Geometric and topological rigidity for compact submanifolds of odd dimension

We investigate rigidity problems for odd-dimensional compact submanifolds.We show that if Mn(n 5)is an odd-dimensional compact submanifold with parallel mean curvature in Sn+p,and if RicM(n-2-1n)(1+H2)and Hδn,whereδn is an explicit positive constant depending only on n,then M is a totally umbilical sphere.Here H is the mean curvature of M.Moreover,we prove that if Mn(n 5)is an odd-dimensional compact submanifold in the space form Fn+p(c)with c 0,and if RicM(n-2-εn)(c+H2),whereεn is an explicit positive constant depending only on n,then M is homeomorphic to a sphere.     

The hydrological response of heavy clay grassland soils to rainfall in south‐west England using δ2H

Stable isotopes of water have been previously used in catchment studies to separate rain‐event water from pre‐event groundwater. However, there are a lack of studies at the smaller scale looking at the separation of event water from pre‐event water. This is particularly relevant for heavy clay soil systems through which the movement of water is uncertain but is thought to be rainwater‐dominated. The data presented here were collected at a rural site in the south‐west of England. The historic rainfall at the site was isotopically varied but similar to the global meteoric water line, with annual weighted means of ?37‰ for δ²H and ?5.7‰ for δ¹⁸O and with no seasonal variation. Drainage was sampled from the inter‐flow (surface runoff + lateral through‐flow) and drain‐flow (55 cm deep mole drains) pathways of two 1 ha lysimeters during two rainfall events, which had δ²H values of ?68‰ and ?92‰, respectively. The δ²H values of the lysimeter drainage water suggest that there was no contribution of event water during the first, small discharge (Q) event; however, the second larger event did show isotopic variation in δ²H values negatively related to Q indicating that rainwater was contributing to Q. A hydrograph separation indicated that only 49–58% of the inter‐flow and 18–25% of the drain‐flow consisted of event water. This was surprising given that these soil types are considered retentive of soil water. More work is needed on heavy clay soils to understand better the nature of water movement from these systems. Copyright © 2010 John Wiley & Sons, Ltd.     

复合结构与流体耦合运动方程的时域分析方法

本文就复合结构与流体耦合的时域运动方程，利用核函数矩阵的特点，将二阶微分积分方程变形为Volterra型积分方程，然后引入积分变换，得到一组一阶常微分方程组，该微分方程组的形式与现代控制论中的状态方程类似。     

凸几何经典不等式的蕴含关系

该文指出了凸几何分析中几个具有较高应用价值的经典不等式之间的蕴涵关系.     

降低聚氯乙烯膜黄连素选择性电极检出限的新方法

PVC药物选择性电极的检出限主要是由膜中活性物质的溶解和内参比溶液中被测离子在膜中的迁移所决定的。为了减少这两种不利因素的影响 ,采用内参比为含可乐定的氯化钠溶液的可乐定选择性电极测定黄连素。测定的线性范围为 1.0× 10 - 4～ 1.0× 10 - 8mol L ,平均斜率为 5 8.6mV decade ;检出下限为 2 .5×10 - 9mol L ,比已报道的检出下限要低 2～ 3个数量级。电极的选择性明显提高 ,选择性系数的测定更加可靠真实 ,并获得良好的重现性和稳定性。以标准加入法测定回收率 ,结果令人满意。     

飞秒激光烧蚀石英玻璃的实验与理论研究

实验研究了800nm飞秒激光作用下石英玻璃的破坏机理和烧蚀规律，给出了破坏阈值与脉冲宽度的关系.发展了雪崩击穿模型，计算了材料的烧蚀阈值与脉冲宽度的依赖关系，烧蚀深度、烧蚀体积与脉冲能量的依赖关系，研究了导带电子的扩散对材料中激光能量的沉积、分布，以及材料的破坏阈值和烧蚀规律的影响. 关键词： 飞秒激光脉冲 破坏机理 石英玻璃 电子扩散     

正交共轭滤波器的构造

It is very importent for generating an orthonormal multiwavelet system to construct a conjugate quadrature filter(CQF). In this paper, a general method of deriving a length-L 1 conjugate quadrature filter from a length-L conjugate quadrature filter and vice versa is obtained. As a special case, we study generally the construction of any length-L 1 compactly supported symmetric-antisymmetric orthonormal multiwavelet system with multiplicity 2 from a length-L multiwavelet system and vice versa. Examples of conjugate quadrature filter are given.     

Generation of near transform-limited ultrashort laser pulses in kilohertz chirped-pulse amplification system by compensating high order phase distortions

The effects of gain narrowing and high order dispersions on the pulse duration in our kilohertz chirpedpulse amplification system have been compensated experimentally. Using an acousto-optic programmable dispersive filter (AOPDF), the spectral full-width at half-maximum (FWHM) is expanded from 30 to50 nm. Stable laser pulses with the duration of 30 fs (FWHM), which is 1.07 times Fourier-transformlimitation, have been acquired by pre-compensating the high order phase distortions using the phase measured by spectral phase interferometry for direct electric-field reconstruction (SPIDER).     

H4PMo11Vo40杂多酸及其镧盐的合成与性质

本文提出主要用~(51)V NMR、CV并辅以IR、XRD、DTG、元素分析等作为有效地核查纯度和表征催化剂的手段。