黄铜镀液中铜的光度测定

黄铜镀液中铜的测定常用ＥＤＴＡ滴定法 ,但此法只能测定铜锌合量 ,且许多常见的金属离子如钙、镁等均有干扰。本文用Ｃｕ ＥＤＴＡ光度法测定 ,方法具有良好的选择性 ,且简便快速。1　试剂和仪器铜标准溶液 :准确称取 1.9647ｇ优级纯ＣｕＳＯ4·5Ｈ2 Ｏ溶于水中 ,移入 2 50ｍｌ容量瓶 ,定容并混匀。此液含铜 2ｍｇ/ｍｌ。显色液 :称取 4ｇＥＤＴＡ二钠盐和 7ｇ氯化铵溶于 57ｍｌ氨水中 ,用水稀释至 10 0ｍｌ,混匀备用。分光光度计 :72 1型 (上海第三分析仪器厂出品 ) ,2ｃｍ光程比色皿。2　分析方法( 1)待测液的制备　准确吸取镀液 2 .0 0…     

单柱离子色谱法测定化学镀镍液中的HPO32-和H2PO-2

应用ＨＩＣ－６Ａ型离子色谱仪,以１．５ｍｍｏｌ／Ｌ苯甲酸钠作淋洗液,可快速分离和测定化学镀镍液中的ＨＰＯ３＾２－和Ｈ２ＰＯ２＾－的线性范围分别为１０￣２５０ｍｇ／Ｌ和１５￣１２０ｍｇ／Ｌ,精密度分别为０．５％和１．３％,最低检出浓度分别为０．７ｍｇ／Ｌ和０．８ｍｇ／Ｌ。     

分光光度法测定余氯的标准曲线线性范围的探讨

在用分光光度法测定水样中余氯的实验过程中,发现按照国标ＧＢ１１８９８－１９８９中所要求的在整个的浓度范围内（余氯０￣５．００ｍｇ／Ｌ）所制得的标准曲线的相关系数０．９９￣０．９９９之间。为此笔者对其标准曲线的线性范围进行了一些探讨。发现,当余氯的浓度范围为０￣１００ｍｇ／Ｌ时,标准曲线的线性较好,相关系数〉０．９９９;当余氯的浓度〉１．００ｍｇ／Ｌ后,所绘制的标准曲线呈负偏离现象,相关系数〈０．９     

碱性高速电镀耐蚀性锌铝合金工艺简介

介绍了碱性电镀锌铝合金工艺流程、镀层质量和镀液性能。镀液中Ｚｎ＾２＋浓度为２５～３５ｇ／Ｌ,电流效率为８０％,测极电流密度范围宽０．５～２５．０Ａ／ｄｍ＾２,可实施不同镀速的电镀０．５～６．０μｍ／ｍｉｎ。     

氰化镀锌和无氰碱性锌酸盐镀锌通用光亮剂的研究

介绍了一种新的碱性镀锌通用型光亮剂，可用于氰化物镀锌以及无氰碱性锌液中，使用时，镀液的基本成分和条件是：ＺｎＯ１０－４５ｇ／Ｌ，ＮａＯＨ１００－１５０ｇ／Ｌ，ＮａＣＮ０－８０ｇ／Ｌ，ＷＤ９２８８－１０ｍｌ／Ｌ，ｔ＝０－４５℃，Ｄｋ＝０．５－６．０Ａ／ｄｍ＾２，还讨论了溶液中ＮａＯＨ的浓度对镀液的性能和镀层质量的影响。     

火焰原子吸收法直接测定电镀液中铜和铁离子

本研究采用火焰原子吸收法直接测定电镀槽液中铜、铁离子 ,操作简便 ,分析灵敏度高。用分析纯化学试剂 ,按各镀种主要成分的含量 ,配制空白溶液 ,加入一定量的铜、铁标准溶液 (0 0 1ｍｇ/ｍＬ)进行测量。1　电镀溶液中铜、铁杂质离子的测定镀镉、镀铬电镀液 :移取 5 0 0ｍＬ镀镉电镀液于 5 0ｍＬ容量瓶中 ,用水稀释至刻度 ,混匀后 ,测量吸光度值 ,从工作曲线上查出铜含量。取 2 0 0ｍＬ镀镉电镀液于 2 0 0ｍＬ容量瓶中 ,测定铁含量。碱性锌电镀液 :移取 5 0 0ｍＬ镀镉电镀液于5 0ｍＬ容量瓶中 ,测定铜的含量。移取 5 0 0ｍＬ镀镉电镀液…     

