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991.
H. Günther M. Foerste M. Kunze G. zu Putlitz U. von Stein 《Zeitschrift für Physik B Condensed Matter》1996,100(4):613-617
We review the previous conclusion [J.Y. Ryu, Y.C. Chung and S.D. Choi, Phys. Rev. B 32, 7769 (1984)] that the trace property Tr(ABC) = Tr(CAB) leads to two different cyclotron transition absorption formulae in the electron-phonon systems in the lowest order approximation. The pictorial expression and the calculated linewidths in Ge and Si show that the socalled EWC scheme is more seeming than the socalled MWC scheme. The difference is expected to disappear if we take into account all the higher order perturbation terms or start with the many body formalism in the complete scheme. 相似文献
992.
The hyperfine interaction couples the atomic electrons and the nucleus, and because of this interaction, there is a fundamental link between the fields of atomic physics and nuclear physics. Of course, information flows in both directions through this link. This paper reviews in broad terms the previous applications of atomic physics methods to the study of nuclear properties and fundamental interactions, and then focuses on the possible applications of atom trapping methods to nuclear physics problems.Supported in part by the National Science Foundation. 相似文献
993.
V. É. Distanov A. G. Kirdyashkin 《Journal of Applied Mechanics and Technical Physics》1998,39(1):85-90
In model experiments, the layer of melt bounded by the crystallization front and the heater for heating the diaphragm in a
growing furnace is shown to determine crystal growth by the Stockbarger method under conditions of induced convection and
also to control the crystallization process. The free volume of the melt exerts no effect on its hydrodynamic and thermal
structures. Optimum values of the exposure time are estimated for constant maximum and minimum velocities of modulated rotation
of the growing ampoule.
Institute of Mineralogy and Petrography, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 1, pp. 98–104, January–February, 1998. 相似文献
994.
V. V. Dovlatyan É. N. Ambartsumyan G. S. Amazaspyan 《Chemistry of Heterocyclic Compounds》1996,32(1):75-77
New approaches have been developed for the application of cyanamino-sym-triazines in the synthesis of imidazolidinyl-sym-triazines. 相似文献
995.
996.
J. C. Meiners A. Ritzi M. H. Rafailovich J. Sokolov J. Mlynek G. Krausch 《Applied Physics A: Materials Science & Processing》1995,61(5):519-524
We have used atomic force microscopy to study the adsorption of PolyStyrene-Poly(VinylPyridine) (PS-PVP) block copolymers from a selective solvent onto atomically smooth mica surfaces. At certain copolymer concentrations, we observe a highly regular array of spherical surface micelles covering macroscopic areas of the substrate surface. Evidence is given for a thin homogeneous layer underneath the micelles which is probably due to adsorption of free copolymer chains and brush formation prior to the formation of the micellar structures. We discuss the quality of the self-assembled structures regarding different types of defects and try to identify means for improving the long range periodicity of the structures. 相似文献
997.
B. D. Symeopoulos P. G. Koutsoukos 《Journal of Radioanalytical and Nuclear Chemistry》1993,173(1):23-36
The formation of barium sulfate in aqueous media causes problems of insoluble scale formation. On the other hand, the coprecipitation of uranium and transuranium elements with barium sulfate has been suggested for the determination of these elements in environmental monitoring processes. Therefore, the study of barium sulfate crystal growth is required. The investigations done so far suffer from the low sensitivity of the analytical methods used. In the present work we have overcome this problem by using131Ba for the preparation of supersaturated solutions. Thus kinetics parameters such as induction time and precipitation rates were measured. The polynuclear mechanism was found to be operative at high and the spiral growth at low supersaturations. 相似文献
998.
M. A. Morón C. Romero F. R. Ruiz del Portal 《Journal of Optimization Theory and Applications》1996,91(3):643-649
The purpose of this paper is to seek utility functions satisfying a weak condition which guarantees that the utility optimum always belongs to the compromise set. This set is a special subset of the attainable or feasible set, which is generated through the application of the well-known operational research approach called compromise programming. It is shown that there are large families of utility functions satisfying this condition, thus reinforcing the value of compromise programming as a good surrogate of the traditional utility optimum.Thanks are due to the reviewers for their helpful suggestions. The English editing by Ms. Christine Méndez is appreciated. The authors have been supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT), Madrid, Spain. 相似文献
999.
G. M. Zharkova S. A. Streltsov V. M. Khachaturyan 《Journal of Structural Chemistry》1993,34(6):934-937
Light transmission of nematic liquid crystals dispersed in a polymeric matrix is investigated. The paper gives a theoretical analysis of light transmission by the liquid crystal-polymer and liquid crystaldye-polymer systems based on determination of the total cross section of extinction. The mathematical model is considered in the anomalous diffraction approximation. The theoretical calculations are in good agreement with experimental data obtained for films based on cyanodiphenyl dispersed into a polyvinyl acetate matrix.Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 6, pp. 118–122, November–December, 1993.Translated by L. Chernomorskaya 相似文献
1000.