“镍”催化酰氯和有机锡试剂交叉偶联反应的研究

镍络合物催化酰氯与有机锡试剂交叉偶联合成有机酮的反应,其反应选择性强,反应彻底,转化率高,工艺简单。在有机锡过量的情况下,对不同催化剂的催化活性和包括投料比,反应温度,反应时间,反应溶剂等反应条件进行了考察。     

Thermodynamic and kinetic consideration on the corrosion of Fe, Ni and Cr beneath a molten KCl-ZnCl2 mixture

Thermogravimetric (TG) experiments have been carried out to study the kinetics of hot corrosion of Fe, Cr and Ni, covered by a molten KCl-ZnCl₂ mixture of a composition close to the eutectic (50 mol% KCl-50 mol% ZnCl₂). Furthermore binary and ternary phase diagrams were calculated in order to describe the corrosion process. The tests were conducted at a temperature of 320 °C in an atmosphere consisting of argon and oxygen. For iron different stages are observed in a TG curve. They can be attributed to the different reaction steps of iron chloride formation (incubation phase), oxide precipitation (linear stage) and scale formation (parabolic or logarithmic stage). Based on these observations a model, described by Spiegel [A. Spiegel, Molten Salt Forum 7 (2003) 253], is confirmed. For Cr and Ni these stages are not observed. At 8 vol% O₂ only slight oxidation of Cr and Ni was observed accompanied by evaporation of the salt deposit. At 16 vol% O₂ the rate of oxidation increases and the experiments yield a curve that is either parabolic or logarithmic for both Ni and Cr. As a result it is shown that the solubility of iron chloride in the KCl-ZnCl₂ melt is higher than the solubility of nickel chloride and chromium (III) chloride in the KCl-ZnCl₂ melt. This enables a higher diffusibility of iron chloride to the upper region of the melt where a higher oxygen partial pressure (p(O₂)) is present leading to a higher oxidation rate of iron.     

In situ regeneration of the Ni-based catalytic reformer of a 5 kW PEMFC system

The paper reports the results of on-site regeneration catalytic bed of the natural gas reformer in a 5 kW PEM fuel cell system. The Ni catalyst previously poisoned by sulphur from the available natural gas, could be re-activated by injection of pure water steam, following the method developed for industrial reformers using the same metal catalyst: this method was shown to be perfectly efficient, provided no natural gas was fed during the operation. Results of the tests conducted are presented and discussed in relation to published data on S-sorption on Ni surfaces.     

Characterisation of inter-particle forces within agglomerated metallurgical powders

The strength of agglomerates of nickel flash furnace concentrate and dust was determined from experimental observations of agglomerates forming under controlled conditions, combined with mathematical equations from the literature. It was found that the agglomerates had a tensile strength ranging from 0.01 Pa to 38.7 Pa, while inter-particle forces ranged from 2.2 × 10^− 12 N to 1.5 × 10^− 10 N. These values were compared to the expected magnitude of van der Waals, electrostatic, magnetic and capillary forces within the agglomerates, and it was found that both electrostatic and van der Waals forces are likely to contribute to the cohesion of agglomerates, although sub-micron particles and the presence of sufficiently large asperities on the surface of particles limit the magnitude of van der Waals forces. Magnetic forces are large enough to contribute to the cohesion of dust agglomerates, which is in keeping with the high magnetite content of the recycle dust. It is postulated that electrostatic forces, acting over a longer range than van der Waals forces, may be responsible for initially bringing particles together. The methodology for determining inter-particle forces can be applied to the computer modelling of flash smelting systems, as well as other gas/particle systems such as fluidized beds.     

Experimental assessment of the Ru–Al–Ni ternary phase diagram at 1000 and 1100 °C

Knowledge of phase equilibria in the Ru–Al–Ni ternary system is relevant to the development of new single crystal Ni-based superalloys as well as to new high temperature protective coating systems for these alloys. A series of diffusion couple investigations have been performed across the Ru–Al–Ni ternary system in order to establish phase fields and possible diffusion paths. A continuous B2 phase has been shown to exist across the Ru–Al–Ni ternary between the RuAl and NiAl phases at temperatures of 1000 and 1100 °C. Ternary isothermal sections for Ru–Al–Ni at 1000 and 1100 °C are presented.     

PAN／Ni－P纤维和碳黑填充的HIPS复合材料的导电性

研究经化学镀镍的聚丙烯腈（ＰＡＮ）导电纤维（ＰＡＮ／Ｎｉ－Ｐ）填充的高抗冲聚苯乙烯（ＨＩＰＳ）复合材料的导电性与导电填料浓度的关系及加入有机钛酸酯偶联剂的影响、为了进一步提高复合材料的导电性，在ＰＡＮ／Ｎｉ－Ｐ纤维填充的复合材料中又加入不同量的碳黑，由于碳黑粒子的加入改善了纤维间的接触状态，更有利于导电网络的形成，从而大大提高了复合材料的导电能力。     

聚乙二醇-硫酸钠-硫氰酸钾体系中Co(Ⅱ)、 Ni(Ⅱ)、 Mo(Ⅵ)的萃取分离研究

用硫氰酸钾作萃取剂，探讨了在聚乙二醇（ＰＥＧ）２０００硫酸钠硫氰酸钾双水相体系中Ｃｏ（Ⅱ）、Ｎｉ（Ⅱ）、Ｍｏ（Ⅵ）等金属离子的萃取行为。控制一定条件，实现了Ｃｏ（Ⅱ）与Ｎｉ（Ⅱ）、Ｃｏ（Ⅱ）与Ｍｏ（Ⅵ）及Ｃｏ（Ⅱ）与Ｎｉ（Ⅱ）、Ｍｏ（Ⅵ）混合离子的定量分离，并研究了不同类型的表面活性剂对ＰＥＧ相萃取行为的影响。     

Electrochemical behaviour of Invar in phosphate solutions at pH=6.0

Electrochemical studies were carried out with disk electrodes of Invar (Fe-36%Ni) in phosphate solution at pH 6.0, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques, comparing the results with those for low carbon steel and pure Ni. Invar shows a reduced corrosion when compared to carbon steel in the weakly inhibitive solution though inferior to pure Ni. Phosphate anion is responsible for the formation of a protecting and stable film on the alloy surface at pH 6.0.Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with Invar disk electrodes (Fe-36%Ni) in phosphate solutions at pH=6.0 were carried out. Results were compared with those of carbon steel and pure Ni.     

Nickel-Carnosine complex:A new carrier for enzymes immobilization by affinity adsorption

Immobilization is an effective method to promote the application of enzyme industry for improving the stability and realizing recovery of enzyme.To some extent,the performance of immobilized enzyme depends on the choice of carrier material.Therefore,the development of new carrier materials has been one of the key issues concerned by enzyme immobilization researchers.In this work,a novel organic-inorganic hybrid material,nickel-carnosine complex (NiCar),was synthesized for the first time by solvothermal method.The obtained NiCar exhibits spherical morphology,hierarchical porosity and abun-dant unsaturated coordination nickel ions,which provide excellent anchoring sites for the immobiliza-tion of proteins.His-tagged organophosphate-degrading enzyme (OpdA) and ω-transaminase (ω-TA)were used as model enzymes to evaluate the performance of NiCar as a carrier.By a simple adsorption process,the enzyme molecules can be fixed on the particles of NiCar,and the stability and reusability are significantly improved.The analysis of protein adsorption on NiCar verified that the affinity adsorp-tion between the imidazole functional group on the protein and the unsaturated coordination nickel ions on NiCar was the main force in the immobilization process,which provided an idea way for the develop-ment of new enzyme immobilization carriers.