脲

Adhesive has environmentally-friendly products are mainly urea-formaldehyde resin, melamine urea-formaldehyde resin and modified phenolic resin; concrete water reducer products are mainly water-reducing agent has Sulphamate, polycarboxylate water reducer and superplasticizer melamine.

胶粘剂产品主要有环保型脲醛树脂、三聚氰胺改性脲醛树脂和酚醛树脂；混凝土减水剂产品主要有氨基磺酸盐减水剂、聚羧酸减水剂和三聚氰胺减水剂。

Thiadiazole ; acyl urea; acyl thiourea; synthesis; plant growth regulating activity; auxin activity; cytokinin activity

1； 3； 4-噻二唑；酰基脲；酰基硫脲；合成；植物生长调节活性；生长素活性；细胞分裂素活性

The results showed that granular urea amended with dicyandiamide and N- thiophosphoric triamide induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C a...

结果表明，施用硝化抑制剂和脲酶抑制剂涂层大颗粒尿素肥料的土壤硝酸还原酶活性最高；施用大颗粒尿素，脲酶活性最强，微生物量碳、氮最高。

The title compounds were synthesized by the reaction of symmetric N , N '-diarylthioureas with hexylamine in the presence of triethyl amine,and the intermediate N , N '-diarylthioureas were formed by the direct reaction of carbon disulfide and arylamines.

首先采用二硫化碳与胺直接反应得到对称的N， N'-二芳基硫脲，然后在三乙胺存在下与环己胺反应得到1-环己基-3-芳基硫脲。产物结构经核磁共振和质谱分析确证

The reaction kinetics of poly urethane formation and that of trimerization of isocyanate in a system of modified by urethane were studied by FTIR.

采用傅里叶快速红外光谱技术研究了氨酯改性聚异氰脲酸酯反应体系中氨酯、聚异氰脲酸酯生成的反应动力学，结果表明，在该反应体系中，氨酯反应和异氰酸酯的三聚反应是同步发生并同步进行的，其中三聚反应是一级反应；氨酯对异氰酸酯是一级反应，对聚醚二元醇为0级反应。

The reaction kinetics of polyurethane formation and that of trimerization of isocyanate in a system of polyisocyanurate modified by urethane were studied by FTIR. The results show that the two competing reactions occurred and progressed simultaneously, and the trimerization was found to be first order, and the polyurethane formation was first order with respect to the isocyanate concentration and zero order with respect to the polyol concentration.

采用傅里叶快速红外光谱技术研究了氨酯改性聚异氰脲酸酯反应体系中氨酯、聚异氰脲酸酯生成的反应动力学，结果表明，在该反应体系中，氨酯反应和异氰酸酯的三聚反应是同步发生并同步进行的，其中三聚反应是一级反应；氨酯对异氰酸酯是一级反应，对聚醚二元醇为0级反应。

Particularly, the neutral anion fluorescence chemical sensor uses cholic acid molecules as the molecule frame, and introduces a neutral thiourea or ureido to the positions of a 3 bit carbon atom and a 24 bit carbon atom to be used as a bonding unit; a fluorescence chemical functional group is introduced to the positions of the 3 bit carbon atom and the 24 bit carbon atom or to other positions and used as a signal unit, and then a neutral anion fluorescence chemical sensor is synthesized.

具体而言是以胆酸分子为分子骨架，在其3位碳原子和24位碳原子上引入中性硫脲或脲基，作为键合单元；在3位碳原子和24位碳原子上或其他位置引入具有荧光化学官能团，作为信号单元，合成中性阴离子荧光化学传感器。

OBJECTIVE To explore the pathogenesis of Ureaplasma urealyticumand Mycoplasma hominisin urogenital tract infection and their susceptibility to antibiotics.

目的探讨解脲脲支原体和人支原体在泌尿生殖系统感染中的致病作用及其药敏情况。

In this study, three model compounds of urea-formaldehyde resin, such as methylene diurea, Uron and tetrahydro-5-ethyl-2(1)-s-triazone, were synthesized.

本工作合成了脲醛树脂模型化合物亚甲基二脲、Uron和5-乙基-2(1)-s-四氢三嗪酮，并测定了它们在pH=4和80℃温度下的水解率。

Results indicated that introducing some ring-structure into UF molecule during the synthesis could efficiently improve the water resistance of UF resin. The Uron ring would form if reaction temperature was more than 75 degrees C, and the higher Uron content was obtained at pH 8 and 85 degrees C in the absence of catalyst when the reaction time was long enough.

结果表明：通过在脲醛树脂合成中引入Uron环等环状结构物质能够有效提高脲醛树脂胶黏剂的耐水性；当反应温度高于75℃时，反应产物都生成了一定量的Uron环物质；在pH值为8左右、温度控制在85℃、不使用催化剂、尽可能延长反应时间的条件下，尿素与甲醛成环化反应生成的Uron相对值最多。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