Spontaneous and stimulated emission of radiation from hot holes from uniaxially stressed germanium

Far-infrared radiation from hot holes in Ge under streaming conditions is investigated. Stimulated emission is observed from uniaxially compressed samples without magnetic field. The existence of inversion is due to a strain splitting of the light and heavy hole bands.     

Nuclear rotations studied by the time-dependent variational method

A general nuclear rotation including precession and wobbling motion is studied by the time-dependent variational method and a classical equation of motion is derived. The intrinsic wave function associated with the general rotational motion is constructed by making use of the constrained Hartree-Fock method and variables necessary in solving the equation are calculated. The method developed here is applied to a schematic extension of the Nilsson model.     

The Photochemical Methylenecyclopropane Rearrangement of Feist's Ester

In contrast to the thermal rearrangement, the photochemically induced methylenecyclopropane rearrangement of diethyl trans-methylenecyclopropane-2,3-dicarboxylate (I) and of ethyl ethoxycarbonylcyclopropylideneacetate (syn or anti) produced diethyl cis-methylenecyclopropane-2,3-dicarboxylate. A true photoequilibrium was not observed.     

Functional integral mean field expansions for nuclear many fermion systems

We present a careful analysis of the auxiliary field functional integral formalism for many fermion systems. We examine the limiting procedure used in construction of such integrals and show that a wide flexibility exists with respect to the choice of the one-body field representation upon which mean field expansions are made. We demonstrate the utility of this flexibility in the context of the evaluation of the grand canonical partition function. We examine the zero order. RPA and certain higher-order terms. The above-mentioned flexibility is reflected in the dependence of the results on a trial two-body interaction, different choices of which produce Hartree, Fock, HartreeFock or other forms of the mean field expansions. A standard variational procedure selects the Hartree-Fock as the optimal choice. With this choice we find certain corrections to previously reported RPA contribution for the Hartree mean field. We also indicate the relevance of our formulation for the recent applications of the functional integral mean field approach to nuclear dynamical problems.     

Low-temperature thermal conductivity of tellurium-doped bismuth

Phonon thermal conductivities κ₂₂ (?T ‖ C1) and κ₃₃ (? T ‖ C₃) of tellurium-doped bismuth with an electron concentration in the range 1.8 × 10¹⁹ ≤ n_L ≤ 1.4 × 10²⁰ cm^?3 were studied in the temperature interval 2 < T < 300 K. The temperature dependence of the phonon thermal conductivity obtained on doped bismuth samples of both orientations exhibits two maxima, one at a low temperature and the other at a high temperature. The effect of various phonon relaxation mechanisms on the dependence of both phonon thermal conductivity maxima on temperature, impurity concentration, and electron density is studied.     

Observation of radio-wave-induced red hydroxyl emission at low altitude in the ionosphere

We report the discovery of radio-wave-induced red emission of OH Meinel rotation-vibrational bands at 629.79 nm. These are the first measurements of artificial aurora below 100 km. We believe that the 629.79-nm OH emission was due to radio-wave focusing by sporadic ionization clouds near 80-85 km altitude, thus giving a technique to visualize the low-altitude sporadic ionization and providing insight into ionospheric interactions at these low altitudes.