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431.
The diagonal elements of the first and second order spinless density matrices have been calculated for the lowest excited1
P and3
P terms of Be, B+ and C++ using wavefunctions at different levels of approximations published in the literature. The analysis of these functions has
resulted in a new interpretation of Hund's first rule in terms of an anisotropic screening effect. 相似文献
432.
Dynamic Interfacial Tension Behavior of Water/Oil Systems Containing In situ-Formed Surfactants 总被引:1,自引:0,他引:1
Time-dependent interfacial tension (IFT) has been investigated for an interfacially reactive immiscible system composed of model-acidified oil and alkaline water. The acidified oil was composed of either lauric acid or linoleic acid dissolved in n-dodecane. Drop volume tensiometry was employed to measure the interfacial tension between the two phases. In the case of lauric acid, the IFT value was found to decrease sharply with increasing alkali concentration, even at low drop formation times. In the case of linoleic acid, the IFT decrease with the drop formation time was more gradual, especially at low alkali concentration. The rate of formation of the interfacial area was also found to be dependent on alkali concentration. 相似文献
433.
I. S. Belostotskaya V. B. Vol'eva N. L. Komissarova M. O. Dekaprilevich V. N. Khrustalev A. Yu. Karmilov V. V. Ershov 《Russian Chemical Bulletin》1997,46(7):1272-1280
Oxidative transformations of 2-dialkylaminomethyl-4,6-di-tert-butylphenols depend on the nature of the oxidant, the character of the substituents at the nitrogen atom, and the medium.
A mechanism of the oxidation of these compounds is suggested. The molecular structure of the compound obtained as a result
of oxidative trimerization of 2-dimethylaminomethyl-4,6-di-tert-butylphenol was established by X-ray structural analysis.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1328–1335, July, 1997. 相似文献
434.
Zein films plasticized with oleic acid were formed by solution casting, by the stretching of moldable resins, and by blown film extrusion. The effects of the forming process on film structure were investigated by X-ray diffraction. Wide-angle X-ray scattering (WAXS) patterns showed d-spacings at 4.5 and 10 A, which were attributed to the zein alpha-helix backbone and inter-helix packing, respectively. The 4.5 A d-spacing remained stable under processing while the 10 A d-spacing varied with processing treatment. Small-angle X-ray scattering (SAXS) detected a long-range periodicity for the formed films but not for unprocessed zein, which suggests that the forming process-promoted film structure development is possibly aided by oleic acid. The SAXS d-spacing varied among the samples (130-238 A) according to zein origin and film-forming method. X-ray scattering data suggest that the zein molecular structure resists processing but the zein supramolecular arrangements in the formed films are dependent on processing methods. Structural model for a zein molecular aggregate (based on Matsushima et al.10). Rectangular prisms of individual zein molecules are hexagonally aligned parallel to each other. 相似文献
435.
喷雾热解法合成球形(Y,Gd)BO3:Eu荧光粉的研究 总被引:1,自引:0,他引:1
采用喷雾热解法合成了无团聚的球形(Y,Gd)BO3∶Eu荧光粉。研究了各因素对(Y,Gd)BO3∶Eu荧光粉体的结晶性能、外观形貌及发光强度的影响。结果表明,按120%硼酸的化学计量比于900℃喷雾热解,再经过1200℃后处理2 h,可以合成结晶良好的(Y,Gd)BO3∶Eu荧光粉体;喷雾热解溶液的浓度和载气流量对荧光粉的外观形貌影响较大;铕含量为10%时可以获得最佳的发光强度。在优化喷雾热解实验条件下成功合成出良好发光强度的PDP用(Y0.6Gd0.3)BO3∶Eu0.1荧光粉。 相似文献
436.
437.
C. AutretC. Martin A. MaignanM. Hervieu B. RaveauG. André F. Bourée 《Journal of solid state chemistry》2002,165(1):65-73
The Ho0.5Sr0.5MnO3 perovskite, synthesized in air, has been studied by combining neutron powder and electron diffraction techniques. The Pnma-type structure exhibits a strong tilting of the MnO6 octahedra. This octahedra tilting and microtwinning involve a complex strained structure. No structural transition is observed down to 1.4 K, but short-range A-type antiferromagnetism running over only a few perovskite subcells is evidenced below ≈90 K. The different behavior of this perovskite compared to other Ln0.5Sr0.5MnO3 perovskites is discussed in terms of A-site cationic mismatch. 相似文献
438.
Application of multiple scattered-wave X_α method with overlapping atomic-sphere to ionization potentials is reported for benzene, pyridine, pyrazine, pyrrole and imidazole. The calculated results show that the orbital charges in the intersphere region are non-negative and the energy levels get improvements in orderings. 相似文献
439.
Yu. V. Fedorov O. A. Fedorova N. E. Shepel’ S. P. Gromov M. V. Alfimov L. G. Kuz’mina J. A. K. Howard J. Saltiel 《Russian Chemical Bulletin》2005,54(9):2119-2128
Benzobisthiazole-based bis(crown ether) was synthesized and its complexation with alkali and alkaline earth cations was studied.
Photochemical transformations of the free ligand and its complexes with alkaline earth cations involve E,Z-photoisomerization and [2+2] photocycloaddition.
Dedicated to Academician N. S. Zefirov on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2056–2065, September, 2005. 相似文献
440.
A. A. Toropov V. O. Kudyshkin N. L. Voropaeva I. N. Ruban S. Sh. Rashidova 《Journal of Structural Chemistry》2004,45(6):945-950
For a series of monomers, QSPR test analysis is performed by optimizing the correlation weights of the local invariants of molecular graphs representing monomer structures in order to construct models of the reactivity parameters of monomers Q and e. This approach may be used as a tool in reactivity predictions for monomers for which no experimental data on Q and e are available.Original Russian Text Copyright © 2004 by A. A. Toropov, V. O. Kudyshkin, N. L. Voropaeva, I. N. Ruban, and S. Sh. Rashidova__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 994–998, November–December, 2004. 相似文献