利用金属络合物的电火花加工研究

在电火花加工的工作液中添加络合剂，使之与被蚀除的金属颗粒产生络合化学反应，生成可溶于工作液中的络合物。利用这种原理，可提高电火花加工性能，在小孔、深槽等加工应用中起到促进排屑的作用。     

Defect structure and chemical diffusion in nickel sulfide β-Ni3S2

The chemical composition, defect structure, and diffusion in nickel sulfide -Ni₃S₂ have been investigated in H₂S-H₂ mixtures containing between 1 and 65% H₂S between 560 and 700°C. Gravimetric, density, and X-ray studies were carried out. In the thermodynamically stable compound the ratio of Ni/S varied between 1.3 and 1.75. The X-ray examination showed a step change in the lattice parameter at the Ni/S ratio 1.4. A linear dependence of the density values (between 5.5 and 6.2 g/cm³) on the composition was observed. On the basis of the chemical composition and density measurements the number of nickel and sulfur atoms in 1 cm³ were determined. It has been shown that the Ni₃S₂ phase is defected in both anion and cation sublattices and that its chemical formula may be described as follows: Ni_3±yS_2x, where y 2x. It has been found that in the mixture containing 10% H₂S the process of defect formation is determined by their diffusion in the sulfide. The temperature dependence of the diffusion coefficient is described by the equation D = 13.15 exp(-30,000/RT) cm²/sec. No dependence of D on the sulfur partial pressure was observed, but this may be due to the relatively large uncertainties in the measurement of the diffusion coefficients.     

比较5-Cl-PADAB光度测定Pt(Ⅳ)时的几种活化剂

比较了不同活化剂(KI-Vit C,KI,Vit C,KI-Na_2SO_3,Na_2SO_3,H_2C_2O_4)对5-Cl-PADAB光度测定Pt(Ⅳ)的影响。实验表明,KI、KI-Vit C、KI-Na_2SO_3这3种活化体系最好。其优点为:测定酸度较高,重现性和线性关系好,是良好的活化剂。     

国内外不锈钢精炼剂研究发展现状

分析了精炼剂组元元素的作用能力，讨论并总结了精炼剂组元的复合作用，介绍了几种国内、国外精炼剂产品，提出发展高效复合精炼剂的想法。     

泡沫塑料表面的磁控溅射镀膜技术研究

对硬质聚氨酯泡沫塑料进行适当的前处理(涂刮不饱和聚酯腻子和喷涂双组份聚氨酯清漆),再采用磁控溅射镀膜技术对其进行紫铜T2镀膜,能够有效地降低泡沫塑料的吸水率,提高尺寸稳定性.     

Preparation and characterization of GaN films grown on Ga-diffused Si （111） substrates

Hexagonal GaN films were prepared by nitriding Ga2O3 films with flowing ammonia. Ga2O3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. This paper have investigated the change of structural properties of GaN films nitrided in NH3 atmosphere at the temperatures of 850, 900, and 950℃ for 15 min and nitrided at the temperature of 900℃ for 10, 15, and 20 rain, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the structure, surface morphology and composition of synthesized samples. The results reveal that the as-grown films are polycrystalline GaN with hexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained when nitrided at 900℃ for 15 min.     

离心铸造大口径球铁管用复合功能型脱硫剂的研制

为使硫量波动的高炉铁液能适应大型离心铸造球铁铸管生产,研制了一种成本较低廉、添加操作简单的复合功能型脱硫剂。其主要组分包括强脱[S]去[O]材料钝化镁粒、碳化钙,增加石墨核心元素Zn和膨胀集渣材料珍珠岩,以及能抑制反球化作用和净化铁液的材料等。采用冲入法进行球化处理,这种脱硫剂覆盖在球化剂和孕育剂上,使用方法简单,效果良好。     

Effect of theθ-α-Al2O3 transformation on the oxidation behavior ofβ-NiAl + Zr

Isothermal oxidation of NiAl + Zr has been performed over the temperature range of 800–1200°C and studied by TGA, XRD, and SEM. A discontinuous decrease in growth rate of two orders of magnitude was observed at 1000° C due to the formation of -Al₂O₃ from -Al₂O₃. This transformation also resulted in a dramatic change in the surface morphology of the scales, as a whisker topography was changed into a weblike network of oxide ridges and radial transformation cracks. It is believed that the ridges are evidence for a shortcircuit outward aluminum diffusion growth mechanism that has been documented in a number of¹⁸O tracer studies.