Higher order symmetrizer and application to an unusual transport equation

We study a class of stationary transport equation with nonlocal low-order tems We obtain the existence and uniqueness of a solution in sobolev spaces     

求解复杂湍流的非线性涡黏性系数模型和代数应力模型

非线性涡黏性系数模型和代数应力模型联系了线性涡黏性系数湍流模型和完整的微分 雷诺应力模型.随着它们受到日益关注,其形式也越来越多样化.本篇综述的目的是对这些模 型加以总结并比较它们之间的共同点及不同之处,指出它们与完整微分雷诺应力模型之间的 关系,以及相对于线性涡黏性系数模型而言它们在预报流场上所具有的优势.     

An Image Processing Problem for Computer-Synthesized Full-Color Holograms

The article considers relief computation for computer-synthesized holograms creating full-color images. The propagation of radiation from the optical element to the focal plane is described by scalar wave theory and is considered both in the long-focus approximation and in the geometrical optics approximation. The phase function specifying the optical element is from the set of admissible phase functions defined by purely technological constraints. A composite phase element is constructed in the geometrical optics approximation. The algorithms rely on numerical solution of the inverse problem in the long-focus approximation and on the analytical form of the phase function in the geometrical optics approximation. The optical elements generated by the proposed procedure have been manufactured by electron-beam lithography. Their comparison has shown that the composite phase element is much more efficient. Translated from Prikladnaya Matematika i Informatika, No. 3, pp. 65–70, 1999.     

Diffraction of a shear plane wave in a compound elastic space with a half-infinite crack parallel to the inhomogeneity line

Problems of stress wave propagation and diffraction in elastic inhomogeneous media are undoubtedly of interest to scientists from the viewpoint of investigation of fundamental laws of dynamic processes and of the use of the results in technical and technological applications. The paper deals with the dynamic contact problem of shear plane wave diffraction at the edge of a semi-infinite crack in a compound space consisting of two elastic half-spaces. The questions related to the onset of surface waves and the wave field behavior in far-field regions are also considered.     

Experimental evidence for crossover to mean-field tricritical behavior in a concentrated salt solution

We have discovered a mean-field multicritical point on the critical locus in an aqueous solution of 3-methylpyridine and sodium bromide. Light-scattering measurements indicate Ising-like asymptotic critical behavior at the lower salt concentrations. However, the temperature range of Ising critical behavior shrinks with increasing salt concentration and the critical behavior becomes mean-field-like at a concentration of about 17% mass fraction of NaBr. Emergence of a new characteristic length scale diverging at this point and a simultaneous pronounced increase in the background scattering suggests mean-field tricritical behavior associated with the formation of a microheterogeneous phase due to clustering of ions and molecules.     

Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry

Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd.