数环

In this paper, we study syzygies of injective resolvent s and cosyzygies of injective resolutions, and probe the relationship of injective resolvent s and injective resolutions, and then prove that if R is a Noetherian ring with id≤n, then every left R-module has injective dimension at most n or ∞.

研究了内射预解式的合冲模与内射分解式的上合冲模，并探讨了内射预解式与内射分解式之间的联系，证明了如果环R是Noether环且id≤n，则每个左R-模的内射维数小于等于n或者为∞。

The smaller fullerenes C2n (2n 60) violating IPR, inevitable suffer large strain energies and show high lability. Besides that, quasi-fullerenes violating the classical definition, contain rings of other size, for example 4 or 7, are expected to suffer extra local strain or/and further loss ofπdelocalization, and thus highly unstable.

碳原子数少于60的小富勒烯，和结构中含有除五元环、六元环之外的其他结构的准富勒烯，由于不满足IPR规则，结构中必然存在较大的张力，因此具有较高的化学活性，难以在实验中合成和分离。

A Theoretical Study on the Reaction Mechanism of Epoxidation Reaction of the 4- Bicyclo

CEPS 思博网--文章书目；-1页数：7 需求点数：28 电子全文：请登入。篇名（4-溴甲基双环[4.4.1]-1，3，5，7，9-十一碳五烯基－3-）甲醇环氧化反应机理的理论研究

Based on this core reaction, two significant libraries of isoxazole and triazole substituted methane derivatives and triazole substituted triazine derivatives were synthesized concisely from the inexpensive and readily obtainable small molecular starting materials which had been used in previous two chapters mostly.

以此为核心，以价廉易得的小分子原料通过数步反应，分别合成了异噁唑、三氮唑杂环取代的甲烷衍生物和三嗪联三氮唑杂环衍生物这两个比较有意义的小分子化合物库，达到了分子的多样化。

The microwave-assisted reactions could be finished within several minutes to give high conversion and selectivity.Substrates whose aryl groups were substituted phenyl or naphthyl groups were more suitable in this reaction.

以TfOH为催化剂，在优化的反应条件下，大部分反应都可在数分钟内完成，该反应对于芳基是取代苯环或萘环的的底物效果较好，能得到较高的原料转化率和产物选择性。

Monroe discovered that the Earth was surrounded by several rings, or bands, that appeared deep grey or brown in color, and that these bands were occupied by discarnate or exteriorized entities who either still occupied physical bodies or who had recently left their bodies as a result of the death of the body.

门罗发现，地球被数个环或带所环绕，颜色显现为深灰色或褐色，这些环带被非肉身的或形象化的实体所占据，他们不是依然占据肉身，就是因肉身死亡而刚离开他们的身体。

Steel banding before the foundation set in the center of the cushion, and cross through the center axis for vertical and horizontal, and then through the center ring for radiation tendons and tendon distance and ring the number.

钢筋绑扎前，先在垫层上定出基础中心点，并通过中心点定出纵横十字轴线，再通过中心点定出辐射筋和环筋的距离和环数。

To optimize the reaction condition for the purpose of target compounds synthesis, the advance of 1,3-dipolar cycloaddition and click chemistry is reviewed. The conditions of the reaction between azides or nitrile oxides and terminal alkynes were optimized experimentally and the best operation condition was established.

以此为核心，以价廉易得的小分子原料通过数步反应，分别合成了异噁唑、三氮唑杂环取代(来源：29ABceC论文网www.abclunwen.com)的甲烷衍生物和三嗪联三氮唑杂环衍生物这两个比较有意义的小分子化合物库，达到了分子的多样化。

This paper show you target center and cirques can be eliminated from target image little by little because of the high image background contrast, and the results of shooting therefore can be determined.

本文针对靶图像背景颜色对比度大的特点，采用逐步处理分离的方法，将靶中心和靶环从背景中分割出来，提取弹点坐标，进而判定打靶环数。

Moreover, the above results are applied to the planar systemsto get the cyclicity of the rough 2-point-loop.

同时，我们把所得结果应用到平面系统获得平面系统两点粗异宿环的环性数。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。