乙脲

Acetamide and thiouera had the parallel effect with GdnCl on the renaturation of lysozyme , both of them were able to prevent the aggregation of peptide, and at the high concentration they were able to restrain the refolding of peptide , but the structure of lysozyme under experiment condition could not be destroyed by them.

乙酰胺和硫脲则起着和盐酸胍近似的作用，能够抑制肽链间的聚集和肽链内的折叠，但是两者在本实验浓度内不能使溶菌酶变性。

OBJECTIVE:To study the effects of acetylsalicylic magnesium-ureaon thrombosis and platelet aggregation and its mechanism in animals.

目的：观察乙酰水杨酸镁-脲对血栓形成及血小板聚集的影响并探讨其机制。

The studies segmented polyester polyurethaneurea elastomers based on 4,4'-diphenylmethane diisocyanate, ethylene diamine and polybutylene adipate (M. W. 1975 and M. W. 1228) were studied by means of IR spectrascopy.

用红外光谱法对基於4，4'-二苯基甲烷二异氰酸酯、乙二胺和聚己二酸丁二醇酯（分子量分别为1975和1228）的嵌段聚脲氨酯弹性体进行了研究。

Hydrogen bonding in hard segment domains of segmented polyester polyurethaneurea based on 4,4'-diphenylmethane diisocyanate, ethylene diamine and polybutylene adipate(M. W. 1975 and M. W. 1228) was studied by means of IR spectroscopy.

用红外光谱法对基於4，4'-二苯基甲烷二异氰酸酯、乙二胺和聚己二酸丁二醇酯（分子量分别为1975和1228）的两系列嵌段聚酯型聚脲氨酯硬段微区中的氢键化进行了研究。

Eight hydrazone Schiff bases have been synthesized by the reaction of salicylaldehyde, o–vanillin, 2-hydroxy-1-naphthaldehyde with nicotinic or isonicotinoyl hydrazide in anhydrous ethanol respectively; Three thiosemicarbazone Schiff bases have been synthesized by the reaction of salicylaldehyde, o–vanillin, o–hydroxyacetophenon with thiosemicarbazide in hydrous-ethanol respectively.

主要包括以下五部分的工作： 1、以水杨醛、邻香草醛、邻羟基萘甲醛、邻羟基苯乙酮分别与烟酰肼和异烟酰肼按1：1的比例在无水乙醇中反应，制备了八种酰腙类Schiff碱；以水杨醛、邻香草醛、邻羟基苯乙酮与氨基硫脲在水-乙醇混合溶剂中反应，合成了三种Schiff碱配体，并对Schiff碱配体的结构进行了表征。

Naphthalene acetyl chloride was prepared firstly by the reaction betweenα-naphthylacetic acid and SOCl2 in anhydrous benzene, then reacted with potassium thiocyanate to obtainα-naphthalene acetyl isosulfocyanate, as taking an addition reaction with p-chloro benzoyl hydrazine the novel compound N-naphthalene acetyl-N'-p-chloro benzoylamino thiocarbamide was finally synthesized.

通过α-萘乙酸和SOCl2在无水苯中反应制得α-萘乙酰氯，然后与硫氰酸钾反应生成α-萘乙酸基异硫氰酸酯，再与对氯苯甲酰肼进行加成反应，生成新型化合物N-萘乙酰基－N'-对氯苯甲酰氨基硫脲。

To synthesize the octreotide, Phe-Leu-Glu-Glu-Leu and C_(15)H_(31)-CO-Lys-Thr -Thr-Lys-Ser peptides, the strategies are as followings: Fmoc- group as protective group for α-NH_2; TBTU, DIEA and HOBt as coupling reagent; and ethanedithiol -phenol - thioanisole - H_2O - TFA ( 2.5:5:5:5:82.5 , V/V ) as cleaving solution.

采用Fmoc固相合成法，以苯并三哗四甲基脲四氟硼酸盐、二异丙基乙胺和1-羟基苯骈三氮唑为缩合剂；苯酚—乙二硫醇—苯甲硫醚—水—三氟乙酸(5：5：2.5：5：82.5，V/V)为切割试剂，合成了奥曲肽、Phe-Leu-Glu-Glu-Leu及C_(15)H_(31)-CO-Lys-Thr-Thr-Lys-Ser三种小分子多肽，并对奥曲肽的合成规模进行了放大。

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。

It is found that when the molar ratio of sulphoxide,pyridine and acetyl bromide is 1∶0.6∶0.4,the catalytic effect on the ring-enlargment is the best,and the yield and purity of the final product can reach 76% and 97% respectively at a pH of 1.8 in toluene under refluxing for about 3.5h.

通过正交实验可得出以下结论：当N，N′-双脲-亚砜为2.5∶1，乙酰溴-亚砜为0.4∶1，吡啶-乙酰溴为1.5∶1，回流时间为3.5h，酸化pH值为1.8时，扩环反应结果最好，总收率可达76%，纯度97%以上。

The results showed 3 types of aluminum compound prepared in this paper all had good poison protection effectiveness on such impurities as stannous chloride,lead oxide,sodium hydrogen sulfate,and so on.Moreover,the mechanism of the poison of catalyst was also discussed.

结果表明，合成的3种防中毒剂即防－1、防－2(主要成分为乙酰丙酮合铝)及防－3(主要成分为二乙酰丙酮基异丙氧基铝)对二月桂酸二丁基锡、氯化亚锡、二正丁胺、硫脲、氧化铅及硫酸氢钠等杂质均有较好的防中毒作用；不同防中毒剂对不同杂质的防中毒作用有一定的选择性。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。