基于微分变分不等式的多商品流网络动态模型

针对由多个制造商和多个零售商构成并且具有多商品流的供应链网络,建立了制造商、零售商之间从事微分Nash博弈的供应链网络动态模型.首先,在介绍微分变分不等式定义的基础上,利用微分变分不等式的方法建立了制造商、零售商以及供应链网络的均衡条件.然后,在正则条件下分析了供应链网络动态模型解的存在性条件.最后,利用数值算例验证了模型的合理性.     

The elementary symmetric functions of a reciprocal polynomial sequence

Erdös and Niven proved in 1946 that for any positive integers m and d, there are at most finitely many integers n   for which at least one of the elementary symmetric functions of 1/m,1/(m+d),…,1/(m+(n−1)d)$1/m,1/(m+d),\dots ,1/(m+(n-1)d)$ are integers. Recently, Wang and Hong refined this result by showing that if n?4$n?4$, then none of the elementary symmetric functions of 1/m,1/(m+d),…,1/(m+(n−1)d)$1/m,1/(m+d),\dots ,1/(m+(n-1)d)$ is an integer for any positive integers m and d. Let f   be a polynomial of degree at least 2 and of nonnegative integer coefficients. In this paper, we show that none of the elementary symmetric functions of 1/f(1),1/f(2),…,1/f(n)$1/f(1),1/f(2),\dots ,1/f(n)$ is an integer except for f(x)=x^m$f(x)=x^m$ with m?2$m?2$ being an integer and n=1$n=1$.     

Modification of nano-fibriform silica by dimethyldichlorosilane

The modification of nano-fibriform silica by dimethyldichlorosilane was studied by transmission electron microscopy, X-ray powder diffraction, infrared spectroscopy, Raman spectroscopy, physical N₂ adsorption techniques, differential thermal and thermogravimetric analysis, scanning electron microscopy, and elemental analyzer.The results show that dimethyl silane derivatives have been successfully covalently grafted on nano-fibriform silica. The polarity of the modified product decreases with the substitution of -OH groups by siloxyl groups. Therefore, the modified product can be easily dispersed in organic solvent and its compatibility with organic molecules is improved. After modification the pore volume decreases and the ductility greatly increases, indicating that the modified product is of a higher strength than before. The study demonstrates that the modified product can be used as an ideal additive to reinforce the strength of organic materials.     

The comparative pharmacokinetics of four bioactive ingredients after administration of Ramulus Cinnamomi–Radix Glycyrrhizae herb pair extract,Ramulus Cinnamomi extract and Radix Glycyrrhizae extract

Ramulus Cinnamomi (RC)–Radix Glycyrrhizae (RG) is a classic herb pair, which is commonly used as a fixed form to treat cardiovascular disease in the clinic. Our work aimed to compare the pharmacokinetic difference of cinnamic acid, liquiritin, isoliquiritigenin and glycyrrhetinic acid in rats after oral administration of the RC–RG herb pair extracts [Guizhigancao Decoction (GGD) and Lingguizhugan Decoction (LGZGD)] and the single RC or RG extract. A HPLC‐MS method was developed and validated to study comparative pharmacokinetics. The pharmacokinetic parameters (C_max, AUC, MRT) of four compounds between the RC–RG herb pair group and the single herb (RC or RG) group showed significant differences (p < 0.05). Compared with the single herb (RC or RG) group, higher peak concentration, slower elimination and larger exposure could be observed after giving the RC–RG herb‐pair extracts. The pharmacokinetic differences might indicate the relativity of remedy in the RC–RG herb pair and provide scientific information for rational administration of the drug in the clinic. Copyright © 2016 John Wiley & Sons, Ltd.