查询词典 membered

The first part reports some new reactions of BNAH, especially the reductive cyclizations of some activated ethylenic compounds to five-membered carbocycles and a sevenmembered enolic ether ring, both of which may be useful in related areas.

详细论文的研究对象是重要的辅酶NADH的化学模型1-苄基-1，4-二氢烟酰胺。论文包括一个对近期该领域进展的综述和三部分工作。

The synthesis of DPEP and ETIOP were investigated, and our studies was focused on the porphyrins with five-membered exocyclic rings.

石油卟啉DPEP和ETIOP的全合成：合成石油卟啉可以为天然石油卟啉的结构鉴定提供标准样品。

The sodium ions located in the 12-membered ring main channel (with Q〓〓0.2 MHz) of zeolite omega are fully hydrated and so mobile to average out the 〓H-〓Na dipolar interaction, while those in the gmelinite cage (Q〓=2.3 MHz) are less hydrated and closely bonded to the lattice oxygen.

3〓Na MAS及〓Na二维四极章动实验的研究表明，在NaΩ分子筛中存在两类不同水合状态的钠离子：一类处于12-圆环主孔道中(四极作用常数Qcc＝0.2MHz)，另一类处于菱钾沸石笼里(Qcc＝2.3MHz)。

But the six-membered α-hydroxylactone of CPTs can hydrolyzed to its inactive carboxylate form readily at physiological pH.

但是，喜树碱的六元α—羟基内酯环在体内易水解，且存在毒性较大、具有种属差异等不足。

Toxicity and species difference are the other problems of CPTs. Homocamptothecins , a novel CPT analog which contain an expanded seven-membered β-hydroxylactone, have shown elevated antitumor activity and improved stability without species difference.

高喜树碱是近年来刚刚出现的一类CPT类似物，其特征是将α—羟基内酯环改造成七元的β—羟基内酯环，不仅活性明显提升，而且体内代谢稳定性也大大提高，并且不存在种属差异现象。

It is worthwhile to note that only the α-amino acids, could be activated into the five-membered cyclic imino acetoxyphosphoranes, while the β-ones not.

实验表明，仅α-氨基酸能发生这种自组装成肽反应，而β-氨基酸却不能进行，这是由磷的五元环特性决定的。

A series of five-membered lactams containing 1, 3-diene moity were prepared by RCEM reaction, the scope of this reacrion was expanded.

在上述研究的基础上，我们利用烯炔关环复分解反应合成了一系列含 1， 3-二烯结构单元的五元内酰胺化合物，从而进一步拓展了关环复分解反应的应用范围。

The absorption maxima and emission maxima didnt change obviously between the five-membered compounds when N-methyl as the bridge atom. The value of extinction coefficient was increased obviusly compared naphthalimide with naphthalic anhydride.

甲基化氮为桥原子的五元化合物之间最大吸收和发射波长相差不大，萘酰亚胺的消光系数比萘酐增加明显，loge最大相差可达0.45，荧光强度也略有增加，相差0.1左右。

Avermectin are 16-membered pentacyclic lactone compounds produced by Strephomyces avermitilis, which have extensive and high effect on many kinds of insect and mite.

阿维菌素是从阿维链霉菌的发酵产物中分离出来的16元大环内酯类抗生素，对多种动物寄生虫及农业害虫害螨有很高的杀虫活性，但是该药剂光照易降解而持效期短。

Two novel pyrazolone derivatives 2-ethylamino-6H-5-(1-phenyl-3-methyl/phenyl-5-pyrazolone-4-ylene)-1,3,4-thiadiazine (PMCP-ETSC/DPCP-ETSC) containing NNS six-membered heterocycles were synthesized by the condensation reaction of 1-phenyl-3-methyl/phenyl-4-chloroacetyl-pyrazolone-5 with 4-ethyithiosemicarbazide. The title compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR and single-crystal X-ray diffraction.

利用1-苯基－3-甲基／苯基－4-氯乙酰基－吡唑啉酮－5与4-乙基氨基硫脲发生缩合反应，生成了2个新的双杂环化合物2-乙氨基－6H-5-（1-苯基－3-甲基／苯基－5-吡唑啉酮－4-基）－1，3，4-噻二嗪(PMCP-ETSC/DPCP-ETSC)，并对其进行元素分析、红外光谱、核磁共振表征和晶体结构分析。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。