A STUDY ON THE KINETICS OF EXCHANGE REACTIONS OF W（VI） OR Mo（VI） WITHIN人MACROPOROUS ANION EXCHANGE RESIN（D290） PHASE

The exchange behaviors of WO4^2-,MoO4^2-,H2W12O46^6- and Mo8O26^4- anions within macroporous exchange resin(D290) phases have been studied.The values of diffusion constant(B),inner diffusion coefficient(D^-),retarted time(τd) half-exchange-period(t1/2), and activation energy(ΔE） were found from the kinetic analyses.A new method to separate W(VI) and Mo(VI) from each other was also suggested.     

Electrodeposition, Structure and Corrosion Resistance of Nanocrystalline Ni-W Alloy

Ni—W alloy was electrodeposited from the electrolyte solution containing sodium tungstate, nickel sulfate and ammonium citrate. The electrodeposition, heat treatment, structure, surface morphology and corrosion resistance in w=0.03 NaCl solution, of Ni-W alloys were studied by means of DSC, XRD, SEM and electrochemical techniques. The results showed that the obtained Ni-W alloy electrodeposit with W weight content (Ww=0.471) was presented in more typical nanocrystaUine, After heat treatment at 400 ℃ for 1 h, the phase structure of the deposits was not obviously changed whereas the agglomerate for the reunion of tiny grains on deposit surface caused the granule in a more smooth morphology, the microhardness was slightly increased and the corrosion resistance was enhanced.     

o-ZrWl.6Mo0.408： A Novel Orthorhombic Intermediate Phase Formed During the Synthesis of the Negative Thermal Expansion Cubic ZrWl.6Mo0.4O8 Material by the Precursor Dehydration Route

The mechanism of the precursor dehydration route was revealed for the synthesis of NTE c-ZrW1.6Mo0.4O8. The hydrate precursor was dehydrated at 473 K and transformed to a NTE cubic compound above 800 K. A novel intermediate phase o-ZrWl.6Mo0.4O8 occurs between the temperature range of 573-800 K. The XRD pattern of novel intermediate was refined with the structural model of LT-ZrMo2O8 by using Rietveld method.The residuals are Rwp=7.80% and Rp=5.79%. The space group is Pmn21 and the lattice parameters are α=0.5917(4)nm, b=0.7273(4) nm, c =0.9148(6) nm, and Z=2.     

用氧化锌基准试剂作校正标准样品测定钨合金中的氧

RO－416型氧测定仪用氧化锌基准试剂校正后，用于测定钨合金中的氧，利用RO－416型氧测定仪在输入1．000g质量时测量范围是0．0％－4．5％的特点，分析质量为0．003－0．006g的氧化锌基准试剂，手动输入1．000g质量，测得氧含量在0．06％－0．12％，与钨合金粉末中的氧含量接近，用氧化锌基准试剂校正仪器是可行的。     

稀土对3Cr2W8V钢多元共渗及金相组织的影响

(一)实验方法 经调质处理尺寸为10×10×10mm的3Cr2W8V钢试样,在7kW井式滴控坩埚炉中,采用滴注式气体共渗工艺,共渗介质为自配的稀土渗剂,稀土加入量为5g/L,在580℃进行共渗处理。 用Plasma 300 ICP和X射线衍射仪分析检测稀土;用显微硬度法确定渗层深度和显微硬度分布。     

纳米钨合金块体材料的制备

高比重钨合金由于具有一系列优异的物理力学性能, 因此在航空航天、国防军工和民用中有着广泛的应用前景.采用纳米技术制备高比重钨合金块体材料有望进一步提高其性能, 促使其应用.本文分析了纳米钨合金在粉末制备和成型烧结中存在的问题, 并针对纳米钨合金粉末成型和烧结过程中晶粒长大问题以及块体材料中存在大量微孔问题, 介绍了数种可行性控制方法.     

含有环己巯基配体的钨簇合物的合成及晶体结构研究

C6H11Na, Et4NBF4, FeCl2, (NH4)2WS4在20mL CH3OH溶剂的反应中, 标题簇合物(Et4N)3[W2Fe6S8(SC6H11)6(OCH3)3]被分离得到, 对其进行X-ray 单晶衍射和结构解析。 该化合物属正交晶系,空间群 Pmmn, 晶胞参数 a = 17.370(5), b = 15.986(4), c = 17.858(3), V = 4958.6(6)3, Z = 2,C63H135N3O3S14Fe6W2, Mr = 2134.47, Dc = 1.43g/cm3, F(000) = 2172.0, m(MoKa) = 3.49 mm-1, T = 293(2)K。 采用2966个I > 2.0s (I) 的衍射点对所有非氢原子参数进行结构修正。 得到最后的偏离因子为R = 0.072, Rw = 0.091。 这是一个双类立方烷的结构, 2个单类立方烷的端基金属钨原子通过3个甲氧基桥联。 [WFe3S4] 与 [MoFe3S4]簇核结构比较说明, 两者存在一定的相似性。     

钨铜难熔合金中铜含量的测定

钨铜合金在微电路中具有广泛的用途,用它制作的微电路底衬具有良好的导热性和很低的热膨胀系数,是一种优良的电子工业材料。该难熔合金中铜含量的测定方法尚未见报道,本文给出了钨铜合金中铜含量的测定方法。根据合金中钨和铜的溶解属性,用硫酸铵和浓硫酸进行溶解。在酸性体系中采用碘量法使Cu~(2 )与碘化钾作用,定量析出的碘用硫代硫酸钠标准溶液进行滴定。试验及实践表明,该方法简便、准确、结果重现性好,完全可以满足工厂生产的常规分析需要。     

钨-氨三乙酸-邻氯苯基萤光酮-溴化十六烷基三甲基铵体系的分光光度法研究

在阳离子表面活性剂存在下，邻氯苯基萤光酮(O—CIPF)与钛、钼、钨和钽的显色反应已有报道，光度测定的灵敏度较高，但对钨的测定却受锡和钛等金属离子的严重干扰。     

固相配位化学反应研究：LXVII.金属铜表面M—S（M=Mo,W）簇合物的组成

采用ＦＴＩＲ、ＸＰＳ和ＡＥＳ研究了金属铜表面Ｍ－Ｓ（Ｍ＝Ｍｏ，Ｗ）簇合物膜。结果表明，Ｍｏ（Ｗ）Ｓ＾２－４与铜表面的Ｃｕ２Ｏ反应，形成了Ｍｏ（Ｗ）－Ｓ－Ｃｕ键。簇合物膜由Ｍｏ（Ｗ），Ｓ，Ｃｕ，Ｏ元素组成，分别呈＋６、－２、＋１、－２价，膜为多分子层结构并保持，ＭｏＳ４或ＷＳ２单元，膜表面只有Ｃｕ，Ｏ而不存在Ｍｏ（Ｗ），Ｓ，膜层厚度与反应时间有关，时间越长，膜越厚，膜为多组分的复杂体系，其颜色是各组