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761.
用~1HNMR和~13CNMR对La(HSal)_2·hq(镧-水杨酸-8羟基喹啉)和La(NoA)_2·hq(镧-萘氧乙酸-8羟基喹啉)三元配合物的研究结果表明:La(HSal)_2·hq中La~(3+)与Hhq上的O、N配位,同时H_2Sal中羧基失去质子,与La~(3+)配位,而H_2Sal中羟基未参与配位;La(NOA)_2·hq中La~(3+)与Hhq上的O、N配位,并且使HNOA中羧基失去质子,与La(2+)配位。  相似文献   
762.
763.
The dissociation constants for N-(l-naphthyl)ethylenediamine (NEN) and the formation constants for binary (ML) and ternary metal complexes (MLA), where M = Cu(II), L = alanine, phenylalanine, tryptophan, lysine, arginine, serine, threonine, aspartic acid or histidine and A = NEN or ethylenediamine (EN) have been determined by pH titrations and are reported at 35°C (gm = 0.2 M KNO3). The relative stability of the ternary complexes are discussed in terms of statistical effects and the nature of ligands in the coordination sphere of the metal ion.  相似文献   
764.
Three series expansions are examined for use in extracting ternary diffusion coefficients from Rayleigh interferometric data for free diffusion experiments. Convergence comparisons show that, providing enough terms are used, two of the three are suitable, including one used earlier by Albright and Sherrill. A new simpler analysis, using only linear least squares, has been applied to simulated and real data with good results. Advantages and disadvantages of series methods are compared to a direct non-linear least squares analysis.  相似文献   
765.
叔丁醇—醋酸乙烯—水三元系液液平衡研究   总被引:1,自引:0,他引:1  
该三元系的相平衡是在含有叔丁醇、醋酸乙烯(以下简称VAC)、水的三元系中测定的。理论上可根据二元平衡数据预测三元数据,但活度系数和组成间的关联式种类繁多,它们均应满足热力学一致的要求,但每个关联式在应用时或多或少地受不同程度的限制,使得理论值和实测值...  相似文献   
766.
About Alkali Seleno Bismuthates (III), with a Comment Regarding the Th3P4 Structure Type The synthesis and X-ray single crystal structure determination of the ternary selenides Rb3BiSe3, Cs3BiSe3, and RbK2BiSe3 are described. The compounds were synthesized via a reaction of Bi2O3 with the alkali carbonate in a selencharged hydrogen stream at 850°C. They crystallize in the Na3AsS3 structure type (space group P213). In the discussion of the structure, the aristotypic Th3P4 structure is included.  相似文献   
767.
768.
测定了RbNO3-C2H5OH-H2O体系在25℃和50℃的等温平衡溶解度及饱和液的性质(密度和折光率).绘制了相图,计算了盐析率,评价了盐析效果.用经验公式分别对溶解度、密度和折光率进行了关联,效果良好.体系没有产生分层现象,得到的平衡固相皆为无水铷盐,没有新化合物或水合物生成.  相似文献   
769.
Crystals of the title compounds were obtained by arc-melting cold-pressed pellets of the elemental components, followed by annealing the reaction products in an argon atmosphere slightly below the melting point. The crystal structures of these isotypic, hexagonal carbides (P63/m, Z=2) were determined from single-crystal X-ray data; Gd3Mn2C6: a=815.0(2) pm, c=504.93(9) pm, R=0.012 for 526 structure factors and 18 variable parameters; Tb3Mn2C6: a=810.5(2) pm, c=500.5(2) pm, R=0.025 (225 F′s, 18 variables). The carbon atoms form pairs with C—C bond distances corresponding to double bonds. The three-dimensional, polyanionic managanese carbon network contains relatively large trigonal-bipyramidal voids formed by three lanthanoid and two manganese atoms. The rationalization of chemical bonding on the basis of the 18-electron rule suggests that these voids are filled by nonbonding electrons of the adjacent manganese atoms.  相似文献   
770.
The effect of very low concentrations of ethanol, 2-propanol and phenol on the swelling degree of poly(ethylene-co-vinyl alcohol) (EVAL) in water was investigated. The effect of phenol on the swelling degree of EVAL was remarkably large compared to that of ethanol and that of 2-propanol. Theoretical analysis on the basis of Flory-Huggins theory using three binary interaction parameters could appropriately predict the EVAL swelling degree in ethanol/water and 2-propanol/water mixtures. However, the theoretical swelling degree of EVAL in phenol/water mixtures needed a ternary interaction parameter (χT) to match with experimental data points. An optimum value of χT for the water-phenol-EVAL system was found to be −3.3. The relationship between the ternary interaction parameter and the structure of water from observations of the effect of phenol on the EVAL swelling was discussed. Based on the analysis of low-frequency Raman spectroscopy reported by Suzuki et al. [J. Chem. Phys. 107 (1997) 5890], the contribution of χT to the EVAL swelling was attributed to the increase of the entropy in bulk water due to the effect of phenol on the disruption of the tetrahedral hydrogen-bonded networks of water molecules. This, in turn, induced an increase of water absorption in EVAL.  相似文献   
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