查询词典 explicit differential equation

On the basis of gas migration equation -Darcy Law,coal seam gas content equation -parabola equation ,ideal gas state equation and the continuity equation s of the gas flow,a dynamic model of gas unilateral flow in the coal seam is set .

根据基本假设，对煤层瓦斯流动规律进行了研究，运用瓦斯运动方程—达西定律、煤层瓦斯含量方程—抛物线方程、理想气体状态方程以及气体流动的连续性方程，建立了煤层单向瓦斯流动的动力学模型，并根据边界条件和初始条件，对动力学模型进行了求解，推导出煤壁单位面积的瓦斯涌出量的计算公式，分析了瓦斯涌出量的影响因素，利用测得的数据，进行了实例计算，并用vc编制了计算机程序。

Thirdly, according to the development of the frozen soil, the coupling model of single freezing pipe of axial symmetry of temperature field, stress field and moisture migration is put forward firstly. Then, by means of the progressing principle of potential field, the coupling model of temperature field, stress field and moisture migration which is under the condition of the multi-freezing pipes is extended. At last, the energy balance equation, stress balance equation, quality balance equation, geometric equation, physical equation, initial and boundary conditions etc are adopted to give the analytic solution to the problem of plane axial symmetry of single freezing pipe.

第三，在对室内试验和现场实测结果研究的基础上，分析了土体冻结过程中温度场、应力场、水分场耦合原理，并按照冻土体形成发展过程，首先建立了单一冷源冻结轴对称温度、应力、水分场耦合模型；接着利用势场的迭加原理，将单一冷源情况的三场耦合问题推广到多冷源情况的三场耦合；最后根据能量守恒平衡方程、应力平衡方程、质量守恒平衡方程、几何方程、物理方程、初始及边界条件，解出了单一冷源平面轴对称问题的解析解。

Under the condition of the slide between pile and soil around pile is taked into account,five equations are established, including the equation of compatibility between the settlement of pile cap soil and the settlement of pile cap; the equation of compatibility between the settlement of pile head soil and the settlement of pile head; the physical equation between the settlement of soil around pile shaft and the settlement of pile shaft;the equation of equilibrium between loads on the pile cap, side frictional stress and restraints of pile head; the equation of compatibility between the deformation of the pile body and the subtraction between the settlement of pile cap and the settlement of pile heap.

桩身单元和土单元存在着相互作用，在允许桩土相对滑移的前提下，建立桩顶土体沉降与桩顶沉降的协调方程、桩底土体沉降与桩端沉降的协调方程、桩土相对位移与桩侧摩阻力的物理方程、桩身力的平衡方程、桩身压缩和桩顶沉降与桩端沉降之差的协调方程。

In order to determine the solution set of the equation , by the means of meet-irreducible element and irredundant finite meet-decomposition, we first obtain the maximal solutions to the simple equation in the case that b has an irredundant finite meet-decomposition, and then consider the relation between the equation and the equation , based on this, we obtain the maximal solutions to the equation in the case that each element of the matrix B has an irredundant finite meet-decomposition and so determine its solution set completely.

为了确定方程的解集，本文利用交既约元与不可缩短的有限交分解等工具，同样地先求出简单形式的型矩阵方程的所有极大解，然后讨论方程与方程之间的关系，在此基础上，在B的每个元素均有不可缩短的有限交分解的情况下，求出了方程的所有极大解，从而完全确定了方程的解集。

One way is to regard them as the random variables submit to a certain distribution; another is to take them as a random process—— we derive random variables form any of its function's time development, and, the diffusion equation could be partially approached by a equation which is similar to the Ito stochastic integral equation so that the Ito stochastic integral equation is inter-related with the diffusion equation. Therefore, this process could basically reflect the uncertainty in different models.

