查询词典 conservative vector field

The divergence of the vector field w; it is the dot product of the vector operator with the vector w , or .

向量场w的散度；为向量算符与向量 w 的内积，或。

An elliptic rotating field is produced when an induction motor operates in asymmetry, this paper proposes a model of jointed motion to describe the motion of an elliptic rotating vector and states that the elliptic rotating vector is jointed with two components, the main one rotates forward at a uniform speed while the adjunctive one jointed at the topend of the main one rotates backward around the joint point at a double speed, both make the elliptic rotating vector rotate at swinging amplitude, speed and direction.

感应电机不对称运转时产生椭圆旋转磁场，本文建立了描述椭圆旋转矢量的接合运动模式，说明椭圆旋转矢量是由一个主矢量带动一个付矢量一起旋转构成的接合矢量，主矢量以匀速旋转，付矢量链接在主矢量顶端同时绕着链接点相对主矢量以二倍速反向旋转，两者共同构成的一个单向椭圆旋转矢量。

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。

The more conservative your field is, the more conservative your suit should be.

并且你的领域越是保守，你的着装也要相应的越保守。

That is that information processing of neural networks is viewed as the composition of the two steps: field organization and field action, in which, field organization transformation converts input pattern into relevant structure representation, extracting the underlying architecture features and forms a architecture representation in action transformation space; The field action transformation converts the features representation into expected output. In strategies, we use the dual affine coordinates in dual flat manifold as way of representation of field organization system and field action system, which established a theoretical framework of analysis the coupling mechanism of information processing from the view of point of structure representation and model generation.

在具体人工神经网络结构描述的策略上，利用对偶流形空间上的对偶仿射坐标概念分别表示场组织变换系统和场反应变换系统，建立起从问题的结构表示和模型生成两种观点来分析信息处理的理论框架；分析了有监督和非监督学习人工神经网络模型在神经场变换机理下的形式化描述。

Furthermore, as stresses in the stress field influence the value of seepage coefficient k, which will results in the change of seepage field in the end, while on the other hand, the seepage field also has an effect on the stress field because of seepage forces. Based on the coupling model of seepage field and stress field, a program by finite element method is developed in this paper. And the comparison of results of the program and criterion method with that of test shows that the test results are reasonable, which can be referred to analyze the causes of dangers, evaluate degree of safety of the body and foundation, and design and optimize the measures of seepage control.

此外，考虑到应力场中的应力会改变土体渗透系数进而影响渗流场、而渗流场也因其产生的渗透力会导致应力场发生变化，两者之间存在耦合作用，本文基于渗流场应力场耦合分析的数学模型编制了渗流计算有限元程序CCOSAS1.0，其计算结果和采用规范方法所获得的解答与实测值的对比分析表明，该规律合理且具有一定的代表性，可用以分析险情发生原因、评价堤身堤基安全状况及设计与优化渗流控制措施。

The simulative model of temperature field and stress field in concrete , Heat and moisture coupling、Parallel simulative calculation of concrete with water pipe cooling、 Parallel feedback analysis of thermal characteristic parameters, and stress intensity factor of induced joint, which are the sixty-four-dollar questions, are studied in this dissertation. The main contents of this dissertation are as follows:(1)Based on the past and current research work, the calculation theory of the transient temperature field and creep stress field of mass concrete which self temperature influence is considered is deduced. The couple effect between the temperature field and humidity field of concrete, is considered on the basis of conservation law of water and energy, and the coupled formulation which coefficient is not constant of the heat and moisture in concrete is deduced. The calculation theory and model which is theoretically strict for solution to thermal problem in concrete with water-cooling pipes are recommended.

本文主要针对混凝土的温度场应力场仿真计算模型、热湿耦合、水管冷却问题的并行仿真、混凝土温度参数并行反演分析以及诱导缝应力强度因子计算等混凝土大坝温度应力数值仿真的关键技术进行了较为深入的研究，全文主要内容如下：(1)在现有研究基础上，推导了考虑自身温度影响的混凝土非稳定温度场和徐变应力场的计算理论；基于水分质量守恒和能量守恒原理考虑混凝土温度场和湿度场的耦合作用，推导了混凝土的变系数热湿耦合方程，并建立了相应的计算模型；引用严密的水管冷却混凝土温度场的计算理论和计算模型，比较了两种简化计算方法用于水管冷却混凝土仿真计算的不足。

From the formula for the field strength of a point charge,by means of the transformation of the field strength tensor in the special theory of relativity,the laws of electrostatic field and magnetic field of steady current s are derived in this paper to give the students a better understanding of the consistency of electric field and magnetic field.

从点电荷的场强公式出发，根据狭义相对论中场强张量的变换，推导出了静电场和稳恒电流磁场的诸定律，使学生对电场和磁场的统一性有了更为深刻的认识。

In the quasi-static area, the field distribution is almost the same as the static field; in the high frequency section, many high order modes occur, but the field uniformity is relatively better, and the field distribution is mainly the vertical polarization field; in the out of the vertical polarization area, the effect of high order modes is very serious so that the field distribution lost the property of vertical polarization.

在准静态区，场分布基本上与静态场相同；在高频区，出现了明显的高次模，但场均匀性较好，场分布主要是垂直极化场；在非垂直极化区，高次模影响非常严重，场分布失去了垂直极化的特性。

The use designs the digital cocurrent current supply and the probe head removable intelligence magnetic field measuring instrument to the Helmholtz coil magnetic field key point is the spool thread magnetic field strength survey, drew up the actual field intensity and the theory field intensity graph, has confirmed the magnetic field principle of superposition.

利用所设计出来的数字直流电流源与探头可更换的智能磁场测量仪对亥姆霍兹线圈磁场重点是轴线磁场强度的测量，绘制出了实测场强与理论场强的图表，验证了磁场叠加原理。

Go to your desktop and right click in a blank space.

请到您的桌面，然后右击一个空白。

Tara appears in Buddhism, Jainism, and particularly, Tibetan Lamaism, as a complex array of manifestations: goddess of ascetism and mysticism, mother creator, protectress of all humans as they cross the sea of life.

度母出现在佛教，耆那教里面，尤其是西藏的喇嘛教，作为一系列的陈列阵容；神秘的女神，创世之母，人类横过生命之海洋的女性保护者。