单柱离子色谱法分离测定复合镀铬液中的F^—和SO4^2—

采用单柱离子色谱系统，在样品中存在大量铬酸根的情况下，以３．０ｍｍｏｌ／Ｌ邻苯二甲酸氢钾作为淋洗液，简单快速地分离测定了镀铬液中的Ｆ＾－和ＳＯ４＾２－，并在此条件下作出了Ｋ２ＳｉＦ６的离解曲线。Ｆ＾－，ＳＯ４＾２－的线性范围分别为１．０￣１５０．０ｍｇ／Ｌ，１．４￣１５０．０ｍｇ／Ｌ，最低检出浓度分别为０．０２ｍｇ／Ｌ，０．０７ｍｇ／Ｌ（信噪比为２）。     

一种简易镀金法

１配 方 三氯化金　５ｇ／Ｌ 氟化氨７５ｇ／Ｌ 柠檬酸钠 ５０ｇ／ Ｌ 次亚磷酸钠 ２０ ｇ／Ｌ 氯化镍 １４ ｇ／Ｌ２ 配制方法 （１） 用３００ｍｌ蒸馏水混合溶解氯化铵、柠檬酸钠、次亚磷酸钠、氯化镍,搅拌均匀,同时用 １００ ｍｌ蒸馏水溶解氯化金,搅拌均匀。 （２）对第（１）步制得的３００ｍｌ混合液,在搅拌过程中加入１００ｍｌ氯化金溶液。 （３）用蒸馏水稀释至１０００ｍｌ。 （４）测量第（３）步所得的镀液的ｐＨ值,并用氨水或柠檬酸,将 ｐＨ值调节至 ５～６间。最后将所得的镀液装入棕色试剂瓶中避光保存。 ３操作过程 …     

反相高效液相色谱法同时测定强化AD牛奶中维生素A,维生素D

本文介绍了用反相ＨＰＬＣ同时测定强化ＡＤ牛奶中维生纱Ａ、Ｄ的方法。Ｃ１８色谱柱,甲醇：水＝９８：２为流动相,流速１．０ｍｌ／ｍｉｎ,检测波长２８０ｎｍ。用于样品测定时,变异系数ＣＶ％为０．２０－４．４５％,加标回收率为９１－１０３％。     

中空纤维超滤膜处理油田含油污水的研究

采用不同材料的中空纤维超滤膜对油田污水进行了实验研究，研究了料液循环速度、操作压力、操作温度和料液浓缩倍数对膜透过性能的影响，探讨了不同清洗方法对膜透过性能的恢复效果。在原液含油量为１００ｍｇ／Ｌ以上，进口压力为０．１６ＭＰａ，出口压力为０．０８ＭＰａ时，膜的透水通量可达１５ｍｌ·ｃｍ＾－２·ｈ＾－１以上，透过液含油量小于１０ｍｇ／Ｌ。不同的膜材料应用不同的清洗方法可达到较好的效果。     

VLE data for CO2-CF2Cl2, N2-CO2, N2-CF2Cl2 and N2-CO2-CF2Cl

Knowledge about vapour-liquid (VLE) is required as a basis of reliable calculations for separation processes. Correlations available for the prediction of T, p, x, y data are less accurate for mixtures at high pressures and mixtures containing supercritical components. The results of VLE experiments are reported and compared with data calculated with equations of state.     

Preparation of ZrO2-CeO2 and HfO2-CeO2 nanopowders

We prepared weakly agglomerated powders of ZrO₂-CeO₂ and HfO₂-CeO₂ solid solutions 5–8 nm in particle size, consisting of monoclinic and tetragonal phases. After heat treatment at 1200°C, the crystallite size was 30 and 14 nm, respectively. We also examined the effect of precipitate freeze drying on the crystallization of hafnia-based solid solutions containing up to 20 mol % CeO₂.     

Thermal diffusion in binary mixtures H2-CCl2F2 and H2-CHClF2

Thermal diffusion coefficients were measured in two gaseous mixtures, in which one component was close to the critical temperature, in the pressure range (19.6–127.4)·10⁴ N/m² and at a freon concentration of 0.25–0.8.     

