Showing papers by "Russian Academy of Sciences published in 1983"
TL;DR: In this article, the authors discuss the possibility that space-time has (3+ N )+1 dimensions, but ordinary (light) particles are confined in a potential well which is narrow along N spatial directions and flat along three others.
1,245 citations
TL;DR: In this article, the cosmological constant problem is solved by raising the number of spatial dimensions a la Kaluza-Klein, and the authors conjecture that quantum corrections and/or additional interactions single out the solution with vanishing physical cosmologically constant.
556 citations
TL;DR: The first evidence for an energy-dependent biosynthesis of pyrophosphate is obtained with animal tissue homogenates and several modern concepts about the role of high molecular-weight polyphosphates and pyroph phosphate in evolution of phosphorus metabolism are presented.
Abstract: Publisher Summary This chapter discusses the physiological role of inorganic polyphosphates. Inorganic polyphosphates are linear polymers in which orthophosphate residues are linked by energy-rich phospho-anhydride bonds. Inorganic polyphosphates have been found in almost all tested representatives of living cells. They have been detected in eubacteria, fungi, algae, mosses, protozoa, insects, and in various tissues of higher plants and animals. In highly organized organisms, polyphosphates perform several specialized functions, being donors of activated phosphate only for quite specific biochemical or physiological processes. The chapter presents new aspects of inorganic pyrophosphate's metabolic and physiological role. Pyrophosphate is only a byproduct of numerous reactions of pyrophosphorolysis involved in biosynthesis of proteins, nucleic acids, lipids, polysaccharides, and nucleoside coenzymes. The energy-dependent synthesis of pyrophosphate during photosynthetic and oxidative phosphorylation is also discussed. The first evidence for an energy-dependent biosynthesis of pyrophosphate is obtained with animal tissue homogenates. Finally, several modern concepts about the role of high molecular-weight polyphosphates and pyrophosphate in evolution of phosphorus metabolism are presented in the chapter.
349 citations
TL;DR: In this article, a complete review of double-layer data obtained with single-crystal faces of sp metals is presented, including seven tables summarizing all data obtained to date and 158 references.
292 citations
TL;DR: In this paper, the authors compared the performance of cyclotron autoresonance masers (CARM's) and ubitrons at mm and sbmm waves.
Abstract: FEL's based on the stimulated undulator radiation (ubitrons) are compared with those based on the stimulated cyclotron radiation [cyclotron autoresonance masers (CARM's)]. If the high-current accelerators are used as electron injectors, then from the viewpoint of simplicity of oscillatory electron energy pumping, criticality with respect to electron velocity dispersion, and efficiency, CARM's seem to be more effective than ubitrons at mm and sbmm waves. For such HF generators, resonators based on selective Bragg reflection of electromagnetic waves in corrugated metallic tubes are most atractive. CARM's of this type yield 6 MW at a 4 mm wavelength and 10 MW at a 2 mm wavelength in the single-mode regime.
279 citations
TL;DR: In this article, two methods for calculating the force of the adhesion of an elastic sphere with a rigid plane are considered, under conditions where the surface profile of the deformed sphere under the effect of a normal load and surface forces is very similar to that described by Hertz theory.
277 citations
TL;DR: In this paper, the effect of two-photon absorption of powerful laser UV radiation by liquid water has been investigated using a method of picosecond spectroscopy and it was shown that the absorption of two UV quanta with λ = 266 nm by water results in its ionization with a quantum yield of 15% or in its dissociation with 13%.
249 citations
TL;DR: In this article, a review paper on the multiple-photon excitation of molecules by intense infrared laser light is presented, which brings forward general concepts on spectroscopy, molecular physics and chemical kinetics essential for understanding the later material.
Abstract: This paper begins our review paper on the multiple-photon excitation of molecules by intense infrared laser light. The whole review will be given in installments. In this first part we bring forward certain general concepts on spectroscopy, molecular physics and chemical kinetics essential for understanding the later material.
