5-Br-PADMA分光光度法测定微量铂

研究了２－〔２－（５－溴吡啶）偶氮〕－５－二甲氨基苯胺（简称５－Ｂｒ－ＰＡＤＭＡ）与Ｐｔ（ＩＶ）配合物的光度特性和显色反应的最佳条件。在ｐＨ３５～４８ＨＡｃ－ＮａＡｃ缓冲介质中，沸水浴加热２０ｍｉｎ，Ｐｔ（ＩＶ）与５－Ｂｒ－ＰＡＤＭＡ形成１：３的紫红色配合物。配合物形成后，提高酸度为０８～３６ｍｏｌ·Ｌ－１盐酸溶液，最大吸收波长红移至６２０ｎｍ，灵敏度和对比度显著提高，表观摩尔吸光系数ε６２０＝６５×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，对比度λ＝１８６ｎｍ。Ｐｔ（ＩＶ）浓度在０～２８μｇ／２５ｍｌ遵守比尔定律。大多数常见金属离子不干扰Ｐｔ的测定，可满意地应用于催化剂中微量Ｐｔ的测定。     

Rh（III）—5—Br—PADAP配合物吸附波研究

Ｒｈ（Ⅲ）在０．１ｍｏｌ／Ｌ ＨＡｃ－０．１ｍｏｌ／Ｌ ＮａＡｃ，１。６０×１０＾－５ｍｏｌ／Ｌ５－Ｂｒ－ＰＡＤＡＰ和０．００２５％ＯＰ溶液（ＰＨ≈４．７）中，良好的极谱波，峰电位Ｅｐ＝－０．６４Ｖ（ｖｓ．ＳＣＥ）．Ｒｈ（Ⅲ）浓度在３．９０×１０＾－９～６．８０×１０＾－７ｍｏｌ／Ｌ（即０．４０～７０ｐｐｂ）与峰电流成线性关系；检出下限为１．９×１０＾－９ｍｏｌ／Ｌ。作直线法测定配合比为：Ｒｈ（Ⅲ     

协同系数补偿的动力学方法用于钼和钨同时测定的研究

以Ｉ３－淀粉配合物为指示剂，用停流ＦＩＡ光度法研究了钼（ＶＩ）和钨（ＶＩ）对Ｈ２Ｏ２－Ｉ氧化还原反应体系的协同催化效应，并定义了协同催化系数Ｄ以表示这种协同作用的大小。将此系数引入到停流ＦＩＡ－动力学体系多组份同时测定的方法中，可有效地补偿吸光度对加和性的偏离，并可降低检出限。用本法测定钼（Ⅵ）和钨（Ⅵ）的线性范围分别为０～１．１μｇ·ｍｌ－１和０～２．０μｇ·ｍｌ－１，而未补偿时则分别为０～０．６μｇ·ｍｌ－１和０～０．８μｇ·ｍｌ－１。测定了钢样及模拟样品中的用和钨含量，结果满意。钼、钨的回收率分别为９７．３％～１０２．８％，９６．５％～１０２．１％，相对标准偏差ＲＳＤ分别为２．１％～２．９％，２．３％～３．４％。     

吸附还原计时电位溶出法测定钯

用悬汞电极在ＨＡｃ－ＮａＡｃ介质中（ｐＨ４．２），用还原计时电位溶出分析法研究了Ｐｄ（Ⅱ）－１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）络合物。其适宜条件为：ＮａＣｌ０．１６ｍｏｌ／Ｌ，ＰＡＮ６．０×１０＾－６ｍｏｌ／Ｌ，乙醇１０％（Ｖ／Ｖ），电解电位０．００Ｖ（ｖｓ．ＳＣＥ）。线性范围为２．４×１０＾－１１￣９．４×１０＾－８ｍｏｌ／Ｌ，络合物组成为Ｐｄ（Ⅱ）：ＰＡＮ＝１：１。试验了２０多种金属离子     

铱—钼酸盐—丁基罗丹明B—PVA_（－124）体系光度法测定铱

在聚乙烯醇（ＰＶＡ）存在下，Ｉｒ（Ⅳ）与钼酸盐和丁基罗丹明Ｂ（ＢＲＢ）形成离子缔合物。测定Ｉｒ的适宜条件为Ｃ＿（ＨＣιＯ４）＝１．３ｍｏｌ／Ｌ，Ｃ＿（ＭｏＯ＿４）￣（２－）＝１．１×￣（－３）ｍｏｌ／Ｌ，Ｃ＿（ＢＲＢ）＝３．８×１０￣（－５）ｍｏｌ／Ｌ，ＰＶＡ０．０８％。离子缔合物的最大吸收位于５７０ｎｍ，摩尔吸光系数ε值为８．７５×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），至少可稳定一周，Ｉｒ量在０～２．５μｇ／２５ｍｌ服从比尔定律，测定极限为８．３ｎｇ／ｍｌ（ｎ＝１１），对于０．０８μｇ／ｍｌＩｒ测定的相对标准偏差为２．８％（ｎ＝８）。考察了４１种共存离子的影响，其他贵金属和Ｓｂ（Ⅱ）。Ｇｅ（Ⅳ）、Ｓｉ（Ⅳ）干扰，需采用火试金分离。本法已用于某些岩矿和冶金中间产品中Ｉｒ的测定，结果满意。用平衡移动法测定缔合物的摩尔比为Ｉｒ：ＢＲＢ＝１：４，探讨了反应机理。     

