Poly(lactic acid) composites with poly(lactic acid)‐modified carbon nanotubes

This work reports the study of the effect of chemical functionalization of carbon nanotubes on their dispersion in poly(lactic acid). The nanotubes were functionalized by the 1,3‐dipolar cycloaddition reaction, generating pyrrolidine groups at the nanotube surface. Further reaction of the pyrrolidine groups with poly(lactic acid) was studied in solution and in the polymer melt. The former involved refluxing the nanotubes in a dimethylformamide/polymer solution; the latter was carried out by direct melt mixing in a microcompounder. The carbon nanotubes collected after each process were characterized by thermogravimetry and by X‐ray photoelectron spectroscopy, showing evidence of polymer bonded to the nanotube surface only when the reaction was carried out in the polymer melt. The composites with polymer modified nanotubes present smaller average agglomerate area and a narrower agglomerate area distribution. In addition, they show improved tensile properties at low CNT concentration and present lower electrical resistivity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3740–3750     

Effects of Sequence on Transmission Properties of DNA Molecules

A double helix model of charge transport in DNA molecule is given and the transmission spectra off our DNA sequences are obtained. The calculated results show that the transmission characteristics of DNA are not only related to the longitudinal transport but also to the transverse transport of molecule. The periodic sequence with the same composition has stronger conduction ability. With the increasing of bases composition, the conductive ability reduces, but the weight of θ direction rises in charge transfer.     

Analysis of Electromagnetic Scattering from Plasma Antenna Using CG-FFT Method

A gaseous plasma column as an efficient radiator of electromagnetic waves is well known. This paper presents the scattering analysis of a plasma antenna using the conjugate gradient fast Fourier transform (CG-FFT) method. Radar cross sections (RCS) of designed plasma antenna for different plasma parameters are computed mainly. Numerical results show that the plasma antenna with appropriate parameters can offer lower RCS than the metal one. It is evident from the observed scattering characteristics that the plasma antenna can be regarded as a rod of imperfect conductor with losses.     

Instrumentation of coherent X-ray imaging and the primary experimental results

Coherent X-ray microscopy has advanced towards higher-energy, more brilliant sources over the past decade since its demonstrations, and many advancements have been made towards optimizing this imaging technique. Here we present both the experimental instrument for obtaining diffraction patterns and the primary reconstruction of yeast cell 2D projection. In addition, the characteristics of the existing optics at BL29XUL of SPring-8 Facility and the method of image reconstruction are discussed.     

Synthesis and Structure of E-2-(2,4,6-tri tert butylphenylphosphinyl)-2-〔N-(tert-butyldimethylsilyl)-N-(p-chrolophenyl)〕amino-1-(2,4,6-tri tert-butyl-phenyl)phosphacthylene

1　INTRODUCTIONItwaswellknown thatelementsofthesecondary and higherrow are in generaldifficulty to form multiplebondsin which apπ hybridized stateisinvolved〔1〕.Thus,simple compounds containing multiple phosphorus carbon bonds,such as methyl dynephosphine( HC≡P) 〔2 - 3〕 and methylenephosphine( H2 C=PH〔4〕,are notstableat room temperature.Three methods to stabilize compounds containing double ormultiple bond involving phosphorusatom in the pπ hybridized state are often used.The f…     

火焰原子吸收光谱法测定医药原料黄体酮中的铬

本文研究了黄体酮中微量元素铬的火焰原子吸收分光光度法的测定，方法简便、快速，省时，具有良好的精密度和准确度。平均相对标准偏差为３．０２％，平均回收率为９８．８％。     

平面电磁波性质的推导与讨论

简洁推导平面电磁波的基本关系式并由此讨论平面电磁波的性质．     

基于关键词的WEB文献自动跟踪系统的实现方法

提出一种基于搜索词位置信息的搜索方法和在此基础上web文献自动跟踪系统的开发过程。用户输入搜索词，并对部分返回结果进行阅读、评价，系统据此分析用户的偏好与需求，然后按照用户设定的主题扫描间隔自动搜索相关文章，并把用户读过的文章，待读的文章，新发现的文章都清晰标明，节约读者大量的查找、阅读的时间，适合各种人士使用。本算法也可能用于个性化智能搜索引擎的开发。     

二次有限元解的渐近展开与外推

在Poisson方程的求解域Ω存在一致的三角剖分,并且相邻两初始单元构成平行四边形的假设下,证明了若Poisson方程的解u属于H6(Ω),那么二次有限元的误差有h4的渐近展开.基于误差的渐近展开,可以利用h4-Richardson外推进一步提高数值解的精度阶,并且能够得到一个后验误差估计.最后,一个数值算例验证了理论分析.