钨酸钠溶液中的钨钼分离研究

研究了用硫酸铜沉淀法除去粗钨酸钠溶液中钼的方法。试验在一定的条件下，使钼酸钠优先与硫化钠反应形成硫代钼酸盐，钨化合物仍以钨酸盐形式保留的溶液中。硫化后的粗钨酸钠溶液加入硫酸钠，硫代钼酸根与之结合生成难溶化合物沉淀，实现钨钼的分离。该方法流程简单，原材料来源广泛，操作条件易于掌握控制，污染小。     

球形钼酸锌的制备

以硫酸锌和钼酸铵为原料,运用非晶态相变理论试验并研究了硫酸锌浓度,酸度和温度等因素对钼酸锌微球粒度及其分布的影响。结果表明,影响非晶态球形钼酸锌结构与形貌的因素不仅有温度因素,而且有浓度和酸度等因素。通常球形钼酸锌的粒度随着温度和浓度的降低而增大;随pH值的增加而增大。该产品可应用于高分子聚合物的阻燃和抑烟剂以及金属防锈白色颜料等领域。     

Regulation of expression of a cDNA from barley roots encoding a high affinity sulphate transporter

A cDNA encoding a high-affinity sulphate transporter has been isolated from barley by complementation of a yeast mutant. The cDNA, designated HVST1, encodes a polypeptide of 660 amino acids (M(r) = 72,550), which is predicted to have 12 membrane-spanning domains and has extensive sequence homology with other identified eukaryotic sulphate transporters. The K(m) for sulphate was 6.9 microM when the HVST1 cDNA was expressed in a yeast mutant deficient in the gene encoding for the yeast SUL1 sulphate transporter. The strong pH-dependency of sulphate uptake when HVST1 was expressed heterologously in yeast suggests that the HVST1 polypeptide is a proton/sulphate co-transporter. The gene encoding HVST1 is expressed specifically in root tissues and the abundance of the mRNA is strongly influenced by sulphur nutrition. During sulphur-starvation of barley, the abundance of mRNA corresponding to HVST1, and the capacity of the roots to take up sulphate, both increase. Upon re-supply of sulphate, the abundance of the mRNA corresponding to HVST1, and the capacity of the roots to take up sulphate, decrease rapidly, concomitant with rises in tissue sulphate, cysteine and glutathione contents. Addition of the cysteine precursor, O-acetylserine, to plants grown with adequate sulphur supply, leads to increases in sulphate transporter mRNA, sulphate uptake rates and tissue contents of glutathione and cysteine. It is suggested, that whilst sulphate, cysteine and glutathione may be candidates for negative metabolic regulators of sulphate transporter gene expression, this regulation may be overridden by O-acetylserine acting as a positive regulator.     

用四钼酸铵生产试剂级钼酸钠的工艺研究与实践

论述了用四钼酸铵生产试剂级钼酸钠的工艺研究与实践.针对产品质量存在的问题,对生产工艺作了认真分析,提出对四钼酸铵采用预处理、碱溶、浓缩结晶、烘干等工序生产试剂级钼酸钠,并研究确定了各工序的操作参数.同时,对杂质富集后母液中的钼作了综合回收,为生产试剂级钼酸钠提供了借鉴.     

异戊醇萃取分离钼酸钠溶液中微量硅的研究

对钼酸钠溶液中的微量杂质硅的萃取分离进行了研究。结果表明,在一定条件下,溶液中的硅能够被异戊醇非常高效地去除。试验研究了最佳的反应条件以及影响萃取分离的主要因素。在硅钼杂多酸形成阶段,当初始反应的pH为0.7~1.0,低浓度和高浓度的钼酸钠与硅酸反应都比较完全;用异戊醇对硅钼杂多酸进行萃取分离时,溶液中氢离子、硅、钼酸钠的浓度等对萃取率均有影响;当水相的起始pH为0.5左右,硅和钼酸钠质量浓度分别为40 mg/L和50 g/L时,经过三级逆流萃取,硅的萃取率可达98%以上。     

Differential regulation of glucose transport and glucose transporter (GLUT-1) gene expression by vanadate, phorbol ester and okadaic acid in L6 skeletal muscle cells

Vanadate, an inhibitor of protein tyrosine phosphatases (PTPases), elicited time-and-dose-dependent increases in glucose transport in rat muscle L6 cells in culture: the rate was increased by 150-175% over control in 24 h at 75-100 microM. In contrast, molybdate, another inhibitor of PTPases, failed to stimulate glucose transport. The effect of vanadate was not blocked by tyrosine kinase inhibitors, genistein or tyrphostin RG 50864, implying that tyrosine kinase activation may not mediate the action of vanadate. The ability of vanadate to stimulate glucose transport was preserved in cells whose protein kinase C (PKC) activity was down-regulated by prior exposure to phorbol esters (TPA), suggesting that the vanadate effect was unrelated to the TPA-sensitive PKC isoform(s). Okadaic acid, an inhibitor of protein phosphatases 1 and 2A, was a potent activator of glucose transport increasing the rate 7-fold in 24 h at a concentration of 50 nM. The increases in GLUT-1 mRNA level in response to vanadate and TPA were paralleled bh much smaller increases in immunoreactive GLUT-1 protein level, whereas okadaic acid treatment markedly elevated GLUT-1 protein without a concomitant change in GLUT-1 mRNA levels.     

