钨酸

Copper ions greatly enhanced the sensitivity of the determination of molybdenum, which based on the color charge transfer complex of molybdotungstophosphate-3,3",5,5"-tetramethylbenzidine, in the presence of poly vinyl alcohol.

提出了一种基于铜离子增敏形成磷钼钨杂多酸-3，3'，5，5'-四甲基联苯胺电荷转移复合物测定痕量钼的方法。

_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。

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。

Three isomorphic pendant derivatives based on monovacant Keggin heteropolytungstate [SiW11O39]8- as building block have been synthesized through the decoration of Co-Im complexes using bench method:5Na_4H_2[SiW_(11)O_(39)CoIm]_(0.63)[SiW_(11)O_(39)Co(H_2O)]_(0.37)·7H_2O (1)_6[SiW_(11)O_(39)NiIm]_(0.8)[SiW_(11)O_(39)Ni(H_2O)]_(0.2)·7H_2O (2)_4Na_6[SiW_(11)O_(39)MnIm]_(0.69)[SiW_(11)O_(39)Mn(H_2O)]_(0.31)·7.5H_2O (3) Complexes 1–3 are the first examples of crystallographically characterized 3d-transition metal mono-substituted POMs with an antenna organic ligand synthesized under normal bench conditions.

以单缺位Keggin型杂多钨硅酸盐[SiW11O39]8-为建筑单元，在水溶液中通过过渡金属-咪唑配合物的修饰，成功地获得了三个同构的悬臂式衍生物：5Na_4H_2[SiW_(11)O_(39)CoIm]_(0.63)[SiW_(11)O_(39)Co(H_2O)]_(0.37)·7H_2O (1)_6[SiW_(11)O_(39)NiIm]_(0.8)[SiW_(11)O_(39)Ni(H_2O)]_(0.2)·7H_2O (2)_4Na_6[SiW_(11)O_(39)MnIm]_(0.69)[SiW_(11)O_(39)Mn(H_2O)]_(0.31)·7.5H_2O (3)它们是第一例在常规水溶液条件下合成得到的X-射线表征的3d-过渡金属取代的悬臂式多酸衍生物。

Isobutyl acetate was synthesized from isobutyl alcohol and acetic acid with silicotungstic heteropolyacid as catalyst.

字数：6943 页数：24）摘要：以硅钨杂多酸为催化剂，以异丁醇和乙酸为原料合成了乙酸异丁酯。

The influences of doping on the structure growth and properties of TB type niobate crystals are studied in this paper.

研究了掺杂对钨青铜型铌酸盐晶体的结构、生长及性能的影响。

Choosing heteropolyacid tungsten phosphoric acid as catalyst, single and double octyl phosphate was synthesized with phosphoric acid and iso-octanol.

以磷酸和异辛醇为原料、以杂多酸钨磷酸为催化剂合成了磷酸单、双辛酯。

Polyoxometalate; Phosphotungstate; Hydrothermal Synthesis; Crystal Structure

多金属氧酸盐；钨磷酸盐；水热合成；晶体结构

The preparation methods of phosphotungstic acid catalyst with Keggin structure were under discussion and research. In order to gain the maximum yield, the best experimental conditions were determined by orthogonal test.

对Keggin型磷钨杂多酸催化剂的制备方法进行了讨论研究，为获得最高收率由正交实验确定了最佳实验条件。

The results showed that phosphotungstic acid -, PW12/C and PW12/SiO2 were eminent catalysts and had no pollution.

实验结果显示：磷钨杂多酸、PW_(12)/C和PW_(12)/SiO_2是优良的酯化催化剂，对环境无污染。

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。