碳环的

The brushless permanent magnet automobile a. c. generator has the advantages of high reliability, long service life, high efficiency, good performance at both low and high speed, low radio interference, simplifying its associated voltage regulator, cutting down materials, technology simplified, as well as high power/weight ratio, etc.,and will be a new product with broad prospects and large market.

无刷永磁汽车交流发电机由于取消了碳刷、滑环及励磁绕组，可大大提高可靠性，延长使用寿命，具有效率高，低、高速性能好、无线电干扰小，与之匹配的电压调节器结构简单、节约原材料、工艺性能好、比功大等优点。

Carbonization is the use of carbon graphite - graphite seal ring when one of the main reasons.

石墨炭化是使用碳—石墨环时密封失效的主要原因之一。

Hoist chain using low-alloy steel forging, and quenching by the carburization treatment, has a very high tensile strength and wear resistance.

提升机环链采用低合金钢锻造，并经渗碳淬火处理，具有极高的抗拉强度和耐磨性能。

It can stead of the collector ring,carbon brush of winding motor.

它可以代替绕线电机的滑环、碳刷及其起动装置。

The inner diameter of b-CD cone is 0.65nm and the extra is 1.53nm. The hydroxyl groups of C(6)(the sixth carbon atoms of glucose unit and the same as follows) are located on the smaller opening of the cone with counterclockwise direction, while the hydroxyl groups of C(2) and C(3) are located on the larger opening of the cone with reverse direction.

环糊精外型是内空的圆台形，其中β-环糊精内空腔的直径为0.65 nm，外径为1.53nm.C(6)(葡萄糖单元上第六个碳，下同)上的羟基位于空腔的细口端指向逆时针方向，C(2)、C(3)上的羟基位于空腔的宽口端指向相反的方向。

The relative molar concentration ratios of c(superscript * subscript NO)/c(superscript * subscript NO2) changes as the temperature and pressure change. These results reveal that the two competitive reactions of C-NO2 homolysis (to form NO2) and isomerization may occur during the fast thermolysis of DNTF. NO formation from the cracking of furazan or furoxan rings may be limited by pressure.

结果表明，DNTF快速热裂解的主要产物CO、CO2、NO和NO2的相对摩尔浓度c与温度和压强有关，通过分析相对摩尔浓度比c(上标*下标 NO/c(上标*下标 NO2)随温度和压强的变化，揭示了DNTF中碳硝基C-NO2存在均裂生成NO2和异构化生成NO两条竞争分解的可能途径，同时压强可能抑制呋咱环和氧化呋咱环生成NO的可能性。

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。

These compounds are of substantial interest both inviewpoints of theory and practical applications, mainlyunder the stimulus to achieve synthetic models either foractive sites of iron-sulfur proteins or for transitionmetal catalysts. This thesis describes the synthesis, structures andconformations of 51 new iron-sulfur cluster complexes,which have been characterized by elemental analysis andstandard spectroscopic methods. In addition, single-crystalX-ray diffraction analyses were performed for 4 representa-tive new compounds. Reactivities of μ-〓 with mono- and di- Grig-nard reagents derived intermediates toward various organicelectrophilic substrates were studied, along with complexa-tion of arynyl-containing iron-sulfur clusters by 〓Thus, several bridged, non-bridged, monomeric, dimeric,homonuclear, heteronuclear iron-sullfur and iron-sulfur co-balt-carbon cluster complexes were synthesized. A novelreaction and convenient route for the synthesis in highyield of tetranuclear iron complexes 〓 containing atetracoordinated sulfur atom was discovered, whereas aplausible mechanism based on experimental results was propo-sed for the formation of the new cluster type.

