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These two types of coupling reagents can effectively promote the condensations between N-methyl or Ca,Ca-dialkyl amino acids, and the yields are usually more than 90%. The reactions can be carried out using the so-called ￠one-pot￠ procedure without the preactivation of the carboxylic components.

这两类新型缩合剂可以高效地促进N-甲基氨基酸间或Ca，Ca-二烷基化氨基酸间的缩合，产物的收率一般在90%以上，反应可以采用&一锅法&进行，无须首先对羧基组份预活化。

METHODS:U937 cells were labeled with ［3H］ thymidine in the culture medium, test reagents were added into the cell suspension in 24-well plates. The counts*min-1 were counted in a liquid scintillation counter.

［3H］-TdR标记的U937细胞培养于24孔板，在高分子激肽原，激肽释放酶(kallikrein，KK)，因子Ⅻ和纤溶酶原的作用下，观察U937细胞的粘附情况。

According to The Montreal Protocol on Substances that Deplete the Ozone Layer, Halons that are used widely for fire control are controlled gradually. It is very urgent to find safe extinguishing reagents replacing Halons.

由于《关于破坏臭氧物质的蒙特利尔协定书》，一直作为消防灭火的主力军的哈龙灭火剂逐步被禁用，寻找一种新安全可靠的灭火剂成为世界各国的迫切要求。

The effects of electronic and steric effect of substituted groups, the structure of chiral catalysts and chiral reagents and the reaction system on optical activity of products are summarized.

文章概述了芳香酮取代基的电子效应与空间效应、手性催化剂和手性试剂的结构、反应体系等对产物光学活性的影响，以及全细胞酶、分离酶等不同生物催化体系中芳香酮结构对产物光学活性的影响，并展望了不对称还原的研究及应用前景。

Methods In this paper, samples of inkpad seals were printed on 4 different kinds of paper with 6 different brands of inks. The strong and weak extraction reagents were selected in the experiment of the double solvent extraction method. The size of slit and scan wavelength were measured, and the relation curve of the extraction percentage of inks with time was drawn.

选用6种不同品牌的印泥和4种纸张分别制作印泥印文的历时性样本，通过实验确定适用于双溶剂提取法判定印泥印文形成时间的弱提取剂和强提取剂；确定薄层扫描时狭缝的大小和扫描波长；绘制盖印时间与提取率的关系曲线。

Knowledge of synthesis methods, reactivities, reagents, protective groups and much more is best acquired - and retained - by way of detailed analysis and processing of complex synthesis paths.

合成法的知识， reactivities，试剂，保护组和更多被最好获得-并且保留-作为详细分析并且复杂综合道路的处理。

Cooked using the process of German companies BASF professional fur cooked reagents, using the most advanced production of chrome rubbing the skin and hair of a centralized processing, the main process are: skin pretreatment ---- 24小时Baptist acid -- Paper plates - rubbing the oil to heat the system ---- skim softening --------- forming fat -- stain-kneading fine - hot - such as dozens of fine cut Road, skin color into the finished product production Section, according to a fineness of wool ratio, and then after cutting, stitching, shape, and quality inspection procedures can only be a few dozen packaging factory.

熟制过程使用德国BASF公司的专业裘皮熟制试剂，采用国际最先进的铬揉生产法，对皮和毛进行集中统一化的处理，主要工艺有：原皮预处理----24小时浸酸---皮板去油---揉制----高温脱脂---成型---软化---加脂—复揉---染色---精烫--精剪等数十道，成品色皮进入成品生产工段后，还要根据毛质细度进行配比，再经过裁剪，缝合，成型，及质量检验等几十道工序才可以包装出厂。

In which actors with nucleophiles known nucleophilic substitution reaction, and the role of electrophilic reagents are known as electrophilic substitution reaction.

其中与亲核试剂作用者称为亲核取代反应，与亲电试剂作用者称为亲电取代反应。

Halogen, proton acids, sub-halogen acid are electrophilic reagents, olefin addition reaction is the electrophilic addition reaction .

卤素、质子酸，次卤酸等都是亲电试剂，烯烃的加成反应是亲电加成反应。

By esterification, saponification, doubledecomposition and formulation, liquid rare earth of monoisooctyl phthalate complex heat stabilizer was prepared with phthalic anhydride, isooctyl alcohol, sodium hydrate, rare earth chloride, mixed solvent and other reagents. The optimum conditions are: the temperature of esterfication is 130～140℃,and the reaction time is 1h. The temperature and time of saponification is 60℃ and 10min respectively. The temperature of double decomposition is 60～70℃,and the reaction ti...

摘 要：以邻苯二甲酸酐、异辛醇、氢氧化钠、氯化稀土、混合溶剂、助剂为原料，通过酯化反应、皂化反应、复分解反应以及复配制备了以邻苯二甲酸单异辛酯稀土为主要成分的液态稀土复合热稳定剂，其工艺条件为：酯化反应的温度控制在 130～ 14 0℃，反应时间为 1h ；皂化反应的温度为 6 0℃，反应时间为 5min ；复分解反应的温度在 6 0～ 70℃，反应时间为 1h ；水洗温度控制在 6 0～ 6 5℃；混合溶剂的用量为 5 0 %，稀土含量为 6 0 3%；在复配过程中，采用亚磷酸酯作为辅助热稳定剂，其用量为 5 %～ 7%，PVC中加入 2 %的这种稀土复合热稳定剂，在185℃下，其热稳定时间为 4 5min。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。