硅钼蓝分光光度法测定铝钛硼合金中硅

在采用硅钼蓝分光光度法对铝钛硼合金中硅进行测定时,样品中的钛会与钼酸铵反应生成钼酸钛沉淀,使溶液中钼酸根浓度降低,影响硅钼酸发色,同时钼酸钛沉淀也会因散射作用使吸光度发生变化,从而对测定结果产生影响。实验采用氢氧化钠和过氧化氢溶解样品,于微酸性条件下,在硅钼黄显色阶段加入两倍于普通硅钼蓝分光光度法中钼酸铵的量,可以实现硅钼黄显色完全。在将硅钼黄还原为硅钼蓝前,加入草酸-硫酸混合酸,因草酸对钛有络合作用,能加速钼酸钛的溶解,故而消除了钼酸钛沉淀对测定的干扰。用抗坏血酸还原硅钼黄为硅钼蓝,稳定30 min后,于分光光度计上在波长660 nm处进行测定,建立了不分离钛直接用分光光度法测定铝钛硼合金中硅的方法。结果表明,在优化的实验条件下,硅质量在50~250 μg范围内与其对应的吸光度呈现良好的线性关系,相关系数不小于0.999。检出限为0.002 8%(质量分数),定量限为0.009 3%(质量分数)。共存离子的干扰试验表明,铝钛硼合金中钛、硼、铝、铁、钒在其含量上限时,不干扰硅的测定。将实验方法用于测定铝钛硼合金样品中硅,结果与电感耦合等离子体原子发射光谱法(ICP-AES)或重量法测定结果吻合,相对标准偏差(RSD,n=11)小于1%。     

Determination of inorganic phosphorus on the (Cobas) Bio (direct method without deproteinization) (author's transl)

The direct molybdate method for the determination of inorganic phosphorus was adapted to the (Cobas) Bio centrifugal analyzer. We evaluated test characteristics such as reaction time, linearity range, accuracy and precision within series and from day to day. Accuracy was checked using control sera, three different types of recovery experiments, and by experiments running in parallel. Because the results of the determination of inorganic phosphorus depend greatly on the method and the procedure used (with/without deproteinization), we checked the accuracy not only by experiments running in parallel, but by comparison with the following methods: the malachite green method without and with two different techniques for deproteinization, the molybdate/p-methylaminophenol sulfate method with and without deproteinization, and the molybdate/vanadate method with deproteinization. Using patients' sera as well as control sera, it was shown that the preferred molybdate method gave, within the normal range of errors, the same results as the malachite green method without deproteinization.     

从钼酸盐溶液中分离微量钨的机理研究

概括了目前钼酸盐溶液中分离钨的研究。通过热力学计算,得出特定条件下溶液中钨、钼的离子存在形态,推断从钼酸盐中除钨的可行性,并确定了最佳分离条件,且通过实验验证该结论的正确性。     

Completely removing vanadium from ammonium molybdate solution using chelating ion exchange resins

Some chelating resins were used to remove a small amount of V (0.35 g/L V₂O₅) from ammonium molybdate solution with Mo concentration around 90 g/L. The results showed that vanadium can be easily extracted over molybdenum from ammonium molybdate solution by DDAS, CUW or CW-2 resins. More than 99.5% V and less than 0.27% Mo was extracted with a contact time of 60 min at pH = 7.4 and ambient temperature. The effluent was pure ammonium molybdate solution with a Mo/V gram ratio of more than 50,000 from an initial 255. Stripping of loaded resin was excellent using 5% ammonia solution, with a maximum V concentration of 20 g/L in comparison to 0.8 g/L Mo in the eluate. The mechanism for adsorption of V from ammonium molybdate solution by chelating resins was also proposed.     

钼酸铵生产的湿法冶炼工艺

钼酸铵是冶金化工生产的一种重要的深加工原料。以钼焙砂为原料生产钼酸铵的湿法冶炼工艺比较多,目前应用比较广泛的主要有2种,既经典氨浸法和离子交换法。本文对2种工艺作了利弊分析,研究认为离子交换法所排放的生产污水氨氮含量低,基于环境保护国策,我国今后钼酸铵生产项目的改扩建或新建工程宜采用离子交换工艺。     

从生产三氧化钼的废母液中回收钼及氯化铵

介绍利用ＨＴ吸附剂从钼酸铵母液及氨浸钼渣酸分解母液中回收钼及氯化铵的实验过程。吸附钼后的吸附剂用氨水反洗，得到的钼酸铵溶液，通过蒸发、浓缩、中和结晶出仲钼酸铵，从而回收其中的钼。而吸附钼后剩下的母液蒸发、浓缩、结晶出氯化铵，可用作农用化肥。     

Electrochemical evaluation of the synergistic effect of molybdate tungstate inhibitor mixtures in chloride ion medium and effect of Cl− ion on inhibition efficiency of molybdate

