查询词典 Chain Reaction

In our research on study chemical reaction of active methylene compounds and brom-acetophenone. Because of brom-acetophenone is compound that contain carbonyl and halogen ,which will take place electrophilic substitution and nucleophilic addition. When active methylene compounds are ethyl acetoacetate and β-diketone, controlling reaction condition, we have found that mono-substitution's production and di-substitution's. production is isolated; active methylene compounds are acetoacetanilide and acetoacetanilide derivate, pyrrolidin-2-one derivants were obtained by substitution and close-ring reaction .but there is no report about it.

本文是让活泼亚甲基类化合物与溴代苯乙酮发生化学反应，由于溴代苯乙酮是含有羰基的卤代烃结构，它可以发生亲电取代和亲核加成反应，当活泼亚甲基类化合物为乙酰乙酸乙酯和β-二酮时，控制反应条件可以发生单取代和双取代两种产物；当活泼亚甲基类化合物为乙酰乙酰芳胺类化合物来反应时，溴代苯乙酮中的羰基与氨基会发生分子内的关环反应生成吡咯烷-2-酮衍生物，这在以前的研究中是没有发现的。

The nucleic acid in the virion was determined to be single-strande d RNA by means of diphenylamine reaction,orcinol reaction and formaldehyde reaction.

病毒核酸地衣酚反应呈阳性，联苯胺反应呈阴性结果。而紫外吸收实验则呈明显的单链特征，辅以酶消化实验的结果，证实该病毒为单链RNA病毒。

NO elimination reactions are much complicated in the system of NO-CO-CO2-N2 with the existence of metallic oxides. Homogeneous reaction between NO and CO, reduction of NO by the lower valued metallic oxides, direct decomposition of NO as a catalytic reaction and catalytic reaction of NO/CO may all contribute in NO elimination.

金属氧化物存在条件下NO-CO-CO2-N2体系中，NO去除反应较为复杂，NO/CO气相直接反应、低价氧化物对NO的还原作用、金属氧化物对NO分解反应的催化作用及金属氧化物对NO/CO反应的催化作用等都可能存在。

The effects of reaction temperature ,reaction time and dosage of catalyst on the oxidation reaction were examined.

考察了反应温度、反应时间和催化剂用量对氧化反应的影响，找到适宜的氧化反应条件。

The result showed that the optimum reaction conditions were as follows: molar ratio of BPAD to ECH 1:15, reaction temperature 80 ℃, reaction time 6 h and the product DGEBAD had high epoxy value and yield (0.376 mol/100 g and 147.1% respectively).

结果表明，DGEBAD最优合成反应条件如下：BPAD与ECH物质的量比为1：15，反应温度80℃，反应时间6 h，所得DGEBAD具有较高的环氧值和产率（分别为0.376 mol/100 g和147.1%）。

In this paper,we discuss the hydration electron resulted from chemical reaction,and demonstrate the mechanism of reaction about electrotyping oxidation-reduction reaction by the hydrated electron.

本文讨论了在实验室产生水化电子的方法，并用水化电子的概念分析了电解过程氧化还原反应机理。

In addition, ioding was found to be an efficient catalyst for the imino Diels-Alder reaction of N-arylimine and enol ethers and the reaction provided tertrahydroqinolines in good yields. One pot synthesis of tetrahydroqinolines from aldehyde, aniline and enol ethers was also achieved using iodine as the catalyst. The chemical yield of the"one pot"reaction was comparable with that obtained using preformed N-arylimine.

此外我们也发现碘能够有效地催化N-芳基亚胺与烯醇醚的Diels-Alder反应，以很高的化学收率得到了四氢喹啉衍生物，并且发现碘也能够直接催化芳香醛、苯胺、烯醇醚的三组分"一锅"反应，获得的化学产率与使用预制的N-芳基亚胺相当。

The comparison of hydrolysis-polycondensation reaction and microstructure of ORMOSILs derived by TEOS, MTES, VTES, ETES confirms that the influence of organic group such as methyl, vinyl, ethyl and ethoxyl on the hydrolysis and polycondensation reaction rate depends on several factors including electron-donating capability, size and number of ethoxyl group which can participates polycondensation reaction.

确认甲基、乙烯基和乙基和乙氧基等改性基团对硅醇盐水解-缩聚反应速度的影响是取决于有机改性基团的电负性、尺寸和可水解的-OR基团数目等因素综合作用的结果，其水解速度依MTES＞TEOS＞VTES＞ETES的顺序递减。由于Si原子上可聚合的基团数目减少，导致MTES、VTES和ETES的聚合反应速度降低，而与水解速率失配。

Immunohistochemistry showed a positive reaction to cytokeratin and a negative reaction with smooth muscle actin..Conclusions:.The Alcian blue negative stain, the negative reaction to SMA, and the fact that the patient is still alive 10 years after exenteration favored the diagnosis of basal cell adenocarcinoma.

免疫组化显示，细胞角蛋白反应阳性，平滑肌肌动蛋白（结论：阿尔辛蓝染色为阴性、SMA反应阴性及病人在眶内容去除术10年后仍然存活的事实都倾向于基底细胞腺癌的诊断。

Immunohistochemistry showed a positive reaction to cytokeratin and a negative reaction with smooth muscle actin..Conclusio :.The Alcian blue negative stain, the negative reaction to SMA, and the fact that the patient is still alive 10 years after exenteration favored the diagnosis of basal cell adenocarcinoma.

免疫组化显示，细胞角蛋白反应阳性，平滑肌肌动蛋白（结论：阿尔辛蓝染色为阴性、SMA反应阴性及病人在眶内容去除术10年后仍然存活的事实都倾向于基底细胞腺癌的诊断。

Smoking cigarettes adds to the Computer Desk Computer manufacturer computer mouse Computer Computerized collar knitter machine Conduit Bodies construction board Container Bag Control Arm Cooking Thermometer general levels of air pollution as well as damaging our health.

吸烟不仅对健康有害，而且增加空气污染程度。香烟雾含有多种有害物质：不仅有致癌化学物质、有某种能阻止氧气进入血液的气体，还有引起血压增高、心速加快的被称为尼古丁的物质。

He is one of my favorite actors.

他是我最喜欢的男演员之一。