Comparison of the Electronic Structures of La2CuO4, Sr2CuO2Cl2, and Sr2CuO2F2

First-principles cluster calculations are reported of the local electronic structure of the three compounds: La₂CuO₄, Sr₂CuO₂Cl₂, and Sr₂CuO₂F₂. The copper ${\text{3d}}_{x^2 - y^2 } $ and the planar oxygen 2p _σ atomic orbitals exhibit a similar degree of covalency. The out-of-plane orbitals, however, are quite different with the ${\text{3}}d_{3z^2 - r^2 } $ atomic orbital lowered significantly in energy for chlorine and fluorine apical positions.     

Radial GRIN glasses in Li2O-Na2O-Al2O3-TiO2-SiO2 systems

A series of GRIN glass rods have been developed in Li2O-Na2O-Al2O3-TiO2-SiO2 systems. Negative radial refractive index profiles were generated by exchanging Na+ for Li+ ions in these glass rods. It has been observed that TiO2 plays a vital role in increase in the profile depth and maximum change in the refractive index because of its ambivalent nature. Change in the refractive index can be further increased by increasing the concentration of exchanging cation in the base glass.     

Elastic and Electronic Properties of Superconducting CaPd 2 As 2 and SrPd 2 As 2 vs. Non-superconducting BaPd 2 As 2

The first-principles calculations were performed to predict the elastic and electronic properties of the superconducting ThCr₂Si₂-type phases CaPd₂As₂ and SrPd₂As₂ in comparison with the non-superconducting CeMg₂Si₂-type phase BaPd₂As₂. Besides, the same properties were compared for CeMg₂Si₂- and ThCr₂Si₂-type polymorphs of BaPd₂As₂. We found that all these phases are mechanically stable and belong to soft materials with low hardness. The near-Fermi region is formed by the valence states of the blocks [Pd₂As₂] with decisive contributions of Pd 4d states. The values of N(E _F) increase in the sequence: CaPd₂As₂ < SrPd₂As₂ < BaPd₂As₂, i.e. in the reverse sequence relative to the transition temperatures T _C. Thus, the change in T _C cannot be explained by the electronic factor, i.e. by the simple correlation T _C～N(E _F). Most likely the decrease in T _C in the sequence CaPd₂As₂ → SrPd₂As₂ and the absence of a superconducting transition in BaPd₂As₂ are related to the structural factors and the peculiarities of the electron–phonon coupling mechanism.     

Si_2N_2O-Al_2O_3-La_2O_3和Si_2N_2O-Al_2O_3-CaO系统的亚固相关系

本文给出了 Si_2N_2O-Al_2O_3-La_2O_3和 Si_2N_2O-Al_2O_3-CaO 系统的亚固相图。实验结果表明:在 Si_2N_2O-Al_2O_3-CaO 系统中有一个未知结构的新化合物 CaO·Si_2N_2O,在3CaO·Si_2N_2O 和3CaO·Al_2O_3两化合物之间形成连续立方固溶体。而 Si_2N_2O-Al_2O_3-La_2O_3系统中则没有发现新化合物。在两个系统的富 Si_2N_2O区,过量的 Si_2N_2O 与 La_2O_3和 CaO 分别反应形成 Si_3N_4与 La_(10)[SiO_4]_(?)N_2(H-相)(和 CaSiO_3。所研究的这两个三元系统中,分别形成了如下几个四元相容性区。在 Si_2N_2O-Al_2O_3-La_2O_3系统内有:H-Si_3N_4-La_2O_3·Si_2N_2O-La_2O_3·Al_2O_3;H-Si_3N_4-La_2O_3·Al_2O_3-La_2O_3·11 Al_2O_3;H-Si_3N_4-La_2O_3·11 Al_2O_3-Al_2O_3;H-Si_3N_4-Al_2O_3-O′s.s;H-Si_3N_4-O′s.s-Si_2N_2O在 Si_2N_2O-Al_2O_3-CaO 系统内有:Si_3N_4-CaSiO_3-CaO·Si_2N_2O-3CaO·Al_2O_3;Si_3N_3-CaSiO_3-3CaO·Al_2O_3-2CaO·Al_2O_3·SiO_(?);Si_(?)N_(?)-CaSiO_3-2CaO·Al_2O_3·SiO_2-Al_2O_3;Si_3N_4-CaSiO_3-Al_2O_(?)-O′s.s;Si_3N_4-CaSiO_3-O′s.s-Si_(?)N_(?)O