一阶理论

Design parameter based on finite element model updating is part of an inverse problem of structure dynamics. Features of the structure are used as a function of design parameters. Parameters are updated based on the first derivative. This paper presents a new method which treats the model updating as a positive problem.

设计参数型有限元模型修正属於结构动力学反问题，其理论基础是将结构的特徵量视为设计参数的函数，然后依据特徵量对设计参数的一阶导数信息进行迭代求解。

The equations of buckled equilibrium were derived based on the displacement field of the first order shear-deformation theory.

用一阶剪切变形理论的位移场推导出5个屈曲平衡方程。

By using virtue work principle and first order shear plate theory,the finite element formulations of piezoelectric sensors and actuators arederived.

给出了采用虚功原理及一阶剪切变形理论导出的压电传感和作动有限元方程。

Based on the first order shear theory and the Von Karman non-linear assumption , the corresponding finite element formula was developed , and an appropriate progressive failure criterion was adopted.

基于一阶剪切理论和 Von Karman非线性变形假设建立了含分层损伤复合材料 A GS结构的有限元模型，并推导了考虑温度和湿度效应的 AGS结构有限元列式，同时给出了材料破坏准则。

Based on deformation assumption and Mindlin first order shear deformation theory, a finite element method was proposed for free vibration analysis of the composite sandwich plates with debonded damage along the face/core interface.

基于Zig-Zag变形假定和Mindlin一阶剪切理论，提出了具有面板和芯体开裂损伤复合材料夹层板自由振动的有限元分析方法。

In chapter 2, a tangent stiffness matrix formula of four-node C〓 element for the laminated plate is deduced, which is based on the first order shear deformation theory and the Von-Karman nonlinear deformation assumption.

第二章首先给出了在一阶剪切效应和Von-Karman大挠度理论下复合材料层合板的几何关系，然后基于单元域内和边界一致概念，推导了在大变形下"无剪切闭锁"的层合板单元切线刚度阵，并给出了复合材料层合板后屈曲分析的有限元平衡方程。

Considering the interaction between theΓvalley and the folded L valley, we calculated the dependence of theΓvalley of ordered GaInP on pressure using first order perturbation theory.

在考虑有序GaInP中Γ能谷和折叠到Γ点的L能谷相互作用的基础上，用一阶微扰理论计算了有序GaInP直接带隙发光峰峰值能量随压强的变化，计算结果和两个样品的实验结果符合得很好。

Moreover, students should know some basic theories of initial value problem of differential equation, stability theory and first order linear or quasi-linear differential equations.

稳定性理论或一阶线性偏微分方程有所认识。

Both a free volume approach for Helmholtz free energy and a theoretically-based fitted formula for radial distribution function of hard sphere solid were employed to describe the Helmholtz free energy of Lennard-Jones solid in the framework of first order thermodynamic perturbation theory.

结合描述硬球固体Helmholtz自由能的自由体积方法与描述硬球固体径向分布函数的拟合的分析表达式与一阶热力学摄动理论，用于描述Lennard—Jones固体的Helmholtz自由能。

The procedure estimating the regularization parameter is the same as that the adaptive Marquardt algorithm used. The Frechet derivative is directly derived from the forward methods: SAM and FEM. With the theory of SAM and Zhang′s geometric factor, the relationship between the Frechet derivative and the geometric factor is established, at the same time, one useful corollary is given, i.

选取正则化因子时，沿用自适应的Marquardt算法中阻尼因子的选取计算方法；计算Frechet导数时，根据逐次逼近解法和张氏几何因子理论，推导出了Frechet导数与张氏几何因子的关系，得出了Frechet导数为张氏一阶积分几何因子的结论。

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。