p-Hg0.8Cd0.2Te based large area fast photoresistor

The design and manufacturing technology of large area fast photoresistors by drawing additional electrodes on their back side are described. The measurement of the modernized p-Hg_0.8Cd_0.2Te based pho-toresistornal has shown that its operation speed increases inversely proportional to the reduction of the distance between adjacent electrodes.     

Effect of a phase transition on the electron energy spectrum in Ag<Subscript>2</Subscript>S

Temperature dependences of electrical conductivity σ, Hall coefficient R, and thermopower α₀ in Ag₂S are reported. It is established that at T ≈ 435 ± 5 K, all kinetic parameters vary drastically, which is associated with a change in parameters of the conduction band. It is shown that the dispersion law of electron energy in β-Ag₂S corresponds to the Kane model.     

Formation of highly porous materials in the combustion wave of systems based on 5-aminotetrazole with potassium perchlorate

The formation of highly porous materials in the combustion wave of mixtures of 5-aminotetrazole with potassium perchlorate is studied. Under normal conditions with an oxidizer deficiency, the combustion of such mixtures proceeds in an unsteady oscillatory regime with formation of condensed products of incomplete oxidation of 5-aminotetrazole. It is shown that in the presence of metallic iron or its oxide, the completeness of interaction of the mixture components increases sharply and combustion becomes steady-state. In the presence of silicon dioxide, a highly porous solid residue forms which retains the shape of the initial block. At a certain ratio of iron and silicon dioxide in the initial composition, the solid combustion products have the form of interwoven thin fibers about 1 µm in diameter and 10–30 µm long.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 2, pp. 75–80, March–April, 2005.     

Specific features of the capacitance–voltage characteristics of a Cu–SiO<Subscript>2</Subscript>–<Emphasis Type="Italic">p</Emphasis>-InSb MIS structure

The capacitance–voltage and conductance–voltage characteristics of InSb-based MIS structures are measured at different probe signal frequencies with the aim of studying the influence exerted by the technological-synthesis conditions on the capacitive properties of these structures. The influence of positive charge built into the insulator on the sample characteristics is discussed. This influence manifests itself as a sharp capacitance “switch” upon changing the polarity of a low-field (E < 10⁶ V/cm) external signal.     

Charge transport in silver chalcogenides in the region of phase transition

Data on the σ(T), R(T), and U(T) dependences in Ag₂Te, Ag₂Se, and Ag₂S in the region of the phase transition are analyzed. It is found that the phase transition in Ag₂Te is accompanied by a decrease in the electron concentration and this transition in Ag₂Se is accompanied by an increase in this concentration. The concentration of intrinsic charge carriers in Ag₂Te decreases by a factor of 4 as a result of the phase transition and increases by a factor of 2 in Ag₂Se. The effect of variation in the energy-band parameters in the region of phase transition on the electron mobility is considered. It is established that, in Ag₂Te and Ag₂S, electrons are scattered by optical phonons in the region of the phase transition, while electrons are scattered by acoustic phonons in the α and β phases. It is assumed that the anomalously large increase in σ and U in Ag₂S as a result of the phase transition is caused by an increase in the concentration n and a simultaneous decrease in σ _g and m _n ^* by a factor of about 2.     

Water Sorption by Carbon Fibers

Protection of Metals and Physical Chemistry of Surfaces - The degree of crystallinity of carbon fibers (CFs) of different manufacturers has been determined by means of the Raman scattering method....     

Introduction to U-Number Calculus

Commonsense reasoning plays a pivotal role in the development of intelligent systems for decisionmaking, system analysis, control and other applications. As Prof. L. Zadeh mentions a kernel of the theory of commonsense is the concept of usuality. Zadeh suggested main principles of the theory of usuality, unfortunately up to present day; a fundamental and systemic approach to reasoning with usual knowledge is not developed.
In this study, we develop a new approach to calculus of usual numbers (U-numbers). We consider a U-number as a Z-number, where the second component is “usually”. Validity of the suggested approach is verified by examples.     

Oligomerization of hexene-1 in the presence of catalytic systems on the basis of ionic liquids

The results of hexene-1 oligomerization in the presence of recyclable catalysts on the basis of chloroaluminate ionic liquids and in combination with Ti-containing complexes with “grafted ionic liquid” ligands are reported. The possibility has been shown of the selective preparation of products with an oligoalkylnaphthene structure with a narrow molecular mass distribution (M _w/M _n = 1.03−1.55) characterized by the absence of double bonds. It has been found that the molecular mass of oligomer products can be regulated by changing the molar ratio of the components of the catalytic system.