Platymonas subcordiformis吸附镍离子的研究

分别研究了不同生长期海洋绿藻Platymonas subcordiformis对不同浓度Ni2+的吸附能力,以及藻液pH、光照强度和共存金属阳离子对藻细胞吸附能力的影响。对数生长前期藻细胞藻液和Ni2+的初始浓度为80 mg/L时的吸附能力较强,分别为7.76×10-5μg/个细胞和7.85×10-5μg/个细胞。当藻液pH介于9~10,光照强度为4 500 Lx时,藻细胞吸附Ni2+能力较强。此外,共存金属阳离子会抑制藻细胞对Ni2+的吸附。     

铁氧体法处理沉镍残液研究

采用铁氧体法处理沉镍残液,此法处理沉镍残液效果明显。研究了pH值、温度、搅拌时间、投料比对处理效果的影响。试验结果表明:在pH=11~12,温度50℃,搅拌时间25~30 min,投料比10的操作条件下,处理后的沉镍残液中各重金属离子浓度均达到排放标准。     

光谱法研究Ni[S2P（OCH2CH2Ph）2]2与α,α＇-联吡啶加合反应

利用紫外光谱法研究了Ni[S2P（OCH2CH2Ph）2]2与α,α-联吡啶的加合反应。研究发现Ni[S2P（OCH2CH2Ph）2]2与α,α-联吡啶形成1∶1型加合物,在25℃的苯溶剂中,加合物的离解度α=0.07,稳定常数K稳^θ=2.1×10^6。     

Antiferromagnetic Exchange Interactions. Part 1. Newly Reported Nickel(II) Complex of the Antiprine Schiff Base of 3-Formylsalicylic Acid

This study reports the magnetic properties of newly reported nickel(II) complex of the antiprine Schiff base of 3-formylsalicylic acid. Using the isotropic magnetic interaction model it is suggested that there is a strong antiferromagnetic interactions between metal centers in dimeric units. It is also suggested that the system become demagnetized below a certain temperature. An erratum to this article can be found at     

导电有机硅密封剂的研究

以镀银镍粉为导电填料、端羟基聚二甲基硅氧烷为基胶、经硅烷表面处理的白炭黑为补强填料,有机锡为催化剂,制成了高导电室温硫化双组分有机硅密封剂;研究了导电机理、镀银镍粉的加入量对有机硅密封剂的导电性能和电磁屏蔽性能的影响。结果表明,当镀银镍粉的体积分数超过25%时,有机硅密封剂的电性能明显提高;当镀银镍粉的体积分数达到35%以上时,有机硅密封剂的体积电阻率下降近10个数量级;当镀银镍粉的体积分数为50.5%时,有机硅密封剂在高频率范围具有良好的电磁屏蔽性能。     

The effect of sulfur on the dissociative adsorption of methane on nickel

The dissociative adsorption of methane was carried out on a Ni(100) surface covered with various amounts of sulfur under the high incident flux conditions of 1 Torr methane. Auger electron spectroscopy was used to measure the rate of carbon buildup and thus to determine the initial methane decomposition rates on the surface. It was shown that the sulfur atoms poison this reaction by a simple site-blocking process. These results are consistent with the activated dissociative adsorption of methane on Ni(100) occurring via a direct adsorption process.     

（Nb，Ti）C－Ni金属陶瓷的抗氧化性

用热等静压方法制备了（Ｎｂ，Ｔｉ）Ｃ－Ｎｉ金属陶瓷并作了８５０℃，９００℃，１０００℃及１１００℃下的等温氧化和室温～１１００℃的不等温氧化试验。在高温下，该金属陶瓷的表面被氧化成ＴｉＯ＿２，ＮｉＯ，ＮｉＴｉ＿３。认为Ｏ＿２通过氧化层向反应界面的扩散是控制氧化速率的主要步骤。氧化增重遵循抛物线规律，其激活能约为２３４ｋＪ／ｍｏｌ。     

催化加氢制备3,4-亚甲二氧基苯胺

3,4 亚甲二氧基硝基苯在95%乙醇溶剂中用雷尼镍催化加氢制备了3,4 亚甲二氧基苯胺。对催化剂用量和活性稳定性进行了研究,讨论了溶剂用量、温度、压力等因素对加氢反应的影响。结果表明最佳工艺参数为:雷尼镍∶乙醇∶3,4 亚甲二氧基硝基苯=0.15∶6∶1(质量比),反应温度40℃,氢压0.45～0.50MPa,搅拌速度450r/min,反应至不再吸氢为止,产品收率在97%以上,纯度为98%。     

Oxidation and intergranular disintegration of the aluminides NiAl and NbAl3 and phases in the system Nb-Ni-Al

The oxidation behavior is very different for an aluminide with a wide homogeneity range such as -NiAl than for a line compound such as NbAl ₃.Oxidation of -NiAl at temperatures 1273 K leads to a slow-growing -alumina layer. The metal phase beneath the scale remains as -NiAl; however, cavity formation is observed. The cavity formation may be favored by sulphur surface segregation. Oxidation of NbAl ₃ at temperatures 1273 K initially leads to -Al ₂O₃,but the Al depletion causes the formation of Nb ₂ Al beneath the oxide layer. Cracking of the Al ₂O₃ layer opens Nb ₂ Al to the atmosphere, which oxidizes rapidly to Nb ₂O₅ and NbAlO₄.After consumption of the Nb ₂ Al, a layer of Al ₂O₃ formed again on the NbAl ₃ phase, but failure of the alumina and the fast growth of the other oxides occur as a repeated process. Thus, NbAl ₃ exhibited rapid linear oxidation kinetics. Multiphase alloys in the system Nb-Ni-Al generally behave better than NbAl ₃,and the low oxidation rates of -NiAl can be approached. In the temperature range below 1273 K, with a maximum at 1000 K, both NiAl and NbAl ₃ show the pest phenomenon, an intergranular disintegration. Preceding the disintegration, oxygen diffuses into the grain boundaries of the material and Al ₂O₃ is formed at the grain boundaries, beginning from the surface region. NiAl is susceptible only in a very limited range of oxygen pressures and temperatures, whereas NbAl ₃ is much more susceptible.     

Thermodynamic properties of ni nitrides and phase stability in the Ni-N system

The thermodynamics of the Ni-N system is poorly known from experiments, and there is a need of information on the stability of the various nitride phases and the Ni-N phase diagram. This kind of information has been obtained by us, by combining the few measurements available with predictions, based on recently reported regularities in bonding properties and vibrational entropy of 3d transition metal compounds. A calculated Ni-N phase diagram is presented. A certain range of homogeneity for the hexagonal nitride phase is obtained, which is comparable to that of other 3d transition metal-nitrogen systems. The question of the possible existence of a stable Ni₄N phase is examined. According to our results, Ni₄N is metastable in the Ni-N system.