查询词典 reaction

It was increased ethyl hexanoate synthesis substrate concentration mediated by Rhizopus chinensis 2113 whole-cell lipase after improved synthetic activity and optimized reaction condition. The reaction condition were: caproic acid concentration 2.4mol/L, substrate molar concentration ratio 1:1.1, initial water content ≤0.2%, lipase water activity 0.3~0.66, enzyme amount 16%, reaction temperature 30℃, agitation speed 150 r/min.

通过合成酶活的提高及反应条件的优化，提高了华根霉2113全细胞脂肪酶催化己酸乙酯合成的反应底物浓度，其反应条件为：己酸浓度为2.4mol/L；酸醇摩尔浓度比1：1.1；反应体系含水量≤0.2%；脂肪酶水活度0.3～0.66；加酶量16%；反应温度30℃；150r/min振荡反应。

The results show that isobutene oligomerization is fast liquid-solid reaction. Under the temperature of 80 ℃～120 ℃ and pressure of 2.0 MPa, the products of oligomerization are mainly dimers and trimers of isobutene. The yield of trimers is higher than that of dimers and the mass fraction of trimers decreases with reaction temperature increasing. The yield of tetramers is much lower than that of dimmers and trimers. The tetramers are formed by reaction of isooctenes and C8 carbonium ion.

结果表明，异丁烯齐聚反应为快速液固相催化反应，在80 ℃～120 ℃，2.0 MPa的实验条件下，反应产物主要是异丁烯的二聚物和三聚物，且三聚物的收率远高于二聚物，两者的浓度比值随反应温度的升高而下降；少量四聚物的生成主要源于碳八烯烃与碳八正碳离子的反应。

The experiments for determining the mechanism and kinetics of catalytic pyrolysis reaction for a simple petroleum feedstock, were carried out in a batch micro-reactor using Daqing light gas oil. The results showed that carbonium and free radical reactions were the key reactions in catalytic pyrolysis. The carbonium ions were induced by catalytic reaction, whereas free radical reaction was predominantly due to thermal cracking.

首先在重油微反装置上考察大庆减压馏分油催化裂解反应产品分布，并将反应结果与相同温度范围内的热裂解反应相比较，二者的产品分布随温度等操作参数的变化规律明显不同，进而推断催化裂解反应过程为正碳离子反应机理和自由基反应机理并存；并建立了大庆减压馏分油催化裂解消失动力学模型，求得了化学反应速率常数。

To be different from the already chloromethylation catalyst, it has a certain amount of moisture wet, which will not produce huge amounts of doughtic cancerogenic chloromethyl methyl ether during and after the reaction.4,4\'-bisbiphenyl, 1,4-bisbenzene, 1,4-bis(chloro- methyl)-2,5-dimethylbenzene, 1,5-bis-2,4-dimethylbenzene, 4-(chlor- omethyl)-1,2-dimethylbenzene, 1,2-bis-4,5-dimethylbenzene, 5,8-bis-1,2,3,4-tetrahydronaphthalene, 3,3\',5-tris-4,4\'-bisbiphenyl and 3,3\', 5,5\'-tetrakis-4,4\'-bisbiphenyl were synth- esized by using this new catalyst. Results indicated that when the reaction temperature was 55～60℃, the reaction time was 12h, the catalyst which consists of the concentration of 80%H_2SO_4, HAc and Lewis acid, the amount of Lewis acid 0.15 mol(nLewis:nbiphenyl=1.5:1), yield of biphenyl chloromethylation product 4,4\'-bis(chrolomethylbiphenyl can reach a maximum 85%.

采用这种催化体系完成了4，4′-二氯甲基联苯、对二氯甲基苯、1，4-二氯甲基-2，5-二甲基苯、1，5-二氯甲基-2，4-二甲基苯、4-氯甲基-1，2-二甲基苯、1，2-二氯甲基-4，5-二甲基苯、5，8-二氯甲基-四氢萘、3，3'，5-三氯甲基-4，4'-二甲基苯和3，3'，5，5'-四氯甲基-4，4'-二甲基苯的合成，结果表明：在反应条件为：反应温度55～60℃，反应时间12h，选择80%H_2SO_4、冰醋酸和Lewis酸为催化剂，反应最佳反应Lewis酸用量是0.15mol(和原料比为1.5：1)，反应效果最好，联苯氯甲基化产物(4，4′-二氯甲基联苯)收率为85%；在反应条件为：反应温度70℃，反应时间8h，80%H_2SO_4、冰醋酸和Lewis酸为催化剂，反应最佳反应Lewis酸用量是0.1mol(和原料比为1：1)时，反应效果最好，苯的氯甲基化产物收(来源：ABd0C论文eded网www.abclunwen.com)率为75%；在反应条件为：在反应条件为：反应温度40℃，反应时间10h，60%H_2SO_4和Lewis酸为催化剂，反应最佳反应Lewis酸用量是0.1mol(和原料比为1：1)时，反应效果最好，对二甲苯氯甲基化产物(1，4-二氯甲基-2，5-二甲基苯)收率为78.5%；在反应条件为：反应温度35℃，反应时间10h，60%H_2SO_4、冰醋酸和Lewis酸为催化剂，反应最佳反应Lewis酸用量是0.1mol(和原料比为1：1)时，反应效果最好，间二甲苯氯甲基化产物(1，5-二氯甲基-2，4-二甲基苯)收率为81.5%。

Analyse and compare what adopt a variety of pair of methods, the Michael addition reaction of ester of acerbity second of second of hydroxyl of protection of benzyl of the response of close nucleus addition that uses second nitrile and ester of formic acid second certainly, chloridize, cyanogen, reaction that take off carboxyl generates 3- benzyl oxygen radical the fifth of the ten Heavenly Stem the method of 2 nitrile, detailed discussion the action that wait and the by-product that arise possibly reach the reactant in each pace reaction, activator, dissolvent avoid a method.

