结构单元

The SMPEES copolymers have high ion exchange capacity because of o-methylhydroquione itself simple structure,which results in a high proton conductivity in reactively low degree of sulfonation...

发现邻甲基对苯二酚结构单元的存在，使聚合物具有较高的离子交换容量，从而使低磺化度的共聚物具有相对高的质子传导率。

The SMPEES copolymers have high ion exchange capacity because of omethylhydroquione itself simple structure, which results in a high proton conductivity in reactively low degree of sulfonation.

发现邻甲基对苯二酚结构单元的存在，使聚合物具有较高的离子交换容量，从而使低磺化度的共聚物具有相对高的质子传导率。

The molecular compositions of PCE-CGH and PCE-CGL were investigated by chromatography and chemical analysis. Rhamnose, arabinose, glucose and galactose were proved to be the main strctural unit of PCE-CGH, and trifle glucoronic acid was identified in the molecule. The compositions of PCE-CGL were relatively complicated. Inositol and amino sugars besides for glucose and galactose were also identified in its molecule.

其中，PCE-CGH主要是以鼠李糖、阿拉伯糖、葡萄糖和半乳糖为结构单元的大分子多糖类物质，并含有少量的己糖醛酸；PCE-CGL的分子组成相对复杂，除含有葡萄糖和半乳糖外，还含有一定量的肌醇和氨基糖。

The synthesis of the pentacyclic skeleton of Et-743 and the construction of the five chiral centers thereof.1. The core pentacyclic skeleton of phthalascidin was constructed with L-dopa as the starting material via thirteen steps. First, two basic synthons, the C-1 functionalized tetrahydroisoquinoline compounds 8 and N-protected Z-dopa derivative 9, were prepared from L-dopa. They were coupled via amide bond to form the dipeptide compounds 10, which were the first key intermediates. Then the primary hydroxyl groups were transformed into the corresponding amino aldehydes 11 via Swern oxidation. Followed by the intramolecular Pictet-Spengler cyclization, the pentacyclic compounds 12 were synthesized.

五环骨架的构建及五个正确手性中心的确立：1.1我们以L-多巴为起始原料，经过多步官能团保护和转化合成了基本结构单元8然后和苯丙氨酸衍生物9，通过缩合反应生成酰胺中间体10，经Swern氧化得到醛化合物11，然后再次利用分子内改良的Pictet-Spengler反应一步构建c，d两环，得到五环骨架化合物12，最后，实现了21-位羰基向氰基的转化，得到了C-1位官能化的化合物14，化合物14不但具有和Et-743一致的五环骨架，而且分子中五个手性中心立体构型也与其完全相同：其中，3，位和13，位的手性中心由原料L-多巴带入，而1，位，11，位和21，位手性中心则通过不对称诱导而确立。

Based on these, several problems with this method and its relationship with sequence stratigraphy are discussed.

在此基础之上，讨论了结构单元分析法存在的几个问题以及它与层序地层学的关系。

We also developed several experiential formula based on structural unit model for high-index surfaces, which can give an estimate of the energies of the high-index surfaces if the value of surface energy of (001),(110) or (111) are known.

作为各条曲线表面结构单元的两个低密勒指数面[001]晶带的(100)面和(110)面，[-110]晶带的(110)面和(111)面或(112)面其表面能值分别是对应曲线上的一个极小值点。

Chondroitin sulfate is aminocaproic acid and glucose sugar as the basic unit consisting of polymers, molecular weight of 1 × 104 ~ 5 × 104D.

硫酸软骨素是由氨基己糖和葡萄糖醛酸为基本结构单元构成的聚合体，分子量为1×104～5×104D。

In order to learn the influence of entanglements and other factors on the structural changes of atactic polystyrene, freeze-dried single-chain samples were prepared from dilute solutions of atactic poly- styrene in benzene at different concentrations (1×10-4 and 2×10-5 g/mL).

利用FTIR测试方法，测定a-PS在等温处理时红外吸收峰的时间依赖性与温度依赖性，研究样品中链缠结和链结构单元的堆积等因素对红外吸收峰的影响，进而探讨链缠结对a-PS分子运动的影响。

A series of sulfonated poly(arylene thioether/ether phosphine oxide)s was prepared by direct polycondensation of sBFPPO and BFPPO with the diphenol-type or dimercapto-type monomers such as hydroquinone, bisphenol-A, 4,4'-biphenol, 4,4'-diphenol (6F), 1,5-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, and 4,4'-thiobisbenzenethiol, respectively.

将BFPPO与sBFPPO分别与多种二羟基或二巯基单体，如对苯二酚、双酚A、4，4'-二苯酚、双酚F、1，5'-二羟基萘、4， 4'-二羟基二苯硫醚和4，4'-二巯基二苯硫醚，直接共聚制备了一系列磺化聚芳醚三苯基氧膦，侧重考察了二羟基和二巯基单体结构单元对产物的耐氧化性能的影响。

The reciprocity between PPCG and caffeine molecule was also simulated and calculated.It was found that the caffeine molecule was selectively distributed in CO2 habitat,but never in γ-butyrolactone habitat.

通过对PPCG与药物分子咖啡因相互作用的分子模拟和计算，进一步了解咖啡因分子是选择性地分布到CO2结构单元的区域中，而在GBL区域无分布。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失