On the problem of renewal of a Poisson field on a plane

We perform the renewal of a Poisson field at a point on the basis of its values generated by a monotonically increasing curve. We obtain the best mean-square estimate and its error. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 9, pp. 1272–1277, September, 1998.     

Approximation of solutions of operator-differential equations by operator polynomials

We prove theorems that characterize the classes of functions whose best approximations by algebraic polynomials tend to zero with given order. We construct approximations of solutions of operator-differential equations by polynomials in the inverse operator. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 11, pp. 1506–1516, November, 1998.     

The contact problem of electroelasticity for a plane elliptic die

We obtain an exact solution of the problem of the stress-strain state of an elastic piezoelectric half-space acted on by a rigid elliptic die with a flat base. The axis of symmetry of the body coincides with the direction of the field of preliminary polarization of the body. The solution is confined to the case of translational displacement of the die. We determine the quantities that characterize the mechanical and electric fields that arise in the region of contact of the die with the half-space. Bibliography: 7 titles. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 28, 1998, pp. 40–52.     

Asymptotic behavior of neutron small-angle multiple scattering spectra

The asymptotic behavior of the spectra for large values of the scattering vector for the case of elastic multiple small-angle neutron scattering (SANS) is investigated theoretically and experimentally. An expansion of the spectrum in terms of the reciprocal of the magnitude of the momentum transfer is obtained taking account of the influence of the instrumental line. It is shown that, to within some factor, the leading term of the expansion is identical to the differential single-scattering cross section averaged over a statistical ensemble of particles; several subsequent terms in the expansion are calculated and the range of applicability of the resulting expressions is determined. The asymptotic behavior of the multiple SANS spectrum is measured, using a two-crystal neutron spectrometer, for samples of an HTSC ceramic, the alloy Fe-Ni, and Al powder. The agreement between the experimental results and the theoretical predictions is analyzed. Zh. éksp. Teor. Fiz. 114, 2194–2203 (December 1998)     

Anisotropy of cubic semimagnetic Cd1−x MnxTe solid solutions and excitonic magnetic polaron energy from polarized-luminescence measurements

Polarized photoluminescence of Cd_1−x Mn_xTe crystals in a weak magnetic field has been studied in Faraday and Voigt geometries. A simple method is proposed to determine the exciton mobility edge and excitonic magnetic-polaron energy. “Forbidden” polarization components of the recombination radiation have been experimentally detected. It has been established that the moments of magnetic polarons are oriented predominantly along the {111} axes. Fiz. Tverd. Tela (St. Petersburg) 40, 894–896 (May 1998)     

二氯和邻菲罗啉二酮的镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)配合物的合成与表征

以ＭＣｌ２和配体Ｌ（Ｌ＝１，１０－菲罗啉－５，６－二酮）为原料，合成了标题配合物ＭＬＣｌ２，Ｍ＝ＮｉⅡ，ＣｕⅡ，ＺｎⅡ，并经元素分析、热谱、ＩＲ和摩尔电导表征．三者均为四配位的电中性配合物，热稳定性高于５００Ｋ，易溶于ＤＭＦ、ＤＭＳＯ和吡啶，可溶于乙腈和水．它们在ＤＭＦ中于３５０ｎｍ和３１５ｎｍ附近显示出强的Ｍ－Ｌ荷移跃迁     

Distinctive features of time-resolved photoluminescence of porous silicon coated with a layer of diamondlike carbon

Time-resolved photoluminescence from porous silicon coated with a diamondlike carbon film is investigated. The intensity of the photoluminescence from the carbon film is obserd to increase after deposition, and there is an accompanying change in the intensity and a shortwavelength shift of the photoluminescence band of porous silicon that depends on the porosity of its original layers. These changes are explained by the formation of carbon nanoclusters on the surface of the silicon filaments. Zh. Tekh. Fiz. 68, 83–87 (April 1998)     

Structure of the attraction zones of the final states in the presence of dynamical period doubling bifurcations

The structure of the attraction zones of the final states associated with dynamical period doubling bifurcations is investigated. It is found that on the “initial value—transition rate” plane the attraction zones of the two possible final states alternate with each other and that a subdivision of the attraction regions occurs with a decrease in the transition rate. It is shown that the boundaries of the attraction zones are smeared out because of the effect of noise and in this situation the fine structure of the attraction zones is destroyed. As analytical and numerical calculations have shown, the critical value of the noise variance, corresponding to the boundary between the dynamical (or predictable) and stochastic (or unpredictable) modes, has a power-law dependence on the transition rate with a typical exponent value of one. The existence of “noise” invariants is also observed: the integrated (over all initial values) probability of achieving the final state is invariant with respect to the noise level. Zh. éksp. Teor. Fiz. 113, 369–380 (January 1998)