环

In this disseration, the cationic ring open-polymerization mechanism of THF、 butylene oxide and ethylene oxide were studied on the basis of electronic microstructures by using quantum chemicl method.

本文选取四氢呋喃、环氧丁烷和环氧乙烷的阳离子开环聚合为研究对象，运用量子化学方法从微观层次上对烷氧基化开环聚合过程进行了较为全面的研究。

The radial vibration of a piezoelectric ceramic thin ring and a metal thin circular ring are analyzed and their electro-mechanical equivalent circuits are obtained.

该换能器由一个厚度方向极化的压电陶瓷薄圆环及一个金属圆环组成。对压电陶瓷圆环和金属圆环的径向振动分别进行了分析，得到了各自机电等效电路。

By means of analyzing the influence of OD surface roundness error on the outer raceway of bearing ring, the processing method of bearing on internal grinder electromagnetic centerless clamper was improved, the influence of roundness error on outer raceway was decreased, meanwhile, the product quality was raised with less waste products.

通过分析轴承环外径表面圆度误差对轴承环外滚道的影响，改进了轴承在内圆磨床电磁无心夹具上的加工方法，降低了轴承环外径定位表面圆度误差对轴承环外滚道的影响，提高产品质量，达到了降低废品损失的目地。

The results indicate: 1 closed- loop gain and open-loop gain to meet basic relationship; 2 the stability of feedback is enhanced and output resistance increased. Furthermore, the result of open-loop and closed-loop gain of theoretical calculation is consistent with simulation which is applied by EWB software, which confirmed elementary conclusions and relationships in negative-feedback amplifier quantitatively.

结果表明：闭环增益与开环增益满足基本关系式；引入负反馈后稳定性得以提高，输出电阻增大；同时使用EWB对开环与闭环增益也进行了仿真分析，结果与理论计算一致，从而定量地验证了负反馈放大电路中的结论与关系。

So before applying Mather's theorem of connecting orbits to concrete Hamiltonian system, we have to check whether the set W〓 is empty or not, and which cohomology classes are C-equivalent. In present paper, by investigating the topological structure of action minimizing sets near a co-dimensional one torus which is preserved under generic perturbations and becomes hyperbolic in nearly integrable Hamiltonian system.

与传统的Poincaré-Melnikov方法相比，我们方法明显优越之处在于，一方面我们的方法不仅可以得到双曲环面之间的异宿轨道，而且当该环面附近的其它环面破裂时，可以得到不同Mather集之间的连接轨道，另一方面，我们把异宿轨的存在性的证明转化为双曲环面极小同宿轨的某种弱孤立性的证明，所需条件比Poincaré-Melnikov方法弱得多。

In chapter three, we study the strongly cleaness of some 3 times3 matrix rings over a commutative local ring and prove that if R is a commutative local ring, Then TM_{3} is a strongly clean ring.

本文第三章主要研究可换局部环上的某些三角矩阵环的强clean 性，并且证明如果 R是可换局部环，则 TM_{3}是强clean矩阵环。

The number of polynomial function over a finite commutative ring. This paper is on the basis of the research for the first question.With the structure of finite commutative ring,we know that a finite commutative ring can be expressed by direct sum of some finite commutative local rings.

本文主要基于对问题一的研究，并由有限交换环的构造可以知道，有限交换环可以由一些有限交换局部环的直和表示，于是就将问题简化到对有限交换局部环上多项式的判定。

Soc _RR is a injective left R-module.(4) Soc _RR is a left self-injective ring.|Theorem 4.2.9 Let R be a commutative notherian ring, then the following are equivalent:(1) R is a FS-ring.(2) R is a PS-ring.(3) Every minimal ideal of R is injective.(4) Every minimal ideal of R is p-injective.

定理4.2.9若R是交换的Noethe(来源：Aae0eBe0C论文网www.abclunwen.com)r环，则以下条件等价：R是FS-环；R是PS-环；R的每个极小理想都是内射的；R的每个极小理想都是p-内射的；R是IS-环；R的每个极小理想都是投射的；R的每个极小理想都是平坦的。

Using properties of zero-divisors, regular elements and subdirectly irreducible ring , we obtain some results on the commutativity of semi-prime ring and Jacobson semi-simple ring as follows 1 Let R be a semi-prime ring ,a∈R and 2a is not zero-divisor,If R satisfies one of the conditions in this paper , then R is commutative.

在某些特殊环的交换性方面取得了进一步的结果，并得到了一些新的结论，主要有一设R 为半质环，a∈R ，且2a 为非零因子，如果R 满足论文中八个条件之一，则可以证明环R 为交换环。

Our results indicate that not only the poloidal convection patterns in uppermost mantle have good correlations to surface tectonic motion, but also the toroidal ones reveal important information of their horizontal motion and rotation for the first time. There is a SEE_NWW strong convection zone close to the equator in toroidal convection patterns, which probably correlates with the large_scale shear zone near the equator and is the deep dynamic background of strong earthquake occurrence in this zone. The opposite rotating large_scale convection rolls in the Southern and Northern hemispheres suggest that maybe there is differential rotation between them.

研究结果表明，不但地幔浅部的极型场对流图像显示出了与大地构造运动的相关性并揭示了其深部动力学过程，更重要的是，地幔浅部的环型场对流图像首次为我们认识和理解板块构造的水平与旋转运动提供了重要的信息：环型场速度剖面中在赤道附近存在一条大致南东东—北西西向的强对流条带，可能与环赤道附近大型剪切带的形成相关，进而表明可能是该带强震发生的深部动力学背景；在南北半球存在的旋转方向相反的对流环表明它们整体上可能存在差异旋转。

Shop assistant: Please check at the door.

店员：请您到门口柜台交费。

In the end, transportation of PAHs in the environmental matrix was preliminarily investigated and discussed according to PAHs data of soils and sediments from a certain region in Shanghai. The result indicated that there are two or more pathways on PAHs transportation in the environmental matrix.

最后，对上海特定地区内PAHs在环境介质中的迁移径途进行了分析讨论，结果表明上海市土壤和沉积物等环境介质中PAHs的迁移存在多种途径。