钨酸

The main work as follow: 1. The precursor of W-Cu composite powders was prepared by chemical coprecipitation using tungstenic acid and chalcanthite.

以黄钨酸和五水硫酸铜为原料，用化学共沉淀法制备钨铜复合粉前驱体粉。

In the presence of the combination of sulphuric and phosphoric acid, with sodium diphenylamine sulfonate as the indicator, standard solution of potassium dichromate was used to titrate total iron value.

试样以盐酸溶解后，在酸性介质中，先以氯化亚锡将三价铁大部分还原为二价，然后在钨酸钠指示下，再以三氯化钛将剩余的三价铁还原为二价，过量的三氯化钛以重铬酸钾氧化消除干扰，在硫磷混合酸存在下，以二苯胺磺酸钠为指示剂，用重铬酸钾标准溶液滴定全铁量。

A series of supported tungsten phosphide catalysts were prepared by the method of temperature-programmed reduction of phospho-tungstate in hydrogen.

本文采用氢气程序升温还原磷钨酸盐的方法，制备了一系列负载型磷化钨催化剂。

Its technology of scheelite recovery and the mixed flotation dressing has been popularized.

赣州的仲钨酸铵生产技术居世界领先地位，白钨综合回收技术和黑白钨混合矿浮选技术得到推广。

The technology of producing APT in Ganzhou is the most advanced in theworld. Its technology of scheelite recovery and the mixed flotationdressing has been popularized.

赣州的仲钨酸铵生产技术居世界领先地位，白钨综合回收技术和黑白钨混合矿浮选技术得到推广。

In this paper,that a series of sodium tungsten bronze crystals were prepared by electrolysis of molten salts containing sodium tungstic and tungstic oxide was reported.

文中采用熔盐电解法，电解钨酸钠与三氧化钨熔盐制备出系列钠钨青铜晶体，选用离子选择电极分析法快速、简便、可靠地测定了晶体中的钠含量，并通过X－射线粉末衍射确定了晶体的晶型结构及晶格常数a。

A mineral consisting of calcium tungstate; an ore of tungsten .

一种由钨酸钙组成的矿物，是一种钨矿石。

The invention provides a chemical nickel tungsten phosphorus plating solution for magnesium alloy, which consists of 10-20 g/L of nickel sulfate, 7-15 g/L of sodium tungstate, 29-50 g/L of sodium citrate, 14-30 g/L of sodium hypophosphite, 14-30 g/L of sodium carbonate, 5-12 g/L of ammonium bifluoride, additive accounting for 0.00005-0.003 percent of total weight and the balance being water.

本发明提供的是一种镁合金化学镀镍钨磷镀液。它由硫酸镍10-20g/L、钨酸钠7-15g/L、柠檬酸钠29-50g/L、次亚磷酸钠14-30g/L、碳酸钠14-30g/L、氟化氢铵5-12g/L、占总重量0.00005-0.003％的添加剂和余量的水组成。

In order to solve the problem of producing large amounts of wastes and undesired o-nitrotoluene in synthesis of p-nitrotoluene with the mixed concentrated mineral acids,the catalytic activity of phosphotungstic acid for selective nitration of toluene was studied and the optimum conditions for preparing the catalyst were investigated.

为解决硝硫混酸对硝化甲苯过程中因甲苯的非选择性硝化产生的o-MNT和大量废酸对环境的危害，研究了磷钨酸对甲苯硝化反应的催化活性。

Study on technics of synthesize dimethyl fumaricate, firstly prefabricated fumaric acid, with furfural as raw material, V2O5 as catalyst and potassium chlorate as oxidizer then synthesized dimethyl fumaricate through esterication of fumaric acid and methanol with phosphor tungstenic acid as catalyst.

研究了以糠醛为原料，V2O5作催化剂，用氯酸钾氧化制取富马酸，然后以磷钨酸为催化剂，用甲醇进行酯化合成富马酸二甲酯的合成工艺。

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。