氟硼二吡咯类阳离子荧光探针的研究进展

荧光探针提供了方便、快捷、廉价的分析测试手段,并具有很高的灵敏度和选择性,因而在分析化学、临床生物化学、医学以及环境科学等领域有广泛的应用前景.氟硼二吡咯(BODIPY)是一种光物理和光化学性能优异的荧光染料,本文综述了近年来BODIPY类阳离子荧光探针的最新研究进展和发展趋势.     

Eu(Ⅲ)与EHPG配合反应的循环伏安特性和光谱研究

在0.02mol/LpH6.0的HAc-NaAc缓冲溶液和室温条件下,用循环伏安法、荧光光谱和紫外差光谱研究了Eu3 与N,N′-亚乙基-二[2-(2-羟基苯基)甘氨酸](EHPG)的配合反应。结果表明,Eu3 与EHPG形成1/1的配合物。循环伏安法测定Eu3 在-0.2～-1.2V电位扫描范围内裸玻碳电极上有一对氧化还原峰,EHPG无电化学活性,Eu-EHPG在电极上呈现准可逆电化学行为。荧光光谱测定表明,随着Eu3 的不断滴加EHPG在310nm处的最大荧光峰强度逐渐降低。而其紫外差光谱在240nm和293nm处的吸收峰逐渐增强,当Eu3 达到一定量时,在310nm处的荧光强度、240nm和292nm处的吸收峰强度不再发生变化。通过计算,在240nm处配合物Eu-EHPG的摩尔吸光系数为Δε=19.06×103cm-1.mol-1.L,条件稳定常数为lgKEu-EHPG=13.90。     

二氧化碳多相催化加氢的新进展

就近年来关于ＣＯ２活化、几个重要的ＣＯ２多相催化加氢反应及廉价氢的供给的研究进展进行综述。参考文献３４篇。     

Metrological role of neutron activation analysis. IB. Inherent characteristics of relative INAA as a primary ratio method of measurement

This is the second part of a paper which deals with the advantages and disadvantages of relative instrumental neutron activation analysis concerning traceability and uncertainty, and the current scope and possible future extensions of neutron activation analysis as a primary ratio method. The first part of this paper has been published in this Journal [1]. Received: 19 March 2001 Accepted: 2 October 2001     

聚合物-Ni(II)膜电极的研究

Ni(Ⅱ)离子可与聚8羟基喹啉、聚邻氨基酚、聚邻苯二胺和聚苯胺络合。聚合物-Ni(Ⅱ)膜电极的循环伏安图有明显的氧化还原蜂, 和彼此相似的电化学特性。聚8羟基喹啉膜(聚邻氨基酚, 聚邻苯二胺)可用以交换Ni(Ⅱ)与H~+离子和分离Ni(Ⅱ)、Co(Ⅱ)和Fe(Ⅱ)离子。     

超导相(Bi1.7Pb0.2In0.1)Sr2Ca2Cu3O10的制备和晶体结构研究

The superconducting phase(Bi_(1.7)Pb_(0.2)In_(0.1))Sr_2Ca_2Cu_3O_(10) with on-set T_c near 112K and zero resistivity at 95K has been prepared. The Unit cell is. body-centered tetragonal, space group I4/mmm, a=0.3.817(1) nm, c=3.704(1) nm. Chemical substitution of Pb and In in Bi—Sr—Ca—Cu—O series results in the growth of 2223 phase. The superconductivity and the formation mechanism are associated with the structural features.     

双N—乙酸取代氮氧杂大环及其镧系配合物的合成

首次合成了一种新的1.2-双(3,4:9,10-二苯并-5,8-二氧杂-1,12-二氮杂环十五烷-N-乙酸)乙烷大环配体,制备了它的8个镧系元素(La,Pr,Nd,Sm,EU,Gd,Dy,Yb)配合物,用红外光谱、元素分析、核磁共振谱及电导等方法进行了表征,讨论了可能的配位情况。     

Analysis of Chlorogenic Acid in Herbal Medicines by Capillary Electrophoresis

Atpresent,thecommonlyusedmethodforanalyzingherbalmedicinesishighperformanceliquidchromatography(HPLC).However,theuseofHPLCisrestrictedformanyreasons.Themostseriousproblemisthatthechromatographiccolumniseasilycontaminated.ComparedwithHPLC,capillaryelectrophoresis(CE)ischaracterizedwithhighefficiency,rapidity,lowcostandmultiplemodestobechosen.Inaddition,thecapillarycanbeeasilyregenerated.SoCEisidealforanalyzing"dirty"samples,suchasChineseherbalmedicines.Infact,studiesintheareaarebecoming…     

Tradeoff between mixing and transport for electroosmotic flow in heterogeneous microchannels with nonuniform surface potentials

Electroosmotic flow (EOF) is a phenomenon associated with the movement of an aqueous solution induced by the application of an electric field in microchannels. The characteristics of EOF depend on the nature of the surface potential, i.e., whether it is uniform or nonuniform. In this paper, a lattice Boltzmann model (LBM) combined with the Poisson-Boltzmann equation is used to simulate flow field in a rectangular microchannel with nonuniform (step change) surface potentials. The simulation results indicate that local circulations can occur near a heterogeneous region with nonuniform surface potentials, in agreement with those by other authors. Largest circulations, which imply a highest mixing efficiency due to convection and short-range diffusion, were found when the average surface potential is zero, regardless of whether the distribution of the heterogeneous patches is symmetric or asymmetric. In this work, we have illustrated that there is a trade-off between the mixing and liquid transport in EOF microfluidics. One should not simply focus on mixing and neglect liquid transport, as performed in the literature. Excellent mixing could lead to a poor transport of electroosmotic flow in microchannels.