利用层层自组装技术制备聚电解质多层膜高效液相色谱固定相

以聚(乙烯-alt-马来酸)的苯乙胺衍生物与聚烯丙基胺盐酸盐为原料,通过层层自组装技术(LBL)在色谱硅胶表面交替沉积得到聚电解质多层膜高效液相色谱(HPLC)固定相;利用紫外光谱、红外光谱和元素分析研究了HPLC固定相的结构和组成.结果表明,聚电解质多层膜HPLC固定相被成功构筑在硅胶颗粒表面;制备的多层膜固定相可方便地用于6种芳香烃类及4种烷基苯类物质的分离分析.本文的研究结果说明LBL技术在制备HPLC固定相方面具有一定的应用价值.     

A Novel Xanthone from Garcinia oligantha

One novel xanthone, oliganthone A ( 1 ), was isolated from the stems of the plant Garcinia oligantha. It features the O‐bearing C(3)‐atom and absence of C(4) compared with the structures of related known xanthones, which have never been reported before. The structure of this compound was elucidated by spectroscopic analysis. Compound 1 showed strong HeLa cell growth‐inhibiting effects with IC₅₀ values below 10 μM .     

重复变函数(下)

§4 双曲数环 一、双曲数 在重复数中令得,称ξ为双曲数。所有双曲数组成的子环,称为双曲数环,记作,中所有零因子和零的集合也称零集,记作。 根据前面的讨论,有     

Partial Regularity of Solutions to the Four-Dimensional Navier-Stokes Equations at the First Blow-up Time

The solutions of incompressible Navier-Stokes equations in four spatial dimensions are considered. We prove that the two-dimensional Hausdorff measure of the set of singular points at the first blow-up time is equal to zero. Hongjie Dong was partially supported by the National Science Foundation under agreement No. DMS-0111298. Dapeng Du was partially supported by a postdoctoral grant from School of Mathematical Sciences at Fudan University.     

On-axis irradiance distribution of axicons illuminated by spherical wave

The focusing properties of an axicon illuminated by spherical wave are investigated. We define the Fresnel number of the focusing axicon impinged on by spherical wave. The on-axis irradiance distribution versus Fresnel number is studied. It is shown that, similar with the plane wave, focal squeeze, which is defined as deviations for the position of the maximum irradiance, also appears in low Fresnel number. Besides, the on-axis irradiance will be smoothed for appropriate curvature radius of the divergent spherical wave; meanwhile, when the convergent spherical wave is incident on the axicon, the on-axis irradiance varies more seriously.     

一类奇摄动三阶系统边值问题的渐近解

本文获得了一类三阶系统边值问题解的存在性及其精确到任意精度的一致有效估计.     

Photocatalytic water splitting of La2AlTaO7 and the effect of aluminum on the electronic structure

A new photocatalyst La₂AlTaO₇ with orthorhombic structure was synthesized by the solid-state reaction method. The formation rate of H₂ evolution from CH₃OH/H₂O solution under the irradiation of a 350 W high-pressure Hg lamp is about 108.9 μmol h^?1 for La₂AlTaO₇ (0.1 g). It also showed activity leading to the decomposition of pure water into H₂ and O₂ even in the absence of co-catalysts under UV light irradiation. The photocatalyst loaded with 0.2 wt% NiO co-catalyst was found to have the highest activity. It was found from the electronic band structure study, using the density functional theory (DFT) with plane-wave basis, that the valence band top mainly consists of O 2p orbitals and the conduction band bottom is mainly constructed of Al 3s3p. The effect of aluminum on electronic structure was discussed in close connection with the UV–vis absorption spectrum.     

非线性Schrödinger方程组的精确解组

运用Maple语言程序,在没有假设的条件下,得到了具有耦合特性的非线性Schr(o)dinger方程组的行波精确解组及其约束条件方程,它们的表达式涵盖了所有的耦合解组与非耦合解组,具有任意性.耦合解组的算例函数及其特性分析,解释了a螺旋蛋白质螺旋链运动模型的行波孤立子解的耦合效应,揭示了增加、稳定和控制蛋白质活性和功能的方向.文章的研究方法,为求解耦合的非线性微分方程组的行波精确解组探索了蹊径.     

动物骨中痕量元素铅和镉测定方法的研究

本文建立了一种用石墨炉原子吸收光谱法测定动物骨中的痕量Ｐｂ和Ｃｄ的方法，试样以ＴＭＡＨ溶解后直接测定，方法简便。快速，回收率为９６．９５－１０３．１５％，相对标准偏差小于４．８１％。     

二维核磁共振谱测定植物新环肽-太子参环肽A和B中氨基酸序列

在植物新环肽[太子参环肽A(HA)和B(HB)]的结构研究中,应用COLOC谱较成功地解决了其氨基酸序列。结果表明当J值选择在6Hz-15Hz时,COLOC谱能满意地给出氮上含有活泼氢的氨基酸序列。