Magnetic properties of nickel filament polymer-matrix composites

The magnetic properties of polyethersulfone-matrix composites with 3-19 vol.% polycrystalline nickel filaments (0.4 (im diam) were investigated. These filaments were found to exhibit hysteresis energy loss 10800 J/m³ of nickel and coercive force 16.9 kA/m, compared to corresponding values of 4930 J/m³ and 4.7 kA/m for 2 μ.m diam polycrystalline nickel fibers, 1020 J/m³ and 0.5 kA/m for 20 μm diam polycrystalline nickel fibers, and 1280 J/m³ and 2.3 kA/m for solid polycrystalline nickel.     

纳米镍粉的制备工艺及产业化研究进展

综述了纳米镍粉的制备方法(包括物理法和化学法)及产业化现状,对纳米镍粉的各种制备方法进行了分析和评价。与物理法相比,化学法的产量高、成本低廉,能制备出性能优异的纳米镍粉,适合规模化生产;使用化学法制备的纳米镍粉的纯度、粒径及成本的控制仍需进一步加强。同时,对今后纳米镍粉的制备和产业化发展提出了建议。     

化学镀镍合金在电子工业中的应用

对化学镀镍合金铁工艺和性能特性及其在电子工业中的应有委展现状作了评述。化学镀镍合金具有镀层均匀，适用基材广，结合力高，硬度高，优良的耐磨、耐蚀性，可焊性好和特殊的电磁性能等特性，在电子工业中获得了广泛的应用。文中着重介绍了化学镀镍合金在磁盘、电磁屏蔽、微电路、半导体、连接器及薄膜电阻上的应用情况。这些案例说明，合理应用化学镀镍合金技术，有利于提高电子元器件的质量，降低成本，促进技术进步。     

钛合金的银脆,镉脆敏感性及其控制

利用慢应变速率拉伸技术（ＳＳＲＴ），并结合恒载实验，较全面地研究了Ｔｉ－６Ａｌ－４Ｖ合金的银脆行为、固态与液态镉脆行为，确定了应变速率、接触条件、热处理制度、试样取向、温度等因素对Ｔｉ－６Ａｌ－４Ｖ合金银脆与镉脆敏感性的影响，探讨了Ｎｉ阻挡层对控制Ｔｉ－６Ａｌ－４Ｖ合金和ＴＣ１１合金银脆开裂的作用。     

Effect of oxygen flow rate on the structural and electrochemical properties of lithium nickel oxides synthesized by the sol–gel method

The structural and electrochemical properties of LiNiO₂ powders were investigated as a function of the oxygen flow rate employed in the preparation of lithium nickel oxide. It was found that oxygen played an important role in the synthesis of highly crystallized LiNiO₂(R3¯m). In the crystallization process of LiNiO₂, a deficiency of oxygen in the calcination reactor induced the formation of impurities and cubic rock-salt structure (Fm3m) in LiNiO₂ powders. For LiNiO₂ prepared at higher oxygen flow rates, the electrode delivered high discharge capacities with relatively good retention rates. But very low electrode capacity was obtained from LiNiO₂ prepared at lower oxygen flow rates.     

镀镍云母导电复合材料的研究

对云母粒子化学镀镍及以LDPE为基材,镀镍云母粒子为填料制备的导电复合材料进行研究。认为此种导电复合材料只有质量轻、强度大及良好的导电等性能。     

镍基均相络合催化剂苯加氢反应动力学研究

采用工业上应用较成功的HC-402-2型镍基均相Z iegler型络合催化剂,在排除扩散影响的条件下,研究了苯均相催化加氢制环己烷的反应动力学。在反应温度150~210℃、总压1.0~2.4MPa的范围内,考察了反应温度、氢分压和苯浓度对反应速率的影响。实验结果表明,苯加氢均相催化反应对苯浓度的反应级数为零级,对氢分压的反应级数为一级,反应活化能为36 435.27 J/mol。经检验,该动力学模型的相关系数大于0.9,模型合理,能够描述实际反应过程。     

Crystalline and viscoelastic properties of branched polyethylenes synthesized using bidentate nickel (II) catalyst

In this work, five branched polyethylenes with different branching units were synthesized using bidentate nickel (II) catalyst containing -diimine ligands. For comparison, one linear polyethylene was also prepared using tridentate iron (II) catalyst containing -diimine ligand. The crystalline structure of the polyethylenes was investigated using X-ray diffraction (XRD) and polarized optical microscope. The crystalline properties were also measured by differential scanning calorimeter (DSC). Viscoelastic properties of the polyethylenes were investigated using rheometric dynamic analyzer. The DSC and XRD results showed that highly branched polyethylenes exhibit no melting points and no predominating crystalline forms, while the linear polyethylene exhibits clear orthorhombic (110) and (200) reflections on XRD pattern and a clear melting point at 118 °C. The viscoelastic properties of the branched polyethylenes were very complicated due to the combined effect of the molecular weight difference and the degree of chain branching as well as the branching structure.     

有机镍化合物催化烯烃聚合的研究进展

综述了有机镍化合物如烯丙基镍、乙酰丙酮镍、茂镍、二亚胺镍等催化烯烃聚合的研究进展。有机镍化合物可催化烯烃、α-烯烃(如乙烯、丙烯等)的齐聚及聚合、催化极性单体(如甲基丙烯酸甲酯、降冰片烯等)以及位阻较大的环烯烃、取代二烯烃、苯乙烯等的均聚和共聚。     

高铝钛镍基合金晶粒度的研究

研究了对高温镀镍基高温金晶粒度的影响因素。以便减少晶粒度不合格废品，结果表明，在冶炼工艺和变形量一定的条件下，碳含量、高温带加热时间和终轧温度是影响晶粒度的关键因素。