查询词典 problem

The numercial simulation has been carried out, and the experimental results show that this method has been improved significantly comparing with the traditional one in nonlinear optics. Secondly, a second order system of semilinear elliptic equations, which comes from a mathematics model of the electric potential distribution of a media surrounded with the protein, is transformed into a variational problem, the existence of solution of it is proved by using variational principle and Trudinger—Moser inequality, and the relation between the solutions of variational problem and the solutions of its dual problem is obtained.

首先，讨论了非线性光学中的二次谐波产生的耦合方程组，利用变分法证明了耦合方程组非平凡解的存在性，然后进行了数值模拟，实验结果表明文中方法比经典的非线性光学中的方法有较大的改进，这对优化光倍频器件的设计将有所帮助；其次，将一类二阶半线性椭圆型方程组转化为一个变分问题，然后利用变分法和

Harmonic measurement is an important embranchment of harmonic problem. It is not only the main basis of studying the harmonic problem, but also the starting point of analyzing the problem.

谐波测量是谐波问题的一个重要分支，它是谐波问题研究的主要依据，也是研究分析问题的出发点。

Firstly, we consider the problem of the representation formula for the transition probability density of a right process under Girsanov transform. Secondly,we consider the problem of the MEMMs (minimal entropy martingale measure)for Markov switching Levy processes, and justify that the minimal entropy martingale measure is obtained by some regime switching Esscher transform. At last,we consider the problem of the invariant measure and the ergodic property of recurrent right processes. This paper includes 5 chapters.

首先，我们考虑了满足一定条件的右过程在Girsanov变换下的转移概率密度的表达式问题；其次，我们考虑了由Markov调制的Lévy过程的最小相对熵鞅测度的问题，证明了其最小相对熵鞅测度是某个状态转换Esscher变换；最后，我们考虑了右过程的不变测度及其遍历性的问题。

In the last chap-ter,the natural integral equation and natural boundary element method forharmonic problem on exterior elliptic domain are introduced.Then,based onthis,the natural boundary reduction method for a kind of exterior problem ofanisotropic constant coefficients elliptic equation is discussed, the natural inte-gral equation and its solving method on circular boundary and elliptic bound-ary are obtained.These results can be directly applied in coupled methodand DDM for exterior boundary value problem.

最后，讨论了椭圆外区域调和问题的自然积分算子即D-N算子及自然边界元方法，并基于此研究了一类各向异性常系数椭圆型方程外问题的自然边界归化方法，首次得到其在圆周边界及椭圆边界上的自然积分方程及其求解方法，并将这些结果直接应用于外边值问题的耦合算法。

At first, numerical simulation are made on the temporal developing gas-phase mixing layer where the convective mach number is in the region of subsonic(0.5) and transonic(0.8). For the temporal problem where Mc is 0.5, researches where the computational field contains different numbers of initial disturbances(so-called n period problem) are made respectively, and vortex's types of evolution in mixing layer including different numbers of initial disturbances are investigated; For the temporal problem where Mc is 0.8, the distinct shock let structure is obtained, and its mechanism is analyzed at the same time.

文中首先对对流马赫数为亚声速(0.5)、跨声速(0.8)的时间发展单气相混合层作了数值研究，对Mc为亚声速单气相时间发展混合层，分别研究了计算域包含不同数目的初始扰动周期问题，考查了不同周期数的混合层中涡的不同演化方式；对Mc为跨声速的单气相时间发展混合层，得到了清晰的小激波结构，同时分析了小激波的形成机理。

Under the assumption that the feasible region of the problem is n dimension, if the algorithm is terminated after finite step, the point obtained must be a global optimal solution of the problem, else each accumulation point of sequence {vk} which the algorithm produces must be a global optimization solution of the problem.

在问题的可行域是n维的条件下，如果这个算法有限步后终止，得到的点必是问题的整体最优解；否则，该算法产生的点的序列{vk}的每一个聚点也必是问题的整体最优解。

For the first time, in [3] the authors discussed the inequalities of B-B and by using them the authors give a proof of the existence and uniqueness of the generalized solution for magnetostatic field problem with zero boundary value. By using the inequalities of B--H in, in[-5,6] the authors give a proof of the existence and uniqueness of the generalized solutions for 3-D magnetostatic field Neumann problem and 2-D magnetic field first boundary value initial problem.

前人已讨论了B—H间的几个基本不式，并由之证明了三维静磁场带零边值问题广义解的存在与唯一性，作者也曾利用给出的B—H间的不式证明了三维静磁场Neumann问题和二维时变场第一边值初值问题广义解的存在与唯一性。

In this paper,we consider the existence and uniquness of solution for Dirichlet problem of the Helmholtz equation on the domain with corners, i.e problemFor smooth boundary,we use potential theory to transform the problem into second kind boundary integral equation ,and use Fredholm alternative theorem,we obtain the existence and uniqueness of Dirichlet problem.

在本文中，我们考虑边界含尖点的有界区域上Helmholtz方程△u+k~2u=0的Dirichlet问题即问题与问题解的存在及唯一性。

The article first introduces the slide problem that occurred for testing the friction drive capacity of traction wheel after the lift is installed, then analyzes reasons for the problem, and also puts forward a solution to solve the problem.

结合电梯安装后的曳引轮摩擦传动能力检查时所出现的滑移现象，分析了产生这种现象的原因，提出了解决办法，且对解决所出现问题的施工可行性进行了探讨。

The frontogenesis process involves in the interactions among the systems of multiple scales. Since the hardness of the nonlinear problem, it is difficult to study frontogenesis analytically. The introduction of the effects of orography, friction and diabatic processes generally makes impossible the analytical resolution of the problem and leads to the use of numerical models. Primitive equations are numerical integrated together with a detailed description of physical processes. The circulation obtained is then used to diagnose and test theoretical mechanisms. It should be noted, however, that a fully description of frontogenesis in explicitly resolving the of large-, meso- and micro-scale flow in the same framework is not yet possible because of the excessive computer capacity and the time required. In order to deal with the problem, the action of large-scale background has been simplified and taken into consideration through the addition of the forcing into the nonhydrostatic cloud model.

大气锋生是一种多尺度相互作用的过程，理论研究遇到非线性的困难，在考虑地形、摩擦、非绝热等物理过程之后，解析研究更加棘手，通过数值模拟搞清其中的物理机制是重要的研究手段，但是把大、中、小尺度甚至微尺度的系统及其相互作用过程在一个模式里同时模拟好仍然受计算机速度和容量的限制，本论文在非静力云模式中通过强迫方式加入大尺度变形场的作用，在考虑到大尺度背景作用的同时，可以充分利用云模式所提供的丰富物理过程、非静力和高分辨率特点，开展一些过去较难进行的研究工作。

The work of this paper is as follows: 1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper "the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.

本文主要开展了以下几个方面的工作： 1 回顾了直线电机发展历史，电机的驱动技术演变，特别是针对直线电机的驱动，简要介绍了直线感应电机驱动电梯的优点和不同结构类型，对传统的v／f控制，基于空间矢量法的v／f控制，矢量控制，和基于电压空间矢量的直接转矩控制进行了比较，确立了本课题的研究主题：直线感应电机双边直推式驱动电梯的全数字变频控制。

The article combines with the treatment of a superficial civil air defense work to introduce how the grouting method to improve the performance of the backfill soil.

文章从治理漂浮人防工事的角度提出了注浆技术在改善回填土性质方面的应用，并详细阐述了注浆技术的施工流程。