Pharmacokinetics of isofraxidin in rat plasma after oral administration of the extract of Acanthopanax senticosus using HPLC with solid phase extraction method

High-performance liquid chromatography coupled with solid phase extraction method was developed for determination of isofraxidin in rat plasma after oral administration of Acanthopanax senticosus extract (ASE), and pharmacokinetic parameters of isofraxidin either in ASE or pure compound were measured. The HPLC analysis was performed on a Dikma Diamonsil RP(18) column (4.6 mm x 150 mm, 5 microm) with the isocratic elution of solvent A (acetonitrile) and solvent B (0.1% aqueous phosphoric acid, v/v) (A : B = 22 : 78) and the detection wavelength was set at 343 nm. The calibration curve was linear over the range of 0.156-15.625 microg/ml. The limit of detection was 60 ng/ml. The intra-day precision was 5.8%, and the inter-day precision was 6.0%. The recovery was 87.30+/-1.73%. When the dosage of ASE is equal to pure compound caculated by the amount of isofraxidin, it has been found to have two maximum concentrations in plasma while the pure compound only showed one peak in the plasma concentration-time curve. The determined content of isofraxidin in plasma after oral administration of ASE is the total contents of free isofraxidin and its precursors in ASE in vitro. The pharmacokinetic characteristics of ASE showed the priority of the extract and the properities of traditional Chinese medicine.     

Analysis of Electromagnetic Information Leakage Based on Cryptographic Integrated Circuits

Cryptographic algorithm is the most commonly used method of information security protection for many devices. The secret key of cryptographic algorithm is usually stored in these devices’ registers. In this paper, we propose an electromagnetic information leakage model to investigate the relationship between the electromagnetic leakage signal and the secret key. The registers are considered as electric dipole models to illustrate the source of the electromagnetic leakage. The equivalent circuit of the magnetic field probe is developed to bridge the output voltage and the electromagnetic leakage signal. Combining them, the electromagnetic information leakage model’s function relationship can be established. Besides, an electromagnetic leakage model based on multiple linear regression is proposed to recover the secret key and the model’s effectiveness is evaluated by guess entropy. Near field tests are conducted in an unshielded ordinary indoor environment to investigate the electromagnetic side-channel information leakage. The experiment result shows the correctness of the proposed electromagnetic leakage model and it can be used to recover the secret key of the cryptographic algorithm.     

Optical damage resistance of Hf:Fe:LiNbO3 crystals with various [Li]/[Nb] ratios

Hf:Fe:LiNbO₃ crystals were grown in air by the Czochralski technique with various [Li]/[Nb] ratios ([Li]/[Nb]=0.94, 1.05, 1.20) in melt. The defect structure and location of doped ions were analyzed by the UV‐visible absorption spectra. The optical damage resistance of Hf:Fe:LiNbO₃ crystals was investigated by the photoinduced birefringence change and the transmitted light spot distortion method. The results show that the optical damage resistance ability of Hf:Fe:LiNbO₃ crystals decreases with the increase of the [Li]/[Nb] ratio. The dependence of the optical damage resistance of Hf:Fe:LiNbO₃ crystals on the defect structure is discussed in detail. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

时滞效应对弹性地基上梁主共振响应影响分析

本文研究了弹性地基上梁主共振响应的时滞效应．基于Hamilton原理,建立了时滞影响下弹性地基上梁的非线性运动微分方程,采用多尺度法,求得了时滞效应下主共振响应调制方程以及稳定性条件．通过数值算例,分析了时滞和调谐参数影响下主共振响应的峰值及幅频响应特性．结果表明,地基反力中的时滞效应对主共振响应影响较大,会导致共振域偏移,在一定区间内,响应幅值随时滞变化先减小再增大,呈现出周期性,并导致幅频曲线弯曲程度增大．     

温压炸药坑道内爆炸冲击波的数值模拟研究

基于二次反应理论,采用AUTODYN程序对温压炸药(RDX/AP/AL/粘合剂=20/43/25/12,质量比)坑道内爆炸冲击波进行了数值模拟研究。将温压炸药与传统炸药TNT的计算结果进行了比较,结果表明:①在爆炸近区,温压炸药比TNT的爆炸冲击波超压峰值低。但在爆炸远区,温压炸药的爆炸冲击波超压峰值则逐渐超过了TNT,最高达到了TNT的1.48倍;温压炸药爆炸冲击波的冲量峰值始终高于TNT,约为TNT的1.33～1.43倍。②最小二乘拟合得到了温压炸药坑道内爆炸冲击波超压峰值随距离衰减的计算公式,具有一定参考价值。     