It is well known to corrosion community about chromates and nitrates which are widely used as corrosion inhibitors. However, it is also well known that these inhibitors are oxidizing inhibitors of which chromates are carcinogenic also. Therefore, use of non toxic inhibitors such as molybdate and tungstate are gaining importance. AC impedance analysis of mild steel panels exposed to 3% NaCl containing 6000 ppm molybdate, 5000 ppm molybdate + 1000 ppm tungstate, 3000 ppm molybdate + 3000 ppm tungstate, 1000 ppm molybdate + 5000 ppm tungstate, 6000 ppm tungstate were evaluated. The impedance studies were carried out for different durations viz. 1 hour, 1 day and 7 days. From impedance analysis, it is clear that molybdate and tungstate are not forming any promising synergistic mixtures. The effect of chloride ion concentration viz. 0.01M, 0.05M, 0.1M, 0.3M and 0.6M on inhibition efficiency of molybdate has been discussed. Addition of small amount of tungstate along with molybdate enhances long term film stability on mild steel. It has been found that the inhibition effect is decreasing with increase in concentration up to 0.1M and on further increase in concentration viz. 0.3M and 0.6M, an increase in inhibition efficiency was observed. It has been found that deaeration negatively affected the film properties and did not form a stable film. The corrosion products formed were analyzed using Mössbauer spectroscopy and FT-IR spectroscopy, which showed the presence of oxyhydroxides.     

用工业氧化钼生产钼酸钠试剂的新工艺

针对传统工艺生产钼酸钠试剂存在产量小、成本高的问题，提出了用工业氧化铝直接生产钼酸钠式剂的设想，经过小度、中试试验研究，确定了新的生产工艺，并投入批量生产，各项技术经济指标显著提高，对试剂及工业级钼酸钠的生产具有现实意义。     

工业钼酸钠杂质氯离子的控制

根据国际贸易标准要求，进行了工业钼酸钠杂质氯离子的控制试验，得出了降低杂质氯离子较佳的工艺技术条件，并应用于生产实践，使钼酸钠杂质氯离子含量降低至0．01％以下，满足了出口要求。     

Glycated hemoglobin reference limits obtained by high performance liquid chromatography in adults and pregnant women

Pentachlorophenol (PCP) and molybdate have been shown to inhibit the sulfoconjugation of various chemicals in rats and therefore are useful to examine the role of sulfoconjugation on the toxicity of a chemical. PCP inhibits sulfation by competing with substrates for phenol-sulfotransferases, but not hydroxysteroid-sulfotransferases. In contrast, molybdate decreases sulfation by limiting sulfate availability and thereby decreasing the synthesis of 3'-phosphoadenosine 5'-phosphosulfate (PAPS), which is the obligate cosubstrate for sulfation. Therefore, it was of interest to determine whether PCP or molybdate is effective in decreasing the in vivo sulfation of dehydroepiandrosterone (DHEA), which is a substrate for hydroxysteroid-sulfotransferases. PCP (40 micromol/kg ip) or molybdate (7.5 mmol/kg po) was given 45 min and 4 h, respectively, prior to the start of DHEA infusion. The effects of these two sulfation inhibitors on DHEA sulfation were dependent on the rate of DHEA infusion in rats. PCP had different effects on the sulfation of various infusion rates of DHEA in rats. PCP had little effect on the sulfation after the two lowest infusion rates of DHEA (12.5 and 25 mg/kg) and actually increased (233%) DHEA-sulfate serum concentrations with the highest DHEA infusion rate (50 mg/kg). Although molybdate had little affect on the sulfation of the lowest DHEA infusion rate, it significantly decreased (50-85%) DHEA-sulfate serum concentrations with the two higher DHEA infusion rates. These data indicate that molybdate, unlike PCP, decreases the sulfation of DHEA and may be a useful tool to decrease the sulfation of other substrates of hydroxysteroid-sulfotransferases.     

分光光度法测定炉渣中的二氧化硅

采用碳酸钠和硼酸熔融分解试样,稀硝酸浸取,在硫酸介质中,硅与钼酸铵生成硅钼黄络合物,以硫酸亚铁铵还原硅钼黄为钼蓝,探讨了吸收波长、加热时间、钼酸铵用量、硫酸用量、还原剂用量五个因素对吸光度的影响。结果表明：该法快速、准确且精密度较高,适合炉渣中SiO2的测定。     

钼酸银无机抗菌剂

简要叙述了钼酸银、钼酸银与钼酸锌无机抗菌剂的制备、抗菌活性及其应用。     

以钴钼废催化剂为原料制备仲钼酸铵试验研究

进行了以钴钼废催化剂为原料制备仲钼酸铵试验研究，采用加碱焙烧、湿式球磨、沉钼酸和氨溶工艺路线。研究结果表明，焙烧温度、时间和纯碱加入量对钼的提取率均有一定的影响，沉钼酸过程除P效果较好，产品仲钼酸铵质量稳定。     

钼酸盐阻燃抑烟剂研发现状

简要地叙述了钼酸盐类阻燃抑烟剂 ,如八钼酸铵、钼酸锌、钼酸钙、钼酸钴和三氧化钼等阻燃抑烟剂的研发现状