Pd—5—Br—PADAB分光光度法的研究

本文研究了４－（５－溴－２－吡啶偶氮）－１，３－二氨基苯（简称５－Ｂｒ－ＰＡＤＡＢ）与Ｐｄ（Ⅱ）的显色反应条件，确定在ＨＡｃ条件ＴＰｄ（Ⅱ）与５－Ｂｒ－ＰＡＤＡＢ生成紫红色络合物，在０．８ｍｏｌ／Ｌ的ＨＣｌ介质中进行光度测定，以提高方法的选择性。实验结果表明，络合物的络合比为１：１，表现摩尔吸光系数ε＝５．２０×１０￣４，条件稳定系数Ｋ＿稳＝１．６×１０￣７，钯离子浓度在４．２７×１０￣（－８）～１．５４×１０￣（－５）ｍｏｌ／Ｌ时服从比尔定律。应用所拟方法测定冶金生产过程中间产品中微量钯，获得满意的结果。     

Pd（Ⅱ）－ATP－杂环碱混配合物的稳定性

用ｐＨ电位法测定了在４０％（ｖ／ｖ）二恶烷一水介质中（Ⅰ＝０．１，２５±０．℃）Ｐｄ（Ⅱ）与腺苷５′－三磷酸（ＡＰＴ）的三元混配合物Ｐｄ（Ａ）（ＡＴＰ）￣（ｎ－）（杂环碱Ａ＝Ｂｐｙ，Ｔｒｐ；ｎ＝２或３）的稳定常数，其值分别为，比较了三元混配合物和二元配合物的稳定性大小，其差值Δ１ｇＫ要比预期的统计值Δ１ｇＫ＿ｓｔ大。这种三元混配合物稳定性的增加可归因于π－酸和π－碱之间的合作效应和配体分子间的芳环堆积效应。     

尿苷5＇－三磷酸与含氧或氮配位原子配体的三元混配Pd（Ⅱ）配合物

用ｐＨ电位滴定法测定三元混配配合物Ｐｄ（Ⅱ）／尿苷５＇－三磷酸／配体Ａ（Ａ＝１，１０－邻菲啉，２，２＇－联吡啶和Ｌ－色氨酸）在４０％（Ｖ／Ｖ）二烷－水溶剂中的稳定常数（Ｉ＝０．１，ＫＮＯ＿３；２５±０．１℃）。讨论三元混配配合物和二元配合物的稳定性差异。用＇ＨＮＭＲ法研究三元混配配合物体系中分于内芳环配体一配体之间的堆积作用，计算的堆积度和参与堆积的芳环大小顺序一致。     

Au—（Ⅲ）—5—Br—PADAP配合物吸附波的研究

在ｐＨ４．３０的ＨＡｃ－ＮａＡｃ缓冲液中，Ａｕ（Ⅲ）与５－Ｂｒ－ＰＡＤＡＰ经沸水浴加热形成１：１紫色配合物，在示波极谱仪上－０．６０Ⅴ（ｖｓ．ＳＣＥ）产生一灵敏的配合物吸附波。线性范围５．０×１０＾－８～２．００×１０＾－６ｍｏｌ／Ｌ，检出限２．０×１０＾－８ｍｏｌ／Ｌ。研究３０多种离子的干扰及分离条件。用聚氨酯泡沫塑料分离金用于矿样中金的测定，结果良好。     

3,5diCl—PADMA与Rh（III）的高灵敏显色反应

研究了３，５－ｄｉＣｌ－ＰＡＤＭＡ与Ｒｈ（Ⅲ）的显色反应。在ｐＨ４．０～５．２试剂与Ｒｈ（Ⅲ）形成稳定的紫红色络合物。再提高盐酸溶液２酸度至０．７２～６．０ｍｏｌ．Ｌ＾－１，其最大吸收峰红移至６１４ｎｍ，灵敏度显著提高，表观摩尔吸光系数ε６１４＝１．４０×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。铑含量在０～０．７２μｇ．ｍｌ＾－１内符合比尔定律。所拟方法操作简便，用于催化剂中微量铑的测定。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。