233 citations
TL;DR: A molecular theory of protein secondary structure is presented that takes account of both local interactions inside each chain region and long‐range interactions between different regions, incorporating all these interactions in a single Ising‐like model.
Abstract: A molecular theory of protein secondary structure is presented that takes account of both local interactions inside each chain region and long-range interactions between different regions, incorporating all these interactions in a single Ising-like model. Local interactions are evaluated from the stereochemical theory describing the relative stabilities of α- and β-structures for different residues in synthetic polypeptides, while long-range effects are approximated by the interaction of each chain region with the averaged hydrophobic template. Based on this theory, an algorithm of protein secondary structure prediction is proposed and examples are given of “blind” predictions made before the x-ray structural data became available.
225 citations
TL;DR: The P-T location of the reaction diopside + magnesite + dolomite has been determined by experimental reversals from 800 to 1300°C, 20-50 kbar as discussed by the authors.
201 citations
TL;DR: In this article, the density of wavefront dislocations for optical fields as a function of radiation parameters is investigated both theoretically and experimentally, and it is shown that a field with dislocation cannot be conjugated by means of flexible adaptive mirrors.
Abstract: The density of wave-front dislocations for optical fields as a function of radiation parameters is investigated both theoretically and experimentally. A field with dislocations cannot be conjugated by means of flexible adaptive mirrors.
TL;DR: Ionic channels responsible for excitation of plasmalemma and tonoplast of fresh-waterNitellopsis obtusa were studied using the voltage-clamp technique and possess activation-inactivation kinetics.
Abstract: Ionic channels responsible for excitation of plasmalemma and tonoplast of fresh-waterNitellopsis obtusa were studied using the voltage-clamp technique. Voltage was clamped on each separate membrane. Chloride channels were inhibited with ethacrynic acid. 1. Along with anion (chloride) channels the cation channels have been revealed in the membranes. The corresponding channels are similar in both types of membranes. 2. The cation channels are controlled by membrane voltage being activated under membrane depolarization. The channels possess activation-inactivation kinetics. ForN. obtusa characteristic times of activation and inactivation are ∼0.1 and 0.5 sec, respectively. 3. Conductance of cation channels depends on the type of cation and the orders of conductivity decrease are the following: Rb+>K+>Cs+>Na+>Li+ and Ba2+>Sr2+>Ca2+>Mg2+. Ratio of conductance for bivalent ions to that of monovalent ones decreases with the increase of normal concentrations. When the external medium contains both mono- and bivalent cations in comparable concentrations, the current is mainly determined by the latter. In natural environment of the algae such conditions are realized for Ca2+ ions which create the bulk of the inward current through cation channels under cell excitation. That is why we term these channels “calcium” ones. 4. Ca2+ ions entering the cytoplasm through the calcium channels located in both membranes activate the chloride channels. Ba2+ and Mg2+ also activate the chloride channels but to a lesser extent than Ca2+ does. Characteristic inactivation time of these channels inN. obtusa is about 1 to 2 sec.
TL;DR: In this paper, a generation mechanism of the quark and lepton masses in gauge models with horizontal symmetry is proposed, based on the mixing of quark-lepton families with heavy horizontal fermions, acquiring large masses directly after breaking of horizontal symmetry.
TL;DR: In this article, a method has been suggested for an approximation of the unary and binary distribution functions derived in [1] with an accuracy 10 times higher than that of the Percus-Yevick equation and 25 times more than the HNC equation.
Abstract: The exact equations for the unary and binary distribution functions derived in [1] contain infinite functionals M (i), i=1, 2, whose calculation encounters considerable difficulties. These equations cannot therefore find practical application. A method has been suggested for an approximation of these functionals. Even in the first approximation, this method leads to an equation which enables the pressure in a system of high-density hard spheres to be calculated with an accuracy ten times higher than that of the Percus-Yevick equation and 25 times higher than the accuracy of the HNC equation.
