电感耦合等离子体质谱法测定高纯铼酸铵中19种痕量杂质元素

本文采用电感耦合等离子体质谱法（ICP—MS）测定高纯铼酸铵中19种痕量杂质元素，应用屏蔽炬技术消除了^56ArO^＋等多原子离子对Fe、Ca、K等元素的干扰，讨论了质谱干扰和锥的接口效应，优化采样时间，研究了铼酸铵的基体效应，采用在线样品标准加入法消除基体效应。各元素的方法定量下限（15σ）为0．014-0．63μg／g，对样品加标0．4μg，g的回收率在85％～112％之间。方法适用于纯度为99．999％的高纯铼酸铵中痕量杂质元素的测定。     

顺铂注射液的高效液相色谱分析

提出了测定顺铂注射液中顺铂含量的反相高效液相色谱法,其线性相关系数为0．994,精确度为0．45％（n＝8）,顺铂的回收率为99．7％。该法也能用于顺铂注射液中杂质反铂的测定,实现顺铂与水合物、三氯氨铂（铂B）的分离。提出了用氯化钠溶液替代空白溶剂（顺铂注射液所用的溶剂简称）作为顺铂对照品溶剂的可能性。     

ICP—AES法测定纯铂中的杂质元素

1.引言采用化学方法分离富集试样中的杂质元素,然后用ICP-AES法测定之,是充分发挥ICP特性和有效利用直读光谱仪分析下限的途径.文献用JY-38型顺序扫描等离子光谱仪测定纯铂中15个杂质元素时,标准中不配进基体,对于固定检测型的仪器分析线波长不能选择.同时,考虑到从铂基体中将杂质元素分离出来,其难度大流程长,故采用不分离基体的方案. 配合贵金属冶金产品的有关研究工作,我们用ICPQ-1015直读光谱仪研究了纯铂中13个杂质元素的测定方法.     

电感耦合等离子体质谱法测定纯铝中痕量杂质

建立了电感耦合等离子体质谱法(ICP—MS)测定纯铝中痕量铜、铁、锰、锌、钛、钻、铅、镍和铬等杂质元素的测定方法。考察了基体效应及接口效应对仪器测定灵敏度的影响,选择适当的待测元素同位素克服了质谱干扰,定量加入内标元素有效校正了基体效应、接口效应及仪器波动等因素而带来的测量偏差。结果表明,方法的检出限为0．011～0．12μg／L,回收率为90.0％～106．0％,相对标准偏差(RSD)小于3．57％。该法准确、快速、简便,应用于纯铝中杂质元素的测定,结果满意。     

ICP－AES法分析Au－Ga合金

研究了用ＩＣＰ─ＡＥＳ法测定高纯Ａｕ─Ｇａ合金中Ｇａ及萃取Ａｕ后测定微量Ｐｔ、Ｐｄ、Ｒｈ、Ｊｒ、Ａｇ等２５个杂质元素的方法。元素间的干扰用等效浓度法校正。杂质元素标准加入回收率为８４～１０３％：相对标准偏差为２．６～１７％，取２．５ｇ样品时测定下限为５×１０￣（－５）～２×１０￣（－４）％。     

旋流雾室系统ICP—AES法测定Pd中的杂质

用旋流雾室系统代替原用的Ｓｃｏｔｔ雾室系统，降低了ＩＣＰ直读光谱仪分析下限。并引入外加内标元素（Ｙ）的方法测定纯钯中的１３个杂质元素。本法适用于纯度为９９．９－９９．９９５％纯钯的分析。     

旋流雾室系统ICP─AES法测定Pd中的杂质

用旋流雾室系统代替原用的Ｓｃｏｔｔ雾室系统，降低了ＩＣＰ直读光谱仪分析下限。并引入外加内标元素（Ｙ）的方法测定纯铯中的１３个杂质元素。本法适用于纯度为９９．９～９９．９９５％纯他的分析。     

ICP-MS法测定氢氧化钽中Mg,Fe,Cr,Zn 4种杂质

研究了直接采用ICP—MS的等离子体屏蔽技术（PS）测定高纯氢氧化钽中Mg，Fe，Cr，Zn4种杂质元素的分析方法。实验了的仪器工作参数，用Co做内标补偿基体效应，方法的回收率在80％-130％之间，相对标准偏差均低于18．40％，检出限为0．01ng／ml-0．56ng／ml，测定结果与ICP-AES测定结果基本一致。     

ICP-AES法分析Au-Sb合金

用乙醚萃取Ａｕ－Ｓｂ合金中的Ａｕ，加络合剂抑制Ｓｂ的水解，提高了测定杂质元素的准确度。查明Ｓｂ对杂质元素测定的干扰。杂质元素标准加入回收率８２～１０３％，相对标准偏差２．０～１４％。制定了Ａｕ－Ｓｂ合金中Ｐｔ、Ｐｄ、Ｒｈ、Ｉｒ、Ａｇ等２６个杂质元素及合金成份Ｓｂ的测定方法。取２．５ｇ样品时杂质元素的测定下限为１×１０－４～２×１０－４％。测定Ｓｂ时相对误差＜２％。     

辉光放电质谱法测定纯铂中杂质元素

采用辉光放电质谱法(GDMS)测定纯铂中杂质元素含量,获得了仪器最佳工作条件,并对比了不同样品制备方式对测定结果的影响。结果表明,GDMS对大部分杂质元素的检出限低至10^-9量级,对含量在10^-6的杂质元素,测定相对标准偏差(RSD)在10%以内,可满足高纯铂的测定要求。与ICP-AES和ICP-MS测定结果对比表明,采用仪器提供的相对灵敏度因子(RSF)所得到的半定量结果与前二者存在一定的偏差,有必要采用标准样品进行RSF的校准。纯铂样品采用金属片、铟片粘附或粉末压片均可得到相似的检测结果,其中粉末压片法在标样制作中具有较好的应用前景。     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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).     

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.