磷酸三乙酯改性HZSM-5沸石的活性及理论研究

采用XRD表征了水蒸气和磷联合改性的HZSM-5沸石分子筛的结构．通过NH3-TPD和N2吸附脱附研究了样品的酸性和比表面．采用正庚烷的裂化反应研究了样品的裂化活性，研究结果表明，磷改性样品与母体样品相比，经过水蒸气处理后显示出较高的酸量和正庚烷裂化活性．上述结果首次用模型簇和计算量子化学方法进行了解释．采用Gaussian94软件包和PM3半经验量子化学方法对模型簇进行了全优化和频率分析．计算结果显示磷改性后样品的脱铝补硅反应热大于母体样品脱铝补硅反应热，从而显示出磷对骨架的稳定化作用．     

溴化-1-(α-辛基吡啶)-6-(α-十二烷基吡啶)己烷的合成与表征

双子表面活性剂是通过联结基将两个相同头基和相同疏水链的普通表面活性剂在头基或靠近头基处以化学键方式连接在一起,这种表面活性剂与相应的普通表面活性剂相比,具有更高的表面活性[1],已引起学术界和工业界人士的广泛兴趣和关注。分子结构不对称的双子表面活性剂,包括不同化     

Protein and Dye Adsorption on Poly(ethylene terephthalate) Nucleopore Membranes Modified with Polymers

Adsorption of basic, neutral, and acidic proteins on poly(ethylene terephthalate) nucleopore membranes was studied as a function of solution pH. Higher adsorption values were observed for basic and neutral proteins and lower, for acidic proteins. The value of pH corresponding to maximal adsorption was somewhat lower than the isoelectric points of proteins, thus suggesting that the adsorption was governed by a combination of ionic and hydrophobic interactions between proteins and the membrane surface. Proteins were adsorbed in an associated form. Membrane surface was modified with poly(ethylene imine) and poly(ethylene glycol). Combined modification of the membranes with these polymers was found to substantially decrease the adsorption of basic and neutral proteins, as well as basic dye and to slightly increase the adsorption of acidic proteins. The modifying coating had a high hydrolytic stability.     

Synthesis, Characterization and Crystal Structure of （Z）-1-[2-（Triarylstannyl）vinyl]-1-indanols and Their Arylhalostannyl Derivatives

(Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-indanol (1) and (Z)-1-[2-(tri-p-tolylstannyl)vinyl]-l-indanol (2) were synthesized by the addition reaction of 1-ethynylindanol with tri-o-tolyltin and tri-p-tolyltin hydride. The aryl groups in compound 1 and 2 were substituted by Br2 or I2 to yield monohalide derivatives (3-6). The compounds 1-6 were characterized by elemental analysis, ^1H NMR and FT-IR spectroscopy. The crystal structures of 1, 2 and 4 have been determined by single crystal X-ray diffraction analysis. The Sn atom in 1 and 2 exhibits a tetrahedral geometry distorted towards trigonal bipyramid due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [0.2839(4) nm and 0.2744(5) nm], while the Sn atom in 4 adopts a trigonal bipyramidal geometry with a significant O→Sn(1) interaction [0.2552(5) nm].     

Influence of UV Pretreatment on Thermooxidative Degradation of Poly(Methyl Methacrylate) Films with Fullerene C<Subscript>60</Subscript> or C<Subscript>70</Subscript>

Wariation of the concentration of fullerenes C₆₀ and C₇₀ in poly(methyl methacrylate) films under UV exposure in atmospheric oxygen was studied. The mechanism of the influence exerted by addition of some photostabilizing polymers and xanthene dyes on the photooxidative degradation of fullerene in the polymer matrix was analyzed.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 1038–1042.Original Russian Text Copyright © 2005 by Troitskii, Khokhlova, Konev, Denisova, Novikova, Lopatin.     

基于迭代小波变换的光谱信号本底扣除方法研究

本底会对光谱分析结果产生很大的干扰作用,为获取特征峰的有效信息,必须首先去除本底。该文提出了一种基于小波变换的本底扣除算法,通过对光谱及后续光谱迭代进行小波变换,利用逼近系数估计本底,直到本底收敛。提出了判断多次估计的本底最大误差是否足够小的收敛准则。利用该算法去除本底后,即可进行特征峰信息的提取。分别利用仿真光谱和实验能量色散X射线荧光光谱对算法进行了验证,并与传统小波变换和多项式拟合法进行了对比。结果表明,该算法能够更准确扣除光谱本底,对其他光谱的本底扣除也具有借鉴意义。     

Adsorption of dyes on activated carbon and graphitic thermal carbon black

The adsorption of a basic dye (Methylene Blue; MB) and an acidic dye (Acid Orange; AO) has been studied on three activated carbons (ACs; FAS, SKD, and BAU) significantly differing in their porous structures and surface concentrations of ion-exchange groups and on graphitic thermal carbon black (GTCB). The effective specific surface area of FAS, SKD, and BAU determined by dye adsorption is, respectively, 60, 50, and 40% of the BET nitrogen adsorption surface area. The MB uptake on ACs and GTCB increases with rising pH, while the AO uptake decreases. Addition of an electrolyte (0.3 M NaCl) virtually does not effect the adsorption of dyes on ACs and GTCB. It is suggested that hydrophobic interactions, and not ionic ones, are the major contributors to the adsorption of dyes on ACs.     

数学软件在高等数学研究型教学中的应用

这些年来,我们积极尝试将数学软件应用在高等数学课程的教学中,获得了一些可喜的成绩.起到了启发学生思维,增强学生主动参与,教会学生发现问题并使用工具来解决问题的能力.本文以一种特殊曲线的性质分析为例讲述了数学软件在研究性教学中的应用.     

一种分解指数算符的简洁方法

提出一种新的分解指数算符的方法,这种方法不仅简单易懂,而且有助于找到更多的算符恒等式.