查询词典 boundary

Starting from the concept of Measured Equation of Invariance and the local equivalent theorem, it regarded the determination of the truncation boundary condition as a question of field simulation in a small area near the grid boundary. The practical disposal in the 2D and 3D cases was discussed.

基于测度不变方程的概念和局部等效原理，将截断边界条件的确定归结为网格边界上一小区域的电位场模拟问题，并讨论了在二维、三维情况下的具体处理。

Special attention should be paid when we apply the decomposition method to two-point boundary value problems, it is necessary to solve a algebraic system;It should be noted that a modification of inverse operator should be made when dealing with singular boundary value problems;Laplace transform and Pade approximants can be coupled to enhance the efficiency of the decomposition method.

比如，在求解两点边值问题时就需要特别注意，这时需要采用待定系数法，最后会涉及到系数方程组的求解；在处理奇异边值问题时需要重新定义逆运算；不少研究人员还把分解方法与Laplace变换和Padé逼近相结合来进一步提高分解方法的精度。

In the present work,the existence and uniqueness results aboutperiodic boundary value problems for different kinds of the nonlin-ear periodically perturbed nonconservative systems are establishedthrough the discretization technique,under suitable assumptions,by using global inverse function theorem and result about the ex-istence and uniqueness of periodic solution for nonhomogeneouslyfirst order linear periodic boundary value problem.

本文的第一章概述了在讨论原问题解的存在唯一性过程中以及构造和分析相关的数值求解方法时将要用到的全局反函数定理、有关矩阵特征值的若干重要引理、线性常微分方程非齐次周期问题解的存在唯一性定理和单参数影射方法及有关结论，并简单回顾了已有的证明非线性微分方程周期边值问题解的存在唯一性的方法，其中包括谱理论、最大最小化形式方法、摄动技术和全局反函数理论方法，最后，介绍了两类数值求解非线性微分方程问题的方法。

Then, the methods used for elastic mixed boundary problems, and the inverse integral transformation method may be employed to solve viscoelastic mixed boundary problems in time domain.

结合在求解粘弹性边值问题中的应用，对各类方法的特点进行了评述，并指出存在的问题及发展新的数值方法的研究重点。

The stability of algorithm, the condition of absorbing boundary and free surface boundary, the grid dispersion and the process of source are discussed in details. The numerous simulations of wave propagation are carried out in isotropic media, transversely isotropic media and anisotropic media induced by fractures. The difference between anisotropic and isotropic effects on surface records is analysized.

接着讨论了有限差分算子的稳定性和收敛性，以及吸收边界条件、自由边界条件、数值频散和震源的处理，对各向同性介质、横向各向同性介质以及裂隙引起的各向异性介质中传播的弹性波场进行了数值模拟，分析了多波多分量数据中的各向异性效应以及各向同性在地表地震记录中的反映。

The present method is applied to two-dimensional potential problems and the corresponding discrete equations are derived. Because the shape functions so-obtained possess the Kronecker delta property, the essential boundary conditions can be enforced as the FEM; furthermore, the Heaviside step function is used as the test function, there is no domain integral, and only a regular boundary integral is involved.

因为滑动Kriging插值方法构造的形函数满足Kronecker函数性质，所以本文建立的改进的无网格局部Petrov-Galerkin法可以像有限元法一样直接施加边界条件；由于采用Heaviside分段函数作为局部弱形式的权函数，因此在计算刚度矩阵时只涉及边界积分，而没有区域积分。

The conversion boundary of self-incompatibility was researched by sowing by stage. Sunshine of day and temperature was studied critically by investigating leafage and researching traits indoors. The results showed that the daily minimum temperature was the principal factor of affinity conversion and the affinity conversion boundary was 16.5~18.1℃.HE97 was primarily regard as self-incompatible line in this research. The method was by inbreeding and sib HE97, Half the silk of HE97 and Zheng58. Inbreeding and cross have been done simultaneously. The extending condition of pollen tube was observed by dying the silk after pollinating 4 hours. The individuals with pollen tube were observed having seeds, while the individuals without pollen tube were observed having few seeds or no seeds. So this study regard HE97 as sporophytic self-incompatibility .The planting ration of female parent HE97 and male parent 87-1 was 4:1.The nature cross-pollination was studied by the theory of endosperm xenity, the study show that the setting percentage of HE97 was 625%, in which the seed in self was 70% and the seed in hybrid was 30%. This was consistent with the study of silk anatomy structure, then come to the same conclusion: compatible pollen germination and fertilization can stimulate the self-incompatible pollen germination and fertilization in the same corn cob.

通过分期播种，进行了光温敏自交不亲和材料HE97亲和性转换区间的研究，依据田间跟踪调查叶龄及室内考种研究了HE97亲和性转换区间的光温临界值，结果表明：1日最低温度是影响HE97自交不亲和性的主要原因，亲和性转换区间在16.5℃～18.1℃之间。2通过HE97自交和姊妹交以及将HE97与郑58作为双亲，各自的花丝一分为二，分别正反交，授粉后4个小时分别取其花丝进行固定、染色，观察花粉管的伸长情况，根据结实率与花粉管伸长的对应关系，结果发现观察到花粉管的对应植株收获到了种子，而没有观察到花粉管的对应植株结实率极低或没有结实，本研究把HE97初步划为孢子体自交不亲和类型。3以HE97为母本，87-1为父本，按4母：1父行比，通过花粉直感效应研究天然异交率，结果母本HE97结实良好(62%)，其中自交粒占70%，异交粒占30%，结合花丝切片观察表明，亲和花粉的萌发及受精会导致落在同一果穗柱头上不亲和花粉的萌发不再受抑制。

By coupling the moving least squares approximation with a modified functional, the Hybrid Boundary Node Method is a boundary-only, truly meshless method.

中文摘要：杂交边界点方法是一种纯边界类型的无网格方法，它将修正泛函和移动最小二乘近似结合。

Then, the boundary points are extracted. By using Shu's theorems the sum of Legendre polynomial of the boundary points is calculated.

首先使用Yang-离散格林公式将二值图像矩计算中区域内求和转换为沿区域边界求和；然后提取该图像的边界点；再利用Shu提出的公式计算出边界点的Legendre多项式的叠加值。

Research results show that the latter is more suitable to describe the artificial boundary accuracy of near-field wave motion decoupling numerical simulation, and the former can be used to estimate the upper limit of artificial boundary error.

研究结果表明：理想暂态情形下的反射系数，更适合描述近场波动解耦数值模拟中的人工边界精度；而理想稳态情形下的反射系数可用于估计人工边界误差的上限。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。