电感耦合等离子体质谱法测定高纯钨中26种痕量杂质元素

采用电感耦合等离子体质谱法(ICP-MS)测定高纯钨中26种痕量杂质元素,讨论了溶样方式,研究了质谱干扰和钨基体效应,应用屏蔽炬技术消除56Ar O+等多原子离子对Fe、Ca、K等元素的干扰,采用在线样品标准加入法消除基体效应。各元素的方法检出限(15σ)为0.03⁰.45μg/g,对样品加标0.5μg/g的回收率在88%0.45μg/g,对样品加标0.5μg/g的回收率在88%¹16%之间。方法适用于纯度为99.999%的高纯钨中痕量杂质元素的测定。     

AAS法测定纯铼中痕量元素K试验研究

用AAS法测定纯铼中的痕量元素K。通过优化原子吸收测量条件,研究了硝酸用量以及基体铼对测定K含量的影响,建立了AAS法测定纯铼中痕量元素K的分析方法。结果表明,AAS法测量K的相对标准偏差不大于9.04%,测定范围为0.000 1%~0.001%,方法检出限为0.003 5μg/m L。本检测方法不仅准确可靠,而且简便快速。     

乙酸乙酯萃取-ICP-MS测定高纯金中杂质元素含量

采用乙酸乙酯萃取分离金基体,用电感耦合等离子体质谱(ICP-MS)内标法测定高纯金中31种杂质元素。萃取酸度为1 mol/L HCl,用25 mL乙酸乙酯可去除金基体对待测元素的干扰,对金的萃取率大于99.9%。将31种元素用~(45)Sc、~(133)Cs、~(159)Tb、~(187)Re等4个内标元素分组测定。方法检出限为0.25μg/L,定量限为0.83μg/L,精密度(RSD,n=12)为0.31%～5.97%,加标回收率为95.3%～109.2%。可满足99.999%的高纯金样品中杂质元素含量的检测。     

ICP-AES测定三氧化钨中硼、铼、钼量

提出了分离基体ICP-AES测定三氧化钨中痕量硼、铼及标准加入法测定三氧化钨中痕量钼的分析方法。研究了基体光谱干扰的情况,选择了最佳分析线,测定了方法检出限,B<0.5μg/g,Re<2.5μg/g,Mo<2.5μg/g。回收率为(95～99)%。     

电感耦合等离子体原子发射光谱法测定铌中磷含量

铌中磷元素的含量高低直接影响铌的性能,关于铌中磷的分析方法,目前普遍采用GB/T15076.7-1994方法《4-甲基-戊酮-[2]萃取分离磷钼蓝分光光度法》。本方法采用硝酸和氢氟酸溶解试样,用电感耦合等离子体原子发射光谱法测定铌中磷含量。实验对元素分析谱线、试剂用量、雾化器流量、泵速、检出限和测定下限进行了研究。应用基体匹配消除基体对待测元素的干扰,工作曲线在磷质量分数0.001 0%～0.080%范围内相关系数为0.999 9,检出限为0.026 2μg/mL,测定下限为8.9μg/g,方法加标回收率在93.00%～108.0%之间,相对标准偏差(RSD,n=11)≤7.20%,分析结果同GB/T15076.7-1994方法进行了对照,结果一致。     

电感耦合等离子体原子发射光谱法测定硼钢铸件中的钆

钆对高质量硼钢屏蔽铸件研究有重要意义。试验采用王水和硫磷混酸分解样品,选择分析线Gd376.839 nm,使用电感耦合等离子体原子发射光谱法(ICP-AES)建立了硼钢铸件中钆的测定方法。仪器的工作条件为:发生器功率1.2 kW、冷却气流量20 L/min、辅助气流量0.1 L/min、雾化器压力36PSI、蠕动泵泵速1.40 mL/min。钆质量浓度在0.5～5.0μg/mL范围内与发射强度呈线性,相关系数大于0.999 9,方法检出限为0.024μg/mL。按照试验方法测定三种硼钢材料中的钆,结果相对标准偏差(RSD,n=11)为1.28%～1.52%,加标回收率为95.0%～106.5%。     

电感耦合等离子体原子发射光谱法测定羰基镍粉中16种杂质元素量

建立电感耦合等离子体原子发射光谱法测定羰基镍粉中砷、镉、铅、锌、锑、铋、锡、钴、铜、锰、镁、铝、铁、钙、钼、硅等杂质元素含量的方法。采用硝酸（3+2）溶解样品，考察了酸度对测定的影响，确定了各元素最佳的分析谱线。在标准溶液中，元素含量分别为0、0.025、0.1、0.5、1.0μg/mL时，十六种元素的强度与浓度呈现良好的线性关系，对应的相关系数均大于0.999。最终的加标回收率为94.0%～104.0%，相对标准偏差RSD<6.53%(n=7)。该方法有效的提升了羰基镍粉中多元素分析的效率，满足硬质合金生产工艺的要求。     

原子吸收法测定化合物三氯化钌中的钠

在5%盐酸介质中,采用原子吸收分光光度计测量三氯化钌中的钠含量。波长选择589.0 nm,钠标准工作曲线范围为0～2.0μg/mL,线性相关系数为0.9999。研究了酸介质、仪器工作条件、基体、干扰元素等因素对测量结果的影响。方法的加标回收率为94.7%～101.5%,不确定度为0.0082μg/mL,检出限为0.001μg/mL。     

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。     

ICP-AES测定纯金饰品中的痕量钯及其不确定度评估

建立了王水溶解纯金样品、标准基体匹配、电感耦合等离子体发射光谱(ICP-AES)测定纯金饰品中痕量钯元素的定量分析方法。该方法具有简便、快速、灵敏度高、重现性好等优点。方法检出限为0.08μg/g,加标回收率为104%,相对标准偏差(RSD)为7.52%,A类不确定度为0.0119 mg/L。     

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.     

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。     

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.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.     

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.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.