偶氮氯膦Ⅰ光度法同时测定硅砂中氧化钙和氧化镁

试验了Ca2 、Mg2 与偶氮氯膦Ⅰ同时显色的条件,Ca2 、Mg2 对显色的相互影响。试验结果表明,100μg CaO(50 ml)存在下,不影响MgO的显色,0～50μg MgO(50 ml)符合比耳定律,相关系数r=0.999 8,表观摩尔系数ε=1.83×104 L/mol.cm。30μg MgO(50 ml)存在下,不影响CaO的显色,0～100μg CaO(50 ml)符合比耳定律,相关系数r=0.999 1,表观摩尔系数ε=1.53×104 L/mol.cm。建立了偶氮氯膦Ⅰ光度法同时测定硅砂中CaO、MgO的方法。用所建立的方法对硅砂标准样品进行测定,结果十分满意。     

DBC-偶氮氯膦褪色分光光度法测定铈（IV）

在1.0 mol·L-1～2.0 mol·L-1的H2SO4介质中,Ce(Ⅳ)与DBC-偶氮氯膦反应产生褪色反应,测定铈表观摩尔吸光系数为ε530nm=4.89×104L·mol-1·crm-1,Ce(IV)浓度范围在0.020μg·mL-1～0.88μg·mL-1范围内遵守比耳定律.考察了24种共存离子对测定铈的影响.本方法已满意地用于测定分子筛中的铈.     

Ti(Ⅳ)与CPA-mk显色反应的研究与应用

研究了Ti4 与偶氮氯膦-mk(CPA-mk)的显色反应.实验结果表明:在0.01～0.1mol/L的H2SO4介质中,在乳化剂OP存在下,Ti4 与CPA-mk形成络合比为1:2的蓝绿色络合物,ε672=2.2×104L/(mol·cm),符合比耳定律的线性范围Ti4 0～60μg/25ml.测定了黏土、硅石等试样中的钛,结果满意.     

棕刚玉中二氧化钛的高灵敏度光度分析

本文报道了二氧化钛与新显色剂对溴偶氮羧-M的高灵敏显色反应的研究结果。以磺基水扬酸掩蔽Fe3 ,A l3 ,在pH2.1-3.6时新显色剂对溴偶氮羧-M与钛在室温下形成稳定的β型配合物。其最大吸收波长为715nm,表观摩尔吸光系数ε715=1.2×105L.mol-1.cm-1,TiO2含量在0-53μg/50m l范围内服从比耳定律。配合物的组成比为Ti:R=1:2。用于棕刚玉中二氧化钛的测定,结果满意。     

偶氮氯膦Ⅲ高灵敏分光光度法测定钛

详细地研究了显色剂偶氮氯膦Ⅲ与Ti(Ⅳ)的显色反应和所形成的络合物,该络合物的λmax=690nm,表观摩尔吸光系数为1.47×105L·mol-1·cm-1,钛在0～1.0μg/ml内服从比尔定律,所拟定的方法能满意地用于还原用铁粉、粉末冶金铁粉和钢铁中微量钛的分光光度测定。     

新显色剂CNDAA与银显色反应的研究及应用

研究了新显色剂邻氯对硝基苯基重氮氨基偶氮苯(CNDAA)与银的显色反应。在非离子表面活性剂Triton X-100存在下,于pH8.0的磷酸二氢钾—硼砂缓冲溶液中,银与该试剂形成1:2稳定的红色配合物,其最大吸收位于525nm,摩尔吸光系数ε=9.0×10~4L·mol~(-1)·cm~(-1)。银浓度在0～15μg/25ml符合比尔定律。方法已用于废水及矿石中微量银的测定。     

5,7-二溴[杯(4)芳烃偶氮]氨基喹啉与Pd(Ⅱ)显色反应的研究与应用

合成了新试剂5,7-二溴[杯(4)芳烃偶氮]氨基喹啉(DBCAQ),经红外光谱、元素分析和薄板层析检验其结构.研究了该试剂与Pd(Ⅱ)的显色反应的适宜条件.在pH=5.0的HAc-NaAc缓冲溶液中及非离子表面活性剂吐温-80存在下,试剂与Pd(Ⅱ)生成11的稳定配合物,建立了测定Pd(Ⅱ)的光度法新体系,该体系至少可稳定10h,λmax=680nm,ε=8.26×104L/mol@em,Pd(Ⅱ)浓度在0～35μm/25ml内服从比耳定律.方法已用于钯催化剂中Pd(Ⅱ)的测定,结果与原子吸收法(AAS)结果相符.     

DBC-偶氮氯膦固相光度法测定痕量镧

在0.5 mo1·L-1盐酸介质中,La(Ⅲ)-(DBC-偶氮氯膦)所形成的络合物可吸附到201×7型苯乙烯阴离子树脂上.该固相显色体系最大吸收波长位于650 nm,镧的表观摩尔吸光系数为ε650nm=2.08×l05L·mol-1·cm-1.该固相分光光度法测定镧灵敏度为La(Ⅲ)-(DBC-偶氮氯膦)液相分光光度法灵敏度的2.31倍.镧在0～0.44 μg.ml-1范围内遵守比尔定律.考察了26种共存离子对测定镧的影响.本研究所建立的方法已成功地用于分子筛中镧的测定,结果满意.     

烟尘中微量锗的测定

研究了Ge(Ⅳ)与槲皮素(Quercetin)、十二烷基苯磺酸钠(SDBS)、聚乙烯醇(PVA)混合体系的显色反应特性.在1.4～3.8 mol/L HCl范围内,最大吸收峰(λmax)为470 nm处、摩尔吸光系数ε470为1.8×105L·mol-1·cm-1.在SDBS和PVA混合表面活性剂存在下,配合物的组成比为Ge(Ⅳ)∶Quercetin=1∶3.0～20μgGe(Ⅳ)/50 ml范围内,服从比尔定律.在混合掩蔽剂存在下,几乎没有干扰离子.已成功地应用到测定烟尘中微量锗的含量,结果十分满意.     

分光光度法测定金合金中的钆、钇

建立了测定金合金中Gd、Y质量分数的偶氮氯膦Ⅲ分光光度法,研究了基体金的还原条件和提高测定方法选择性的条件。结果表明:亚硫酸可完全还原金,并对Gd(Ⅲ)、Y(Ⅲ)无吸附影响;加入EDTA可提高方法的选择性,一定量常见金属离子不干扰测定;在0.1 mol/L盐酸介质中,体系的最大吸收峰为λmax=673 nm、λmax=672 nm,表观摩尔吸光系数ε6G7d3=6.37×104L.mol-1.cm-1、6Yε72=7.01×104L.mol-1.cm-1,Gd(Ⅲ)、Y(Ⅲ)的质量浓度分别在0~50μg/50 mL、0~40μg/50 mL符合比尔定律,加标准回收率分别为99.80%~100.40%、99.80%~100.30%,测定质量分数为0.6%的Gd、Y,相对标准偏差为0.004%、0.005%。方法选择性好、操作简便、易于掌握,应用于金合金中Gd、Y质量分数的测定,结果满意。     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.