查询词典 atomic element

Shadow effect can not be neglected for thermal analysis of spacecraft,Accroding to the angle between solar light and antenna orbit plane and its orbit location,analytical geometry method was used for accurately calculating solar radiation heat flux distribution of reflector surfaces.To analyze the temperature field under heat flux,the formulations of net radiation flux density between two gray elements and the net flux density of gray surface under external thermal flux were deduced.Based on the characteristic of space environment,the nonlinear temperature distribution in transverse direction of reflector shell self radiation were considered,the finite element formulations were given for orthogonal material layered shell by Galerkin method.A layered element including a inner heat source layer was proposed,and the finite element formulation expressed by DOF of the inner heat source layer were put forward with temperature and heat flux boundarys between adjacent layer.

单馈反射面赋形天线是未来星载天线发展的一个重要形式，分析了基于物理光学、几何光学和几何绕射理论的理想反射面辐射场；介绍了基于几何光学的反射面天线赋形方法；针对赋形过程中辐射场的快速分析要求，比较分析了基于物理光学的Fourier-Bessel和Jacobi-Bessel级数展开方法以及GB展开分析方法；利用GB展开快速分析方法在20GHz频率下对0.6m口径的天线进行赋形分析，实现中国大陆的30dB增益覆盖，通过数值计算研究了固定增益期望下的口径尺寸随频率的变化，以及频率为20GHz的不同尺寸天线赋形后的覆盖目标区域最大增益的变化情况。

In this paper we introduce a finite element program design method for solving 3 D thoracic electrical field distribution,based on Borland C++ for DOS and using isoparametric element of arbitrary hexahedron.In the process of solving final finite element equation,this paper uses the method of blocking and 'getting big number' to deal with total coefficient matrix and boundary conditions.

本文介绍了一种采用等参数8节点任意六面体单元来求解人体胸腔三维恒定电场分布的有限元程序设计方法，程序的编制基于BorlandC＋＋ForDOS的编程环境，在对最终形成的有限元代数方程的求解过程中采用了分块处理总系数矩阵及"取大数"处理边界条件的方法。

Usually, distribution networks operate in arborescence mode, so in the simulation of fault analysis the impact of faulty switch element on system reliability is apportioned to failure consequences of adjacent sections that connect to switch, and then an equivalent analytical model considering switch fault is proposed. Thus, not having to conduct the reliability analysis of switch element singly, the impact of switch element fault on system reliability can be calculated. Applying the proposed algorithm in RBTS-BDS6 system, RBTS-BUS4 system and actual medium-voltage distribution network to conduct reliability assessment, the results show that the proposed algorithm is superior in speed and possesses efficiency and engineering practicality.

配电网常具有树状运行特点，在故障解析模拟时，将开关元件故障对系统可靠性的影响分摊到连接开关的相邻分块的故障后果中，进而提出计及开关故障的可靠性等值解析模型，不需单独进行开关元件故障的可靠性分析即可计算其对系统可靠性的影响，应用该算法对RBTS-BUS6和RBTS-BUS4系统及实际中压配电网进行了可靠性评估，结果表明该算法有较明显的速度优势，具有高效性和工程实用性。

Then, taking the wave problems governed by the Helmholtz equation as an example, several conventional infinite elements such as the Bettess element, the Astley element and the Burnett element are compared and reviewed.

首先介绍无限单元的概念和无限元方法的特点；围绕求解以Helmholtz方程控制的波动问题，评述几种常规无限单元的优劣，这些单元包括Bettess元、Astley元和Burnett元。

The former, such as Bettess element and Astley element, needs geometry mapping and shape functions in terms of local coordinates, while for the latter, the shape functions are directly expressed in terms of global coordinates. This paper reviews the state-of-the-art and recent advances of the infinite element method for unbounded domains.

无限元分为映射无限元和非映射无限元：映射无限元需要引入几何映射，在局部坐标系中构造插值形状函数，如Bettess 元和Astley元；非映射无限元则直接在整体坐标系中构造插值形状函数，如Burnett元。

This paper presents the concept of structure basic element, structure variable element and the structure variable element design method.

从产品整个生命周期的产品数据模型分析入手，结合结构设计本身的特点，对结构设计的产品数据建模进行了研究。

Variable structure element design method was established, and basic structure element and variable structure element were defined.

本文以液压支架设计为背景，采用结构设计原型和基于原型的设计方法解决瓶颈问题，对结构设计、基于原型的设计方法和实现工具进行了深入的研究，主要工作如下： 1。

A comparative study of the bilinear, biquadratic quadrilateral element and quadratic triangular element for solving incompressible viscous flows was presented. These elements make use of the Galerkin/Least squares stabilized finite element formulation, in which the pressures and velocities are interpolated with the equal orders.

本文比较了用于求解不可压缩粘性流的四边形双线性、双二次单元及三角形二次单元的性能，这些单元采用GLS稳定化有限元格式，而压力和速度采用等阶数插值。

In chapter 2,all kinds of numerical methods of computational fracturemechanics are summarized,the development histories and present situation ofboundary collocation method,boundary integral method,finite difference method,boundary element method and finite element method are expounded,and theapplication of finite element method in fracture mechanics are emphaticallydiscussed.

第二章 总结了计算断裂力学中各种数值方法，论述了边界配位法、边界积分法、有限差分法、边界元法及有限元法的发展历史和现状，并着重讨论了有限元法在断裂力学中的应用。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

The shaping method of noncircular part and the tool holder's radial motion characters in noncircular turning process are discussed in detail in the thesis.

论文详细研究了非圆零件的成型方法和加工过程中刀架的径向运动规律。

I have not really liked him,I do not like his this kind of disposition.

我没有真的喜欢他，我不喜欢他的这种性格。