查询词典 catalyst

The acetalization and ketalization of various aldehydes and ketones with glycols using FeCl3 as catalyst were studied. The effects of reaction time, mole ratio of reactants and amount of catalyst on the yield of acetals were investigated.

研究了在FeCl3催化下，乙二醇与环己酮、丁酮、丙酮、丙醛、丁醛、异丁醛、戊醛、异戊醛、正辛醛、二苯甲酮、苯甲醛等十余种醛的缩合反应。

_6P_2W_(17)VO_(62) catalyst was prepared and characterized by FTIR,and synthesis of fraistone over as-synthesized catalyst from ethyl acetoacetate and 1,2-propylene glycol was investigated.

制备了Dawson型磷钨钒酸铵催化剂，用FT-IR分析方法对催化剂进行了结构表征，并以乙酰乙酸乙酯与1，2-丙二醇为原料催化合成了苹果酯-B。

For the synthesis reaction of chalcone, cyclohexanone aldolization and biodiesel,γ-Al_2O_3-NaOH-Na solid superacid has a satisfactory catalytic activity. With hypnone and phenylaldehyde as raw material, amount of catalyst 7.5% wt% of material, mole ratio of hypnone and phenylaldehyde 1:1.1, reaction temperature 40℃, after 3 hours, the yield of chalcone can be up to 96.88%. With cyclohexanone as raw material, amount of catalyst 10% wt% of material, reaction temperature 190℃, after 3 hours, dimmer of cyclohexanone can be up to 85.66%.

将该固体超强碱催化剂应用于查尔酮、环己酮自缩合以及生物柴油的合成反应中，该改性固体超强碱催化剂表现出了良好的催化活性：以苯乙酮和苯甲醛为原料，反应温度为40℃，催化剂用量为反应物总质量的7.5％，苯甲醛与苯乙酮摩尔比为1：1.1，反应3h查尔酮产率可达96.88％；以环已酮为原料，催化剂用量为原料总质量的10％，反应温度为190℃，反应3h，二聚物的总收率可达85.66％；以动物油和甲醇为原料，醇油摩尔为9：1，催化剂用量为动物油质量的2％，反应温度为70℃，反应3h后，生物柴油的收率可达91.8％。

With a quantitative amount of catalyst, the yield of acetyl alginic acid was increased with reaction time; but as time being constant, the yield was increased with the amount of catalyst.

在相同的催化剂量下，乙酰褐藻酸的产率随反应时间加长而提高；当反应时间相同时，其产率随催化剂用量加大而提高。

This article analyzed nucleophilic substitution mechanism of amidation reaction which was the key step in new process, the effect factors such as catalyst type, catalyst volume, solvent and temperature were also involved.

其中酰胺化反应是关键步骤，文章分析了该反应的亲核取代机理及催化剂种类、催化剂用量、溶剂、温度等条件对反应的影响。

The synthesis of azelaic acid through oxidation of ol eic acid with 50% aqueous hydrogen peroxide has been studied by using catalyst containing tungsten and phase transfer catalyst .

以 5。 0 %过氧化氢为氧化剂，钨化合物为催化剂，在三辛基甲基氯化铵和双十八烷基二甲基氯化铵为相转移试剂的条件下，考察了油酸氧化制备壬二酸的催化反应活性。

The effects of catalyst dosage, the amounts of hydrogen peroxide and phase transfer agent, the pH value of the solution, the reuse of catalyst and the reaction temperature on the azelaic acid yield were investigated.

以30%过氧化氢作为氧化剂，在相转移试剂和磷钨酸催化剂作用下催化油酸制备壬二酸，考察了催化剂磷钨酸用量、过氧化氢用量、溶液pH值、相转移试剂用量、反应温度等因素对壬二酸产率的影响。

The invention discloses a method for preparing novel nanometer TiO2 optical catalyst material, comprising that (1) preparing gel solution of modified lanthanide series that mixing butyl titanate, alcohol solvent, azotic acid, polyvinyl alcohol and lanthanide element,(2) using alkali liquid to treat the quartz fiber leaked from side wall,(3) using drawing membrane and high-temperature sintering to form modified TiO2 optical catalyst material on the surface of quartz fiber.

本发明公开了一种制备新型纳米TiO2光催化材料的方法，包括(1)配置镧系元素改性的溶胶溶液：将钛酸四丁酯、醇类溶剂、硝酸、聚乙烯醇和镧系元素的盐类混合搅拌；(2)利用碱液对侧壁漏光石英光纤进行处理；(3)通过提拉成膜和高温煅烧，在石英光纤表面形成改性TiO2光催化材料。

For low molar ratios of Al/Zr, a hypsochromic shift of the initial catalyst absorption band, corresponding to the monomethylation of the catalyst, was observed. Further addition of AlEt2Cl was accompanied by a continuous bathochromic shift of the maximal wavelength corresponding to the formation of more dissociated ionic active species. Then, there would be a coordination of monomer to the ionic active species.

结果表明，无论是AlEt_2Cl还是MAO，少量的助催化剂首先使催化剂发生单烷基化反应，主催化剂金属中心的最大吸收峰波长发生蓝移，而当助催化剂量进一步增加时，金属中心的最大吸收峰波长红移，单烷基取代的催化剂被大量的助催化剂夺去电子成为缺电子的阳离子活性中心，以便烯烃单体的配位插入。

Using levulinic acid and phenol as raw materials, hydrochloric acid as catalyst and thioglycolic acid as assistant catalyst, the synthesis technology of diphenolic acid, a new polymer material substitution for biphenol A, was investigated.

研究了以苯酚和新型平台化合物乙酰丙酸为原料，采用盐酸为催化剂、巯基乙酸为助催化剂催化合成高分子材料单体双酚酸的合成工艺。

There are different types of personal loans available.

有许多不同类型的个人贷款优惠。

The above mentioned teaching model of spiral rising can be used to avoid rigidness in teaching.

上述螺旋式上升的教学模式，可以避免教学形成模式後的僵化现象。