查询词典 definite equation

Due to rotation characteristics of spindle and definite parameterized structure of aerostatics lubricated bearing ,mass-spring structural method equivalent to aerostatics bearing system was introduced and system main coordinates and inherent frequency were obtained by establishing dual movement equation.

针对气体静压主轴的运动特性和气体静压润滑轴承的参数结构，提出了采用质量-弹簧结构方法来等效气体静压轴颈轴承系统，并建立了系统二自由度运动方程，最终确定了系统的主坐标系和固有频率。

Its primary coverage includes: Function and limit, derivative and differential, theorem of mean and derivative application, indefinite integral, definite integral and application, space analytic geometry and vector algebra, function of many variables differential method and application, multiple integral and curvilinear integral, infinite series, differential equation and so on.

其主要内容有：函数与极限，导数与微分，中值定理与导数应用，不定积分，定积分及其应用，空间解析几何与矢量代数，多元函数的微分法及其应用，重积分与曲线积分，无穷级数，微分方程等。

We can ex-tractn roots accurately and easily to each definite equation by the means of converting, discriminat-ing and substituting the auxiliary angle and so forth into the relevant radical formula.

对每个给定方程，通过转换、判别等方式，将其转换出的辅助角等代入配套求根公式，就可求出准确而简便的n个根。

Based on the dynamics fundamental equation, the rigid ships rolling coupled oscillation model was established, then the definite condition of the coupled oscillation equation under the regular transverse wave and first-order ordinary differential equations were presented. The ship vibration rule under the regular transverse wave was analyzed by examples, simultaneously the influence of damping coefficient on the vibration type was discussed.

基于动力学基本方程，首先建立了刚性船舶横摇的耦合振动方程，然后给出了在规则横浪激励下的耦合振动方程的定解条件和一阶常微分方程组，最后通过算例计算了在规则横浪作用下船舶的振动规律，同时研究了阻尼系数等参数对其振动规律的影响情况。

This curriculum primary coverage includes: Function and limit, a circular function derivative and differential, theorem of mean and derivative application, indefinite integral, definite integral, definite integral application, space analytic geometry and vector algebra, function of many variables differential method and application, multiple integral, curvilinear integral and surface integral, infinite series, differential equation.

该课程的主要内容有：函数与极限，一元函数的导数与微分，中值定理与导数的应用，不定积分，定积分，定积分的应用，空间解析几何和向量代数，多元函数微分法及其应用，重积分，曲线积分与曲面积分，无穷级数，微分方程。

In this paper, propose a new method based on the MATLAB/PDETOOL Box to solve the definite solution problems for elliptic equation problem, and the needed time of the program for the different nodes.

基于有限元的MATLAB/PDETOOL工具箱库函数，对MREIT中的椭圆方程定解问题进行数值求解，还给出了求解规则区域的定解问题时，不同节点所需的运算时间。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

Lyapunov second method is applied to analysis of partial stability of equilibrium of linear ordinary differential equation with constant coefficients, the problems on partial stable matrix, partial positive definite matrix and Lyapunov matrix equation are studied.

将Lyapunov第二方法用于研究常系数线性系统零解的部分变元渐近稳定性，可引出相关的一些特殊矩阵问题，包括部分稳定矩阵、部分位正定矩阵、矩阵方程的可解性等。

The first is refered to the vibration model with retardation for the market equilibrium price, where the knowledge of the second order linear ordinary differential equation is used. The second is refered to the optimal pricing model of the price under the frame of the social welfare, where the concept of the definite integral is exploited.

第一个是研究市场调节下平衡价格的阻尼振荡模型，使用了二阶线性常系数微分方程的课程知识；第二个是在引进社会福利因素时商品的最优定价模型，使用了定积分和微分法的课程知识。

First of all, in the study from magnetohydrodynamics equilibrium equations describe the plasma derived from the balance of the Grad-Shafranov equation of the theory of expression, and to analyze its borders in a fixed way to solve the region;then we solved the equation with Variational method in given pressure, and the exact numerical value of poloidal magnetic flux and the profile of the magnetic flux surfaces contours in the definite error range are given.At last, the poloidal and toroidal magnetic field with D-shaped is obtained.

在研究中首先从磁流体力学平衡方程出发推导出描述等离子体平衡问题的Grad-Shafranov方程的理论表达式，并分析其在固定边界区域内的求解途径；然后在给定的压强分布情况下采用基于能量形式的变分法对其进行了数值计算，并在一定的误差范围内得到了极向磁通的大致图像以及等离子体的平衡位形分布；最后求出了D-型截面下的极向磁场以及环向磁场分布。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。