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61.
Yakhvarov D. G. Budnikova Yu. H. Tazeev D. I. Sinyashin O. G. 《Russian Chemical Bulletin》2002,51(11):2059-2064
The material of the sacrificial anode has a substantial effect on the nature and yield of the target products of electrochemical phosphorylation of organic halides by white phosphorus in the presence of the nickel complexes with 2,2"-bipyridine. The use of the zinc anode results in the products with tricoordinated phosphorus, viz., triorganylphosphines, the reaction on the aluminum anode affords triorganylphosphine oxides, and the presence of Mg2+ ions in the reaction mixture provides the transformation of white phosphorus into cyclic phosphines (PhP)5. 相似文献
62.
四元体系KCl-ZnCl2-HCl(~10.61%)-H2O(298.15K)的相平衡及其固相化合物 总被引:1,自引:0,他引:1
0引言研究发现,卤化物KX与ZnX2组成的复盐化合物是一种良好的激光基质材料犤1犦,在掺杂了稀土离子的这些化合物中已经实现了低温或室温下的激光输出犤2,3犦。在卤化物中,氯化物的发光强度又大于氟化物犤4犦。因此,我们以KCl与ZnCl2为研究对象,通过盐酸溶液中的相化学反应来了解它们之间可能形成新化合物的种类和溶液中的反应行为。本文对KCl与ZnCl2在25℃11%的盐酸-水四元体系中的相平衡关系进行了研究,并从体系中发现并得到了未见文献报道的5∶4型新化合物5KCl·4ZnCl2·3H2O。1实验部分1.1药品及… 相似文献
63.
64.
比值光谱导数法同时测定铝合金中铁,铜,锌 总被引:6,自引:0,他引:6
用比值光谱-导数分光光度法,在pH5.5缓冲溶液中,利用金属-2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)-OP三元络合物显色体系,对混合物中铁,铜,锌三组分进行了同时测定。合成试样5次测定回收率在97.3%-104.4%之间。应用于铝合金中铁,铜,锌的测定,各6次测定的RSD分别为3.66%,1.38%,2.03%。 相似文献
65.
The development of a slurry sampling method for the determination of calcium, copper, iron, magnesium and zinc in fish tissue samples by flame atomic absorption spectrometry is described. In comparison with microwave-assisted digestion, the proposed method is simple, requires short time and eliminates total sample dissolution before analysis. Suspension medium was optimized for each analyte to obtain quantitative recoveries from fish tissue samples without matrix interferences. Nevertheless, iron recoveries higher than 46% were not found. Treatment of samples slurried in nitric acid by microwave irradiation for 15-30 s at 75-285 W permitted to achieve efficient recoveries for calcium, iron, magnesium and zinc. Further improvement in the matrix effects for iron determination was accomplished by the use of an additional step of short microwave-assisted suspension treatment. However, standard addition method was required for calcium and copper determination, being necessary hydrochloric acid as suspension medium for the last one. Although copper could not be determined in the certified reference material using microwave-assisted digestion, the accuracy of the slurry sampling method was verified for all the investigated analytes. Detection limits were 22.8 ± 8.0, 0.884 ± 0.092, 5.07 ± 0.76, 35.5 ± 0.7 and 1.17 ± 0.04 μg g−1 for calcium, copper, iron, magnesium and zinc, respectively. The standard deviations obtained using slurry sampling method and microwave-assisted digestion were not significantly different, and the mean relative standard deviation of the over-all method (n = 3) of the slurry sampling method for different concentration levels was below 12%. 相似文献
66.
用X射线衍射分析、FT-IR、小角X光散射等方法研究了浸渍法制备的NiO/SiO_2和NiO/(La_2O_3+SiO_2)样品中组分之间的相互作用。La_2O_3在SiO_2上可形成近乎密置单层的分散。在负载了La_2O_3的SiO_2上,NiO的分散程度比在SiO_2上有明显提高,也更容易被还原,而且还原后所得金属镍粒子的平均粒度降低,小粒子所占百分比提高。这些结果表明,NiO/(La_2O_3+SiO_2)比NiO/SiO_2样品具有更高的加氢还原硝基普鲁卡因为胺基普鲁卡因的活性,与Ni/(La_2O_3+SiO_2)比Ni/SiO_2活性高的情形相一致。 相似文献
67.
Yingxin Liu Zuojun Wei Jiyan Zhang Wei Yan 《Reaction Kinetics and Catalysis Letters》2007,92(1):121-127
Ni-La2O3-SiO2 catalysts were prepared by wetness impregnation and sol-gel method followed by conventional drying and supercritical drying,
respectively. Their physico-chemical properties and activity for the hydrogenation of m-dinitrobenzene to m-phenylenediamine were investigated by BET, XRD, TPR, H2-TPD and activity tests. The results showed that the structural and catalytic properties of the Ni-La2O3-SiO2 catalysts obviously depended on the preparation method and the drying mode. The catalyst prepared by the sol-gel method in
combination with conventional drying exhibited the highest catalytic activity among the catalysts tested, attributable to
its well-dispersed nickel particles and larger active nickel surface area. 相似文献
68.
Krunks M. Madarász J. Leskelä T. Mere A. Niinistö L. Pokol G. 《Journal of Thermal Analysis and Calorimetry》2003,72(2):497-506
Thermal decomposition of the title compound, Zn(tu)2Cl2 (tu=thiourea), was studied up to 1200°C in dynamic inert (N2) and oxidative (air) atmospheres using simultaneous TG/DTA techniques. In addition, XRD and IR were employed ex situ to resolve
the reaction mechanism and products. Cubic ZnS (sphalerite) is formed below 300°C in both atmospheres and is observed until
760°C, whereafter it transforms in nitrogen to the hexagonal ZnS (wurtzite). EGA by FTIR revealed the complexity of the decomposition
reactions involving also the evolution of H2NCN, which reacts to form hexagonal ZnCN2 as revealed by an XRD analysis.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
69.
The influence of hydrothermal modification on the structure and hydrodenitrogenation (HDN) activity of NiMo/γ-Al2O3catalyst was studied in the range 140~180 ℃. The experimental results indicated that the hydrodenitrogenation reaction rate of pyridine was accelerated using the NiMo/γ-Al2O3catalyst synthesized via hydrothermal route due to the change of the structure, the increase of the amount of Mo and Ni and the rise of the specific surface area. The change of the structure of catalysts was enhanced at higher hydrothermal temperature, producing NiMo/γ-Al2O3catalyst with better HDN activity. 相似文献
70.
Usachev N. Ya. Belanova E. P. Krukovsky I. M. Kanaev S. A. Atal"yan O. K. Kazakov A. V. 《Russian Chemical Bulletin》2003,52(9):1940-1949
Thermal transformations in systems formed by interaction of Zn and Na nitrates with Y, X, and A zeolites were studied by TG—DTA technique. Temperature regions of existence of adsorbed water, water of crystallization, and decomposition of NO3
– anion were determined. These intervals depend on the composition, structure, method of preparation, and pre-treatment conditions of zeolite systems. The extent of NO3
– decomposition depends not only on the zinc and sodium content but also on the presence of ammonia involved in NO3
– reduction. The zeolite matrix strongly stabilizes the occluded NO3
– anions. A portion of zinc oxide formed by zinc nitrate decomposition is probably localized inside the zeolite cavities as the [Zn—O—(ZnO)
n
—Zn]2+ particles. The latter compensate charges of the isolated [AlO4]– tetrahedra. 相似文献