鉴于有机铁硫原子簇化学在基础理论发展和应用方面的重要意义，因此我们开展了这一课题的研究，并取得以下主要成果： 1、本文共合成了51个新有机铁硫及含钴碳簇基的有机铁硫原子簇配合物，除用元素分析，NMR，IR，MS法表征其结构和构象外，还用X-光衍射技术测得四个代表性配合物的单晶结构和构象； 2、我们业已发现炔基Grignard试剂同〓可形成一种&开环&与&闭环&中间物的平衡混合物，研究该平衡混合物同各种亲电试剂的反应； 3、研究发现了一种可高产率地形成〓含〓四配位硫挛合簇的新化学反应并对此反应提出了—种有趣的反应机理； 4、首次由1，4-二溴丁烷双Grignard试剂与〓制得一种新型铁硫簇双硫阴离子活性中间体，并进而研究了它的亲核反应性能； 5、找到了通过〓的光化学反应来合成簇合物〓-〓的一条有实用价值的新路线。

85 And 119486/79. They are a novel type of antibiotic having both the wide antibacterial spectrum and high safety of penicillin and cephem antibiotics belonging to beta -lactam antibiotics, as well as the potent antibacterial activity and high beta -lactamase stability of carbapenem antibiotics.Sodium-(5R, 6S)-6-[-1-hydroxyethyl]-7-oxo-3- [-2-tetrahydrofuryl]-4-thia-1-azabicyclo [3.2.0] hept-2-ene-2-carboxylate 5/2 hydrate (faropenem sodium, hereinafter referred to as compound 1) is currently used as an oral drug for various infectious diseases and is reported to show potent antibacterial activity against not only methicillin-sensitive Staphylococcus aureus, Streptococcus pyrogenes and Streptococcus pneumoniae but also gram-positive bacteria for which conventional beta -lactam drugs have proved ineffective such as penicillin-resistant pneumococci, oral staphylococci and enterococci, also showing a wide antibacterial spectrum covering gram-negative bacteria such as Haemophilus influenzae and anaerobic bacteria such as the genus Bacteroides, which activity is due to its novel skeleton penem ring (Kagaku Ryoho no Ryoiki The Field of Chemotherapy, Vol.

他们是一种新型的抗生素都具有广泛的抗菌谱和高度的安全青霉素和cephem抗生素，属于β-内酰胺类抗生素，以及作为强大的抗菌活性和高β-内酰胺酶稳定的碳青霉烯类antibiotics.sodium -（ 5 R ， 6 S ）-6 -[ - 1 -羟乙基] - 7 -氧- 3 - [ - 2 - t etrahydrofuryl] - 4 -硫杂- 1 -氮杂双环[ 3 。2.0]庚- 2 -节能- 2 -羧酸5 / 2水合物（法罗培南钠，以下简称为化合物1 ）是目前用来作为口服药物，为各种传染病和报道，以显示强大的抗菌活性，不仅对甲氧敏感的金黄色葡萄球菌，链球菌pyrogenes和肺炎链球菌，但也克阳性菌为常规β-内酰胺类药物已证明无效，如青霉素耐药pneumococci ，口腔葡萄球菌和肠球菌，也显示出广泛的抗菌谱，包括革兰阴性菌如流感嗜血杆菌和厌氧菌如属杆菌，这活动是由于其新颖的骨架青霉烯环（（化学ryoho没有ryoiki领域的化疗），第13卷，第10号，第74-80 ， 1997年）。

Bisbenzimidazolium salts were used as a tetrahydrofolate coenzyme model, and thus the biomimetic synthesis of twenty-four acyclic diketones as precursors for macrocyclic ketones was successfully accomplished by using the addition-hydrolysis reaction of the bisbenzimidazolium salts with alkyl magnesium halide, wherein six diketones have not been reported in literature.

在本文中，受四氢叶酸辅酶的一碳单元转移反应的启发，作者以双苯并咪唑盐作为四氢叶酸辅酶模型，利用格利雅试剂与双苯并咪唑盐的加成-水解反应，成功合成了二十四种作为麝香酮及类似大环酮重要前体的长链二酮，同时，提供了一种麝香酮及类似大环酮的仿生合成新方法。

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。