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1.
2.
Michail Loulakis 《Communications in Mathematical Physics》2002,229(2):347-367
It is known that the rescaled position of a tagged particle in symmetric simple exclusion processes converges to a diffusion.
If now the tracer particle is driven by a small force, then it picks up a velocity. The Einstein relation states that in the
limit, this velocity is proportional to the small force, and the constant of proportionality can be computed from the diffusion
matrix of the tracer particle with no driving force. Such a relation is believed to be generally valid. In this article we
establish its validity for all symmetric simple exclusion processes in dimension and we prove a density property for certain invariant states of the driven system.
Received: 2 September 2001 / Accepted: 28 March 2002 Published online: 31 July 2002 相似文献
3.
Rastislav Varga Arcady Zhukov Michail Ipatov Juan Maria Blanco Julian Gonzalez Valentina Zhukova Pavol Vojtanik 《Journal of magnetism and magnetic materials》2006
The effect of the glass coating on the single domain wall potential in amorphous glass-coated Fe-based microwire has been studied by the switching field distribution technique. The thermoactivated mechanism model is used to describe the thermally activated switching through the complex energy barrier in amorphous FeSiB microwires. Glass removal leads to the increase of the probability of the thermally activated switching pointing to the decrease of the energy barrier. 相似文献
4.
Alexei Yu. Lukin Sergei V. Shevyakov Alexei V. Laptev Olga I. Davydova Vitali I. Shvets Olga V. Demina Yury P. Strokach Valery A. Barachevsky Michail V. Alfimov Sergei P. Gromov Artem I. Vedernikov Johan Lugtenburg Andrey A. Khodonov 《Journal of inclusion phenomena and macrocyclic chemistry》2004,49(1-2):153-161
An effective synthetic approach to the preparation of a new crown-ether vinylogs involving the Horner–Emmons olefination of carbonyl precursors with the use of C2- and C5-phosphonates was proposed. The effects of the conjugation chain length and the nature of the terminal polar functions in the phosphonate reagent on the yield and process stereoselectivity were discussed. 相似文献
5.
Minko S Müller M Motornov M Nitschke M Grundke K Stamm M 《Journal of the American Chemical Society》2003,125(13):3896-3900
We report a route to fabricate two-level structured self-adaptive surfaces (SAS) of polymer materials. The first level of structure is built by a rough polymer film that consists of needlelike structures of micrometer size. The second level of structure is formed by the nanoscopic self-assembled domains of a demixed polymer brush irreversibly grafted onto the needles. By exposing the surface to solvents that are selective to one of the components of the brush, we reversibly tune the surface properties. The large-scale surface structure amplifies the response and enables us to control wettability, adhesion, and chemical composition of the surface over a wide range. 相似文献
6.
M. A. Haimova M. D. Palamareva C. I. Novkova B. J. Kurtev C. A. Petrova T. I. Arnaudov 《Monatshefte für Chemie / Chemical Monthly》1970,101(3):855-865
Zusammenfassung Durch Umsetzung von Hydramiden mit am aromatischen Ring m,p-dialkoxysubstituierten Arylessigsäureestern in Gegenwart von wasserfr. AlCl3 entstehen Gemische aus Estern der (±)-erythro- und (±)-threo-3-Amino-2,3-diarylpropansäuren. Bei der Umsetzung von Piperonalhydramid mit dem Methylester der Homoveratrumsäure konnte lediglich daserythro-Diastereomere isoliert werden.Die diastereomeren Ester wurden zu den jeweiligen (±)-erythro- und (±)-threo-3-Amino-2,3-diaryl-1-propanolen reduziert, die als N,O-Dibenzoylderivate charakterisiert wurden. Ihre relativen Konfigurationen und die der zugehörigen Ester wurden auf Grund der IR-Spektren der diastereomeren Aminopropanole bestimmt. Die NMR-Spektren eines Diastereomerenpaares von Aminopropanolen bestätigen die ihnen chemisch zugeordneten Konfigurationen und ermöglichen den Nachweis auch ihrer bevorzugten Konformationen.