通过对多种方法的分析和比较，确定采用乙腈和甲酸乙酯的亲核加成反应、氯化苄保护羟基、氰乙酸乙酯的Michael加成反应、脱羧反应生成3-苄氧基戊二腈的方法，并具体的讨论了每一步反应中反应物、催化剂、溶剂等的功能和可能产生的副产物及避免方法。

The result shows that the best reaction conditions for synthesizing CMC with a high degree of substitution (1.68) are that the ratio of chitosan to sodium chloroacetate is 1:5, reaction temperature is 90℃, reaction time is 5h, and the amount of catalyst is 3%.

研究了投料比、反应温度、反应时间、催化剂等单因素对取代度的影响，合成高取代度的最佳反应条件为m：m=1：5、温度90℃、时间5h、催化剂量为3%，可制得取代度为1.68的羧甲基壳聚糖。

The chemical structure of the product was characterized by means of the melting point and IR. The results show that tetraethylammonium bromide which was used as a phase transfer catalyst in this reaction had optimization effect on the interfacial diffusive reaction of BTC and PNP. Higher concentration of sodium hydroxide, lower temperature and a higher dosage of BTC produced a small amount of 4-nitrophenyl chloroformate, while lower concentration of sodium hydroxide and a lower dosage of BTC made reaction incomplete, which affected the yield.

结果表明，在碳酸二（4-硝基苯基）酯合成中使用的相转移催化剂四乙基溴化铵对受界面扩散控制的BTC气与对硝基酚钠反应有良好的相转移催化效果；氢氧化钠质量分数较低时，酚钠盐向溶有BTC的油相扩散速度较小，较高时会产生氯甲酸对硝基苯酯；温度较低、BTC量较高时，会产生少量氯甲酸对硝基苯酯，BTC用量较低会使反应不完全，这些都影响着收率。

The fundamental imaging features of osteosarcoma were showed bone destruction, periosteal reaction, neoplastic bone and soft-tissue mass. Among 49 cases examined by radiography, osteoblastic pattern sarcoma was found in 19 cases, osteolytic pattern sarcoma was found in 13 cases and mixed pattern sarcoma was found in 17 cases. The detection rates of bone destruction, periosteal reaction, soft-tissue mass, neoplastic bone and Codman triangle by radiography were respectively 61.2%, 95.9%, 71.4%, 73.5%and 27.7%. All 10 cases with CT scan were showed bone destruction, soft - tissue mass and neoplastic bone. The detection rates of periosteal reaction,憇ieve sign挶 and Codman triangle with CT scan were respectively 90%, 90% and 11%. The tiny neoplastic bone and"sieve sign"were showed sensitively by CT, but Codman triangle was showed by radiography superior to CT.32 cases with MRI scan presented the normal marrow was replaced by the tumor, which was showed low to intermediate signal intensity on T1-weighted images and promiscuity signal intensity on T2-weighted images. 7 cases presented hemorrhage and 24 cases presented necrosis.

骨肉瘤基本影像表现为骨质破坏、骨膜反应、瘤骨和软组织肿块。49例X线表现为成骨型19例，溶骨型13例，混合型17例；X线对骨质破坏、骨膜反应、软组织肿块、瘤骨和Codman三角的检出率分别为61.2%、95.9%、71.4%、73.5%和27.7%；10例CT表现均可见骨质破坏、软组织肿块及瘤骨，CT对骨膜反应、筛孔征和Codman三角的检出率为90%、90%和11%；CT对显示细小肿瘤骨和筛孔征最敏感，但对Codman三角的显示不如X线平片；32例MRI表现为骨髓腔内正常的骨髓高信号被肿瘤信号所取代，T1WI呈低～等信号，T2WI呈混杂信号，7例合并出血，24例中央坏死囊变，32例增强扫描均呈不均匀强化及瘤周可见水肿区。

Secondly, the reaction of crotyl bromide and carbonyl compounds promoted by dysprosium were studied. The γ-adduct of crotyl was mainly obtained in the reaction of ketone and ester. While the α-and γ-adduct mixture were obtained in the reaction of aldehyde.

其次，还研究了镝促进下巴豆基溴与羰基化合物的反应，酮和酯主要得到巴豆基γ-位进攻的产物，而醛则得到α与γ位进攻的混合产物。

Under the optimized reaction conditions: n (H2O2)/n/n=2/0.04/1,V/V=8.75, reaction temperature 35℃, and reaction time 28 h, the highest yield of glutaraldehyde could reached 78% with a cyclopentene conversion of 99.99%.

在最佳工艺条件：n(H2O2)：n：n=2：0.04：1，V/V=8.75，反应温度35℃，反应时间28h下，环戊烯转化率达99.99%，戊二醛的收率最高可达78%。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。