三键

The hydrogen bonding of 1:1 complexes formed between acetamide and three kinds of isomers of picolines have been completely investigated using B3LYP method at various basis set levels from 6-31G to 6-31+G and 6-31++G. The results show that the interaction energies of hydrogen bond complexes between acetamide and picoline isomers have great effects on the values of h_.

2采用密度泛函理论等方法研究了乙酰胺分子分别与甲基吡啶三种异构体分子以1：1的比例形成的氢键络合物，从B3LYP/6-31G到6-31++G基组水平进行了优化，利用结合能数据讨论了焓对作用系数的差异。

All I have to do is press the function nine key and then return three time to get it to print, right?

我想行。我只要按功能键F9然后回车三次就能打印，对吧？

Each person can throw the shuttlecock three times .

每个人可以扔键球三次。

It was found:(1) the stability of the clusters increased with the bond number in the clusters;(2) the clusters with three dimensional geometry are more stable than ones with two decisional geometry;(3) the ionic potential of the clusters in gas phase and on the surface of the silver bromide grains are all positive, and the electron affinity are all negative.

结果表明；气相中团簇的稳定性随团簇中键数的增加而升高，三维构型的稳定性大于二维构型的稳定性；气相中Ag〓团簇的电离能都大于零，电子亲和势都小于零；溴化银颗粒表面的Ag〓团簇的电离势也是大于零，电子亲和势也是小于零。

We waited three months, and they let us have the space bar from another typewriter.

我们等了三个月，可他们却将其他的打字机上的空格键拆下来装在了我们的机器上。

In stereoisomerism, substances with the same atoms are bonded in the same ways but differ in their three-dimensional configurations.

第二种类型是立体同分异构体，具有相同原子的物质以相同的键合方式结合，但它们的三维构型不同。

In stereoisomerism, substances with the same atoms are bonded in the same ways but differ in their three-dimensional configuration s.

第二种类型是立体同分异构体，具有相同原子的物质以相同的键合方式结合，但它们的三维构型不同。

In stereoisomerism, substances with the same atom s are bonded in the same ways but differ in their three-dimensional configurations.

第二种类型是立体同分异构体，具有相同原子的物质以相同的键合方式结合，但它们的三维构型不同。

Multiple letters are assigned to each key (the "2" key is also "ABC", for example), and tapping repeatedly on a key switches between its corresponding letters until the desired character is chosen.

每个按键上都有若干字母（比如"2"键上同时有ABC三个字母），只要重复按键就可以选择相应字母，直到选到你要输入的为止。

In the process of laboratory study, oxycodone was prepared by oxidating thebaine at 6,14-position under oxydol, hydrodeoxidizing 7,8-position double bond and 14-position ether under palladium catalyst. Furthermore, N-methyl of oxycodone was isolated byα-chloro-ethyl chloroformate under anhydrous condition and protection of 14-position hydroxyl to obtain noroxycodone, which was further converted into methylnaltrexone by N-alkylation in presence of cyclopropyl bromomethane, then by isolating 3-position methyl of methylnaltrexone under boron tribromide, becoming hydrochloride to prepare target compound, natrexone hydrochloride.

实验室工艺方面，本文首先用双氧水氧化蒂巴因的6-位和14-位、在钯炭催化下加氢还原7-8位双键和14-位醚合成羟考酮，然后提出并优化了在无水和14-位保护的情况下，用氯甲酸-α-氯乙酯脱去羟考酮的N-位甲基合成去甲羟考酮，再用环丙甲基溴将去甲羟考酮的N-位烷基化合成甲基纳曲酮，最后采用三溴化硼脱去甲基纳曲酮的3-位甲基和成盐酸盐合成盐酸纳曲酮。

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。