夹芯板结构局部压入力学响应研究

利用材料试验机(MTS)实验研究了复合材料面板、闭孔泡沫铝芯层夹芯板结构在准静态压入时的变形和破坏特征。实验结果表明,夹芯板的破坏主要集中在压头作用的局部区域内;同时,根据最小势能原理建立了泡沫铝夹芯板在半球形压头作用下的压入力学响应理论预测模型。通过引入无量纲参数分析了夹芯板压入载荷-位移响应,并在不同面板厚度、芯层厚度和芯层相对密度情况下,对夹芯板压入响应理论解的有效性和适用性进行了讨论。     

N-soliton solution of a coupled integrable dispersionless equation

<正>A new coupled integrable dispersionless equation is presented by considering a spectral problem.A Darboux transformation for the resulting coupled integrable dispersionless equation is constructed with the help of spectral problems.As an application,the N-soliton solution of the coupled integrable dispersionless equation is explicitly given.     

高温下轻质泡沫铝动态力学性能实验

对传统的分离式Hopkinson压杆装置加以改进,设计了一种长杆直接撞击Hopkinson杆的实验方案,检测出低波阻抗材料在高温动态加载下的应力均匀性。对轻质泡沫铝材料的实验表明,在同一撞击速度下,温度越高,试件两端的应力均匀性越差,增加温度与提高撞击速度均会导致泡沫铝材料冲击端与支撑端的应力不均匀性。根据高温下应力均匀性的实验结果,确定高温下试件均匀变形对应的冲击速度,再通过传统的分离式Hopkinson压杆实验得出泡沫铝在高温动态下的力学性能。     

非线性耦合微分方程组的精确解析解

提出了利用耦合的Riccati方程组的某些特解构造非线性微分方程组精确解析解的一种方法.应用这种方法研究了两个耦合的常微分方程组,系统地获得了它们的一些精确解.给出了非线性浅水波近似方程组和非线性Schr?dinger-KdV方程组若干新的孤波解. 关键词： 非线性耦合方程组 Riccati方程组 符号计算 孤波     

两个非线性方程的准确解

借助于计算机代数系统Ｍａｔｈｅｍａｔｉｃａ利用直接代数方法获得了两个有数学物理意义的非线性耗散－色散方程的准确解，这种方法也适用于高维非线性方程。     

New solitary wave solutions for nonlinear evolution equations

Three important nonlinear evolution equations are solved with the aid of the symbolic manipulation system.Maple,using the direct algebraic method proposed recently,We explicitly obtain several new solutions of physical interest in addition to rederiving all the known solutions.     

Adomian decomposition method and Padé approximants for solving the Blaszak--Marciniak lattice

The Adomian decomposition method （ADM） and Pade approximants are combined to solve the well-known Blaszak-Marciniak lattice, which has rich mathematical structures and many important applications in physics and mathematics. In some cases, the truncated series solution of ADM is adequate only in a small region when the exact solution is not reached. To overcome the drawback, the Pade approximants, which have the advantage in turning the polynomials approximation into a rational function, are applied to the series solution to improve the accuracy and enlarge the convergence domain. By using the ADM-Pade technique, the soliton solutions of the Blaszak-Marciniak lattice are constructed with better accuracy and better convergence than by using the ADM alone. Numerical and figurative illustrations show that it is a promising tool for solving nonlinear problems.     

Copyright protection in digital museum based on digital holography and discrete wavelet transform

A new method to protect the copyright of digital museum based on digital holography is proposed. The Fresnel hologram of watermark image is embedded in the object to be protected through discrete wavelet transform （DWT）. After the watermark detection, the copyright information appears in the reconstructed hologram. With the higher redundancy feature in the hologram, the proposed technique can actually survive several kinds of image processing. Experimental results prove that the presented method has good robustness in image protection.     

吸附氢气后的钯团簇在氧化亚铜表面上的稳定性研究

为了探究吸附H2后的Pdn团簇在Cu2O（111）完整表面和铜缺陷表面上的稳定性,计算了负载在Cu2O（111）完整表面和铜缺陷表面上的Pdn（n=1-4）对H2分子的最稳定吸附结构;利用在给定H2压力和温度下Pdn / Cu2O表面吸附H2的相图揭示了Pdn团簇在Cu2O（111）两个表面的变化情况。结果表明,在吸附了H2分子以后,Pdn团簇更倾向于保持原有的结构,且随着Pd团簇的增大,吸附H2的数量也逐渐增长。     

固相萃取-在线凝胶渗透色谱-气相色谱/质谱法测定板栗中44种有机磷农药残留

建立了板栗中44种有机磷农药多残留的分析方法.样品以V(乙腈)∶ V((水)=4∶ 1为提取剂,经高速匀浆方法提取,提取液以ENVI-18固相萃取柱净化,除去样品中大部分的脂肪和甾醇等干扰基质,再经在线凝胶渗透色谱-气相色谱/质谱(GPC-GC/MS)分析,进一步除去样液中色素和脂肪等大分子干扰物质,有效地降低了样品中的复杂基质所带来的背景干扰.加标水平为0.05 mg/kg时,大部分农药的回收率为65%～120%, 相对标准偏差小于15%;44种农药的检出限为0.002～0.05 mg/kg.采用外标法定量,气相色谱-质谱法(GC-MS)定性定量分析,线性关系和回收率结果均满意.实验证明,本方法是一种快速、准确、灵敏度高的同时检测板栗中有机磷农药多残留的检测方法.