环

Since the exchange rings with all idempotents central satisfy the general comparability and have stable range1 [100] , this gives a new class of rings for which S K〓(R , is affinely homeomorphic to M〓 BS

若R为正则环，注意到S仿射同胚于P，便立得Goodearl定理[41]；因为所有幂等元中心的exchange环满足一般可比性且有稳定度1，这提供了S仿射同胚于M〓的一类新环。

The third chapter discusses and proves Il"yashenko"s Theorem, that is, if every vertex on the polycycle of an analytic vector field in the real plane is hyperbolic, then limit cycles cannot accumulate on this polycycle.

第三章详细讨论和证明了Il'yashenko定理，即平面解析向量场的多边环上每一顶均为双曲奇点，则此多边环附近不能结集无限多个极限环。

In the base of above research, establish movement model of hyperboloid clutch with rollers and find the relation between force of outer race and moment of inner race. I establish mechanics model of hyperboloid clutch with rollers with differential geometry.

在上述研究的基础上利用运动转化原理建立了内外环与滚柱之间的运动模型，并利用微分几何的相关知识通过对施加在外环上的主动轴向力的分解及合成，求的其在内环上所产生的力学反应，建立双曲面滚柱加载器力学模型。

And the inverse result of kinematics for the shield hinge equipment is obtained and one-degree inverse coefficient matrix of the impact, two-degree inverse coefficient matrix of the impact and the expression of velocity, acceleration for every component are calculated, all of these lay the foundation for the following kinetics of the shield hinge equipment.

研究盾构铰接装置的能控性问题，讨论铰接液压缸的驱动力对切口环上末端力的控制能力，通过盾构前体切口环的末端力能控性，理论证明盾构铰接装置在土层中工作时切口环的可行运动与不可行运动，并得到可行运动的运动特性曲线。

The Diels-Alder cycloadditions of [60] fullerene for preparation of optical limitingmaterials are discussed in chapter 3 and 6. Soluble cycloaddition derivatives of 〓aresynthesized by the reaction of 〓 with indene,1,1'-biindene andcyclopentadiene derivatives.〓Particular, the Diels-Alder cycloaddition of 〓 with1,1'-biindene under controlled conditions affords the stable monoadduct 〓〓of novel structure, which was confirmed by HPLC, FTIR, FD-MS,〓NMR,〓 NMR, HMQC and HMBC spectra, Its two bridgehead cage carbons resonate at70.91ppm, The 〓 NMR spectra showed 38 lines consistent with the 〓 symmetryassociated with [6,6] addition. The 〓 shows similar optical limitingproperties to that of 〓 in toluene for 8ns laser at wave length 532nm. Moreover, thehigh solubility of this adduct in polar solvents such as THF, acetone enables itsincorporation into sol-gel glass matrix. The thin films prepared via the sol-gel methodshow improved OL behaviour compared to those of 〓. The langmuir-Blodgett filmformation and uv-visible absorption of 〓 are also investigated. LBmonolayer of this compound is prepared on the air-water interface at 〓 mol/l. In chapter 4, three water-soluble derivatives of [60] fullerene: fullerol(1), theaddition product (2)of fullerol (1)with polyvinylpyrrolidone and fumaric acidderivative of 〓(3) are synthesized and characterized.

通过Diels-Alder环加成反应，用茚〓和1，1'-联茚〓及取代茂合成了一系列可溶性的〓环加成衍生物，发现可控制反应条件，使1，1'-联茚与〓反应，并高产率地得到具有新颖结构的单加成物，用HPLC、FTIR、FD-MS 及〓、HMQC、HMBC等多种波谱技术对其结构进行表征，测得它的两个〓杂化的桥头碳的化学位移为〓ppm，证明生成的衍生物为6∶6闭式环加成，〓NMR谱中共给出38个信号，表明〓联茚衍生物分子具有〓对称性；在波长532nm，脉冲宽度8ns的激光下，〓联茚衍生物的甲苯溶液的光限幅性能与〓的甲苯溶液相近，由于〓联茚单加成衍生物熱稳定性好，在四氢呋喃，丙酮等极性溶剂中溶解性好，能分别均匀地掺入溶胶-凝胶中，已发现它的溶胶(so1)光限幅性能优于纯〓的光限幅性能；使用Langmuir-Blodgett技术将〓联茚衍生物在空气和水的界面进行了LB单层膜和多层膜实验以及UV-Vis吸收谱研究，通过等温压缩曲线测试，证明浓度为〓〓时，〓联茚衍生物能够形成单层膜。

Current tuning is introduced, and the speed open-loop transfer function is established based on current closed-loop. A mathematical inequation about the speed open-loop transfer function is deduced, then the measured amplitude-frequency data is introduced in the inequation, thus the mathematic expressions about moment of inertia and mechanism time constant are obtained.

引入了电流校正环节，建立了基于电流闭环的速度开环传递函数，推导了关于该速度开环传递函数的数学不等式，再将实际测得的幅频特性代入此不等式中，得到了关于转动惯量和机械时间常数的数学表达式。

So-called inner point means that one point is located in a certain ring but not in the inclusive ring of this ring.

所谓内点是指位于某个环之内却不在这个环的被包容环内的点。

Three closed loops of output voltage,limited load current and input capacitor error are proposed.

控制策略上采用了电压环、压差环和限流环的三环控制方式。

The instantaneous voltage inner loop is used to control output voltage waveform to track a sinusoidal waveform.

在逆变器控制策略上采用电压瞬时值内环和平均值外环的双环控制方法。并用TMS320LF2407实现数字控制。

In chapter 4, Based on the orthogonality relations and duality of C-algebras, we study the decompositions of C-algebras, and give a Fourier inversion formula on C-algebras, which generalizes the Fourier inversion formula on the center of a finite group algebra over complex. As an application, we characterize the integral closure of C-algebras over the ring of integers, and show a necessary and sufficitient condition for elements of C-algbras being algbraic integral over integers.

第四章 我们应用C-代数的正交性及对偶性刻画了C-代数的一个分解，给出了C-代数上这个完全分解的Fourier反演公式，从而推广了Z分解的Fourier反演公式；作为Fourier反演公式的一个应用，我们刻画了Z在整数环Z上的整闭包，进一步我们研究了C-代数在整数环Z上的整闭包，给出了C-代数在整数环Z上为整元的一个充要条件。

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。