Synthesis and configuration of methyl esters of the diastereomeric (±)-3-amino-2,3-diarylpropanoic acids, the (±)-3-amino-2,3-diaryl-1-propanols and their derivatives
Reaction of hydramides with m,p-dialkoxysubstituted arylacetates in the presence of anhydrous AlCl3 generally leads to mixtures of the esters of the (±)-erythro- and (±)-threo-3-amino-2,3-diarylpropanoic acids. However, in the reaction of piperonal hydramide with methyl homoveratrate, only the correspondingerythro-diastereomer was obtained.Reduction of the diastereomeric esters gives the corresponding (±)-erythro- and (±)-threo-3-amino-2,3-diaryl-1-propanols, which can be characterized as N,O-dibenzoyl derivatives. Relative configurations of both alcohols and esters were determined by means of their IR spectra. Configurations were confirmed for one pair of diastereomeric amino alcohols by means of NMR spectra and preferred conformations deduced.相似文献
7.
The geometry of the 4′-cyano-(4′-CNPTB) and the 4′-methoxy-(4′-MePTB) phenylthiolbenzoates were obtained by ab initio calculations
employing 6–31G basis set at Hartee-Fock level of theory. The results predict an extended form of the molecules and torsional
angle between the phenyl rings at 90.85(6)0 and 90.87(3)0, respectively. On the basis of vibrational analysis the frequency assignment was carried out. The calculated frequencies
were compared with the experimental IR spectral data in carbon tetrachloride, carbon disulfide solutions and in solid state. 相似文献
8.
9.
Janko Dimitriev Michail Arnaudov Vesselin Dimitrov 《Monatshefte für Chemie / Chemical Monthly》1976,29(21):1335-1343
Studies of glasses and their crystalline products in the TeO2–V2O5 system were made in the 1400–400 cm–1 range. A continuous shift of the V=O-band from 1020 cm–1 to 940 cm–1 was found in the glasses with decreasing concentration of V2O5, as well as a sharp decrease in the intensity at 830 cm–1. On the basis of the results obtained, it is concluded that with increasing TeO2 content, the structure of the glasses is changed, caused by the breaking of the V–O–V bonds and the formation of Te–O–Te bridges.The IR-spectrum of the 2TeO2·V2O5 compound in both crystalline and vitreous states was studied for the first time. The behaviour of the absorption bands is related to the structure of the glasses studied. 相似文献
10.
The adsorption kinetics of Triton X-100 and Triton X-405 at solution/air and solution/hexane interfaces is studied by the recently developed fast formed drop technique. The dynamic interfacial tension of Triton X-100 and Triton X-405 solutions against hexane has been measured without preequilibration of the water and oil phases. It is found that the dynamic interfacial tension of Triton X-100 solutions passes through a minimum. This strange behavior is attributed to partial solubility of the surfactant in hexane. Such minima of the dynamic interfacial tension of Triton X-405 solutions have not been observed, which correlates well with the solubilities of both surfactants in hexane reported in the literature. The dynamic surface tension of solutions of both surfactants and the dynamic interfacial tension of Triton X-405 solutions are interpreted by the Ward and Tordai model for diffusion controlled adsorption. It is shown that proper interpretation of the experimental data depends on the type of isotherm used. More consistent results are obtained when the Temkin isotherm is used instead of the Langmuir isotherm. The results obtained with Triton X-100 at the solution/air interface confirm that the adsorption of this surfactant occurs under diffusion control. The adsorption of Triton X-405 at solution/air and at solution/hexane interfaces seems to occur under diffusion control at short periods of time, but under mixed (diffusion-kinetic) control at long periods of time. A hypothesis is drawn to explain this phenomenon by changes in the shape of the large hydrophilic heads of Triton X-405 molecules. Copyright 2000 Academic Press. 相似文献