钨酸

The preparation process includes the following steps: dissolving activator and RE oxide in the molar ratio of 0.01-0.02 in concentrated nitric acid and heating to dry, dissolving the obtain RE nitrate in deionized water to obtain solution of RE nitrate; dissolving soluble tungstate and surfactant in deionized water to obtain tungstate solution; mixing the RE nitrate solution and the tungstate solution through stirring to reaction for 25-60 min to obtain white precipitate; hydrothermal reaction of the precipitate in a reaction kettle at 100-260 deg.c for 24-72 hr; centrifugally separating, washing and drying to obtain the product.

浓硝酸的加入量保证稀土氧化物溶解就可以，过量的硝酸可以加热除去；将可溶性钨酸盐和表面活性剂溶解于去离子水中，得到钨酸盐溶液，表面活剂性的加入量为反应原料重量的0-30wt％；将稀土硝酸盐溶液加入到钨酸盐溶液中搅拌，发生沉淀反应，磁力搅拌时间为25-60分钟，得到白色沉淀；将含有沉淀物的溶液作为前驱物加入到反应釜中，发生水热反应，反应温度为100-260℃，反应时间为24～72小时；离心分离，洗涤，干燥，即得所需产物。

Now, Anda products mainly include sodium tungstate, ammonium metagungstate, ammonium paratungstate, ammonium dimolybdate, ammonium quartmolybdate, ammonium heptamolybdate, ammonium molybdate, molybdenum, barium molybdate pure molybdenum trioxide, etc. All of these products have the stable market domestically which are also sold to more than ten regions and countries abroad including west countries, Southeast Asia and Japan. Anda also becomes the special factory of molybdenum series products in foreign trade.

目前安达产品主要包括钨酸钠、偏钨酸铵、仲钨酸铵、二钼酸铵、四钼酸铵、七钼酸铵、钼酸钠、钼铁、钼酸钡、高纯三氧化钼等，这些产品除在国内有稳定的市场外，还远销欧美、东南亚以及日本等十多个地区和国家，公司也成为外贸钨钼系列产品的定点厂家。

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%。

Although the charge number of isopoly and heteropoly anion was high, they existed mainly in aqueous solution as trivalent and tetravalent anions transferred across the W/NB interface.

系统研究了同多钼酸、同多钨酸、磷钨杂多酸、钒取代的磷钨杂多酸和双1∶11的镝的硅钼杂多酸阴离子在W/NB界面的转移行为，探讨了转移机制和它们在溶液中的存在形式，并计算了有关界面的热力学和动力学参数。

Commodities subject to export quota license are: corn, rice, wheat, cotton, wood products, live ox, live pig, live chicken, natural silk and its products, coal, coke, crude oil, finished oil, rare-earth metal, antimony oxide ore, antimony and antimony products, antimony oxide, tungsten ore, Ammonium Paratungstate, Ammonium metatungstate, Tungsten Trioxide and Blue Tungsten Oxide, Tungstic acid and salt, tungsten powder and its products, Zinc ores, Tin ores, tin and tin-base alloy, and white silver.

实行出口配额许可证管理的货物是：玉米、大米、小麦、棉花、锯材、活牛、活猪、活鸡、蚕丝类、煤炭、焦炭、原油、成品油、稀土、锑砂、锑及锑制品、氧化锑、钨砂、仲钨酸铵及偏钨酸铵、三氧化钨及蓝色氧化钨、钨酸及其盐类、钨粉及其制品、锌矿砂、锡矿砂、锡及锡基合金、白银。

The smaller the electronegativity is, the higher oxidation activity is. Thus phosphomolybdic acid shows better catalytic oxidation activity than phosphotungstic acid.

由于磷钨酸中的钨可以脱出并少量沉积到催化剂表面，而且从电负性来说Mo-O的键能小于W-O，键能小的杂多酸有较强的氧化性，所以钼系杂多酸催化活性要好于钨系杂多酸。

In the preparation of tungstenic acid sol, H_2O_2 and ethanol can make the sol become more stability.

在钨酸溶胶的制备中，H_2O_2、乙醇的加入能增强钨酸溶胶的稳定性，当H_2O_2与钨酸的摩尔比为1：2，乙醇与钨酸体积比为1：2时，溶胶的保存时间较长，成膜质量较好。

In the present paper,the solid state synthesis and luminescent properties of RE activated tungstates are introduced.

本文从单钨酸盐、混合碱土金属钨酸盐、氟钨酸盐、同多钨酸盐、杂多钨酸盐等方面综述了掺杂稀土离子钨酸盐的固相合成及发光特性研究进展。

The luminescent propetties of RE activated tungstates are dealt with in respect to mixed alkali earth metal tungstates,fluorotungstates,isopolytungstates,heteropoly tungstates.

本文从单钨酸盐、混合二价金属钨酸盐、卤钨酸盐、同多钨酸盐、杂多钨酸盐等方面综述了掺杂稀土离子钨酸盐的发光特性研究情况。

The main products are sodium tungstate, tungstic acid, ammonium perchlorate, tungsten trioxide, industrial ammonium molybdate, sodium molybdate, Chung-ammonium molybdate, ammonium tungsten migraine, two ammonium molybdate, barium molybdate, tungsten electrode wire cutter, cerium Tungsten welding electrode, etc., such as tungsten and molybdenum products.

主要产品有钨酸钠、钨酸、仲钨酸铵、三氧化钨、工业钼酸铵、钼酸钠、仲钼酸铵、偏钨酸铵、二钼酸铵、钼酸钡、钨绞丝电极、铈钨等氩弧焊电极等钨钼系列产品。

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。