查询词典 catalyst

The results show that a little amount of heteropolymolybdovanadophosphate can remarkably speed the degradation, the best conditions of the oxidative degradation of chitosan with hydrogen peroxide catalized by heteropolymolybdovanadophosphate in homogeneous condition are as follows: the ratio of catalyst and chitosan is 1 to 10, concentration of hydrogen peroxide is 0.15%, the temperature is 80℃, reaction time is 2h. 0.2g chitosan was degraded under the best condition and the molecular weight by viscometry was degraded from 1460000 to 7812. then water-soluble chitosan was obtained by this method; The heterogeneous method is a high efficient way, the best condition of this method are as follows: the ratio of catalyst and chitosan is 2 to 100, the volume of 30% hydrogen peroxide is about 3mL, the temperature is 90℃, reaction time is 5min～30min.

研究结果表明，适量磷钼钒的存在可显著加速壳聚糖的降解，磷钼钒催化过氧化氢均相氧化降解壳聚糖的适宜反应条件是：催化剂与壳聚糖的质量比为1∶10、过氧化氢百分浓度为0.15％、反应温度为80℃、反应时间为2h，在此条件下对0.2g溶解在100 mL 0.5％稀醋酸中的壳聚糖进行降解，可使壳聚糖的粘均分子量由原来的146万下降到七千多(7812)，成为水溶性低分子量壳聚糖，从而达到应用的要求；在异相条件下以磷钼钒为催化剂催化过氧化氢氧化降解壳聚糖是一种高效快速的方法，此法降解壳聚糖的最佳反应条件是：催化剂与壳聚糖的质量比为2∶100；30％过氧化氢的用量为3mL左右；反应温度为90℃、反应时间为5min～30min。

The optimum reaction conditions were as follows: rosin 5 g, m: in: m 1:2:2, palladium chloride 0.090 %, n: n1:10, hydrogen pressure 5 MPa, reaction temperature 160℃ reaction time 3 h, mass fraction of abietic acid could be under 1%, mass fraction of dehydroabietic acid was 5.6%, which conforms to the national standards. The regeneration of catalyst was investigated. After cycling five times, the product of hydrogenated rosin still conforms to the national standards without any treatment of catalyst.

在松香5g、m：m：m1：2：2、氯化钯0.090%、n：nl：10、氢气压力5MPa，反应温度160℃，反应时间3h的较佳工艺条件下，产物氢化松香中极酸的质量分数小于1%，去氢枞酸的质量分数5.6%，符合GB/T 14020-2006国家标准；并对催化剂的重复使用性能进行了考察，催化剂相不经过处理直接重复使用5次后，产品氢化松香仍然符合国家标准中关于枞酸和去氢枞酸的指标要求。

The acetalization and ketalization of various aldehydes and ketones with glycerol by using KHSO4 as catalyst were studied. Effect of reaction time, mole ratio of reactants and amount of catalyst on yield of acetals were investigated.

研究了在KHSO4催化下，丙三醇与环己酮、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。

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。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。