Minority carrier injection in relaxation semiconductors under illumination

The paper considers the injection of minority carriers into a relaxation semiconductor under uniform illumination. Steady state solutions have been computed, and used to assess the nature of the recovery process after cessation of the light. It is concluded that measurements of photoconductive decay do not in general lead to reliable lifetime estimates because, besides recombination, the movement of space charges is involved in the recovery.     

A topological classification of linear differential equations on Banach spaces

In the present work, we give necessary and sufficient conditions for linear differential non-autonomous equations on a Banach space, that satisfy exponential dichotomy, to be topologically equivalent. We shall also prove that such equations are structurally stable.     

Properties of the 635.4 keV level in171Tm

The properties of some high excited states of¹⁷¹Tm have been studied using Ge(Li) detectors. The directional angular correlation measurements for 277.4-210.5 keV cascade are in agreement with the spins of the 635.4 keV© and 912.8 keV(5/2) levels. The magnetic momentμ=(1.15±0.21)μ _N of the 635.4 keV level was determined by integral perturbed angular correlation (IPAC) in external magnetic field.     

Absorptionsspektroskopie angeregter Cäsiumatome

Cesium atoms, enclosed in a glass vessel, are excited by a weak electrical discharge and irradiated by monochromatic light with wavelengths corresponding to the sharp, diffuse, and fundamental series. By light absorption, highly excited atoms are produced, which are ionized by electron collisions. These ions diffuse into the space charge region of a diode path, compensate partially the space charge, and increase the thermionic diode current. By this method, ionic currents of about 10 ions per sec can be detected. If the wavelength of the incident light is varied continuously, the complete absorption spectrum of excited cesium atoms can be found in the recorded diode current.     

Strongly essential coalitions and the nucleolus of peer group games

Most of the known efficient algorithms designed to compute the nucleolus for special classes of balanced games are based on two facts: (i) in any balanced game, the coalitions which actually determine the nucleolus are essential; and (ii) all essential coalitions in any of the games in the class belong to a prespecified collection of size polynomial in the number of players. We consider a subclass of essential coalitions, called strongly essential coalitions, and show that in any game, the collection of strongly essential coalitions contains all the coalitions which actually determine the core, and in case the core is not empty, the nucleolus and the kernelcore. As an application, we consider peer group games, and show that they admit at most 2n−1 strongly essential coalitions, whereas the number of essential coalitions could be as much as 2ⁿ⁻¹. We propose an algorithm that computes the nucleolus of an n-player peer group game in time directly from the data of the underlying peer group situation.Research supported in part by OTKA grant T030945. The authors thank a referee and the editor for their suggestions on how to improve the presentation     

Thermodiffusive characteristics of some adhesive,film-forming materials and the component solvents

The TG curves obtained for various temperatures and evaporation times allowed establishment of the thermodiffusive characterics of the solvents frequently used in adhesive and film-forming materials. Determinations were carried out in air with a flow rate of 51/h, on pure solvents, on mixtures with solvent ratios corresponding to those in the final products, and on the final products. The temperature range of the study was 17–35°, the evaporation period for most cases at each temperature being 25 minutes. The method leads to the evaporation rates of such solvents with an average standard deviation of 4 per cent.