等环的

Results Two new characterizations of regular rings are given.(1) If R is a left SF'-ring and R/Z is reduced, then R is strongly regular;(2) R is strongly regular if and only if R is a left SF'-ring whose every idempotent element of R is left semi-center and is LANE-ring.

结果 得到了SF'-环是强正则环的两个充要条件：(1)R是左SF'-环，如果R/Z是约化的，则R是强正则环；(2)R是强正则环当且仅当R是满足幂等元左半中心的左SF'-环，且R是LANE-环。

The chapter 1 introduces the background of imidazole, thiazole, tetrazole derivatives and their glycosides, and organic solid phase research.

论文第一章介绍了咪唑环、噻唑环、四氮唑环等杂环的合成，总结了糖苷的合成方法，对杂环的固相合成化学进行了简单介绍。

This paper is generaly devided into three parts,The first prepare knowledge,introduceing some conceptions asssociated with the polynomial ring and ring of power series such as power-zero element,inverse element and primitive polynomia and so on,prepare to introduce characters of power series.

本文主要分为以下三部分：首先介绍与环、多项式环、幂级数环密切相关的一些概念，如幂零元、可逆元、本原多项式等，为接下来介绍幂级数环的定义及其性质做下铺垫；然后着重讨论了环的性质，加深对多项式环与幂级数环的理解；最后讨论了多项式的性质，并将这些性质推广到幂级数环中，这也是本文的重点所在。

In 1999, Nicholson further introduced the concept of strong clean rings as follows: A ring R is said to be strongly clean if every element of R is the sum of an idempotent element and an invertible element that commute with each other.

W.K.Nicholson进一步引入了强clean 环的定义：一个环R 被称为强clean环，如果R中的任意一个元素均可以表示成一个幂等元和一个单位和的形式，并且幂等元和单位可换。

II, Polynomial rings on a general field( on contrast of those over a number field): concepts of ring, ideals, field and several special rings as domains, principal ideal domains and unique factorization domains, the unique factorization theory of polynomial rings.

二、一般域上的多项式理论（是数域上多项式理论的推广）：学习环、域和几类特殊结构的环（整环、主理想环，唯一分解环等）的概念，多项式环的唯一分解定理；三、线性代数：讲述一般数域上的向量空间理论（是数域上向量空间理论的继续和推广），模的概念，主理想环上的模的结构及其线性变换的若当标准型等；四、一元多项式的解及域论：学习域扩张及其相关概念，伽罗瓦理论，用伽罗瓦定理判断根式解的存在性。

During the investigation of the reactivity of O_SCl_2(PPh_3)_2CH=C(PPh_3CHCH=CH_2 and O_SCl_2(PPh_3)_2CH=C(PPh_3C(=CH_2)CH=CH2, several stable osmacycles with novel structure, such as osmabenzenes, osmafurans, osmacycles containing intramolecular-coordinated allene, intramolecular-coordination osmacycles containing osmacarbene, an osmacyclopentadiene, were isolated during the investigation of the reactivity of O_SCl_2(PPh_3)_2CH=C(PPh_3CHCH=CH_2 and O_SCl_2(PPh_3)_2-CH=C(PPh_3C(=CH_2)CH=CH_2.In addition, some convenient and efficient methods to prepare these osmacycles were developed.

首先，合成出两种具有反应活性的金属杂五元环IC配合物OsCl_2(PPh_3)_2CH=C(PPh_3CHCH=CH_2和OsCl_2(PPh_3)_2CH=C(PPh_3C(=CH_2)-CH=CH_2，并对它们进行了系统表征；进而，研究了这些活性五元配合物的反应性，合成出多种稳定的锇杂环配合物，其中包括锇苯、锇呋喃、含配位联烯的锇杂IC环化合化物、含锇卡宾的IC环化物、首例锇杂环戊二烯化合物等多元化的产物。

In order to search for the new pyrazolyl-heterocycles lead compounds, eight pyrazolyl- were synthesized from 3-ethyl-1-methyl- 4-substituted-5-pyrazolecarboxylic acid chloride and nitrogen heterocyclic rings such as 3-methyl-5-pyrazolone, 1H-3-ethyl-5-pyrazole ester, etc.

为了寻求新的含吡唑双杂环先导化合物，用 4 取代 1 甲基 3 乙基 5 吡唑甲酰氯与 3 甲基 5 吡唑酮、3 乙基 5 吡唑甲酸乙酯等含氮杂环反应得到了 8个新的含吡唑环的双杂环类化合物。

The comparison of petrology, lithofacies, petro-geochemistry and tectonic environment of the rapakivi granite both from Qinling-Kunlun and world shows that the rapakivi granite has same or consistent characteristics: rapakivi structure, sub-aluminous, high-potassic, alkali-rich magma, two-peak magma assemblage and formed in post-collision environment. However, there are some certain differences in some geochemical index, forming age of magma, and geotectonic position of outcropping.

通过秦岭－昆仑造山带中的环斑花岗岩同世界元古宙环斑花岗岩的岩石学、岩相学、岩石地球化学和构造环境等方面的对比研究发现，二者具有相同或一致的特征：具环斑结构，属准铝、高钾、富碱岩浆，具双峰式岩浆组合，形成于后碰撞环境，但其地球化学的某些指标、岩浆形成时代和出露的大地构造位置等有一定差异。

Bulk ceramic tower packing has excellent acid and heat resistance, except hydrofluoric acid outside the capability of various inorganic acids, organic acids and organic solvents, corrosion can be a variety of high-temperature, low-temperature occasions the use of a wide range of applications can be used to chemical industry, metallurgy, gas, oxygen and other industries drying tower, absorption tower, cooling tower, regeneration tower Jincheng packing are: Raschig rings, wash ring, different saddle ring, low ring, cross ring, pall ring, moment saddle ring, ladder ring, SK chain, combined plum blossom ring.

陶瓷散堆塔填料具有优异的耐酸耐热性能，能耐除氢氟酸以外的各种无机酸、有机酸及有机溶剂的腐蚀，可在各种高温、低温场合使用，应用范围十分广泛，可用于化工、冶金、煤气、制氧等行业的干燥塔、吸收塔、冷却塔、再生塔等。金诚填料有：拉西环、洗涤环、异鞍环、低环、十字环、鲍尔环、矩鞍环、阶梯环、 SK 连环、组合梅花环等。

Reaction of citric acid with paraformaldehyde gave anhydromethylene citric acid with a yield of 63%;the reaction of compound with acetic anhydride gave the corresponding anhydride with a yield of 87%;the esterification of compound with lauryl alcohol gave anhydrocitric acid monoester with a yield of 76%.

将等浓度的柠檬酸和多聚甲醛加热，反应生成柠檬酸缩醛环酯，产率为63%；与乙酸酐反应得到相应的柠檬酸酐，产率为87%；与月桂醇酯化，生成产物，产率为76%；用二氧六环做溶剂，将与等浓度的碱进行开环反应，生成柠檬酸月桂醇单酯，产率为83%。

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。