查询词典 difference equation

The problem is reduced to a single unknown equation after algebraic elimination. The input-output equation, which is proved to be a 42th degree polynomial equation, is obtained.

首先根据不同的环路列出矢量方程，然后将方程转化成复数形式，经过代数消元后得到了输入输出方程。

After that, the important equation for calculating reverberation time is given based on the definition of reverberation time and least squares method. Finally, we use our new method to calculate reverberation time in a rectangular enclosure; we also compare our results with those given by experiment and Sabine's equation. The comparison shows that the new method is more effective and accurate than Sabine's equation in calculating reverberation time of small enclosures.

给出了描述小尺度封闭空间内声场的有限元模型；在该模型的基础上推导了计算小尺度封闭空间内混响时间的方法，并编制了相应的计算机程式；在算例部分，计算了一矩形封闭空间内的混响时间，通过与实验结果进行比较，验证了这一方法的正确性。

By utilizing the expansion expression of equilibrium point of the system, the homogeneous equation s solution was obtained, and then the nonlinear differential equation was equivalent to its nonlinear Volterra's integral equation of the second kind by the constant variation method.

首先将系统在平衡点附近进行展开，求得其齐次方程的解，然后利用常数变易法将非线性微分方程变为等价的第二类非线性Volterra积分方程。

The dispersion secular equation and displacement equation of Stoneley waves in infinite-solid media are obtained in this paper. The characteristics of Stoneley waves are discussed in this paper by using the secular equation.

推导了流体—固体无限介质斯通利波的特征方程及位移计算公式，并利用这一特征方程分析研究了流体—固体介质中斯通利波特性。

Neutral equation; stochastic functional differential equation; stochastic differential equation with delay; infinite delay; asymptotic propertie; semimartingale convergence theorem; Markovian switching; moment stability; moment boundedness

基础科学，数学，概率论、数理统计中立型方程；随机泛函微分方程；随机延迟微分方程；无限时滞；渐近性质；半鞅收敛定理； Markov调制；矩稳定性；矩有界性

Secondly, for a more general matrix equation in composition, we obtain another equivalent condition for the solvability of this equation and give an equivalent characterization to the solution set of the equation.

第二， 对于一般情况下的型矩阵方程，本文给出其可解的另一个等价条件，同时对其解集作了一个等价性描述。

These weight matrices are actually the least solution matrix and all maximal solution matrices of the min-implication fuzzy relation equation, respectively. The complete solution set of min-implication fuzzy relation equation can be determined by the maximal solution set of this equation.

同时给出了严格的定理证明：这些连接权矩阵分别为对应的最小-蕴涵合成模糊关系方程的最小解和所有极大解，从而得到了此模糊关系方程的完备解集。

A 3rd-Runge-Kutta-5th-WENO scheme is used in this study to get solution of the Level Set advection equation. A Projection method is used to solve the N-S equation, and different discretization schemes are presented. A TDMA algorithm is used to solve the energy equation. With the use of these methods, a numerical simulation of vapor-liquid two-phase flows during condensation with large density ratio has been successfully realized.

本文应用三阶Runge-Kutta－五阶WENO组合格式求解Level Set输运方程，应用投影法求解气－液两相流流场N-S方程，给出了不同投影法的具体格式，应用TDMA算法求解气－液两相流场的能量方程，成功实现了对大密度比气－液两相流冷凝流动问题的数值模拟。

Aiming at the problem that solution FEMequation set needs too much memory, segregated solotion methOd has beenadopted and for the first in China E l em ent- B y- E lement has been introduc edwhen solving flow field parameter equation sets. EBE technology need notassemble and store the global stiffness matrix, and minish effectively memoryrequires of solution equation set, moreover it has inherent high parallelity, andadvance equation solution.

针对求解流场有限元方程组占用计算机内存资源过多、限制求解规模的缺点，采用分离式求解法，在求解流场各参数方程时，在国内首次引入EBE技术，EBE技术不必组集和存储总刚矩阵，能有效地减小了方程组求解时对内存空间的要求，同时EBE技术具有内在的高度并行性，能有效提高方程组的求解速度。

Our conclusion is : For general transport equation and some special transport equations (slab geometry, spherical symmetry, pillar symmetry) we can evaluate some relevant physical quantities and geometrical properties from the exiting photon flux. The method we will use is to transform the transport equation into integral equation by integrating it along its characteristics, then we prove the nonlinear operator K is monotone and continuous with respect to its arguments and obtain the existence of K~-1. Consequently, we can evaluate some relevant physical quantities and geometrical property of the medium.

我们得到的结论是：无论对于一般的迁移方程，还是当介质具有某种对称性时(板对称、球对称、柱对称)的迁移方程，我们都可以根据泄漏的光子流估计介质各种相关物理量和几何特性，所用方法都是将迁移方程通过沿特征线积分转化为积分方程的形式，然后证明非线性算子K关于自变量的单调性和连续性，从而得到逆算子K~(-1)存在，进而达到估计介质各种相关物理量和几何特性的目的。

"The operators will suffer a temporary decrease in the number of consumers and short message services as people may not like having to provide their ID cards for a phone number," Xu Junqi, vice-dean with the Policy-Making Institute of the Telecommunications Research Centre under MII, said yesterday.

信息产业部下属的通信决策研究院副主任徐俊其昨天说：&实行手机实名制后，人们可能不太情愿用身份证注册手机号，所以通信运营商会暂时面临用户减少和短信用户减少的问题。&

I don't believe in make-believe!

我不相信这些虚构的故事。