Response of a Lorentzian gas to an a. c. pulse

The response of a “Lorentz gas” to a pulsed a.c. electric field and its relaxation after the cessation of this field has been studied by solving the Boltzmann's transfer equation. Explicit expressions for the electron distribution function and the current density are obtained under the assumption that the collision frequency is independent of the electron velocity.     

The density of states of a single tight-binding band for a b.c.c. element

Summary An exact expression has been derived for the density of statesn(ε) of a single tight-binding band of a b.c.c. element, within the two-centred approximation with nearest-neighbour contribution. Using this expression, a simple approximate relation is suggested forn(ε), which can be useful in deriving various properties of transition metals. Supporting organization: Shahid Beheshty University.     

Constraints imposed upon a state of a system that satisfies the K.M.S. boundary condition

Using the uniqueness of the K.M.S. automorphism, we investigate the set of automorphisms that commutes with it. The results are applied to gauge invariant quasi-free states of a fermion system.Attaché de Recherche, C.N.R.S.On leave of absence from the Groningen University, the Netherlands.     

The a.c. Josephson effect in a resistive state of narrow superconducting channels

Current steps in the current-voltage characteristic of a narrow superconducting channel in the resistive state under microwave irradiation are calculated. The current steps appear when the frequency of microwave irradiation Ω satisfies the condition $\text{Ω = mω}$, where ω is the Josephson frequency of the phase-slippage and m is an integer.     

Relativistic precession of a gyroscope. I. Circular orbits

The relativistic precession of the rotation axis of a spherical gyroscope is treated in the framework of monadic specification of the frame of reference. It is found that the precession in the comoving frame compensates the rotation of the frame of reference itself. An exact expression is derived for the angular velocity of precession for motion of a gyroscope in circular epiequatorial orbits in the Kerr field. The results are compared with the approximate expression obtained by Schiff. Numerical examples are considered.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 64–68, March, 1981.     

Spectral Investigation of an a. c. Plasma Display

The work presents the spectral investigations on an a.c. plasma display, in order of a better understanding of the physical phenomena taking place in such a device. The spectral characteristics of the panel filled with a Penning mixture Ne + 0.1% Ar are presented and the influence of the nitrogen addition on these characteristics was evidentiated. The presence of the trace of nitrogen in the device may be used in order to evidentiated. The presence of the trace of nitrogen in the device may be used in order to evidentiate small leaks or imperfections in pumping and outgasing processing of the display.     

E.S.R. study of the conformational kinetics of a biradical

Intramolecular motion in the biradical N,N'-bis(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)ethylenediamine which contains two ionizable amine groups has been studied by E.S.R. spectroscopy. The line-shapes of the spectra as a function of pH and temperature were analysed by density matrix methods to give values for rates and free-energies of activation.     

Time dependence of some parameters of a. c. discharges

Acta physica Academiae Scientiarum Hungaricae - The time dependence of the various discharge parameters in a hot-cathode a. c. low pressure mercury vapour argon discharge was investigated. The...     

Highlights of the ARGO-YBJ Experiment at 4,300 m a.s.l.

The ARGO-YBJ experiment in Tibet, China has been operated to survey the northern sky for gamma ray sources, transient or steady, for nearly 6 years. Many astrophysics observational results will be highlighted in this paper, such as the sky survey results, extended source observation, diffuse gamma rays from the galactic plane, and emission mechanism of AGNs and their flares. As the unique detector for EAS with a continuously sensitive area of 5,600 m ², the ARGO-YBJ array catches almost all particles in the central part of showers. The high-quality data set for showers above few TeV has been used for cosmic ray measurements such as the energy spectrum and composition. All those results are summarized here. As one of the next generation ground-based high-altitude air shower detector, LHAASO is briefly introduced as the successor of ARGO-YBJ in the end of the paper.