查询词典 reaction

Results show that 4-oxo-β-ionone is the major product with yield of 53.5% under the conditions as follows: reaction temperature 45℃, reaction time 24 h, the molar ratio of n: n(NaClO3): n 20: 100: 3, and pH value of solution in 1-3; on the other hand, 5,6-epoxy-β-ionone is major product with yield of 25.4% when reaction temperature is 40℃, reaction time is 24 h, the molar ratio of n: n(NaClO3): n is 20: 120: 5, and pH values of solution is 3. The excessive β-ionone can be recovered by vacuum distillation for reusing again. 4-oxo-β-ionone and 5,6-epoxy-3-ionone were purified by recrystallization and silica gel column chromatograph respectively with the purity over 98%.

研究结果表明：氯酸钠氧化β-紫罗兰酮的反应主要生成4-氧代－β-紫罗兰酮和5，6-环氧－β-紫罗兰酮，经重结晶和硅胶柱层析分离，纯度高于98%；4-氧代－β-紫罗兰酮的有利合成条件是反应温度为45℃，反应时间为24h，溶液的pH值为1~3，反应物配比n：n(NaClO3)：n为20：100：3，最佳收率为53.5%；5，6-环氧－β-紫罗兰酮有利的合成条件是反应温度为40℃，反应时间为24h，溶液的pH值为3，反应物配比n：n(NaClO3)：n为20：120：5，其收率为25.4%；未反应的β-紫罗兰酮经减压蒸馏回收后可重复使用。

Through mechanism analyzing on the process of producing HMT , it was known that because the resistance of isobutylene was small ,the yield of outgrowth in such a reaction system was little and the yield of reaction was as high as 86%. 2,3-dimethyI-butene-2 had the biggest resistance and lowest yield of reaction of 18%. 2,3-dimethyl-butene-l had bigger resistance than isobutylene and more outgrowth than isobutyles but its yield of reaction could reach 70%.

通过对上述三种烯烃合成HMT的研究可知，由于新己烯位阻小，反应中副反应少，收率高达86％：而2，3—二甲基—丁烯—2的位阻最大，反应中副反应最多，反应收率最高仅为18％；2，3—二甲基—丁烯—1的位阻比新己烯大，反应副产物比新己烯多，但反应收率仍可达70％。

The formation of our 1D nickel wires can be ascribed to the cooperative effect of the reaction rate and magnetic field.The reaction rate in the system is controlled mainly by adjusting the reactant concentration when other reaction conditions are fixed.When the concentration of Ni~(2+) is low,the reaction rate is correspondingly slow,so the complex[Ni(N_2H_4)_x]~(2+) preferentially migrates to the magnetic line of force since paramagnetic metal ions are attracted toward the maximum field.

当反应物Ni~(2+)浓度较低时，反应速率相对较慢，[Ni(N_2H_4)_x]~(2+)优先选择迁移到磁力线附近并且沿着磁力线方向排列，导致电极电势增大，于是[Ni(N_2H_4)_x]~(2+)的化学还原反应也是沿着磁力线发生，结果导致了镍纳米线的形成。

Finally, pentyl acetate and benteine could be respectively synthesized by esterification reaction in the presence of nanometer rare earth composite solid superacids (SO_4)~(2-)/ZrO_2-Gd_2O_3 and (SO_4)~(2-)/ZrO_2-Nd_2O_3. The effects of reaction time, reaction temperature, the mol ratio of acid to alcohol and the use level of catalyst on esterification yield were discussed. In the end, we obtained their optimal reaction conditions.

采用纳米稀土复合固体超强酸SO_4~(2-)/ZrO_2-Gd_2O_3，SO_4~(2-)，~/ZrO_2-Nd_2O_3分别合成了乙酸戊酯和乙酸苄酯两种香料，实验考察了反应时间、反应温度、醇酸比及催化剂的用量对酯化率的影响，并由此得出反应的最佳条件。

This complex reaction was phenolic electronic substitution reaction, so reaction rate was related with the positive electricity of pro-electronic reagent, as well as the form of aromatic hydrocarbons. Rates of chlorination of phenol and 2-monochlorophenol were faster in alkaline water than that in weak acid water, so 2,4-dichlorophenol and 2,4,6-trichlorophenol formation concentrations increased with the reaction time.