一种铈（Ⅲ）配合物对含石墨粘结涂层耐蚀性的影响

为了改善含石墨粘结涂层的耐蚀性，首先对这种涂层在腐蚀环境中耐蚀性差的原因进行了分析，然后将二正丁基磷酸、ＣｅＦ＿３、Ｓｂ＿２Ｏ＿３和一种Ｃｅ（Ⅲ）配合物Ｃｅ（ＮＯ＿３）（Ｃ＿８Ｈ＿（１８）ＰＯ＿４）＿２分别添加于酚醛环氧－ＭｏＳ＿２－石墨粘结涂层中，考察了它们对这种涂层耐蚀性的影响，并对含Ｃｅ（ＮＯ＿３）（Ｃ＿８Ｈ＿（１８）ＰＯ＿４）＿２的涂层和空白样涂层进行了表面分析。盐雾试验表明，添加Ｃｅ（ＮＯ＿３）（Ｃ＿８Ｈ＿（１８）ＰＯ＿４）＿２可以有效地抑制涂层中ＭｏＳ＿２的氧化和由石墨所引起的金属底材之电化学腐蚀；根据Ｘ射线光电子能谱分析结果可知，添加Ｃｅ（ＮＯ＿３）（Ｃ＿８Ｈ＿（１８）ＰＯ＿４）＿２之所以能够提高含石墨粘结涂层的耐蚀性，应当归因于它在ＭｏＳ＿２晶体表面和金属底材表面的吸附。因此，Ｃｅ（Ⅲ）配合物Ｃｅ（ＮＯ＿３）（Ｃ＿８Ｈ＿（１８）ＰＯ＿４）＿２是含石墨粘结涂层的一种实用性能良好的新型防腐添加剂。     

国外几种大型微机有限元分析系统(FEAS)简介

本文简述当前国际上流行几种大型通用微机用有限元程序的概况，以及它们的比较与应用等     

油溶性Ag纳米微粒的制备及表征

以双十八烷氧基二硫代磷酸吡啶盐为修饰剂 ,以单宁酸为还原剂 ,在水醇混合溶剂中合成了表面修饰的Ag纳米微粒 ,采用X射线粉末衍射仪、透射电子显微镜、傅立叶变换红外光谱仪、热分析仪等对其进行了结构表征 ,在四球摩擦试验机上测试了其抗磨性能 .结果表明 ,表面修饰的Ag纳米微粒粒径分布均匀 ,平均粒径约为15nm ,无团聚现象 ,可溶于液体石蜡等有机溶剂 ,作为润滑油添加剂 ,具有良好的抗磨作用 ,可显著提高基础油的承载力 .     

Synthesis of novel perfluoroalkyl ether derivatives

A series of novel fluoroether-containing monomers has been designed and prepared based on the commercially available perfluoroalkyl ether acid fluoride. Treating acid fluoride with allyl alcohol, 2-hydroxyethyl methacrylate or N-allylmethylamine allowed for the direct formation of corresponding vinyl-containing fluorinated monomers. High yields of the fluorinated epoxy monomers could be obtained from acid chloride with glycidol; meanwhile, fluorinated diol was prepared from diethanolamine or 3-amino-1,2-propanediol. Moreover, fluorinated monoamine, fluorinated monoalcohol and fluorinated dichloride were also obtained. Most of these fluorinated monomers were liquid at room temperature and exhibited good solubility in common organic solvents.     

β-环糊精的固载及其应用最新研究进展

环糊精由于其优异的结构特征和物理化学性质,已成为构筑各种功能材料的优良结构单元.本综述以β-环糊精的共价固载为主,详细综述了目前β-环糊精的固载及其应用最新研究进展,主要包括固载化β-环糊精在环境污染物吸附、药物分子的负载和缓释、分析检测、手性分离、催化、织物整理和表面功能化等领域的应用.上述各部分,根据载体或应用方式的不同,系统介绍了β-环糊精的固载及固载化β-环糊精的性能.指出固载化β-环糊精在催化和表面功能化领域的应用虽然目前还处于起步阶段,却极具研究价值,对固载化β-环糊精进一步的功能化是今后基于β-环糊精构筑超分子仿生催化体系的主要研究方向.