环

Quartz plate area of 154 square meters, about 8 meters in diameter on the inner ring, core and the guidelines set to take off cut flower production, a diameter of about 14 meters between the outer and inner diameter mosaic of 12 bronze reliefs of 2.6 meters, Patterns for the 12 constellations.

石英钟盘面积154平方米，在直径约8米的内环上，盘芯和指针采取花挡镂空制作，直径约14米的外环与内环间镶嵌12个直径2.6米的青铜浮雕，图案为12星座。

In this paper, the innovative improvement of the cyclization and chlorination of quinoxaline was: 1. DHQX was prepared via reactingο-phenylenediamine with ethyl- oxalate in hydrochloric acid, the mixture was stired at 75-80℃for 2h.

本文对喹喔啉环合和氯代反应作了一些革新性的改进： 1、在环合合成DHQX时：以盐酸溶液为介质，邻苯二胺和草酸二乙酯在75-80℃进行环合反应约2h，即可得产物。

On the other hand, when the radical center is located at the 2-position of bicyclic cyclobutylcarbinyl radicals, ring opening pathway is favored unless a radical-stabilizing substituent is placed in the cyclobutyl ring at the bridge position.

另一方面，当自由基中心位于双环环丁基甲基自由基的2-位时，开环过程占主导地位，但是在双环的桥位上存在能够稳定自由基的取代基时，重排主要进行扩环反应。

Since a ring satisfies the related comparability if and only if every regular element is related unit-regular, In Section 2. 3, we first give some equivalent conditions for an arbitrary ring to satisfy the related comparability.

由于环R满足相对可比性当且仅当R的每个正则元是相对幺正则的，§2.2节给出了一般环中给定的正则元是相对幺正则的一些特征刻画，证明了文献[22]（1997）的主要结果在任意环中仍然成立。

In this dissertation, we establish the fundamental theory and methods to study systems of linear matrix equations over regular rings and polynomial rings over finite central algebras; and investigate some significant systems of linear matrix equations over the rings mentioned above.

本文在正则环和有限维中心代数上的多项式环上初步建立了研究矩阵方程组的基本理论和方法，并在上述环上研究了具体的具有重要意义的矩阵方程组。

Then the paper deduced the quench development characteristic of MgB2 tape by all the above study. The work environment cooled by GM cooler is an adiabatic environment. However the environment cooled by liquid helium is incomplete an adiabatic environment. In order to simulate the adiabatic environment, the tape was remodeled as follows. The tape is bundled by vitreous riband in half pile mode, and the angle of the tape and the riband is 45 degree. Then use cryogenic epoxy hardener to coat the surface of the riband.

上述的三个工作环境中，制冷机传导冷却工作环境是绝热工作环境，而后两者并非是绝热工作环境，为了模拟带材的绝热工作环境，对带材作如下处理：用玻璃丝带对已固定好电压引线的带材以半叠包的方式缠绕一圈，玻璃丝带与带材成45度夹角，然后用低温环氧胶均匀涂抹在玻璃丝带的表面，随后用烘箱烘烤已涂匀环氧的带材18-24小时，最后取出带材直到低温环氧完全固化。

From the structure, tetraazaparacyclophane is a ring compound with benzene rings connected by nitrogen-containing carbon bridges. It has a well-defined hydrophobic cavity.

四氮杂环蕃从结构来看是由氮杂碳桥将芳香环连起来的环状化合物，分子内具有空腔，该空腔上的芳环呈侧立状，具有一定的深度，并具有疏水性。

In order to obtained the six-membered ring compound and a thorough assignment of the spectra, and further to prove that the six-membered ring compound was formed from the hydrogen transfer, the compound N-butyl-4-(N-methylphenylamino)-5-amino- 1, 8-naphthalimide 6 was designed to obtained with N-butyl-4-bromo-5-amino-1, 8-naphthalimide and N-methyl phenylamine as the starting material. However it was difficult to obtain the desired product as the different solvent giving the different products except the desired product.

为了能够得到六元环化合物作为定标的物质及其确切的谱图分析结果，并且为了进一步证明由五元环产物通过氢转移得到六元环产物的正确性，设计用N-丁基4-溴-5-氨基-1，8-萘酰亚胺与N-甲基苯胺反应生成N-丁基-4--5-氨基-1，8-萘酰亚胺6，结果发现这种方法很难实现，选择不同的溶剂会生成不同的产物，却都不是目标产物。

In Chapter 5,the pyrolysis of substituted six-membered ring model compound 4-methyl pyridine has been investigated.Instead of detail theoretical analysis of the reaction mechanism,the general results have been proposed from the products distribution and the combination of the pyrolysis investigation of its analogous pyridine.The major products are H_2,C_2H_2,C_4H_2,C_3H_3N and HCN,here HCN is not a primary initial product at low extent of decomposition.The mole fraction profiles of products have been obtained from the near threshold ionization.The pyrolysis of 4-methyl pyridine is initiated from the methyl abstraction and hydrogen abstraction procedures which are associated with the understanding of the soot formation and the NOX precursor correspondingly.

主要产物为H_2，C_2H_2，C_4H_2，C_3H_3N和HCN，其中HCN为非低温时的热解产物；通过近阈值电离并导出物种随温度变化的摩尔分数曲线，更详细地定量地描述了产物随温度的变化。4-甲基吡啶热解主要从母体脱甲基和脱氢两个初始反应出发，一种趋势是形成大质量数的苯并或杂环的多环化合物，有助于了解炭黑形成过程中的复杂化学过程；另一趋势是开环生成小的碳氢和腈类物质，实验得出的含氮物质的种类及随温度变化有助于了解NO_x的前驱物质的形成及其变化规律。

In this thesis, we want to describe the new one-carbon and three-carbon chain extension and ring expansion of 2-aroyl-3,4-dihydro-2H-naphalen-l-one, which is the first report based on our knowledge.

本文在前人的研究基础上，首次开展了α—芳酰基苯并环己酮增加一个碳原子和三个碳原子的自由基扩环和链增长反应，以及自由基加成成环反应。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。