影响皮江法炼镁还原工序的因素

影响皮江法炼镁的还原工序的因素有煅白的水化活性度、灼减、吸湿，球的配比、炉料的粉碎粒度、制球后球团密度和还原温度、还原时间、真空度等．只有了解影响还原的因素，才能合理进行设计及有效指导生产．     

钛合金表面硬化与固体润滑处理层的电化学腐蚀行为研究

分别利用等离子氮化技术和离子束增强沉积(IBED)技术使钛合金表面获得硬质抗磨层和MoS2，MoS2-Ti固体润滑膜层。通过电化学测试技术研究了膜层和钛合金基材在含Cl^-介质中的抗蚀性能和接触腐蚀敏感性：研究结果表明：Ti与MoS2的复合改善了MoS2膜的环境适应性，MoS2—17Ti复合膜层与钛合会接触相容；IBED TiN较钛合金电化学活性低，阳极极化行为与Ti6Al4V合金相近，与钛合金基体间电偶腐蚀敏感性低；钛合金等离子氮化处理层在NaCl水溶液中无论处于自然腐蚀电位还上弱阳极极化状态，均较钛合金电化学活性低，且与钛合金基体间电偶腐蚀敏感性低。     

Epitaxial Growth of CeO<Subscript>2</Subscript>/YSZ/CeO<Subscript>2</Subscript> Buffer Layers on Textured Ni Substrates for YBCO Conductors

CeO₂/YSZ/CeO₂ buffer layers were deposited on textured Ni substrates byin situ pulsed laser deposition. The out-of-plane texture and in-plane texture of the buffer layers were characterized by X-ray diffraction ω-scans and ϕ-scans. Using this CeO₂/YSZ/CeO₂ architecture as the buffer layers, high quality YBCO films with a zero-resistanceT _c about 90 K and a self-field critical current densitiesJ _c above 10⁶ A/cm² at 77 K can be obtained on Ni substrates.     

Magnetic Perovskite Superlattices Grown by Pulsed Laser Deposition

Magnetic multilayers of (SrRuO₃) _m (SrMnO₃) _n were grown artificially using the pulsed laser deposition technique on (001)-oriented SrTiO₃ substrates. The temperature and magnetic field dependent reisistivity of the superlattices consisting of ferromagnetic (FM) SrRuO₃ and antiferromagnetic (AFM) SrMnO₃ are studied as a function of the SrRuO₃ unit cells. We observed a pinned/biased moment instead of the biased field in the superlattices and we redefine the structure as AFM/FM(Pin)/FM(Free)/FM(Pin) units below a critical field.     

Deoxidisation and phase analysis of plasma sprayed TiO2 by X-ray Rietveld method

It is fundamentally important to determine the deoxidisation and phase compositions of plasma sprayed TiO₂ coatings containing anatase. In the present study, plasma sprayed porous TiO₂ coatings containing anatase were prepared using anatase powder and both Ar-He-H₂ and Ar-He-N₂ plasma gases. The deoxidisation of TiO₂ and phase compositions of the starting powder and the prepared coatings were examined using X-ray Rietveld method by refining their crystalline parameters and scale factors. The refined oxygen occupancies showed that there were about 0.08 and 0.1 formula units of oxygen deficiencies for the rutile and anatase phases of the coatings, respectively. Such degrees of deoxidisation and the other crystalline parameters appeared independent of the plasma spraying process parameters. With considerations of the presence of organic adhesive in the starting powder and the formation of titanium ethoxide in the coatings, the degrees of deoxidisation estimated by the X-ray Rietveld method were slightly higher than those quantified by the thermogravimetry curves. The phases of the coatings determined from the refined scale factors were mainly composed of rutile with 10.0% to 22.5% anatase by weight, and the latter content increased with decreasing the intensity of the plasma jet.     

A comparative study of the mechanical strength of chemical vapor-deposited diamond and physical vapor-deposited hard coatings

Four mechanical parameters of physical vapor-deposited (PVD) hard coatings were obtained, which were the residual strain, Young's modulus, film toughness, and interface toughness, concerning titanium aluminum nitride (TiAlN) and titanium nitride (TiN) coatings deposited on WC-Co substrates. The results were quantitatively compared with the author's previous trials for the case of chemical vapor-deposited (CVD) diamond coatings. Due to the significant difference in the mechanical properties between PVD hard coatings and CVD diamond coatings, it was necessary to develop new experimental techniques, which could properly evaluate those parameters for the case of PVD hard coatings. As a conclusion, film toughness of PVD hard coatings was surprisingly brittle. It was an order of magnitude smaller than that of CVD diamond coatings. In contrast, no significant difference was found in interface toughness between these different kinds of coatings. Concerning the residual strain, TiN had far larger level than the other two. These differences in mechanical properties were further discussed in relation to the difference in their wear behavior.     

双硫腙泡塑吸附-化学光谱法定量测定痕量金

文中以泡沫塑料为载体,负载一定量的双硫腙,制成双硫腙负载泡沫塑料;经静态吸附后,以背景做内标,采用发射光谱定量分析测定了化探样品中的痕量金.通过标准样品回收实验及对国家级化探金标准物质进行分析测定,表明该方法具有较好的精密度和准确度,检出限为0.3×10-9,加入标准样品回收率在97%～103%,相对标准偏差RSD(n=10)为7.9%～21.4%,满足15万化探样品中痕量金的分析测定要求.     

稀土Nd掺杂纳米SnO_2薄膜气敏特性

用真空气相沉积法在玻璃衬底上制备纯SnO2和掺稀土Nd的SnO2薄膜,在500℃氧气气氛条件下进行45min热处理,获得良好的纳米SnO2薄膜和掺稀土Nd的SnO2薄膜。结果显示掺Nd和热处理使纳米SnO2薄膜的结构、导电性能得到一定的改善。掺Nd5%的SnO2薄膜对气体的选择性和灵敏性均得到明显的改善,其中,对丁烷的选择性、灵敏度最好,在体积分数为7.2×10-3时,灵敏度可达到340,但对乙醇、丙酮气体的敏感性较差。     

基于van der Waals状态方程的剩余自由能模型

结合 Wong- Sandler的混合规则 ,即在无穷大压力下剩余 Helmholtz自由能与无穷小剩余 Gibbs自由能近似相等的关系 ,给出了一个基于 van der Waals状态方程的剩余自由能模型 ,由此得到可以描述汽液相平衡的活度系数模型。通过对 35个体系的考核表明 ,该模型可以较好的关联实验数据 ,包括极性与极性物系 ,其结果好于 Wilson、Mar-gules、NRTL与 Uniquac等模型的计算结果。同时 ,因为该模型基于 Wong- Sandler的混合规则 ,因此可以实现在理想溶液中 ,由 Wong- Sandler混合规则到 van der Waals混合规则平滑过渡。