查询词典 catalysts

In chapter four molecular modeling method is employed to comparatively study five S-allyl γ-hydroxy ketene dithioacetals reactions of Thio-Claisen rearrangement with and without zeolite catalysts.

第四章用分子模拟途径研究了在有、无分子筛催化条件下五种丙烯基羟基乙烯酮二硫代乙缩醛Thio-Claisen重排反应。

The catalysts were prepared by impregnation and precipitation method, and the active carbon,γ-Al2O3, silica and kieselguhr were selected as the carriers of catalyst. the effects of reaction conditions, such as reaction temperature, types of solvents, and types of hydrogen donors were investigated, It was found that the Pd/C catalyst was the best one, and its proper reaction conditions were also obtained as follow: sodium formate as hydrogen donor, water as solvent, reaction temperature of 70℃ and reaction time of 2.5h.

以活性炭、γ-Al2O3、硅胶和硅藻土等为载体，分别采用浸渍法和沉淀法制备了催化剂，对于反应温度、溶剂及氢供体的种类等反应条件的影响进行了研究，发现以沉淀法制备的Pd/C催化剂是对转移加氢最有效的催化剂，初步确定了适宜的反应条件为以甲酸钠作氢供体、水作溶剂及70℃反应2.5h等。

Unfortunately, enzymes are generally very labile catalysts and easily lose their activity in the presence of organic solvents.

将生物催化剂运用到有机相催化具有多种优势，然而酶是一类不稳定的催化剂很容易在有机溶剂存在的条件下失去活性。

Researchers have tried to mimic the process used by plants with experimental systems that use some of the components of photosynthesis, such as chlorophyll, which makes plants green and helps trap light , and catalysts which facilitate the process of converting carbon dioxide, water and sunlight.

研究人员一直试图用实验体系模拟植物的光合作用。他们想利用一些光合作用中的原料，例如让植物呈现绿色并有助于俘获光子的叶绿素、促进二氧化碳转化过程的催化剂、水和阳光。

It was found that the catalysts with 1.5% Pd content showed a higher activity. At 60—65℃ and 0.6MPa with a total catalyst amount of 0.5%,the conversion of dehydrolinalool was higher than 99% and the selectivity for linalool was higher than 96%. The change in catalyst composition upon reused for 7 times was evaluated by using ICP,and the effect of Pb and Bi to the catalytic behavior was discussed.

结果表明，钯质量分数为1.5%的催化剂活性较高，在反应温度为60～65 ℃，系统压力为0.6 MPa，催化剂用量为原料质量的0.5％，去氢芳樟醇转化率大于99%时，芳樟醇选择性大于96%，催化剂套用7次后，利用ICP对使用前后催化剂的组成进行分析后，根据反应结果分析了Pb和Bi对加氢反应的作用。

The current situation of recovery and utilization of used mercuric chloride catalysts were introduced.

氯化汞触媒是汞行业中生产量最大的产品，也是消耗汞量最多的产品。

He hypothesis has been proved by SEM and TEM. The characterization of TPR and XPS showed that there had reduction process of oxide species before crystallization, and the reduced species and metalloid content increased generally on the surface of catalysts.

PR和XPS表征证实在负载型非晶态合金Ni-P/TiO〓的晶化温度前，有金属氧化物种的还原过程，还原后，催化剂表面的还原态物种增多，类金属相对含量普遍增加。

The results show that the higher yield of CNF obtained by decomposition of carbon monoxide than that of methane over a series of alumina supported Ni/Fe catalysts prepared by deposition-precipitation method is attributed to the role of produced carbon dioxide and the different carbon diffusion mode on metal particle.

结果发现： 1。当采用CO为碳源时，催化剂在36小时内具有较为稳定的活性，当采用CH〓为碳源时，催化剂中Fe的存在不利于得到较高产率的纳米碳纤维；不同的纳米碳纤维产率与生长过程中形成的CO〓及碳在金属表面或者体相中的传递行为密切相关； 2。

The experiment results show that methanol is produced from absorbed CO〓 on the catalysts.

实验结果表明，甲醇是由吸附的CO〓加氢生成的。

We have concluded that the main losing activity reason of SO_4~(2-)/TiO_2-SiO_2 solid superacid catalysts used in synthesis of methyl acetate is the accumulated carbon of catalytic surface and the loss of SO_4~(2-).

3对催化剂的失活机理进行讨论，结果表明用于乙酸甲酯酯化反应的SO_4~(2-)/TiO_2-SiO_2固体超强酸催化剂失活的主要原因是催化剂表面积碳和SO_4~(2-)流失。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