查询词典 field of constants

In this paper it is shown that there are two vector constants of the motion for a charged particle in the central field of force.

证明了带电粒子在有心力场中运动时有两个守恒矢量。

And the influence of the ratio of the two atom-field coupling constants on sudden death of entanglement is discussed.

同时探讨了原子和场的两个耦合系数的比值大小对两个原子的纠缠突然死亡的影响。

A model for computing the electric field dependent rate constants of gas-phase intramolecular electron transfer reactions by classical path method has been proposed within the activated-complex framework.

用经典轨迹方法，在过渡态理论框架下，提出外电场中气相分子内电子转移反应的速率常数计算模型，并用电子定域初始猜测诱导UHF-SCF技巧实现了两电子定域准透热态的分离。

For average magnetic moment, average hyperfine field and roomtemperature elastic constants of 〓, the volume effect and the pure substitution effect of Pt atom are seperated by considering the composition dependence of lattice volume.

利用〓晶胞体积随成份的变化，针对平均磁矩、平均超精细场和室温弹性常数，本工作还区分了Pt原子的体积效应和纯粹的替代效应。

Based on the concept of averaging electromagnetic field, the optical constants of Goodwin synthetic ash, Chinese Qitaihe coal ash and Russian ash Br-1 were calculated by Maxwell-Garnett and Bruggeman effective medium theory. Computational results show that, for the synthetic coal slag, the optical constants estimated by EMT consist with the experimental values, but for the coal-ash produced in combustion, the optical constants estimated by EMT using industrial analytical species deviate far from the experimental values.

基于电磁场平均的概念，利用Maxwell-Garnett和Bruggeman有效介质理论分别对Goodwin人工合成灰渣、中国七台河矸石煤灰、俄罗斯褐煤灰Br-1 3组煤灰的光学常数进行计算，结果表明，人工合成灰渣光学常数的有效介质理论值与实验值吻合，而利用工业分析成分，燃烧生成煤灰光学常数的有效介质理论值与实验值有较大偏差。

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 completely diagonalized Hamiltonian matrices of 3d2/3d8 ion configuration in the trigonal symmetry have been established by irreducible representation method. Taken into account the influence of the spin-spin coupling interactions omitted in previous publications, the spectra and the constants of crystal structure and zero-field splitting parameters of CsNiCl3 crystal and CsNiCl3: Mg2+ crystal are calculated and the influence of the doping to the spectra, the constants of crystal structure, zero-field splitting parameters and Jahn-Teller effect are studied. The results show that doping can change the structure of crystal which brings about the changes in the spectra and zero-field splitting parameters as well as Jahn-Teller effect.

应用不可约张量理论构造了三角对称晶场中3d2/3d8态离子的45阶可完全对角化的微扰哈密顿矩阵，在考虑了以前工作中被忽略的自旋-自旋耦合作用的基础上计算了CsNiCl3晶体和CsNiCl3：Mg2+晶体的基态能级、晶体结构、零场分裂参量和Jahn-Teller效应，研究了掺入Mg2+对CsNiCl3晶体的光谱、零场分裂参量及Jahn-Teller效应的影响和自旋单重态对基态能级的贡献，发现掺杂使得晶体结构产生畸变，从而改变晶体光谱的精细结构和零场分裂参量，不改变Jahn-Teller效应的分裂规律但改变分裂的大小。

This sequence can effectively remove the effect of magnetic field inhomogeneity and suppress the solvent signal. It can recover the spectral information such as chemical shifts, coupling constants, multiplet patterns, and relative peak areas in inhomogeneous fields.

本文提出了一种基于分子间多量子相干的有效消除磁场不均匀性和抑制溶剂峰的脉冲序列，利用该序列可在不均匀场下恢复化学位移、J偶合裂分和相对峰面积等谱学信息。

The irregular variation of lattice constants of the a-LiIO3 single crystal originated in the growth process and the fluctuation phenomena of lattice constants under the action of an electrostatic field were investigated by an X-ray double-crystal spectro-meter in the arrangement.

本文用X射线双晶衍射平行排列的方法，观察了α-LiIO_3单晶体生长过程点阵常数a与c不规则的不均匀性以及在静电场作用下c的起伏现象。观测出在静电场作用下a与c的变化和沿电场方向晶体表面层存在点阵常数的梯度。

The expression of space-charge field is given out in the paper with two time constants τpa and τpb. When considering and not considering the photovoltaic effect, the diagrams of the two time constants as a function of irradiance in units of 1/ are the same.

理论研究表明，空间电荷场的形成和擦除与两个时间参数有关，在考虑或者不考虑光生伏打效应两种情况下，这两个参数随擦除光强的变化有基本相同的变化规律，光栅的写入和擦除有相同的结果。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。