查询词典 catalyst

For the FCCU with a high efficient regenerator, the expressions of catalyst circulating rate in the spent catalyst pipe, the regenerated catalyst pipe and the pipe from the second stage of the regenerator to the first one were obtained on the basis of the pressure balan...

在此基础上，建立了催化剂藏量系统的动态模型及其简化的线性模型。由线性模型和控制系统稳定性理论证明，不作任何控制时催化剂藏量的稳定性是有条件的。给出了该系统的催化剂藏量稳定性判据，并用反应再生系统仿真实验验证了这一判据

The invention comprises a cyclopalladated catalyst with axial chiral binaphthyl backbone containing phosphine ligand as well as the synthesis thereof, and the application of the catalyst with cyclopalladated catalyst with axial chiral binaphthyl backbone containing phosphine ligand with a similar structure to the hetero atom norbornadiene ring cleavage reaction through an asymmetric catalytic organic boron agent.

本发明包括一类具有轴手性联萘骨架含膦配体的环钯催化剂及其合成，以及其与具有类似结构的轴手性联萘骨架含膦配体的环钯催化剂在不对称催化有机硼试剂对杂原子降冰片二烯开环的应用。

The structural and photocatalytic properties of TiO〓 as well as surface acidity were greatly improved by sulfation. SO〓〓/TiO〓 solid superacid with Hammett constant Ho less than -12.14 was prepared by treating the TiO〓 with 1.0mol. L〓 sulfuric acid solution and then calcining at 450℃ for 3h. When compared to unmodified TiO〓, the SO〓〓/TiO〓 superacid catalyst exhibited higher anatase content, smaller crystal size, higher specific surface area, centralized pore size distribution, and the blue-shifted band edge of uv-vis adsorption spectra. Furthermore, the SO〓〓/TiO〓 superacid also showed excellent reaction activity and stability for CH〓Br photocatalytic decomposition even under the moist reaction conditions. The apparent quantum efficiency of SO〓〓/TiO〓 was 10 times of that of TiO〓 catalyst for the photocatalytic degradation of bromomethane. Therefore, the SO〓〓/TiO〓 superacid catalyst is promising for practical application in environmental remediation.It was found that both L and B acid sites exist on SO〓〓/TiO〓 photocatalyst while only L acid sites on TiO〓 photocatalyst. On the basis of experimental results, the synergistic model of superacidic centers was proposed for SO〓〓/TiO〓 photocatalyst to explain the photocatalytic behavior and the mechanism of superacidifing effects, assuming that the adjacent L and B acid sites induced by SO〓〓 comprise cooperatively the superacidic center on superacid photocatalyst. The group cooperation of the superacidic center could strengthen the surface acidity, increase surface acid sites and the adsorbtion of O〓, promote separation of photogenerated electron-hole pair, enhance the interfacial transfer of charges and reversibility of water adsorption. Consequently the excellent photocatalytic activity, reaction stability and resistibility to humidity of SO〓〓/TiO〓 superacid photocatalyst may attributed to the group cooperated effect of the superacidic center on the photocatalyst.

研究结果表明：SO〓〓与TiO〓表面的结合为螯合式双配位结构；TiO〓光催化剂表面经H〓SO〓浸渍处理后，提高了表面酸性，改善了催化剂结构和光催化性能，当H〓SO〓浸渍浓度为1.0mol.L〓、烧结温度为450℃时，可制得SO〓〓/TiO〓超强酸催化剂(H〓＜-12.14)，其结构和光催化活性得到明显改善，与TiO〓相比，SO〓〓/TiO〓光催化剂的锐钛矿含量高、晶粒小、BET比表面积大、孔径分布集中、光谱吸收边蓝移，具有优异的光催化氧化活性、稳定性及抗湿性能，光催化降解溴代甲烷的表观量子效率比TiO〓催化剂提高了一个数量级，是一种有实际应用前景的高效光催化剂；由此提出了SO〓〓/TiO〓超强酸催化剂表面集团协同作用的超强酸中心模型，认为在SO〓〓/TiO〓超强酸催化剂表面，由SO〓〓诱导的相邻L酸中心和B酸中心组成了集团协同作用的超强酸中心，其集团协同作用显著地增强了催化剂表面酸性、增大了表面酸量及O〓吸附量、促进了光生电子和空穴的分离及界面电荷转移，具有可逆吸附水的性能，是SO〓〓/TiO〓超强酸催化剂具有优异的光催化氧化活性、很好的活性稳定性及抗湿性能的重要原因。

