byusing the generalized Sturm criterion and some stability criteria.

其基本思路是先利用多项式方程组的Dixon结式理论导出使各棱边对应的单参数特征拟多项式有纯虚根时，参数值应满足的一个等式条件，即所谓的Dixon结式等于零，然后由广义Sturm判别法验证对所有参数值，Dixon结式不等于零，或使结式等于零的解不产生特征拟多项式的纯虚根。

Equilibrium constant of salts for (liquid +solid) equilibrium at 288 K were evaluated with Pitzer"s model. The solubilities of quaternary and quinary system were calculated by Pitzer "s equations. The prediction results were in agreement with the experimental results essentially.

用288K时二元及三元体系的溶解度数据，运用多元线性回归的方法拟合了PitZer方程中288K时该五元体系所涉及各盐的单盐参数及混合参数；计算出了各盐288K时溶解平衡常数，运用PitZer方程对四元及五元稳定体系相平衡进行了理论模拟，计算结果基本令人满意。

The finite element model of the stochastic truss is built and the random functions of its natural frequencies are obtained by use of the Rayleigh quotient.

文[2-4]对具有随机参数的结构进行了动力特性分析，其基本作法均是以小参数来描述结构中的随机因素，利用有限元和矩阵摄动方法求解。

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。