查询词典 simultaneous differential equation

The adsorption of Lutetium on the peat is studied under static conditions. The adsorption ratio and adsorption rate for Lutetium onto peat are so high that the surface complex reaction reaches equilibrium. The adsorption of Lutetium is not pH and ion strength dependent. The kinetic process of adsorption can be described by the Elovich equation excellently among five kinds of classical kinetic models, and the adsorption isotherm fits both the Langmuir equation and Freundlich equation very well by means of regression analyses.

静态条件下泥煤对溶液中Lu(上标 3+)的吸附率较高，而且吸附速度较快，镥与泥煤能迅速发生表面络合反应达到平衡。pH值和离子强度对低浓度镥吸附动力学影响不大。5个经典动力学方程中Elovich方程能较优地描述泥煤吸附Lu(上标 3+)的过程。

Firstly, the function sinx that appears in the simple pendulum equation is replaced with a polynomial of degree 3 using Maclaurin series expansion and Chebyshev polynomial approximation. Subsequently, the resulting equation which is a Duffing type equation is approximately solved with combing Newton's method and the harmonic balance method.

首先，利用Maclaurin展开和Chebyshev多项式加速技术将单摆振动方程中的正弦型恢复力用三次多项式近似代替，得到一个Duffing型方程；然后，将牛顿法与谐波平衡法结合起来建立Duffing方程的解析逼近周期及周期解，从而给出单摆振动的解析逼近解。

Integrate the load transfer principle and shearing displacement method to set up the load transfer equation between the pile of soil, using the discrete and fitting methods to solve the equation so as to educe the pile displacement of arbitrary section as well as the analytical solution. Comparing the results with the soil settlement solved by the Mair equation, the relative displacement can be gained.

1结合荷载传递原理和剪切位移法的思想建立隧道开挖作用下的桩土荷载传递方程，采用离散和拟合两种方法来对该一元二次非齐次微分方程进行求解，可分别得到桩身任意截面处的桩体位移以及桩身位移的解析解，并与基于Mair公式求得的地面下任意深度处的土体沉降进行比较，即可求出桩与桩侧土之间的相对位移。

The percolation equation of the natural gas and the rock body deformation equation have been discreted respectively to obtain their corresponding functional equation while the calculation method was derived and the coupled solution method was presented bas...

对天然气渗流方程和岩土体变形场方程分别进行离散，得到其相应的泛函方程。根据有限元法原理推出其计算方法，并给出耦合求解方法，这对于真实模拟气藏的开发，指导气田生产具有重要的意义。

The first kind is 0-equation model. It only includes mass and momentum conservation equations. Great progresses have been made in improving this model. It has successfully been applied to many natural rivers with complicated boundary geometry. The second kind is κ-ε model. The κ equation and ε equation are needed, besides mass and momentum conservation equations. Many researchers have studied the depth-averaged mathematical models of turbulence in recent years. However, the models were used mostly in regular artificial canals or natural water areas with simple boundaries.

对于宽浅型河流，采用深度平均法进行流场计算时，用得较多的有两类模型：一类是不增加任何脉动量的偏微分方程的模型，这类模型已在适体坐标下运用得较多且较成功；另一类是κ-ε二方程模型，它是近几十年来广泛应用的一类湍流模型，并发展了许多具体的形式，但大多数只对顺直河道进行了研究，对弯曲较大的河道研究不多，本文运用适体坐标，采用正交交错网格及非正交交错网格，把此模型运用到了弯曲较大的河段及具有汇流的河段，取得了较大的成功。

McRae equation and Nicol equation describing solvent effects on absorption wavelength have been compared, and it is found that McRae equation is more suitable here.

比较了两个典型的用来描写溶剂对吸收波长影响的McRae方程和Nicol方程，发现前者在这里更为适合。

Time scale; delay dynamic equation; neutral dynamic equation; oscillation; generalized characteristic equation; Riccati transformation

基础科学，数学，数学分析时标；时滞动力方程；中立型动力方程；振动；广义特征方程； Riccati变换

Firstly, the three-dimension boundary question and its corresponding variation question concerning the point-source electrical field on a 3-D structure are presented. Secondly, the finite element method is used to solve the variational equation. The study area is divided into many tetrahedral elements. Then, we interpolate with a tri-linear function in each element. So, the variational equation is converted into a linear equation system. Finally, taking into account saving of time, we make use of symmetric successive overrelaxation preconditioned conjugate gradient algorithm to solve large linear system, and obtain the potential value of each node, resulting in the calculation of the apparent resistivity values on the ground surface.

首先给出了三维构造中点源电场的边值问题以及相应的变分问题；然后利用有限单元法求解变分问题，采用四面体单元对研究区域进行剖分，在单元中进行三线性函数插值，将变分方程化为线性代数方程组；最后，考虑到节约计算时间，利用对称超松弛预条件共轭梯度迭代算法求解大型线性方程组，得到了各节点的电位值，进而计算出地表的视电阻率。

Kinetics of methyl parathion or carbaryl adsorption could be described by First-order equation, Elovich equation and Two-constant equation.

结果表明，Langmuir方程能较好的描述甲基对硫磷和西维因在3种矿物表面的等温吸附过程，且蒙脱石对农药的最大吸附量大于高岭石和针铁矿。

In chapter 4, in the frame of partially ordered F-type topological space, we research the existence of the solution of a nonlinear operator equation Lx = Nx, and the convergence of the iterative sequence {u_n} which satisfies Lu_(n+1)= Nu_n for a solution of the equation. Then, we give the conditions for multiplicity of the solutions of this operator equation.

第四章，在半序F-型拓扑空间框架下研究一类非线性算子方程Lx=Nx解的存在性，以及满足Lu_(n+1)=Nu_n的迭代序列{u_n}对于方程解的收敛性，并给出这类算子方程具有多解性的条件。

The two-acre Dunbar Community Garden in Little Rock has served as a model for several years.

几年来，坐落于小石城，占地两英亩的邓巴社区菜园树立了一个标杆。

Jerry points to the jacket hanging in the bathroom. It's ruined, and unwearable What?

杰瑞指着洗手间里挂着的夹克，毁了，不能穿了）什么？