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991.
992.
993.
The renormalization of the dispersion law for two-dimensional excitons in a magnetic field is studied by the Green's-function method taking into account multiphonon processes.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 3–7, April, 1987. 相似文献
994.
995.
996.
G. Carelli A. Di Siena N. Ioli A. Moretti G. Moruzzi F. Strumia 《International Journal of Infrared and Millimeter Waves》1994,15(4):619-633
We have measured the frequencies of four CH3OH far-infrared laser lines that were previously known only by wavelength measurement. Two of these lines turned out to be doublets, bringing the total number of measured lines to six. We can now confirm the assignments of five of them and definitely disprove the assignments proposed for the sixth.In particular we confirm the assignments for the four strong laser lines at 205 and 208 µm pumped by the 9-P(34) CO2 laser line. These lines share a common upper level in the first excited CO-stretch state, and terminate in the upper and lower levels of a hybrid state with J=5. Heterodyne frequency measurements and conventional microwave spectroscopy show that both lines are split into two components approximately 3.5 MHz apart. The origin of this further splitting is interpreted as a perturbed K-splitting.Work supported by Consiglio Nazionale delle Ricerche -Italia 相似文献
997.
Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 7, pp. 103–109, July, 1991. 相似文献
998.
A spinor field interacting with a zero-mass neutral scalar field is considered for the case of the simplest type of direct
interaction, where the interaction Lagrangian has the formL
int
=1/2 ϕαϕ,α
F(S) whereF(S) is an arbitrary function of the spinor field invariantS=ψψ. Exact solutions of the corresponding systems of equations that take into account the natural gravitational field in a
plane-symmetric metric are obtained. It is proved that the initial system of equations has regular localized soliton-type
solutions only if the energy density of the zero-mass scalar field is negative as it “disengages” from interaction with the
spinor field. In two-dimensional space-time the system of field equations we are studying describes the configuration of fields
with constant energy densityT
00
, i.e., no soliton-like solutions exist in this case.
Russian People’s Friendship University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 69–75,
July, 1998. 相似文献
999.
1000.
Summary We review the phase behaviour of mixtures of colloids and non-adsorbing polymers. The exclusion of polymer molecules from
overlapping ?depletion zones? between two neighbouring colloidal particles results in an unbalanced osmotic pressure pushing
the particles together. This depletion potential is separately tunable in range and depth. Theory predicts that the resulting
phase behaviour is sensitive to ξ=r
g/R, the ratio of the radius of gyration of a polymer molecule, to the radius of the colloid. At large ξ, a stable colloidalliquid phase becomes possible. This has been confirmed by recent experiments. The formation of non-equilibrium ?transient gel? states
when the size ratio is small (≈0.08) is also introduced briefly.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献