脉冲中立型时滞抛物方程的振动性

本文研究了一类脉冲中立型时滞抛物方程解的振动性及强振动性,获得了此类脉冲中立型时滞抛物方程解振动和强振动的代数判据.     

Duration-Dependent Asymmetry in Photoionization of H atoms in Few-Cycle Laser Pulses

The photoionization of H atoms irradiated by few-cycle laser pulses is studied numerically. The variations of the total ionization, the partial ionizations in opposite directions, and the corresponding asymmetry with the carrier-envelope phase in several pulse durations are obtained. We find that besides a stronger modulation on the partial ionizations, the change of pulse duration leads to a shift along carrier-envelope （CE） phase in the calculated signals. The phase shift arises from the nonlinear property of ionization and relates closely to the Coulomb attraction of the parent ion to the ionized electron. Our calculations show good agreement with the experimental observation under similar conditions.     

基于SPA的双枝模糊决策分析

将集对理论(SPA)与双枝模糊决策理论相结合,用集对分析的方法研究进行双枝模糊决策的方法,分别对双枝模糊决策因素域和双枝模糊决策的上枝、下枝和双枝进行了集对分析,给出了用SPA进行双枝模糊决策的性质,同时讨论了双枝模糊决策的动态分析方法,以及双枝模糊决策度强弱态势预测的方法,从而为双枝模糊决策理论的研究提供了新的视角和方法,为双枝模糊决策的应用提供了更方便的工具和更强的理论支持。     

养殖池塘沉积物的重金属分布及污染特征

浙江省淅西北地区淡水养殖池塘沉积物重金属调查研究表明，养殖池塘沉积物中7种重金属元素分布不均衡，差异也较大，除Hg和Cr元素外，其余重金属元素已大大超过土壤本底值．虽然其实测含量都未超出国家规定的标准值范围，但沉积物中重金属元素对养殖水环境、养殖品种存在的潜在污染与危害值得关注．污染指数评价显示，养殖池塘沉积物中主要污染物质为Cu和Cr，而Hg、Pb污染程度相对较轻．     

矩阵特征值的几个不等式

研究矩阵特征值的上、下界以及特征值的实部、虚部的不等式 ,给出了特征值一些新的上界和下界     

Banach空间二阶周期边值问题解的存在性

利用一些比较结果，讨论了Banach空间中二阶周期边值问题解的存在性，获得了若干解的存在性与唯一性结果。     

关于态射的Drazin逆

给出了态射的Drazin逆存在的条件及显式表达式，改进并推广了[1]、[2]与[3]中的一些主要定理。     

生物分子拉曼散射测定过程中荧光背景的抑制

拉曼共焦技术、表面拉曼增强技术以及降低入射激光强度的方法，被运用于SOD、DNA等生物分子拉曼散身实验中，以抑制其荧光背景，改善光谱质量。     

On the coupled NBEM and FEM for a class of nonlinear exterior Dirichlet problem in R 2

In this paper, based on the natural boundary reduction advanced by Feng and Yu, we couple the finite element approach with the natural boundary element method to study the weak solvability and Galerkin approximation of a class of nonlinear exterior boundary value problems. The analysis is mainly based on the variational formulation with constraints. We prove the error estimate of the finite element solution and obtain the asymptotic rate of convergence. Finally, we also give a numerical example.

     

Microwave-assisted Regioselective 1-O-Deacylation of Peracylated Glycopyranoses on Alumina

A facile, rapid and regioselective method for the 1-O-deacylation of peracylated glycopyranoses is described which occurs under mild conditions by absorption onto alumina using microwave irradiation.