Catalyst 70, catalyst 80, stannous caprylate were compared based on the impact of different catalyst on surface drying time of gel system.

实验选用催化剂W70、催化剂W80、辛酸亚锡，比较不同催化剂种类对硅凝胶表干时间的影响，得到合适的催化剂种类和用量。

Catalyst 70, catalyst 80, stannous caprylate were compared based on the impact of different catalyst on surface drying time of gel system.

毕业论文字数：3654 页数：7）摘要：实验选用催化剂W70、催化剂W80、辛酸亚锡，比较不同催化剂种类对硅凝胶表干时间的影响，得到合适的催化剂种类和用量。

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%。

In addition, the activties of different catalyst were compered. The test proved the chloroplatinic acid– ethanol catalyst provides high yields of addition products without the formation of undesirable by-products, to provide the possibility of using less rigorous reaction condition, to provide a catalyst material, which is effective at low concentrations.

实验过程中特别对不同催化剂进行了比较，其中氯铂酸—乙醇催化剂提高了加成反应的产率，没有副产物生成，不需要苛刻的反应条件，在低浓度时有很好的催化效果。

After this research work, we know that: HMCM-22 is a better catalyst of selecting naphthalene alkylation; Surface modification of zeolite Y is effective, but the effect of zeolite 3 is not evident and surface modification doesn"t suits mordenite; Surface modification doesn"t affect the frameworks and inner environments of zeolites, but only reduces diameter of orifice and overlays surface acidities; t-butanol is not suitable for alkylating agent of the reaction using modified zeolites as catalyst; Solvents with smaller molecular size are advantageous for naphthalene alkylation reaction using modified zeolites as catalyst, such as cyclohexane is better than decalin.

通过本论文的研究，我们知道：HMCM-22是萘择形烷基化反应较好的沸石之一；Y沸石的外表面改性效果较好，β沸石则效果不明显，而丝光沸石则不适于外表面改性；外表面改性不改变沸石的骨架结构和孔道内部环境，仅减小孔口直径和覆盖外表面酸性位；叔丁醇不适于作外表面改性沸石催化的反应的烷基化试剂，其反应活性很低，且选择性无明显提升；分子较小的溶剂更适于外表面改性沸石催化的反应，环己烷就明显好于十氢萘。

Flexicat yellow/blue catalyst produced by CRI was the fourth dehydrogenization catalyst which was used in Daqing 60KTA styrene equipment. We have taken effective ways and means to prolong the validity-period of the catalyst, including improving in-let temperature, adjusting the radio of steam/ethylbenzen, optimizing the operation of compressor etc.

CRI公司的Flexicat yellow/blue催化剂是大庆石化苯乙烯装置应用的第四批乙苯脱氮催化剂，在延长期采取了合理提高入口温度、合理匹配稀释蒸汽的用量、加强尾气压缩机的操作等有效的操作方法，使该催化剂从装填到卸载共运行了35个月，共生产苯乙烯210913吨，使用周期增加46%，增加经济效益1.5亿元。

When the resulting nitro compounds was reduced over 5% Pd/C catalyst, the nitro phosphinic acids required more catalyst that the esters nitro phosphinic acid, and dinitro compounds required more catalyst than mono-nitro compounds in the case of all nitro groups completely changed into amino groups.

用5％Pd/C作催化剂，将上述硝基物还原时发现，次膦酸形成的硝基物比次膦酸酯形成的硝基物需要更多催化剂才能使硝基全部还原成氨基；二硝基化合物比单硝基化合物需要更多的催化剂。

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？