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121.
《Electroanalysis》2004,16(24):2009-2021
The popularity of contactless conductivity detection in capillary electrophoresis has been growing steadily over the last few years. Improvements have been made in the design of the detector in order to facilitate its handling, to allow easy incorporation into available instruments or to achieve higher sensitivity. The understanding of its fundamental working principles has been advanced and the detection approach has also been transferred to lab‐on‐chip devices. The range of applications has been extended greatly from the initial work on small inorganic ions to include organic species and biomolecules. Concurrent determination of cations and anions by dual injection from opposite ends has been demonstrated as well as sample introduction by using flow‐injection systems for easy automation of the process. 相似文献
122.
The interaction energy of a [Au{C(NHMe)2}2]+ ... [Au{C(NHMe)2}2]+ dimer is investigated using the MP2 method and the LANL2DZ basis set when isolated or embedded in ionic an [Au{C(NHMe)2}2]2anion2 aggregate, a good model for the environment that these dimers feel in ionic crystals. A repulsive interaction energy is obtained when the dimer is isolated. However, it is possible to find short AuI ... AuI separations in [Au{C(NHMe)2}2]2anion2 aggregates, because in these aggregates the sum of the cation ... anion interactions overweight the sum of the cation ... cation plus anion...anion interactions. This explains why short AuI ... AuI separations are found in ionic crystals. The AuI ... AuI interaction found in [Au{C(NHMe)2}2]2 anion2 aggregates shows the same features observed in energetically stable dimers presenting AuI... AuI bonds. This makes appropriate to use the name counterion-mediated bonds for the AuI... AuI interactions found in [Au{C(NHMe)2}2]2 anion2 aggregates and ionic crystals. 相似文献
123.
Dodds ED Kennish JM Von Hippel FA Bernhardt R Hines ME 《Analytical and bioanalytical chemistry》2004,379(5-6):881-887
The perchlorate anion (ClO
4
–
) is an anthropogenic contaminant of increasing concern in water supplies, and has been shown to disrupt thyroid activity. Most perchlorate analyses are currently carried out by ion chromatography (IC) with suppressed conductivity detection (SCD). While this procedure has been demonstrated to provide acceptable performance for analysis of water samples, the determination of perchlorate in high-conductivity aqueous extracts of plant or animal material is not readily accomplished by IC-SCD unless lengthy cleanup protocols are applied. With the addition of electrospray ionization mass spectrometry (ESI-MS) to IC, it was hypothesized that the interference imposed by various ionic species could be significantly reduced without the need for purification; however, the analysis of perchlorate in relatively unpurified extracts of biologically derived homogenates by IC-ESI-MS has not previously been described in the literature. The research presented here represents a comparison of the capabilities of IC-SCD and IC-ESI-MS to detect perchlorate in reagent water and in crude extracts of perchlorate-exposed fish (threespine stickleback, Gasterosteus aculeatus). ESI-MS was found to compare favorably to SCD for the detection of perchlorate in deionized water, and to exceed SCD performance in perchlorate analysis of fish-derived extracts. 相似文献
124.
一种新的磷酸根离子敏感电极研究 总被引:5,自引:0,他引:5
一种新的磷酸根离子敏感电极研究肖丹,俞汝勤,李军,袁孔铨(湖南大学化学化工系,长沙,410082)关键词磷酸根,离子选择电极,磷酸二氢根磷酸根离子浓度的测定在化学化工、环境保护、生命科学和临床医学等领域有着重要的意义。对磷酸根离子敏感电极的研究和探索... 相似文献
125.
126.
From phasebarograms it is possible to construct phase diagrams. We show on example of the system Bi/Se/O how follow ternary sections from the total pressure measurements in equilibrium and how we can attribute the barogram of the ternary region Bi2Se3/Bi2O2Se/Se to the binary system Bi2Se3/Se. The knowledge of the ternary system Bi/Se/I and its coexistent pressure courses allow to followT-p-x conditions for the chemical transport of phases from this system. 相似文献
127.
A novel oligothiophene derivative containing the triphenylamine moiety with high glass transition temperature (Tg; 135 °C), 5,5′‐{bis[4‐di(4‐thiophenyl)amino]phenyl}‐2,2′‐bithiophene (TTPA‐dimer) was synthesized by the dimerization of tris[4‐(2‐thienyl)phenyl]amine (TTPA) with a palladium catalysis. Some types of electroluminescent (EL) devices that use the amorphous material for a hole‐ and an electron‐transporting with an emitting layer were fabricated. These devices emitted a bright green‐yellowish light (λemi; around 510 nm) with a small full width at half maximum (FWHM) rather than that of Alq3. The single layer EL device showed a maximum luminance of 221 cd/m2 at 8 V (0.06 lm/W at 100 cd/m2). On the other hand, the double layer (TTPA‐dimer/Alq3) EL device that used Alq3 as the electron transport material was increased up to 10830 cd/m2 at 12 V (0.89 lm/W at 300 cd/m2) and with a lower turn‐on voltage (3.2 V at 0.1 cd/m2) than other types of EL devices. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
128.
本文研究并探讨了NK-ELN型离子交换树脂在再生贮氢合金材料包覆液过程中,温度、流速、溶液中离子浓度等条件对树脂交换容量和再生效率的影响,为树脂法再生贮氢合金材料包覆液工艺的制定,提供了一系列重要参数。 相似文献
129.
Manabu Tanaka Kaoru Hatta Tomohiko Edura Ken Tsutsui Yasuo Wada Hiroyuki Nishide 《先进技术聚合物》2007,18(11):925-931
The electric conductivity of π‐conjugated and radical‐bearing polymers, i.e., polythiophenes bearing pendant galvinoxyl and phenoxyl radical groups, was measured using a microcomb‐shaped electrode. The electric conductivity was found to be enhanced by the radical content in the polymer. The infrared (IR) and Raman spectroscopies suggested a structural change from an aromatic form to a quinoid one in the polythiophene backbone by the phenoxyl radical generation. The effect of the pendant galvinoxyl radical's unpaired electron on the electric conductivity of the polythiophene was discussed by comparing the conductivity of a radical‐bearing polystyrene and a polythiophene mixed with low‐molecular radical molecules. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
130.
Tatiana Y. Shvareva 《Journal of solid state chemistry》2005,178(2):499-504
Single crystals of the potassium uranyl iodate, K[UO2(IO3)3] (1), have been grown under mild hydrothermal conditions. The structure of 1 contains two-dimensional sheets extending in the [ab] plane that consist of approximately linear UO22+ cations bound by iodate anions to yield UO7 pentagonal bipyramids. There are three crystallographically unique iodate anions, two of which bridge between uranyl cations to create sheets, and one that is monodentate and protrudes in between the layers in cavities. K+ cations form long ionic contacts with oxygen atoms from the layers forming an eight-coordinate distorted dodecahedral geometry. These cations join the sheets together. Ion-exchange reactions have been carried out that indicate the selective uptake of Cs+ over Na+ or K+ by 1. Crystallographic data (193 K, MoKα, ): 1, orthorhombic, Pbca, a=11.495(1) Å, b=7.2293(7) Å, c=25.394(2) Å, Z=8, R(F)=1.95% for 146 parameters with 2619 reflections with I>2σ(I). 相似文献