查询词典 simultaneous differential equations

The forward kinematics is analyzed by choosing one of the mechanisms which have one, two,three or zero angle constraint.Wherein,3-CCC is a new parallel mechanism which has three angle constraints and three distance constraints, Calay\'s formular and direction cosine matrix are used to describe the rotation matrix respectively.By setting Dixon\'s and Sylvester\'s resultant with the three angle constraint equations respectively and using parameters replacement to deal with the distance constraint equations,the 64 order input-output equation of the forward kinematics is obtained under both of the methods.Numerical example confirms these theretical results and the motion simulation is shown in VC++ by integrating OpenGL.

3对高小山提出的广义并联机构进行了研究，以其中具有角度约束的并联机构进行了分析，选取具有一个、两个、三个和零个角度约束类型中各一个机构进行了运动学正解求解，其中3-CCC是一种全部由圆柱副构成的具有三个线线角度和三个距离约束的新型并联机构，文中分别用Calay公式和方向余弦两种旋转矩阵建模方法对其位置正解进行了分析，通过对三个角度约束方程分别构造Dixon结式和Sylvester结式，以及对三个距离约束方程进行变量代换分别导出了位置正解输入输(来源：4040ABC论文网www.abclunwen.com)出方程，得出64组位置正解，并使用数值算例验证了其全部根。

Apparently, the approximate controllability doesn"t hold for generally linear parabolic equations with bounded control. It doesn"t hold for the semilinear heat equations presented there,either. Then, it is proved by analyzing its" solutions that no matter how long the time T is , there are targets that can"t be approximated by the solution of heat equation with Dirichlet boundary conditions;If a given target satisying certain conditions can be reached by the solution of heat equation .

本文先针对两个具体的半线性热方程系统证明了控制加约束后系统是不能控的；然后通过分析方程的解，对带位势及Dirichlet边界条件的热方程系统，无论时间多大，都存在不能控的目标；文中还证明了满足一定条件的目标可达。

The finite volume method is used to discrete the flow controling equations on staggered grid and the SIMPLE algorithm is adopted to solve the equations.

采用有限容积法在交错网格上对流动控制方程离散，然后采用SIMPLE算法求解。

Combining Huangkun's equations and the Maxwell equations for electromagnetic field, we obtain the dispersion relations of polaritons with the effect of nonlinear interactions included.

与这支色散关系相对应，在该频率域的入射电磁波的反射系数R＜1而形成一定的透射窗口，这是个有意义的结果。

Then the fundamental equations for plate/shell bi-nonlinear finite element model were set up with layered finite method. the fundamental geometric nonlinearity equations for the unbonded prestressed tendon and double spring element were proposed, and the double spring element was used to simulate the interaction of unbonded prestressed tendon and deviator.

最后，针对配置体外CFRP预应力筋混凝土梁的受力特性，对各规范和规程中的裂缝计算公式进行了相应的修正，建立了适用于配置体外CFRP预应力筋混凝土箱梁和T梁短期和长期裂缝宽度的计算公式。

Based on dynamic equilibrium equations of three-dimensional elasticity, a state equation was established for orthotropic foundation plates using double Fourier series, in which no assumption about stress or displacement modes was made. Analytical solutions and frequency equations of unified formulas were presented for thin and thick laminated foundation plates.

从三维弹性力学动力平衡方程入手，抛弃应力或位移模式的人为假定，利用Fourier双重级数，建立了正交各向异性地基板的状态方程，并分别给出了地基上任意层厚薄板静力问题的统一解析式和动力问题的频率方程。

The dynamical processes of nutrient release were described correctly by Elovich equation S(subscript t=a+blnt, double constant equation InS(subscript t=a+hlnt and parabola diffuse equationS(subscript t=a+bt^0.5 and nutrient release rate could be described by parameter b of all equations.

结果表明，20℃恒温模擬条件下缓释复合肥氮、磷、钾养分缓释性能较佳，3种养分释放的动力学过程可用Elovich方程S=a+blnt、双常数方程InS1=a+blnt和抛物线扩散方程S=a+bt^0.5表征，各方程参数b值均可用於描述缓释复合肥氮、磷、钾养分释放速率。

This paper is devoted to solving linear saddle point problems, Specifically, We consider nonsymmetric systems, written as usual in block form, where the upper left block is an invertible linear operator with positive definite symmetric part. Such saddle point problems arise, for example, in certain finite element and finite difference discretizations of NavierStokes equations, Oseen equations, and mixed finite element discretization of second order convection-diffusion problems.

中文题名求解鞍点问题的迭代方法副题名外文题名论文作者冯丽红导师曹志浩教授学科专业计算数学研究领域\研究方向学位级别博士学位授予单位复旦大学学位授予日期2002 论文页码总数87页关键词鞍点问题迭代方法网格离散线性方程组馆藏号BSLW /2003 /O241 /15 论文针对鞍点问题的求解分析了一些典型的快速算法。

For Dirichlet problem of elliptic type equations,Chen[7]has proved the existenceof viscosity solutions under nature structure conditions.As for the oblique derivativeproblems,Ishii[6]has obtained the existencec results.But there is no result ofthese types on parabolic type equations.

对于椭圆型方程的第一边值问题，陈亚浙[7]用闸函数方法证得在一定的结构条件下定解问题存在连续粘性解，而斜微商问题的同类结果是Ishii[6]证得的，但对于抛物型方程似乎还是个空白。

According to the construction constituted and the drive principles, the formation methods of the theoretical tooth shape and the practical tooth profile for hypocycloid and epicycloid are studied, and the right-angle coordinate equations and the complex number vector equations are deduced respectively.

根据摆线钢球行星传动的结构组成原理和啮合传动原理，研究了构成钢球摆线槽端面啮合副的内、外摆线理论齿形和实际齿廓的形成方法，并分别推导出内外摆线理论齿形和实际齿廓的直角坐标方程和复数矢量方程。

So it was last week in Selma , alabama.

上星期在亚拉巴马州塞尔马市发生的事件也是这样一个转折点。

The group also spearheads various social programs in China.

该组织还带头参与中国的各种社会活动。