Classical Limit of Expectation Values in a Wave Packet Involving Few Stationary States

Expectation values of physical quantities in a wave packet involving few stationary states in an infinite square well are calculated. Explicit results show that the expectation values in the classical limit go over to the corresponding classical quantity in the form of the arithmetic mean (in mathematical term, the Fejér's average) of the partial Fourier series converging to the classical quantity. The number of the stationary states is that of the partial Fourer series in the Fejér's average. The quantum uncertainty is then demonstrated to have a classical counterpart.     

Role of Na(+)-Ca2+ exchange system in the pathogenesis of myocardial ischemia-reperfusion damage

Results from a systematic experiment on isolated perfused rat heart and isolated myocytes of adult rat showed that the mechanism of calcium influx during myocardial ischemia-reperfusion is due to the development of intracellular sodium overload during ischemic period; on reperfusion, the high intracellular Na+ content activated the reverse direction of Na(+)-Ca2+ exchange over myocardial sarcolemma (SL), thus a large quantity of extracellular Ca2+ fluxed over the SL to the intracellular space, forming a condition of intracellular Ca2+ overload, which leads to irreversible damage of the myocardium.     

Compensated Compactness, Paracommutators, and Hardy Spaces

LetB₁: ⁿ× ^N₁→ ^m₁,B₂: ⁿ× ^N₂→ ^m₂andQ: ^m₂→ ^m₁be bilinear forms which are related as follows: ifμandνsatisfyB₁(ξ, μ)=0 andB₂(ξ, ν)=0 for someξ≠0, thenμ^τQν=0. Supposep⁻¹+q⁻¹=1. Coifman, Lions, Meyer and Semmes proved that, ifuL^p( ⁿ) andvL^q( ⁿ), and the first order systemsB₁(D, u)=0,B₂(D, v)=0 hold, thenu^τQvbelongs to the Hardy spaceH¹( ⁿ), provided that both (i)p=q=2, and (ii) the ranks of the linear mapsB_j(ξ, ·) : ^N_j→ ^m₁are constant. We apply the theory of paracommutators to show that this result remains valid when only one of the hypotheses (i), (ii) is postulated. The removal of the constant-rank condition whenp=q=2 involves the use of a deep result of Lojasiewicz from singularity theory.     

Modifications of the Wolfe Line Search Rules to Satisfy Second-Order Optimally Conditions in Unconstrained Optimization

The line search method incorporating the Wolfe conditions is modified to ensure that a descent algorithm terminates in a finite number of steps at an approximate stationary point where the second-order conditions of optimality are satisfied. A simple procedure based on conjugate directions is proposed to determine directions of negative curvature.     

Angular momentum effect in prescission particle multiplicities for a light system by diffusion model

The effect of angular momentum on the competition between fission and particle emission during light system fission process was studied via fission diffusion model. The prescission particle multiplicities were found to increase with decreasing angular momentum. The experimental prescission proton and α particle multiplicities can be fitted for 10.6 MeV/nucleon ⁸⁴Kr(²⁷Al,binary fission) reaction with this model. Entrance channel effect found in [1] is proved to be angular momentum effect.     

The influence of crystalline grain size on the thermal stability of the Er<Subscript>0.45</Subscript>Ho<Subscript>0.55</Subscript>Fe<Subscript>2</Subscript> compound

The phase composition and the temperature dependence of the magnetization of the Er_0.45Ho_0.55Fe₂ compound in coarse-grained, microcrystalline, and submicrocrystalline states are investigated experimentally. It is found that, upon heating under vacuum, the Er_0.45Ho_0.55Fe₂ microcrystalline powder with a crystalline grain size of ∼1 μm undergoes decomposition into pure iron and rare-earth (erbium and holmium) oxides and nitrides at a temperature of 500 K. The changes observed in the phase composition of the microcrystalline powder due to annealing are confirmed by x-ray diffraction analysis. Heating of the Er_0.45Ho_0.55Fe₂ submicrocrystalline sample leads to a partial change in the phase composition. The phase composition of a large crystal (∼1 mm in size) remains unchanged upon heating to 1080 K. It is shown that the thermal stability of the Er_0.45Ho_0.55Fe₂ compound depends on the crystalline grain size. __________ Translated from Fizika Tverdogo Tela, Vol. 44, No. 6, 2002, pp. 1060–1063. Original Russian Text Copyright ? 2002 by Mulyukov, Sharipov, Korznikova.     

Optical quenching of the magnetoplastic effect in NaCl crystals

Observations indicate that illuminating NaCl crystals by ultraviolet light (λ=350 nm) suppresses the magnetoplastic effect. The processes induced by illumination take place in a subsystem of point defects and are related to a change in the state of magnetically sensitive dislocation pinning sites. Fiz. Tverd. Tela (St. Petersburg) 39, 1389–1391 (1996)     

Two- and three-dimensional analysis of bose-einstein correlations inπ +/K+p interactions at 250 GeV/c

The NA22 data onπ ^? π ^? correlations are analyzed in terms of a number of two- and three-dimensional parametrizations (Gaussian space-time, Goldhaber, Bowler string-like, Bertsch hydrodynamical, Kopylov-Podgoretskii, etc.). Contrary to the results obtained for e⁺e^? andµp collisions, the Goldhaber parametrization, as well as string-like models, fail in describing the hadron-hadron data. Better fits are obtained in the framework of surface-emitting fireball-like models, both when including and excluding hydrodynamical expansion of nuclear matter. Our results indicate that pion radiation occurs at earlier stages of matter evolution than in nuclear collisions.     

Numerical convergence study of the orthogonalized multi-channels approach to three-body Coulomb scattering below breakup threshold

The three-body Coulomb problem for nuclear clusters is solved numerically for a model below three-body breakup threshold. An orthogonalized multi-channels method is employed. The method allows to check for convergence by considering the norm square of the closed-channels part of the wave function. The numerical results show that convergence can well be achieved on present-day computers.