FINITE ELEMENT SIMULATIONS FOR COMPRESSIBLE MISCIBLE DISPLACEMENT WITH MOLECULAR DISPERSION IN POROUS MEDIA

Abstract. We consider a nonlinear parabolic system describing compressible miscible displacement in a porous medium [5]. Continuous time and discrete time Galerkinmethods are introduced to approximate the solution snd optimal H1 error estimatesare obtained. One contribution of this paper is a demonstration of how moleculaxdispersion can be handled.     

Phase-dependent properties for absorption and dispersion in a closed equispaced three-level ladder system

It is shown that in a closed equispaced three-level ladder system, by controlling the relative phase of two applied coherent fields, the conversion from absorption with inversion to lasing without inversion (LWI) can be realized; a large index of the refraction with zero absorption can be gotten; considerable increasing of the spectrum region and value of the LWI gain can be achieved. Our study also reveals that the incoherent pumping will produce a remarkable effect on the phase-dependent properties of the system. Modifying value of the incoherent pumping can change the property of the system from absorption to amplification and enhance significantly LWI gain. If the incoherent pumping is absent, we cannot get any gain for any value of the relative phase.     

平面n次微分系统高次奇点的拓扑结构

本文讨论了平面n次微分系统高次奇点的拓扑结构,并给出了按右端多项式系数的判断准则.     

含有非线性半群的非凸值泛函微分包含

本文研究Banach空间中含有非线性半群的非凸值泛函微分包含，证明了积分解的存在性，得到一个新的存在性定理．     

Strong red fluorescent probes suitable for detecting hydrogen peroxide generated by mice peritoneal macrophages

This paper reports the synthesis, fluorescence properties, and biological applications of naphthofluorescein disulfonate (NFDS-1), as a red fluorescence imaging probe to detect intracellular H2O2.     

一类齐三次系统的全局结构

本文讨论了一类齐三次系统的全局结构，并给出了它们的系数条件．     

Spectrofluorimetric determination of trace amount of coenzyme II using ciprofloxacin-terbium complex as a fluorescent probe

A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using terbium ion (Tb³⁺)-ciprofloxacin (CIP) complex as a fluorescent probe, in the buffer solution of pH=9.00, NADP can remarkably enhance the fluorescence intensity of the Tb³⁺-CIP complex at and the enhanced fluorescence intensity of Tb³⁺ ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.9×10⁻⁷−3.7×10⁻⁶ mol L⁻¹ with detection limit of 1.3×10⁻⁷ mol L⁻¹. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Tb³⁺-CIP system and the Tb³⁺-CIP-NADP system have been also discussed.     

Positive solution of three-point boundary value problem for the one-dimensional p-Laplacian with singularities

In the paper, we deal with positive solutions of the following nonlinear three-point singular boundary value problem with a p-Laplacian operator:

     

Highly sensitive spectrofluorimetric determination of trace amounts of lecithin

A new spectrofluorimetric method was developed for the determination of trace amounts of lecithin using the ciprofloxacin (CIP)–terbium (Tb³⁺) ion complex as a fluorescent probe. In a buffer solution at pH=5.60, lecithin can remarkably reduce the fluorescence intensity of the CIP–Tb³⁺ complex at λ=545 nm. The reduced fluorescence intensity of the Tb³⁺ ion is proportional to the concentration of lecithin. Optimum conditions for the determination of lecithin were also investigated. The linear range and detection limit for the determination of lecithin were 1.0×10⁻⁶–3.0×10⁻⁵ mol L⁻¹ and 3.44×10⁻⁷ mol L⁻¹, respectively. This method is simple, practical, and relatively free of interference from coexisting substances. Furthermore, it has been successfully applied to assess lecithin in serum samples.      

Determination of volatile residual solvents in pharmaceutical products by headspace liquid-phase microextraction gas chromatography-flame ionization detector

This paper demonstrates headspace liquid-phase microextraction (HS-LPME) as used for the determination of volatile residual solvents in pharmaceutical products. This method is based on headspace liquid-phase microextraction capillary column gas chromatography. Under optimum conditions, the linerary of the method ranged from 1 to 1,000 mg l⁻¹. The limits of detection are 0.2–2.0 mg l⁻¹ and relative standard deviations (RSD) for most of the volatile solvents were below 10%. This novel method is applied to the analysis of volatile residual solvents in pharmaceutical products with satisfactory results.