杂原子

Purine: Any of a class of heterocyclic compounds with a two-ring structure composed of carbon and nitrogen atoms.

嘌呤：嘌呤是对由碳、氮原子组成的双环结构的杂环化合物的统称。

Purine: Any of a class of heterocyclic compounds with a two-ring structure composed of carbon and nitrogen atom s.

嘌呤：嘌呤是对由碳、氮原子组成的双环结构的杂环化合物的统称。

Purine: Any of a class of heterocyclic compound s with a two-ring structure composed of carbon and nitrogen atoms.

嘌呤：嘌呤是对由碳、氮原子组成的双环结构的杂环化合物的统称。

Purine: Any of a class of heterocyclic compounds with a two-ring structure compose d of carbon and nitrogen atoms.

嘌呤：嘌呤是对由碳、氮原子组成的双环结构的杂环化合物的统称。

Structural and density of state analysis shows the interaction of O atom and surface is the total contribution of valance orbital of O atom and hybridized surface orbital of NiTi alloy.

态密度分析和结构分析表明，O原子与表面的相互作用主要是由O原子价轨道和NiTi合金杂化表面轨道贡献。

The present invention relates to compounds of formula wherein R is hydrogen, lower alkyl, lower alkoxy, halogen or lower alkyl substituted by halogen; R is hydrogen or halogen; or R and R are together with the carbon atom to which they are attached -CH=CH-CH=CH-; R is hydrogen, lower alkyl, phenyl optionally substituted by halogen, or is hetaryl, optionally substituted by lower alkyl; R is hydrogen, lower alkyl, phenyl, benzyl, lower alkenyl, lower alkoxy, phenyloxy, benzyloxy, S-lower alkyl, halogen, CN, lower alkyl substituted by halogen or O-lower alkyl substituted by halogen; R is hydrogen or lower alkyl, aryl is phenyl or naphthyl; n is 1, 2 or 3; m is 1 or 2; and pharmaceutically acceptable acid addition salts and tautomeric forms thereof.

本发明涉及式化合物及其可药用的酸加成盐和互变异构形式，其中R 1 是氢、低级烷基、低级烷氧基、卤素或被卤素取代的低级烷基；R是氢或卤素；或R 1 和R与它们连接的碳原子一起是-CH＝CH-CH＝CH-；R 2 是氢、低级烷基、任选被卤素取代的苯基或者是任选被低级烷基取代的杂芳基；R 3 是氢、低级烷基、苯基、苄基、低级链烯基、低级烷氧基、苯氧基、苄氧基、S-低级烷基、卤素、CN、被卤素取代的低级烷基或被卤素取代的O-低级烷基；R 4 是氢或低级烷基，芳基是苯基或萘基；n是1、2或3；m是1或2。

The invention concerns a process for preparing heterocyclic carbenes of general formula in which R1, R2, R3 and R4 are identical or different and mean saturated or unsaturated, straight-chain, branched or cyclic, unsubstituted or substituted C1-C10 alkyl, C2-C5 alkylidene, C2-C5 alkylidine, C7-C19 aralkyl or C6-C14 alkyl groups, R3 and R4 can also stand for hydrogen or form jointly anellated, substituted or unsubstituted groups with between 3 and 7 carbon atoms and X stands for carbon or nitrogen, R3 being dropped if X is nitrogen.

本发明涉及一种制备通式Ⅰ的杂环碳烯的方法，其中在通式Ⅰ中，R1、R2、R3和R4是相同的或不同的，并且是饱和的或不饱和的，直链、支链或环状的，未取代或取代的C1－C10－烷基、C2－C5－亚烷基、C2－C5－次烷基、C7－C19－芳烷基或C6－C14－芳基基团，R3和R4可以是氢或它们一起形成具有3－7个碳原子的稠合的、取代或未取代的基团，X是碳或氮，并且当X是氮时，不存在R3。

In this paper,many achievements of studying on the synthesis,thermal decomposition properties and characteristics of the energetic complexes based on high-energetic compounds containing many nitrogen atoms such as carbohydrazide and 5-nitro-2,4-dihydro-3H-1,2,4-triazol-3-one as well as tetrazole,etc.

概述了以高能多氮直链化合物如碳酰肼，富氮杂环化合物如三唑、四唑类为配体的配合物的合成、热行为以及性能的研究情况，同时简要地从分子或原子结构描述了一些其他多氮含能配体如肼、肼基甲酸甲酯等所形成的配合物的晶体结构以及热分解行为，并对含能配合物的发展方向进行了展望。

The reaction barrier will be lowered by the substituents that delocalize the unpair electron in p z orbital of the central carbon atom.

R1和R2位置上取代基对α-氢转移反应势垒的影响取决于取代基对过渡态中碳原子的未参与sp2杂化的p z 轨道上单电子的离域作用。

The results show that:(1) When Cu〓 equatorially coordinated by four nitrogen atoms from amine ligands such as ethylenediamine, N-methylethylenediamine, 1, 2-diaminopropane and 1, 4, 8, 11-tetraazacyclotetradecane, etc., Cu〓 could be axially coordinated by oxygen atoms of-SO〓 group.

研究结果表明：（1）当Cu〓在赤道平面与来自胺配体（如乙二胺、N-甲基乙二胺、1，2-丙二胺和1，4，8，11-四氮杂环十四癸烷等）的四个氮原子配位后，在轴向则可以与来自磺酸根离子的-SO〓基团氧原子配位。

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。