矩

Two non-polar molecules near to a certain extent, they are the instantaneous dipole moment of mutual influence, so that each molecule of electronic Clouds tend to side, the nuclear bias on the other side, that is, two molecules each polarization, resulting in the instantaneous induced electric dipole moment.

两个无极分子靠近到一定程度，它们的瞬时偶极矩相互影响，使每个分子的电子云偏向一侧，核偏向另一侧，即两个分子互相极化，产生瞬时诱导电偶极矩。

The fast algorithm for computation of Zernike moments and normalization method are used to calculate the initial shape feature.

更多ike矩的参数n和m查询计算，减少了系数计算和半径幂次重复计算，对同一幅图像的多阶Zernike矩计算速度明显提高。

The method of moments approach to estimation implies imposing the population moment restrictions on the sample moments.

矩方法是将总体的矩限制应用于样本中。

Based on the mutual inductance,a technical scheme to change the parameters of asymmetrical phase windings was proposed.

通过引入互感的方法可以定量计算磁链的减小量，并给出了互感计算式，利用有限元法分析了一台样机互感随转子位置和电流的变化规律，理论推导了互感对平均转矩影响的程度，研究了四相8/6极开关磁阻电动机稳态转矩波形在两种绕组连接方式下的不规则特性，结合互感特性，提出了改变不对称相绕组参数的技术方案。

The Mo clusters tend to low magnetization and most of the even-numbered linear and planar ones are nonmagnetic.

Mo原子簇的磁矩普遍较小，一维和多数二维偶原子簇的磁矩为零。

Base on normal invariant moment and wavelet character, construct wavelet moment and eigenvector, which can rotate, zoom and is no change when moved.

基于一般不变矩和小波特征，构造出小波矩及一组具有旋转、缩放和平移不变性的特征量用于特征提取。

And the spin-orbital structure of nucleon would shed light on the nucleon spin problem.

而核子磁矩的自旋-轨道结构也对核子磁矩的问题有着重要的启不。

The realize method of ITC strategy in FSTP induction generation system is studied. In order to improve stable performance of FSTP induction generation system, SVM-ITC (ITC based on space vector modulation) is investigated. Creation method of reference voltage vector which includes change trend and magnitude information of flux link and torque is presented. Because there is no zero voltage vector in four-switch system, a method which employs opposite vector in equal time to replace zero voltage vector is proposed. Two vector modulation schemes are presented.

为提高容错型四开关三相异步发电系统的稳态性能，进行了基于空间矢量调制的瞬时转矩控制研究，提出了包含磁链与转矩变化趋势与大小信息的电压参考矢量生成方法；针对四开关系统无零电压矢量的情况，提出用等时间相反矢量来代替零电压矢量的作用，并给出了两种矢量调制方案。

ABSTRACT The researches of this thesis are carried out around the development of high performance machine tool spindle permanent magnet synchronous motor and its drive system. Five parts are included: First of all, concerning the operating characteristics of the machine tool spindle drive system, the optimum current control strategies of spindle PMSM are determined; The design rules of spindle PMSM's key parameters are summarized, based on the study on the influences of the design parameters on the performances of the PMSM operating at different current control strategies; The practical methods to improve the flux-weakening ability of the PMSM are presented; Based on the analysis and comparison of the operating performances of PMSM with different rotor structures, a novel PMSM rotor structure, which is of excellent mechanical performance, suitable for fluxweakening operation and can improve the torque output capacity in the same time, is presented.

本文围绕高性能机床主轴永磁同步电动机及其传动系统的设计研究展开，所做工作主要包括五部分：首先，确定了主轴永磁同步电动机定子电流的最优控制策略；通过对不同控制策略下主要设计参数对主轴永磁同步电动机性能影响的计算研究，总结了参数设计规律；提出了永磁同步电动机弱磁扩速的实用措施；在分析比较不同转子磁路结构电机的性能，尤其是弱磁扩速能力的基础上，提出了一种机械性能优越，易于弱磁扩速，同时能保证电机恒转矩运行时的转矩输出能力的新型转子磁路结构。

To achieve better results,we make use of the discrete Radon transform and a set of discrete orthogonal Tchebichef polynomials to establish relationship between the projection moments and the image moments,and then estimate the unknown projections from the known projections using this relationship.

提出一种新的投影数据估计算法，利用离散Radon变换和Tchebichef正交多项式建立图像矩和投影矩之间的关系，并用这种关系从已知投影数据中估计未知投影数据，达到提高重建图像质量的目的。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。