Characterization of nitrate ions adsorption and diffusion in P（DMAEMA/HEMA） hydrogels

In this work, the adsorption and diffusion behavior of nitrate ions into polycationic P（DMAEMA/HEMA） hydrogels is analyzed. Experimental results indicated that nitrate ions can be removed efficiently from aqueous solutions. Adsorption isotherm of gels was well according to the Langmuir and Langmuir-Freundlich models. At the same time, the diffusion behavior of nitrate ions from P（DMAEMA/HEMA） hydrogels was investigated. The diffusion coefficients are strongly influenced by the changes of temperature and pH value of solutions. At the same time, D does not depend on the gels cross-linking ratio and initial solute concentration.     

Collective Transport of Coupled Brownian Motors with Low Randomness

The transport properties of coupled Brownian motors in rocking ratchet are investigated via solving Langevin equation. By means of velocity, diffusion coefficient, and their ratio （Peclet number）, different features from a single particle have been found. In the regime of low-to-moderate D, the average velocity of elastically coupled Brownian motors is larger than that of a single Brownian particles; the Peclet number of elastically coupled Brownian motors is peaked functions of intensity of noise D but the Peclet number of a single Brownian motor decreases monotonously with the increase of a single Brownian motor. The results exhibit an interesting cooperative behavior between coupled particles subjected to a rocking force, which can generate directed transport with low randomness or high transport coherence in symmetrical periodic potential.     

小议命题思路的改革

学习化学离不开解化学习题,但历来主要是围绕本学科的基本原理、基本概念或重要知识与技术命题。即使是化学竞赛的命题也大致如此。这类习题固然有助于学生巩固与深入学习课程的重要内容,包括有关知识点之间的综合与联系,但是一般难以真正贴近学生的生活和培养他们综合运用从各门课程中所学到的知识,不能不认为是这类习题的重要缺陷之一。     

利用Schlieren效应考察流动注射分析

本文利用ＦＩＡ系统中四氯化碳、葡萄糖、氯化钠和盐酸溶液的Ｓｃｈｌｉｅｒｅｎ效应响应曲线，考察了扩散作用对溶液分散行为即对响应曲线形状、样品运行的时间、保留时间及基线－基线峰宽的影响。通过分析表明，实验结果与理论是王牟。     

利用Schliteren效应考察流动注射分析系统中扩散作用对溶液分散的影响

本文利用FIA系统中四氯化碳、葡萄糖、氯化钠和盐酸溶液的Schlieren效应响应曲线，考察了扩散作用对溶液分散行为即对响应曲线形状、样品运行时间、保留时间及基线-基线峰宽的影响。通过分析表明，实验结果与理论是一致的     

INTRAPARTICLE DIFFUSION OF RARE EARTHS IN POROUS CATION EXCHANGERS

Experiments for determining cerium isotope ion exchange rates with macroporous resins Amberlyst 15,D001 and XN1010 are discribed.The kinetics of the isotope ion exchange reaction has been examined by a simple theoretical equation of intraparticle effective diffustivity De in a porous ion exchanger.The ion exchange proceedes by diffusion within the macropores and the solid phase of the resin,De of cerium was affected by the concentration of the bulk solution C and was separated into a macropore diffusivity D^-p and a solid phase diffusivity D^-g by the equation.The diffusion coefficients of the exchanging ion are shown to have the values in the macropores comparable with those in the bulk solution and to have the values in the solid phase comparable with those in gel resin with the same crosslinkage as the resins used for the experiments.     

Temperature waves in chemical reaction-diffusion-heat conduction systems with two ends respectively subject to Dirichlet and no-flux conditions

Taking the Lindemann model as a sample system in which there exist chemical reactions,diffusion and heat conduction,we found the theoretical framework of linear stability analysis for a unidimensional nonhomogeneous two-variable system with one end subject to Dirichlet conditions,while the other end no-flux conditions.Furthermore,the conditions for the emergence of temperature waves are found out by the linear stabilily analysis and verified by a diagram for successive steps of evolution of spatial profile of temperature during a period that is plotted by numerical simulations on a computer.Without doubt,these results are in favor of the heat balance in chemical reactor designs.     

Interaction between antitumor drug and silver nanoparticles: combined fluorscence and surface enhanced Raman scattering study

Optical methods and MTT method are used to characterize the antiproliferation effect of antitumor drug 9-aminoacridine （9AA） with and without silver nanoparticles. Intracellular surface enhanced Raman scattering （SERS） spectra and fluorescent spectra of 9AA indicate the form of 9AA adsorbed on the surface of silver nanoparticles. Although both silver nanoparticles and antitumor drug can inhibit the growth of Hela cells, silver nanoparticles can slow down the antiproliferation effect on Hela cells at low concentration of antitumor drugs. Our experimental results suggest that silver nanoparticles may serve as slow-release drug carriers, which is important in antitumor drug delivery.