Effect of initial composition on phase selection in Ni–Si powder blends processed by mechanical alloying

The effect of initial powder blend composition on the synthesis and formation mechanism of nickel silicide phases was investigated by mechanical alloying in Ni-60 and Ni-66.7?at.% Si powder blends. It was noted that the equilibrium NiSi phase started to form in the early stages of milling and that the amount of the NiSi phase in the milled powder increased with increasing milling time. Even though, under equilibrium conditions, a mixture of both the NiSi and NiSi₂ phases was expected to be present in the Ni-60?at.% Si composition and the stoichiometric NiSi₂ phase in the Ni-66.7?at.% Si composition, the NiSi phase was present in both the compositions investigated. However, while only the NiSi phase was present homogeneously in the Ni-60?at.% Si powder blend, both the NiSi phase and a very small amount of unreacted Si were present in the powder blend of Ni-66.7?at.% Si composition. This unexpected phase constitution in the milled powders was attributed to a partial loss of Si during mechanical alloying of the powder blends, confirmed by energy dispersive X-ray spectrometer analyses, and explained on a thermodynamic basis.     

Tailoring NiO Nanostructured Arrays by Sulfate Anions for Sodium‐Ion Batteries

In this contribution, a novel sulfate‐ion‐controlled synthesis is developed to fabricate freestanding nickel hydroxide nanoarrays on Ni substrate. As an inorganic morphology‐controlled agent, SO₄²⁻ ions play a critical role in controlling the crystal growth and the nanoarray morphologies, by modulating the growth rate of adsorbed crystal facets or inserting into the metal hydroxide interlayers. By controlling the SO₄²⁻ concentration, the nanostructured arrays are tailored from one‐dimensional (1D) Ni(SO₄)_0.3(OH)_1.4 nanobelt arrays to hierarchical β ‐ Ni(OH)₂ nanosheet arrays. With further graphene oxide modification and postheat treatment, the obtained NiO/graphene hybrid nanoarrays show great potential for high‐performance sodium‐ion batteries, which exhibit a cyclability of 380 mAh g⁻¹ after undergoing 100 cycles at 0.5 C and reach a rate capability of 335 mA h g⁻¹ at 10 C.     

Electrochemical studies of bovine serum albumin immobilization onto the poly-o-phenylenediamine and carbon-coated nickel composite film and its interaction with papaverine

A biosensor based on bovine serum albumin (BSA) and poly-o-phenylenediamine (PoPD)/carbon-coated nickel (C-Ni) nanobiocomposite film modified electrode has been developed to study the interaction of BSA with papaverine (PAP). The well-dispersed C-Ni nanoparticles were dripped onto the glassy carbon electrode (GCE) surface firstly, and PoPD films were subsequently electropolymerized by cyclic voltammetry (CV) to prepare PoPD/C-Ni/GCE. Finally, the BSA was easily immobilized on the PoPD films via electrostatic adsorption. The morphology and the electrochemical properties of the fabricated composite electrodes were examined by scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS), respectively. The interaction of PAP with BSA was monitored by differential pulse voltammetry (DPV), using PoPD as the electrochemical indicator. The binding constant (K), obtained by DPV, was 1.7 × 10⁴ L/mol, which was consistent with the fluorescence analysis. This constructed biosensor also exhibited a fine linear correlation with PAP concentration range of 2.5 × 10⁻⁹-4.5 × 10⁻⁵ mol/L and a detection limit of 8.3 × 10⁻¹⁰ mol/L was achieved by DPV.     

新型多核苊二亚胺镍配合物复合负载催化剂催化乙烯聚合

制备了两种多核苊二亚胺镍配合物N imL1C l2m和N imL2C l2m,并将其负载于M gC l2和S iO2上制备复合载体催化剂,与通用烷基铝组成新的催化体系催化乙烯聚合。研究结果表明,在A lE t2C l为助催化剂的条件下,两种多核苊二亚胺镍配合物能高效催化乙烯进行聚合,制得不同支链的各种支化聚乙烯;聚合条件对乙烯聚合活性和产物性能有较大的影响。制得产物的支链使聚乙烯的熔融峰变宽,并且支化度越高,熔融峰越宽。     

碳纤维镀镍

碳纤维是一种新型的高强度、高模量材料,具有良好的导电能力.以镀镍碳纤维增强的复合材料具有高的比强度、比模量、比刚度和良好的高温性能及尺寸稳定性.本文介绍了碳纤维表面化学镀镍及电镀镍的原理和工艺流程,其中镀前预处理对整个施镀过程至关重要.化学镀镍除Ni-P体系外还有Ni-B体系.     

用N2O-C2H2火焰原子吸收光谱法测试羰基镍粉中镁

运用了N2O-C2H2火焰原子吸收光谱法进行羰基镍粉中镁的测定.介绍了镁最佳测定条件及呈良好线性范围的浓度.同时对样品消化处理条件及在测定中样品的干扰因素进行了综合考虑.该方法具有操作简便,容易掌握,分析周期短等特点.其灵敏度又能达到要求.重复性与准确度都达到了实验室分析计量测试和质量控制的要求.     

"光触媒"抗菌镍金属网在中央空调上的应用

本文简要叙述光触媒(TiO2)在分解有害气体、杀菌的作用机理,以及复合"光催化"抗菌泡沫镍金属网在中央空调方面的应用情况.     

红土矿的过去与未来

从红土矿中生产镍自新喀里多尼亚的硅镁镍矿的处理开始已有100多年了。然而，直到今天。全世界的镍主要采自硫化矿。纵观未采，作者预测产自硫化矿的镍量变化不大，在今后的10年里镍产量的扩大主要来源于红土矿。因此新的红土矿项目的投资和生产费用将对镍的供应和镍价有较大的影响。此文回顾了红土矿项目的历史并分析了近期不同的红土矿项目和在“图板上”的项目的投资和生产费用，也评估了这些项目的风险，并将讨论这些因素对进一步开发红土矿项目的影响。     

我国火法炼铜清洁生产现状及促进措施探讨

分析了我国火法炼铜清洁生产现状,探讨了促进清洁生产的措施。提出因厂制宜改进生产,配套必要的环保设施,提高资源综合利用水平,实施清洁生产,彻底解决该行业的环保问题。