前驱

The membrane micro-structure and its selectivity could be tailored by controlling the mole ratio of PTMOS to TEOS.

通过控制前驱物中的苯基的含量，即PTMOS／TEOS的比值，可以设计膜的结构和分离性能。

The porous SiO2 xerogels with controlled structure were obtained from TEOS in the presence of PEG by sol-gel method.

采用溶胶-凝胶法，以正硅酸乙酯为前驱体，以不同分子量的聚乙二醇为改性剂，制备结构可控的多孔SiO2干凝胶。

ESCA results show that silica is coated on surface of the polymeric microspheres. SEM analysis reveals that when water was used as a solvent, uniform silica coating on the surface of organic microsphere can be obtained, and when the reactive time is 10 minutes, an uniform coating layer can be prepared. But when tetrachloroethylene was used as a reactive solvent, an inhomogeneous silica coating is found on the organic microspheres.

由化学分析电子光谱仪纵深分析可以得到，矽的前驱物是藉由披覆方式附著在有机微球表面；SEM分析发现以水为溶剂所合成出之披覆有二氧化矽的有机微球表面呈现均匀披覆效果，并且当反应时间为10min时表面均匀披覆效果最好；而以四氯乙烯为溶剂的系统所合成之微球则呈现不均匀披覆。

Different types of molecules have been used to approach a selective synthesis of tetrahedral Pt nanocrystals.

本博士论文从前驱体和保护剂的角度研究纳米铂的形状控制合成，高选择性得到了具有广泛应用前景。。。

The results of the dissertation were concluded as follows:(1) It is essential to deposit a basic additive on the Mo-based catalysts for the synthesis of CH_3SH. The potassium-doped Mo-based catalysts exhibit the highest activity than that of the catalysts doped with the otherⅠA andⅡA group basic promoters. H_2-TPR and LRS characterizations suggest that the addition of a base leads to the transformation of octahedrally coordinated Mo to tetrahedrally coordinated Mo, thus leads to the split of low temperature reduction peaks. The interaction between the basic components and Mo lead to the formation of B-Mo interface phase, which are closely correlated with the formation of CH_3SH.(2) It has been found that Fe, Co, Ni and Te have evident promoting effects for the K-Mo/SiO_2 catalysts.

主要结果归纳如下：(1)在Mo基催化剂中，必须添加碱才具有可观的合成甲硫醇活性，在IA和IIA族元素中，K是最佳的碱促进剂，当K/Mo摩尔比为2，前驱体为K_2CO_3，采用共浸法制备的K-Mo催化剂活性最高。H_2-TPR和LRS表征显示，碱的加入导致表面八面体钼氧物种向四面体转化，催化剂的低温还原峰发生分裂，碱助剂与钼之间存在强相互作用形成了B-Mo"界面相"，该物种与合成甲硫醇密切相关。

The thermolysis of organometallic precursors in combined solvents is one of the most effective methods for preparing highly crystalline and size-controlled nanocrystals.

在混合溶剂中热解金属有机前驱体是制备尺寸可控、高度晶化的纳米材料的一个有效的方法。

The preparation factors have great effects on the activity and stability of thiophene HDS reaction.

随着Ni2P负载量、前驱体中Ni/P摩尔比的增加，催化剂的活性和稳定性先升高后降低。

This is mainly because time-table problem belongs to NP-complete category. So this paper will focus on the exploration and study courses scheduling algorithm, especially on the research of classification algorithm.

这主要是由于排课表问题属于NP完全类问题，因此本文将注意力集中于课表编排实用算法的探索与研究，重点研究课程前驱后继算法。

Analysis on precursor in laser ultrasonics in metal and non-metallic materials.

金属和非金属材料中激光超声前驱小波分析。

An official whose duty is to make introductions between unacquainted persons or to precede persons of rank in a procession.

给显贵人物领路的人，前驱职责是为互不认识的人作介绍或在队列中引领重要人物的官员

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。