查询词典 tungstic acid

The anion of tungstotantalate was synthesized for the first time as K_9TaW_(11)O_(40)·15H_2O by the reaction of soluble potassium tantalate and porous white tungstic acid in aqueous solution.

在五氧化二钽基体中加五氧化二铌配成标准溶液，与氟钽酸钾样品在相同条件下经系列处理后进行纸上色层分离，分离后与样品直接进行目视比色。

The synthesis of high purity azelaic acid through oxidation of oleic acid with 50% hydrogen peroxide was studied by using tungstic acid as a catalyst and ionic liquid as a basic reaction system .

以油酸为原料，50%的H2O2为氧化剂，在离子液体作为主要溶剂的条件下，采用钨酸为催化剂所得中间产物用自制的过氧乙酸继续氧化裂解合成了高纯度壬二酸。

In the absence of organic solvent and phase-transfer reagent, the catalytic oxidation of cyclo- hexene to adipic acid with aqueous 30% hydrogen peroxide can be achieved in the presence of tungstic acid/acidic organic additive.

以钨酸/有机酸性添加剂为催化体系，在无有机溶剂、相转移剂的情况下，催化 30%过氧化氢氧化环己烯合成己二酸。当钨酸∶有机酸性添加剂∶环己烯∶过氧化氢=1∶1∶40∶176(摩尔比，钨酸用量为 2.5 mmol)时，使用有机酸性添加剂考察钨酸的催化性能，结果表明以钨酸/间苯二酚催化氧化环己烯的催化效果最优，反应 8 h 时己二酸分离产率达 90.9%、纯度为～100%；而不使用有机酸性添加剂时，己二酸分离产率只有 72.1%，产品纯度为 96.2%。

WO3, an interlayer compound prepared by J. W. Johnson (1981) using yellow tungstic oxide hydrate. Suspension of white powdery tungstic acid in anhydrous pyridine yields on standing for 2 wk whiteHW4O13.3H2O. IR and DTA studies revealed the connection between that pyridine polytungstate and white powdery tungstic acid (microcryst.), whose composition may thereby be assigned as H2W4O13.nH2O.

WO3。粉状白钨酸在无水吡啶中放置两周后可得到另一种化学式为(C5H5NH)HW4O13.3H2O的吡啶化合物，经IR和DTA研究可初步说明该化合物与粉状白钨酸之间的联系，并因此推测白钨酸的组成可能为H2W4O13.nH2O。

The phase composition, morphology and specific surface area of the products can be controlled by the molar ratio of citric acid to tungstic acid n(subscript cit/n(subscript TA.

通过调节柠檬酸与钨酸的物质的量的比n(下标 citn，可以控制产物的组成、形貌和比表面积。

Hydrogen peroxide(H_2O_2)was used as oxidant,oxalic acid as complexing agent and tungstic acid (H_2WO_4)as catalyst.

研究了以环戊烯为原料、草酸为有机络合剂、H2O2为氧化剂，在催化剂钨酸(H2WO4)的作用下一步合成戊二酸的绿色新过程，考察了氧化剂的含量、反应物配比、催化剂用量、反应温度、反应时间等对反应的影响。

When the molar ratio of tungstic acid∶acidic organic additive∶cyclohexene∶ hydrogen peroxide was 1∶1∶40∶176 (tungstic acid, 2.5 mmol) and the tungstic acid/resorcinol used as catalyst, the isolated yield of adipic acid was up to 90.9% for 8 h.

当使用磺酸水杨酸、草酸、水杨酸为有机酸性添加剂时，随反应时间的增加，己二酸分离产率均升高，但反应 6 h 以后，己二酸分离产率随时间的变化不明显。当磺酸水杨酸用量为 2.5 mmol 时，己二酸分离产率和纯度均较高。

The catalyzed oxidation of cyclohexanol with 30% aqueous hydrogen peroxide by mass fraction to produce adipic acid can be achieved using tungstic acid -acidic additive catalyst system in the absence of organic solvents and phase-transfer reagent.

以钨酸-酸性添加剂为催化体系，在无有机溶剂和相转移剂的情况下，催化30%过氧化氢氧化环己醇合成己二酸。

Cyclohexene ; catalytic oxidation ; tungstic acid ; hydrogen peroxide ; adipic acid

环己烯；催化氧化；钨酸；过氧化氢；己二酸

When the molar ratio of tungstic acid∶acidic organic additive∶cyclohexene∶hydrogen peroxide was 1∶1∶40∶176 (tungstic acid, 2.5 mmol) and the tungstic acid/resorcinol used as catalyst, the isolated yield of adipic acid was up to 90.9% for 8 h.

以钨酸/有机酸性添加剂为催化体系，在无有机溶剂、相转移剂的情况下，催化30%过氧化氢氧化环己烯合成己二酸。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。