查询词典 difference equation

The exponential equation had the best fitting effect for the relation of total forestry investment and total production value in 2000～2005,and its fitting equation was y=

结论河南省林业投资的经济效益是以指数型函数增长的，预期效益非常可观的，随着投资的增加，林业产值的增加速度加快。

The optimum models were obtained by non-linear fitting to describe the kinetic processes of adsorption of Cd on four types of soils in Northeast, China. According to the results, exponential equation and exponential function equation were more appropriate to fit the kinetic process than other equations.

通过非线性拟合的方法获取了适宜描述Cd在东北地区土壤上吸附动力学特征的最优化模型，综合来看，指数方程和指数函数方程比较适宜于描4种土壤对Cd的吸附动力学特征。

The existence and uniqueness of the solution with the help of the Banach fixed point theorem and the theory of operator semigroups are verified .The global exponential stability of KS equation and the global exponential stability and asymptotical stability of macro KS equation with the given boundary feedbacks are proved .

通过Banach不动点原理和算子半群理论证明了方程解的存在性和唯一性，并证明了KS方程在给定的边界反馈条件下是全局指数稳定的及广义的KS方程在给定的边界反馈条件下是全局指数稳定和渐近稳定的。

The growth dynamics of leaf length on stem and tiller could be described with a logistic model, leaf width with conic equation, and leaf shape with exponential function and quadratic equation. The effects of nitrogen and water conditions on leaf growth were quantified by the effective values of leaf nitrogen concentration and water content.

模型采用Logistic方程描述了水稻主茎及分蘖叶片随生长度日的动态伸长过程；利用二次曲线描述了叶宽随GDD的动态变化过程；分别用幂函数和一元二次方程描述了叶形的动态变化过程；另外，以叶片氮素和水分因子分别描述了不同水氮水平对叶片形态建成过程的定量影响。

The contents are the following:In chapter two, the existence and multiplicity results for the following equation of p-Laplacian type are obtained.For the elliptic quasilinear hemivariational inequality involving the p-Laplacian operator,in order to use the mountain pass theorem proving the existence result, the authors usually need to use the uniform convexity of the Sobolev space to prove the energy function satisfies the PS condition. But for the p-Laplacian type equation mentioned above, this method is no use. To overcome this difficulty, the potential function is assumed to be convex, then I prove the existence result and by using the extension of the Ricceri theorem, the multiplicity result for the problem is obtained.

在第二章我们首先考虑关于以下p-Laplacian型(p-Laplacian type)方程非平凡解及多解的存在性对于带有p-Laplacian算子的椭圆拟线性半边分不等式问题，为应用非光滑的山路引理证明解的存在性，在证明方程所对应的能量泛函满足非光滑的PS条件时，需利用Sobolev空间的一致凸性，但是对于具有更一般形式的算子的p-Laplacian型方程，不具备上述性质，在文中为克服这一困难，本人对位势泛函做了一致凸的假设，从而证明了解的存在性，并应用推广的Ricceri定理，证明了方程三个解的存在性。

Potential theory is used to transfer the exterior boundary value problem into the boundary integral equation of the first kind. A iterated Tikhonov regularization and a modified Tikhonov regularization are presented to solve the integral equation.

利用位势理论将外边值问题转化为第一类边界积分方程，再分别利用迭代的Tikhonov正则化方法和改进的Tikhonov正则化方法求解积分方程。

Based on the principle of variation, boundary value problem of pressure partial differential equation was transformed into the extreme value problem of fonctionelle and finite element equation of flow model was deduced for calculating the simulation result.

根据变分原理，将压力微分方程的边值问题转化为泛函的极值问题，建立了渗流模型的有限元方程。

The main contents of this course include: introduction, extraction of root from an equation, numerical solution of a system of linear equations, interpolation method, the method of fitting of a curve, numerical integration and differentiation, numerical solution of a differential equation, one-dimensional search method of extreme value problem, etc.

本课程包括以下内容：绪论、方程求根、线性方程组数值解法、插值法、曲线拟合法、数值积分与数值微分、微分方程数值解法、极值问题的一维搜索法。

Due to the effect of curvature of shell, the equation of motion of elastic waves in shell is much more complex than that in plate. The method of operator factorization can't be directly used to solve the equation of motion of elastic waves in shell by reducing it to the second order partial differential equations.

由于壳体曲率的影响，使得壳体的弹性波动方程比平板的运动方程复杂得多，难以直接采用算子因式分解方法，将其化成二阶偏微分方程求解。

Presents the study of second order linear constant coefficient progressive regression equation with the latest achievements in the "greatest common divisor" theory to give the great significance of Fibonacci combination series equation, Fermat Number , and Mersenne Number, and a only exceptional value each.

用"最大公约数"理论的最新结果，研究二阶线性常系数齐次递归方程，给出斐波那契数列组合式、费马数、梅森数在组合数学上的重要意义和它各自有一个且唯一例外

Objective:To compare the response control and attention of Schizophrenic patients with that of the healthy controls by Integrated Visual and Auditorycontinuous performance test. To quantitate the impairment of cognitive function in patients, and to explore the relationship between cognitive function and the severity of the disorder.

目的：探讨精神分裂症病人在IVA持续操作测试中的反应控制能力、注意力等，并与健康人进行比较，从而量化精神分裂症病人的认知功能损害，并进一步探讨其认知功能与疾病严重程度的关系。

Main effective factors including subcooling degree, mechanical vibration, gas hydrate reformation, environment temperature, noncondensing gas and surfactant are analyzed.

指出过冷度、机械振动、重复生成水合物、环境温度、不凝性气体、添加剂是影响气体水合物生成的主要因素，还对R152a水合物的放冷进行了实验研究。