Showing papers by "Moscow State University published in 1981"

Liquid-crystalline ordering in the solution of long persistent chains

Abstract: The orientational ordering in the solution of long persistent macromolecules is studied by means of the Onsager method. It is shown that the liquid-crystalline transition occurs at significantly higher concentrations and that the order parameter at the transition point is much smaller than for the model of freely-jointed segments. It is concluded that the orientational ordering in the solutions of semiflexible chains depends essentially on the flexibility distribution along the chain contour.

The local structure of the spectrum of the one-dimensional Schrödinger operator

Abstract: Let $$H_V = - \frac{{d^{\text{2}} }}{{dt^{\text{2}} }} + q(t,\omega )$$ be an one-dimensional random Schrodinger operator in ℒ2(−V,V) with the classical boundary conditions. The random potentialq(t, ω) has a formq(t, ω)=F(x t ), wherex t is a Brownian motion on the compact Riemannian manifoldK andF:K→R 1 is a smooth Morse function, $$\mathop {\min }\limits_K F = 0$$ . Let $$N_V (\Delta ) = \sum\limits_{Ei(V) \in \Delta } 1 $$ , where Δ∈(0, ∞),E i (V) are the eigenvalues ofH V . The main result (Theorem 1) of this paper is the following. IfV→∞,E 0>0,k∈Z + anda>0 (a is a fixed constant) then $$P\left\{ {N_V \left( {E_0 - \frac{a}{{2V}},E_0 + \frac{a}{{2V}}} \right) = k} \right\}\xrightarrow[{V \to \infty }]{}e^{ - an(E_0 )} (an(E_0 ))^k |k!,$$ wheren(E 0) is a limit state density ofH V ,V→∞. This theorem mean that there is no repulsion between energy levels of the operatorH V ,V→∞. The second result (Theorem 2) describes the phenomen of the repulsion of the corresponding wave functions.

Radiation from relativistic particles in nongeodesic motion in a strong gravitational field

Abstract: The scalar and electromagnetic radiation emitted by relativistic particles moving along the stable nongeodesic trajectories in the Kerr gravitational field are described. Two particular models of the nongeodesic motion are developed involving a slightly charged rotating black hole and a rotating black hole immersed in an external magnetic field.

The Group With Grassmann Structure Uosp(1,2)

Abstract: The finite-dimensional representations of the Lie superalgebraosp(1.2) and the group with Grassmann structureOSP(1.2) have been studied. The explicit expression of the projection operator of the superalgebraosp(1.2) has been found. The operator permits an arbitrary finite-dimensional representation to be expanded in the components multiple to the irreducible ones. The Clebsch-Gordan coefficients for the tensor product of two arbitrary irreducible representations have been obtained. The matrix elements of the irreducible representations of the groupUOSP(1.2) [the analoque of the compact form of the groupOSP(1.2)] are studied. The explicit form of these matrix elements, the differential equations satisfied by them, and the integral of their product have been found.

The optical continuum of solar and stellar flares

Abstract: A further development of the Kostyuk-Pikelner's model is presented. The response of the chromosphere heated by non-thermal electrons of the power-law energy spectrum has been studied on the basis of the numerical solution of the one-dimensional time-dependent equations of gravitational gas dynamics. The ionization and energy loss for the emissions in the Lyman and Balmer lines have been determined separately for the optically thin and thick Lα-line layers. Due to the initial heating, a higher-pressure region is formed. From this region, disturbances propagate upwards (a shock wave with a velocity of more than 1000 km s-1) and downwards. A temperature jump propagates downwards, and a shock is formed in front of the thermal wave. During a period of several seconds after the beginning of this process, the temperature jump intensifies the downward shock wave and the large radiative loss gives rise to the high density jump (ϱ2/ϱ1 ∼ 100). The numerical solution has been analyzed in detail for the case heating of the ionized and neutral plasma, and a value of this heating is close to the upper limit of the admissible values. In this case, the condensation located between the temperature jump and the shock wave front, may emit in the observed optical continuum.

Quantum kinetic equations in systems with bound states

Abstract: Starting from the quantum mechanical BBGKY-hierarchy kinetic equations in systems with two particles bound states are given in this paper. With this equation it is possible to consider transport properties in nonideal gases with three particles reactions.

The effects of high‐intensity uv‐radiation on nucleic acids and their components—i. thymine

Abstract: — The set of final products of thymine conversion induced by high-intensity UV irradiation (λ= 266nm, intensity 1024-5 × 1029 photons·s−1·m−2, pulse duration 10ns) of the dilute aqueous solution to the first approximation is similar to that formed with ionizing irradiation (γ-irradiation of aqueous solution or autoradiolysis of a solid 2-[14C]-thymine). The data obtained suggest that high-intensity UV-induced photochemical conversion of thymine involves photoionization and/or photodissociation. These processes pass through the higher excited state(s) populated as a result of the second photon absorption by excited (most probably in the T1 triplet state) thymine molecules.

Peptide synthesis enzymatically catalyzed in a biphasic system: Water–water–immiscible organic solvent

Abstract: Synthesis of a peptide bond is suggested to be enzymatically catalysed in a biphasic system “water–water-immiscible organic solvent”. The pH dependence of the apparent equilibrium constant is studied for synthesis of N-acetyl-L-tryptophanyl-L-leucine amide from N-Acet-Trp andL-Leu-NH2. The reaction was performed in the biphasic system ethyl acetate plus water [from 2 to 2% (v/v)] in the presence of α-chymotrypsin. The suggested approach is preparative value: with the stoichiometric ratio of the reagents, [N-Acet-L-Trp] = [L-Leu-NH2] = 2 × 10−3M, the yield is practically 100% (in water, with other conditions being the same, the yield is not over 01.%).