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861.
862.
A determinant (permanent) of plane waves for N fermions (bosons) in their lowest-energy state, and a determinant (permanent) of spatially-localized, nonoverlapping, single-particle functions are used to determine conditions on the short-ranged, square-well repulsive plus Yukawa attractive, two-body potential for which the spatially homogeneous or periodic particle-density states are energetically preferred. A considerable region in the coupling parameter-density plane is found where “crystalline” solutions are preferred. In particular, for purely repulsive forces, the low-density region for which the “fluid” solution is lowest shrinks to zero in the limit of infinitely repulsive cores, but faster for bosons than fermions. Inclusion of attractive forces is seen not to alter qualitatively the main results. 相似文献
863.
K.K Singh 《Annals of Physics》1973,75(1):38-55
It is shown that the equilibrium thermodynamic properties of some superfluid models can be calculated by using density matrices defined in suitable irreducible representations. The approach enables one to introduce in a fundamental manner temperature-dependent order parameters and can be used to obtain general formulations of the problems of superfluids. 相似文献
864.
I.J. Galpin F.E. Hancock B.K. Handa A.G. Jackson G.W. Kenner R. Ramage B. Singh R.G. Tyson 《Tetrahedron》1979,35(23):2779-2783
The fully protected 17–26 fragment of a lysozyme analogue has been synthesised. A fragment condensation approach has been employed using the protected subfragments 17–19, 20–22 and 23–26. In the synthesis of the subfragments the use of the diphenylphosphinyl mixed anhydride method has been demonstrated. 相似文献
865.
Kuldeep Singh 《Fresenius' Journal of Analytical Chemistry》1989,335(4):433-435
Abstracts2 Particular products and fields of application
2.5 Soils plants and agricultural-technical products 相似文献866.
867.
A systematic semiquantitative account of all aspects of the strong and electromagnetic interactions of all the newly discovered
hadronic states (theψ’s, theχ’s, etc.) is presented within the framework of the paracharge scheme. Extensions of ideas familiar from the SU3 classification scheme to SU4 are shown to provide an understanding of the new states seen in the decays ofψ (3.1) andψ′ (3.7), including their masses and gross decay characteristics. The decays ofψ (3.1) andψ′ (3.7) themselves are studied in some detail. Since these are of electromagnetic origin in the scheme, their electromagnetic
mixing with the resonance at 4.15 GeV (theP-state of the scheme) is important. Once this is taken into account, the resulting picture is in excellent agreement with
available data. 相似文献
868.
Existence of bicyclo (4.2.0) octa-2,4-diene ? 1,3,5-cyclooctatriene type of valence isomerisation in a polycyclic propellane framework has been demonstrated through cycloaddition and thermolysis reactions. 相似文献
869.
The local or gap mode frequencies of a host lattice-point defect system. XY:Z may be predicted from the properties of the end member pure crystals XY and XZ alone whenever pertinent data on pure crystals are available, without invoking any arbitrary force constant softening. In this instance the molecular model has been used, and relevant examples from alkali halides are presented. A modification of the Green's function technique is also discussed. 相似文献
870.
We derive an exact quantization condition for the energy levels of a particle in a radial potential assumed finite at the origin. This is used to derive corrections to the semiclassical JWKB quantization condition. We further relate the normalization integral of the wavefunction to the energy derivative of wavefunction at origin and use this expression to derive the corrections to the semiclassical JWKB expressions for the wavefunction at origin. An application to upsilon leptonic decay width is also given. 相似文献