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31.
P. Vaňura E. Makrlík Z. Valentová 《Journal of Radioanalytical and Nuclear Chemistry》2002,253(3):527-529
Extraction of microamounts of cesium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of dibenzo-24-crown-8 (DB24C8,L) has been investigated. The equilibrium data have been explained assuming that the complexes HL+ and CsL+ are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. 相似文献
32.
The effects of ion implantation into thin films of the GbBaCuO on Si substrates without any buffer layer at 300 and 77 K have been studied. Using H+ ions, the superconducting transition temperature, the change of electrical properties from conducting to insulating, and the crystalline to amorphous structural transition in the films were studied as a function of ion dose. The implantation energy was 150 keV. 相似文献
33.
Extraction distribution of microamounts of strontium in the water-CsCl-15-crown-5 (15C5,L)-nitrobenzene-cesium dicarbollylcobaltate system has been investigated. The equilibrium data have been explained assuming that the CsL+, CsL2
+ and SrL2
2+ complexes are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. 相似文献
34.
Rijssenbeek JT Malo S Caignaert V Poeppelmeier KR 《Journal of the American Chemical Society》2002,124(10):2090-2091
Sr(3)CaRu(2)O(9), a new 2:1 B-site ordered perovskite ruthenate, was synthesized and its structure determined based on powder X-ray, neutron and electron diffraction data. It is composed of one layer of CaO(6) alternating with two layers of RuO(6) perpendicular to the [111] axis of the cubic perovskite structure. The ordering leads to a [-Ru-Ru-Ca-] repeat unit along each of the pseudocubic directions. Sr(3)CaRu(2)O(9) is the first example of this structure-type to include a majority metal with d electrons (Ru(V), d(3)). Three-dimensional Sr(3)CaRu(2)O(9) can be transformed to the layered Ruddlesden-Popper phase Sr(1.5)Ca(0.5)RuO(4) (i.e., Sr(3)CaRu(2)O(8)) by reduction at 1200 degrees C in flowing argon. The original structure can be restored by oxidation of Sr(1.5)Ca(0.5)RuO(4) at 1000 degrees C in flowing oxygen. This remarkable transformation highlights the structural versatility afforded by the combination of ruthenium and calcium. 相似文献
35.
From several cesium distribution experiments with 134 Cs tracer, the exchange extraction constant corresponding to the equilibrium Ag+ (aq)+CsL+ (nb)AgL+ (nb)+Cs+ (aq) in the two-phase water-nitrobenzene system (L = 18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) was determined as log K
ex (Ag+ ,CsL+ ) = -0.6±0.1. Furthermore, the stability constant of the silver — 18-crown-6 complex in nitrobenzene saturated with water was evaluated for a temperature of 25 °C: log nb (AgL+ ) = 8.2±0.1. Finally, the individual extraction constant of the species AgL+ in the water-nitrobenzene system corresponding to the equilibrium AgL+ (aq)AgL+ (nb) was calculated: K
AgL+
= O1.2±0.1. 相似文献
36.
From extraction experiments with 133Ba as a tracer, the extraction constant corresponding to the equilibrium Ba2+(aq) + 2A-(aq) + 2L(nb) BaL2
2+(nb) + 2A-(nb) in the two-phase water-nitrobenzene system (A- = picrate, L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K
ex (BaL2
2+, 2A-) = 5.7. Furthermore, the stability constant of the benzo-15-crown-5 - barium complex in nitrobenzene saturated with water was calculated: log bnb (BaL2
2+) = 14.6. 相似文献
37.
We take up the question of when a state (= -additive measure) on the product of logics (=-orthomodular posets) depends on at most countably many coordinates. We show that it is always so provided there are no real-measurable cardinals. The manner of dependence is a kind of convex combination. We derive some consequences of the latter statement. 相似文献
38.
Zhenhui Qi Dr. Changzhu Wu Dr. Paula Malo de Molina Han Sun Andrea Schulz Prof. Christian Griesinger Prof. Michael Gradzielski Prof. Rainer Haag Prof. Marion B. Ansorge‐Schumacher Prof. Christoph A. Schalley 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10150-10159
A new and versatile, crown ether appended, chiral supergelator has been designed and synthesized based on the bis‐urea motif. The introduction of a stereogenic center improved its gelation ability significantly relative to its achiral analogue. This low‐molecular‐weight gelator forms supramolecular gels in a variety of organic solvents. It is sensitive to multiple chemical stimuli and the sol–gel phase transitions can be reversibly triggered by host–guest interactions. The gel can be used to trap enzymes and release them on demand by chemical stimuli. It stabilizes the microparticles in Pickering emulsions so that enzyme‐catalyzed organic reactions can take place in the polar phase inside the microparticles, the organic reactants diffusing through the biphasic interface from the surrounding organic phase. Because of the higher interface area between the organic and polar phases, enzyme activity is enhanced in comparison with simple biphasic systems. 相似文献
39.
40.