该复合反应属于酚类电子取代反应，反应速率与亲电子试剂的阳电性以及芳香烃的形式有关，碱性水环境中氯取代苯酚和2-一氯酚的速率要快于在弱酸性水环境；随着pH的升高，2，4-DCP和2，4，6-TCP的生成浓度也不断增加。

The paper compares the reaction of disinfectants of Cl,ClO_2 and ClO_2/Cl to 9 kinds THMs prodrome such as phenol,including volume from disinfectants on their prodrome contents,reaction pH values,reaction time,and reaction temperature.

主要考察了氯、二氧化氯和二氧化氯/氯(二氧化氯占混合溶液的质量分数为50%，90%)这3种消毒剂与苯酚等9种THMS前驱物的反应，并对这3种消毒剂在前驱物含量、反应pH值、反应时间和反应温度等条件下生成的氯仿量进行了比较。

The invention relates to a process for producing polyethylene terephthalate 1, 3-propanediol, which comprises the following steps: using titanic acid ester as major catalyst, using germanium compounds and cobalt compounds as synergic catalyst, conducting esterification reaction for poly terephthalic acid and 1, 3-propanediol according to the molar 1:1.05-2.2 under the nitrogen pressure of 0.1-0.4MPa and 230-265 DEG C, or conducting ester exchanging reaction for poly terephthalic acid and 1, 3-propanediol according to the molar ratio 1:1.8-2.2 in 160-220 DEG C, decompressing reaction to high vacuum 10-150Pa, wherein the final temperature of reaction is 265-275 DEG C, recovering to normal pressure with nitrogen to obtain the PTT product.

本发明涉及一种生产聚对苯二甲酸1，3-丙二醇酯的方法，采用以钛酸酯为主催化剂，锗化合物和钴化合物为协同催化剂，对苯二甲酸二甲酯和1，3-丙二醇按摩尔1∶1.05-2.2，在0.1-0.4MPa氮气压力和230-265℃下进行酯化反应，或对苯二甲酸二甲酯和1，3-丙二醇按摩尔比1∶1.8-2.2，在160-220℃进行酯交换反应，将反应减压至高真空10-150Pa，反应终温在265-275℃，用氮气恢复到常压，得到本PTT产品；大大缩短了反应时间，直接聚合制备特性粘度在0.7-1.05dL/g的PTT切片，使反应产物色相良好，PTT产品可用于纤维加工及工程塑料领域。

Therefore esterification crosslinked reactionbetween polyearboxylic acid and wood can be quantitatively determined.According toexperiment results of stereoscopic configuration choices by crosslinking agents,crosslinkingreaction between model of reaction intermediate and wood,and the intermediate characteristic incrosslinking reaction,crosslinking reaction intermediate was proofed.We can infercrosslinking reactions between polycarboxylicacid and wood want through a mechanism of twosteps reaction process,the first cyclic anhydrides were formed as intermediates by dehydratingbetween hydroxyls in polycarboxylic acids,second esters were occurred by substitution reactionbetween wood hydroxyls and cyclic anhydrides.

从而可全面定量表征木材与多元羧酸类化合物的酯化交联反应；依据交联剂立体构型选择性、反应中间体模型物与木材的交联反应和交联反应中间体的波谱特征实验结果，证实了交联反应中间体，因此可以推测：多元羧酸类化合物与木材化学组分的交联反应是经历两步反应的机理，首先多元羧酸中相邻羧基的羟基之间脱水形成五元环酸酐中间体，然后木材的羟基与酸酐发生亲核取代反应形成酯。

Under the optimal reaction conditions like 140°C of reaction temperature, 2.5 MPa of reaction pressure, 1.5 mg catalyst and 8 h of reaction time, the highest yield of adipic acid and TON were 21.4% and 24 582, respectively.

优选的反应条件是：反应温度为140℃，氧气压力为2.5 MPa，反应时间为8 h，催化剂用量为1.5 mg。在此条件下，己二酸的质量收率可达21.4%，活性转化数可达24 582。

Methods The target compounds were synthesized by Stock enamine reaction,Williamson reaction,Mannich reaction,and arylamine exchange reaction with cyclopentanone as starting material,and their antitumor activities were assayed using human hepatic carcinoma cell line(Bel-7402),human oral cavity epidermis squamocellular carcinoma cell l...

方法以环戊酮为原料，经Stock反应、Williamson反应、Mannich反应和芳胺交换反应合成目标化合物。

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。