PSFEM法是假定基本随机变量在均值点处产生微小摄动，利用Taylor级数把随机变量表示为确定部分和由摄动引起的随机部分，从而将有限元控制方程转化为一组线性的递推方程，求解得出位移的统计特性，进而求出应力的统计特性。

The non-isothermal kinetic data were analyzed with the Achar equation, Coats-Redfern equation, Kissinger equation, Flynn-Wall-Ozawa equation and Starink equation.The mechanism function and kinetic parameters of the thermal decomposition in the third step were obtained.The chemical reaction mechanism (F3) controlled the third thermal decomposition process.The apparent activation energy and the pre-exponential factor were 351 kJ·mol-1 and 2.57×10 30s-1 respectively.

采用Achar方程、Coats-Redfern方程、Kissinger方程、Flynn-Wall-Ozawa方程和Starink方程对非等温动力学数据进行了分析，得到了第3步热分解反应的机理函数、动力学参数和热分解反应动力学方程，其热分解反应过程受F3机理控制，表观活化能为351 kJ·mol-1，指前因子为2.57×

First the three-dimensional Hailmuhz equation of magnetotelluric field is split into two 2D equations which could be changed into 1D equation by Fourier transformation method. The two zootomic coefficients of the equation are found out by the derivation of vertical component of electromagnetic field being sufficient the equation and the boundary condition. The resolution of 1D equation can be confirmed.

首先将大地电磁场满足的三维亥姆霍兹方程降维分裂成两个二维响应方程，然后对每一个二维方程进行傅里叶变换，使二维方程变为一维方程，通过大地电磁场垂向方向的导数在地面上所满足的边界条件，确定外推方程中的两个待定系数，从而得到一维外推方程的解。

Because the equation is a various coefficients second-order parabolical partial differential equation,explicit difference formats usually have high condition for stability. Implicit difference formats have good stability,but they must calculate a set of algebraic equations,which are too complex.

由于泥沙扩散方程是一个二维变系数的抛物型方程，对于多维的方程，显格式往往稳定性要求很高，而隐格式虽然稳定性较好，但它要解大型的代数方程组，工作量也非常大，为了克服这两种格式的不足，常用ADI法求解，但仍存在一些计算量偏大等不足之处，因此构造出更好的差分格式是有必要的。

By the natural and harmonious relationship between differential forms and differential equations and between differential forms and vector analysis, we discuss the properties, which are covariant under the transformation of coordinates in the framework of differential forms, of particle motion in a central force field .

通过微分形式与微分方程和向量分析之间存在的自然而协调的关系，在微分形式框架下讨论了质点在有心力场中运动的特性并得出在坐标变换下其均是协变的

this paper proposes a design method which can improve the performance of fractional order differential filter obviously under the premise of not increasing the structure complexity of the filter.this scheme which bases on mutually compensatory characters of typical differentiator and uses interpolated method to improve performance of iir digital fractional differential filter.the improved frequency response of fractional differential filter is more close to ideal fractional differential filter,it indicates the validity of proposed method.

摘 要：提出一种在不增加分数阶微分滤波器复杂度的前提下，能有效提高分数阶微分滤波器性能的方法。该方法利用几种基于典型微分算子的分数阶微分滤波器之间的互补性，通过相互内插结合的方式，用于提高iir分数阶数字滤波器的性能。改进后的分数阶微分滤波器频率响应更接近理想分数阶微分滤波器，表明所提方法的有效性。

I was just taking her hand, to help her out of a car, and I knew it.

我只是握着她的手，扶她下车，但我知道这一切。

China and South Korea have excoriated Japan over its approval of new school books which they say whitewash the atrocities committed during Japanese occupation, and anti-Japanese protests have been held in Chinese cities. The lingering bitterness over Japan's past imperialism still threatens to mar relations between the big East Asian powers

中国和韩国强烈谴责日本通过新的中学历史教科书，他们认为这一教科书掩盖了日本在其占领期间所犯下的残酷暴行，反日抗议活动在中国数座城市发生，历史上日本帝国主义制造的痛楚无法被忘却，这有可能破坏东亚强国间的关系。