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131.
Tsukasa Nakahodo Ohgi Takahashi Ernst Horn Naomichi Furukawa 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):565-568
Abstruct: The synthesis of σ-selenurane dication salts via transannular interactions and the reactivities of these dication salts are described. The X-ray crystallographic analyses of the dication salts show that the dications have selenium atoms in a trigonal-bipyramidal bonding environment. Ab initio calculations carried out for the dication revealed that the selenium atoms exclusively carry the positive charge. The interesting conformational properties of these dications are also described. 相似文献
132.
Syntheses and Structure of Hexacoordinated Selenium (λ6-Selane) and Tellurium (λ6-Tellane) Compounds
Soichi Sato Takeshi Ueminami Takahiro Yamashita Hiroshi Arakawa Ernst Horn Ohgi Takahashi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):595-598
The first isolation of bis(2,2′-biphenylylene)dichloro- and difluoro-perchalcogenuranes, [12–Se–6(C4F2)] (λ6-selane); [12–Te–6(C4X2), X = Cl, F] (λ6-tellane) and the corresponding tellurane Te-oxide dimer [12–Te–6(C4O2)]2, and their crystal and molecular structures are described. Furthermore, on the basis of the difference between the 3c-4e bonds of the dodecet species and that of the decet species a new molecular orbital concept has been proposed on the 3c-4e bond of perchalcogenurane species [12–M–6, M = chalcogen atoms]. 相似文献
133.
134.
Wang Mingzhang Lin Shi Li Chenghua Wang Zhongguang Xiao Jimei 《Acta Mechanica Solida Sinica》1997,10(4):345-351
The cyclic deformation of aluminium bicrystals was numerically simulated by using a crystalline micromechanical approach to study the effects of crystallographic orientation and deformation properties of constituent grains. Both the macro-and micro-stress-strain responses were analyzed. It was shown that the whole Bauschinger effect and cyclic hardening behavior of bicrystals is primarily controlled by the corresponding properties of the constituent grains, and that the effects of internal stresses induced by the grain boundary and the interaction between grains are secondary. The crystallographic orientation of constituent grains was also shown to have significant influence on the macro-and micro-mechanical behavior of the bicrystals. There were smaller symmetry in the orientation or greater difference in the strength between grains and more remarkable GB effects. 相似文献
135.
B. G. Bazarov R. F. Klevtsova Zh. G. Bazarova S. F. Solodovnikov S. T. Bazarova K. N. Fedorova 《Russian Chemical Bulletin》1999,48(6):1024-1027
The ternary salt systems M2MoO4−AMoO4−Zr(MoO4)2 (M=K, Tl; A=Mg, Mn, Ni, Co, Cu, Zn, Cd) in a sub-solidus region were studied. New ternary molybdates with the M5A0.5Zr1.5(MoO4)6 and MA0.5Zr0.5(MoO4)2 compositions were synthesized by solid-phase reactions in these systems. The crystallographic and thermal characteristics
of the compounds were found. The electrical properties of potassium—manganese—zirconium molybdates were studied.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1036–1039, June, 1999. 相似文献
136.
137.
A. A. Ramadan A. A. Abd El‐Mongy A. M. El‐Shabiny A. T. Mater S. H. Mostafa E. A. El‐Sheheedy H. M. Hashem 《Crystal Research and Technology》2009,44(1):111-116
The problem of structure investigation of thin films using laboratory XRD diffraction intensities was discussed as a matter of debate. Is the variation in relative intensities of the diffraction patterns due to crystallographic preferred orientation, lattice defects or both? The answer to this question shows a discrepancy in the literatures. The present work is an attempt to propose a possible approach to judge the most probable answer. Thin films of SnO2 were prepared by spray pyrolysis technique using solution of different SnCl2 concentrations (molarity); at fixed substrate temperature and deposition time. The theoretically calculated integrated intensities together with the experimentally obtained and calculated XRD data (relative intensities, texture coefficients and profile analysis) were considered together in order to get the proper picture of the structure characteristics of the prepared films. The complete picture can be assembled by integration and correlation of all the crystallographic information that are extracted from the diffraction pattern including not only the observed intensities but also the size/strain analysis and lattice parameters. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
138.
Bing Lin Minsheng Huang Liguo Zhao Anish Roy Vadim Silberschmidt Nick Barnard 《哲学杂志》2018,98(17):1550-1575
Strain-controlled cyclic deformation of a nickel-based single crystal superalloy has been modelled using three-dimensional (3D) discrete dislocation dynamics (DDD) for both [0?0?1] and [1?1?1] orientations. The work focused on the interaction between dislocations and precipitates during cyclic plastic deformation at elevated temperature, which has not been well studied yet. A representative volume element with cubic γ′-precipitates was chosen to represent the material, with enforced periodical boundary conditions. In particular, cutting of superdislocations into precipitates was simulated by a back-force method. The global cyclic stress–strain responses were captured well by the DDD model when compared to experimental data, particularly the effects of crystallographic orientation. Dislocation evolution showed that considerably high density of dislocations was produced for [1?1?1] orientation when compared to [0?0?1] orientation. Cutting of dislocations into the precipitates had a significant effect on the plastic deformation, leading to material softening. Contour plots of in-plane shear strain proved the development of heterogeneous strain field, resulting in the formation of shear-band embryos. 相似文献
139.
Su Shing Chen 《Journal of statistical physics》1982,29(3):579-589
In this paper, we investigate the connection between crystallographic groups and homogeneous statistical solutions of Navier-Stokes equations. Several results of Foias and Temam are extended. Fluid flows invariant under crystallographic groups are studied. This idea may be of interest to the understanding of bifurcation and turbulence. 相似文献
140.
V Ramamurthy 《Pramana》1979,13(4):373-386
The electron-ion interactions are evaluated exactly over the actual shape of the atomic polyhedron, instead of approximating
it by a sphere or an ellipsoid, by making use of simple co-ordinate axes transformations and lattice symmetry in the case
of fct and bct structures. It is shown that there are several alternative ways of expressing the interference factor,S(q), one of which was obtained by Sharan and others in the case of indium. By comparing these expressions with the latter,
with those of corresponding cubic structures as well as with those obtained under spherical approximation respectively, the
crystallographic equivalence and stability of tetragonal structures as well as the validity of Wigner-Seitz approximation
are discussed. 相似文献