VIBRATIONAL SPECTRA AND NORMAL COORDINATE ANALYSIS OF 1,2-BIS(2-FORMYLGLYCINEBENZENESULFENYL) ETHANE Pd(II) DICHLORIDE COMPLEX

The normal coordinate analysis of the title complex, 1,2-bis(2-formylglycinebenzenesulfenyl) ethane Pd(II) dichloride has been carried out by using the Urey-Bradley force field. According to the molecular structure determined by x-ray crystallographic analysis, 182 internal coordinates were established and 112 theoretical vibration frequencies agree well with the observed values with the average difference of 2.53 cm^?1 and the maximum deviation of 16.0 cm^?1.     

Two‐dimensional modeling for stability analysis of two‐phase stratified flow

The effect of wavelength and relative velocity on the disturbed interface of two‐phase stratified regime is modeled and discussed. To analyze the stability, a small perturbation is imposed on the interface. Growth or decline of the disturbed wave, relative velocity, and surface tension with respect to time will be discussed numerically. Newly developed scheme applied to a two‐dimensional flow field and the governing Navier–Stokes equations in laminar regime are solved. Finite volume method together with non‐staggered curvilinear grid is a very effective approach to capture interface shape with time. Because of the interface shape, for any time advancement, a new grid is performed separately on each stratified field, liquid, and gas regime. The results are compared with the analytical characteristics method and one‐dimensional modeling. This comparison shows that solving the momentum equation including viscosity term leads to physically more realistic results. In addition, the newly developed method is capable of predicting two‐phase stratified flow behavior more precisely than one‐dimensional modeling. It was perceived that the surface tension has an inevitable role in dissipation of interface instability and convergence of the two‐phase flow model. Copyright © 2009 John Wiley & Sons, Ltd.     

Design of electromagnetic cloaks and concentrators using form-invariant coordinate transformations of Maxwell’s equations

The technique of applying form-invariant, spatial coordinate transformations of Maxwell’s equations can facilitate the design of structures with unique electromagnetic or optical functionality. Here, we illustrate the transformation-optical approach in the designs of a square electromagnetic cloak and an omni-directional electromagnetic field concentrator. The transformation equations are described and the functionality of the devices is numerically confirmed by two-dimensional finite element simulations. The two devices presented demonstrate that the transformation optic approach leads to the specification of complex, anisotropic and inhomogeneous materials with well directed and distinct electromagnetic behavior.     

单站被动式跟踪新算法研究

在以Ｋａｌｍａｎ滤波为基础的各种被动式跟踪算法中，一直存在初值敏感性难题，由于实际系统中初值往往难以较精确给出，导致滤波器的发散，本文给出了修正的极坐标系下的推广卡尔曼滤波算法，Ｍｏｎｔｅ Ｃａｒｌｏ仿真表明该算法对初值选取不敏感，具有推广应用价值。     

Asymptotic behavior of continuous stochastic games

Summary The aim of this paper is to analyze the asymptotic behavior of the value functions of a continuous stochastic game as the number of stages grows to infinity or the discount factor approaches 1. After the setup of the problem we prove that, in both cases, the extrema of the value functions converge to the same limits. The convergence of the value functions is then obtained from the unicity of the solution of a functional problem and it is thus possible to design hypotheses that assure the convergence to a constant. This allows to assign a value to an undiscounted infinite-stage stochastic game in several senses and to show that optimal strategies are available for both players. Furthermore the boundedness of the remainders of the value function after removing the principal terms is analyzed, with appropriate hypotheses, and related to the existence of solutions of a Howard's type functional equation. This allows to show that for an infinite-stage undiscounted stochastic game optimal stationary strategies exist at least if this functional equation has some solution.     

Stationary phases for gas chromatography; chemical stability of polysiloxanes

A number of polysiloxanes have been shown to be sensitive to acids when dissolved in chloroform. At 26O°C polysiloxanes were found to degrade under the influence of several compounds used or produced during the preparation of glass capillary columns.     

Conditions for the convergence in distribution of maxima of stationary normal processes

The asymptotic distribution of the maximum M_n=max_1?t?nξ_t in a stationary normal sequence ξ₁,ξ,… depends on the correlation r_t between ξ₀ and ξ_t. It is well known that if r_t log t → 0 as t → ∞ or if Σr²_t<∞, then the limiting distribution is the same as for a sequence of independent normal variables. Here it is shown that this also follows from a weaker condition, which only puts a restriction on the number of t-values for which rt log t islarge. The condition gives some insight into what is essential for this asymptotic behaviour of maxima. Similar results are obtained for a stationary normal process in continuous time.     

Electronic and vibrational properties of fluorenone in the channels of zeolite L

Fluorenone (C13H8O) was inserted into the channels of zeolite L by using gas-phase adsorption. The size, structure, and stability of fluorenone are well suited for studying host-guest interactions. The Fourier transform IR, Raman, luminescence, and excitation spectra, in addition to thermal analysis data, of fluorenone in solution and fluorenone/zeolite L are reported. Normal coordinate analysis of fluorenone was performed, based on which IR and Raman bands were assigned, and an experimental force field was determined. The vibrational spectra can be used for nondestructive quantitative analysis by comparing a characteristic dye band with a zeolite band that has been chosen as the internal standard. Molecular orbital calculations were performed to gain a better understanding of the electronic structure of the system and to support the interpretation of the electronic absorption and luminescence spectra. Fluorenone shows unusual luminescence behavior in that it emits from two states. The relative intensity of these two bands depends strongly on the environment and changes unexpectedly in response to temperature. In fluorenone/zeolite L, the intensity of the 300 nm band (lifetime 9 micros) increases with decreasing temperature, while the opposite is true for the 400 nm band (lifetime 115 micros). A model of the host-guest interaction is derived from the experimental results and calculations: the dye molecule sits close to the channel walls with the carbonyl group pointing to an Al3+ site of the zeolite framework. A secondary interaction was observed between the fluorenone's aromatic ring and the zeolite's charge-compensating cations.     

Part I. Chromatography using ultra-stable metal oxide-based stationary phases for HPLC

The first part of the review contrasts the main drawbacks of silica-based packings such as their relative thermal and chemical instability with excellent stability of metal oxides. The paper concerns mainly ZrO2, TiO2 and Al2O3. Methods of preparation of spherical particles for HPLC are described. Surface chemistry of the oxides is, however, very different from that of silica. Ability of the oxides to ion- and ligand exchange is discussed from a chromatographic point of view.     

Generic compactness reformulated

We point out a connection between reflection principles and generic large cardinals. One principle of pure reflection is introduced that is as strong as generic supercompactness of ₂ by -closed forcing. This new concept implies CH and extends the reflection principles for stationary sets in a canonical way.Mathematics Subject Classification (2000): 03E50, 03E55