TL;DR: The comparison of RPE development in three species showed that the pattern and schedule of R PE growth and differentiation causally related to cell proliferation are significantly different, and cell proliferation is essential for RPE melanotic differentiation and for transdifferentiation into other cell types.
Abstract: Publisher Summary This chapter describes the proliferation and differentiation of retinal pigment epithelium (RPE) during development and regeneration. RPE is a pigmented monolayer of hexagonal cells of neural origin located between the neural retina and the choroid. It is one of the most important structures in the visual system because of the role it plays in the viability and function of the neural retina. The comparison of RPE development in three species (rats, chicks, and humans) showed that the pattern and schedule of RPE growth and differentiation causally related to cell proliferation are significantly different. The chapter discusses the proliferation of pigment epithelium cells in the amphibian retina and iris in the process of retinal and lens regeneration. The importance of analyzing the proliferative activity of pigmented epithelia of the amphibian eye is because of the amphibian's striking potential for the regeneration of the neural retina and lens. Cell proliferation is not only closely related to cell multiplication and the reduction of cell volume but is also essential for RPE melanotic differentiation and for transdifferentiation into other cell types.
01 Oct 1983
TL;DR: In this paper, the theory of transitions between electronic states is developed and the analytical results for the full rates of transitions are found in the limiting cases of weak and strong interactions, and it is shown that the result for the rates of transition is independent of the specific form of partial rates and its form is determined fully by the principle of detailed balance.
Abstract: In this work the theory of transitions between electronic states is developed. In the limiting cases of weak and strong interactions the analytical results for the full rates of transitions are found. It is shown that in the case of strong interactions the result for the rates of transition is independent of the specific form of partial rates and its form is determined fully by the principle of detailed balance. Using the Pade approximation, the expression for the full rate of transition is found in the case of interactions of mediate strength. The theory is applied to the description of radiationless transitions in polar solvents.
TL;DR: In this article, a comparison of the properties between La3Ga5SiO14 and crystalline SiO2 is carried out, specifically, elastic, dielectric, and piezoelectric modules and constants are investigated.
Abstract: Absorption, luminescence characteristics, and stimulated emission parameters of Nd3+ ions in the wide temperature region of a full concentration series of (La1−xNdx)3Ga5SiO14 single crystals are studied. Luminescence intensity characteristics are analyzed and transition cross-section at the laser wavelengths of two 4F3/2 4I11/2 and 4F3/2 4I13/2 generation channels of activator are determined. Registered induced transitions are identified. Electromechanical characteristics of La3Ga5SiO14, specifically, elastic, dielectric, and piezoelectric modules and constants are investigated. A comparison of the properties between La3Ga5SiO14 crystals and crystalline SiO2 is carried out.
[Russian Text Ignored.]
TL;DR: In this paper, the growth features of trigonal La3Ga5SiO14 and Nd3GGa5SO14 crystals and their solid solutions from the melt by Czochralski technique are studied.
Abstract: The growth features of trigonal La3Ga5SiO14 and Nd3Ga5SiO14 crystals and their solid solutions from the melt by Czochralski technique are studied. Optimal conditions are found and oriented (La1−xNdx)3 Ga5SiO14 single crystals are grown with 28 mm in diameter and 280 g by weight, of optical quality perfect to carry out excitation experiments on Nd3+ ion stimulated emission as well as investigations of acoustooptic and electromechanical properties of La3Ga5SiO14 crystals. Structural peculiarties and desorderness of La1−xNdx)3Ga5SiO14 crystals are considered. Crystal optics of La3Ga5SiO14 – linear dichroism and dispersion of refractive indexes (by a modified prism method), optical activity, and other optical characteristics are investigated. A comparison is made of some optical properties of La3Ga5SiO14 crystals and crystalline SiO2.
TL;DR: From the data presented it can be said that a mackerel diet exerts a beneficial influence on cardiovascular risk.
TL;DR: In this article, the influence of surface forces on deformation and the mutual adhesion of two elastic spherical particles of different natures and dimensions have been theoretically considered and the limits of applicability of each of the two existing asymptotical descriptions of the influence on the elastic contact of two spheres have been ascertained.
TL;DR: In this article, a method for determining the charge carrier concentration and mobility in n-GaP by Raman spectroscopy of coupled plasmon-phonon modes is presented.
Abstract: A method is presented which allows the determination of the charge carrier concentration and mobility in n-GaP by Raman spectroscopy of coupled plasmon-phonon modes. The results are compared with those of electrical measurements.
TL;DR: The three-dimensional structure analysis of crystalline fungal catalase from Penicillium vitale has been extended to 2.0 A resolution and the amino acid sequence has been tentatively determined by computer graphics model building and comparison with the known sequence of beef liver catal enzyme.
TL;DR: In this article, the authors considered a model system of one-dimensional identical hard rods interacting through elastic collisions and gave a rigorous deduction of the "hydrodynamic" equation which holds in the hydrodynamic limit.
Abstract: We give here a rigorous deduction of the “hydrodynamic” equation which holds in the hydrodynamic limit, for a model system of one-dimensional identical hard rods interacting through elastic collisions. The equation should be considered as the analog of the Euler equation of real hydrodynamics. Owing to the degeneracy of the model, it is written in terms of a functiong(q, v, t) expressing the density of particles with velocityv at the pointq at timet. For this equation we prove an existence and uniqueness theorem in some natural class of functions. Our main result is the proof that if {∈, ∈ >0} is a class of initial states which are homogeneous on a scale much less than e−1, and if the corresponding particle densities tend, ase→0, in the proper scale, to the initial hydrodynamic densityg
o
(q,v), then, under some general assumptions on the states ∈− and ong
0, the particle densities of the evolved states at timee
−1
t, tend ase→0 to the unique solution of the hydrodynamic equation with initial conditiong
0. The proof is completed by exhibiting a large class of initial families {∈, ∈ >0} which possess the required properties.
TL;DR: In this article, the authors derived the equation of motion of a thin-wall vacuum shell at arbitrary values of the vacuum parameters inside and outside the shell, and showed that the velocity of the walls of the true vacuum bubble at its expansion does not tend to the velocities of light.
TL;DR: The use of a double-grating monochromator in the lidar for isolating two portions of the pure rotational Raman spectrum (PRRS) of N2 and O2 and suppressing the line of aerosol light scattering is experimentally shown to be very efficient.
Abstract: A Raman lidar technique for measuring atmospheric temperature using pure rotational Raman spectra of N2 and O2 is discussed in detail. The use of a double-grating monochromator in the lidar for isolating two portions of the pure rotational Raman spectrum (PRRS) of N2 and O2 and suppressing the line of aerosol light scattering is experimentally shown to be very efficient. The feasibility of the method is convincingly illustrated by the results of laboratory experiments, as well as with measurements of air temperature carried out in the atmosphere. The accuracy of temperature measurements using the ratio of intensities of two portions of PRRS of N2 and O2 was ∼±0.74 K in laboratory experiments. The accuracy of the atmospheric temperature profile measurements using the lidar varied from 0.8 K at altitudes up to 300–400 mto, and slightly exceeded, ±1.5 K at 1-km height. Lidar temperature data are in good agreement with radiosonde data.
TL;DR: The crystal structures of five microbial ribonucleases have been determined in the last 2 years and they have been compared by the laboratories concerned in a collaborative exercise to identify the prokaryotic and eukaryotic enzymes.
TL;DR: The general interpretation of these phenomena is proposed, based on the representation of the potential-dependent appearance in the membrane of pores, the development of which is promoted by an electric field.
TL;DR: In this article, two independent methods for determining the surface area of micropore walls of carbonaceous adsorbents have been proposed and their satisfactory agreement has been substantiated experimentally.
TL;DR: In this article, the formation and stability of a cavity in a liquid around the zone of contact between lyophobic particles has been carried out and the parameters of the cavity have been calculated.