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D. G. Mazhakin V. K. Khlestkin A. Ya. Tikhonov L. B. Volodarsky 《Russian Chemical Bulletin》1996,45(4):880-884
Derivatives of 1,4-dihydroxypiperazine-2,3-dione were obtained by reaction of cis-1,2-bis(hydroxyamino)cycloalkanes with diethyl oxalate. Their alkylation with CH2N2 or Mel afforded 1,4-dimethoxypiperazine-2,3-diones. Hydrolysis of the latter gave 1,2-bis(methoxyamino)cycloalkanes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 925–929, April, 1996. 相似文献
3.
1-Hydroxy-2-oxo-3-phenyl-1,2-dihydroquinoxaline 4-oxide under conditions of the Mitsunobu reaction reacts with alcohols giving
the corresponding esters at the hydroxy group in position 1. Other representatives of hydroxamic acids such as 1,4-dihydroxyperhydroquinoxaline-2,3-dione
and 1,4-dihydroxy-3,3,6,6-tetramethylpiperazine-2,5-dione undergo destruction under these conditions.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1240–1243, June, 2008. 相似文献
4.
R. N. Khlestkin V. L. Khlestkina R. B. Valitov N. G. Usanov 《Reaction Kinetics and Catalysis Letters》1981,17(3-4):391-392
A correlation between the temperatures of the maximum thermal decomposition rate of salts or of the maximum heat effects, and the standard heats of formation of the respective metal oxides has been established.
, , .相似文献
5.
R. N. Khlestkin V. L. Khlestkina V. M. Gareev V. I. Dryagina 《Reaction Kinetics and Catalysis Letters》1984,25(3-4):289-291
The problem of predicting the activity of oxide and carbonate catalysts for some reactions of petrochemical synthesis (vapor phase conversion of carboxylic acids, catalytic oxidation of asphaltic tar to bitumen) according to the established dependence of thermal stability variations of intermediates on the formation enthalpy of metal oxides or standard ele.trode potentials is discussed.
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6.
A Gurtu P K Malhotra I S Mittra P M Sood SC Gupta VK Gupta GL Kaul LK Mangotra Y Prakash NK Rao ML Sharma 《Pramana》1974,3(5):311-322
This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR em = 〈n s〉/〈n ch〉, where 〈n ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R em = 1·71 implies an effectiveA-dependence ofR A =A 0.18,i.e., a very weak dependence. Predictions ofR em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production. 相似文献
7.
T. A. Duda V. K. Khlestkin L. L. Sveshnikova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(6):974-977
The 2-(4-hexadecylmethylamino)phenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxy-3-oxide radical, which contains a long alkyl chain and a strong donor substituent conjugated with a nitronyl nitroxide group (an acceptor), was synthesized. The behavior of monolayers formed by this radical on a water surface and the conditions of their transfer onto solid substrates by the Langmuir-Blodgett method were examined. UV-VIS and IR spectroscopies, atomic force microscopy, and small-angle X-ray scattering were used to study the optical and structural characteristics of films prepared from the pure radical and its mixtures with behenic acid. It was revealed that radical aggregates are formed both in solutions and Langmuir-Blodgett films. 相似文献
8.
Zhou C Khlestkin VK Braeken D De Keersmaecker K Laureyn W Engelborghs Y Borghs G 《Langmuir : the ACS journal of surfaces and colloids》2005,21(13):5988-5996
Protein resistant surfaces based on poly(ethylene glycol) (PEG) coatings are extensively applied in the fields of biosensors, tissue engineering, fundamental cell-surface interaction research, and drug delivery systems. The structural organization of the PEG film on the surface has a significant effect on the performance of the film to resist protein adsorption. In this paper, we report an approach using solvent to control the organization of the polymeric monolayer on gold. A water soluble copolymer with grafted PEG side chains and alkyl disulfide side chains was synthesized. A polymeric monolayer was fabricated on a gold surface from different solutions (water- and toluene-based) of the copolymer. The organization of the polymeric monolayers was characterized by means of ellipsometry, cyclic voltammetry, contact angle, X-ray photoelectron spectroscopy, and atomic force microscopy. It was proven that the structural organization of the polymeric monolayer on a gold surface could be controlled by the solvent. A polymeric monolayer with PEG enriched at the outer level is obtained when water is used as the solvent. Various types of proteins, including fibrinogen, albumin, and normal human serum, were used to test the protein resistance of the gold surfaces modified by the polymeric monolayers. The polymeric monolayer formed from a water solution of the copolymer showed excellent protein resistance. In addition, by using water as the solvent, patterning of the polymeric monolayer could easily be achieved through a combination of lift-off and self-assembly. We believe that the approach reported here provides an easy, fast, and efficient way to fabricate a robust protein resistant surface. 相似文献
9.
Interfacial surface properties of thiol-protected gold nanoparticles: a molecular probe EPR approach
Khlestkin VK Polienko JF Voinov MA Smirnov AI Chechik V 《Langmuir : the ACS journal of surfaces and colloids》2008,24(3):609-612
We present a molecular probe technique for accessing interfacial surface electrostatics of ligand-protected gold nanoparticles. A series of ligands with variable length of the hydrocarbon bridge between the anchoring sulfur and the reporting pH-sensitive nitroxide is described. The protonation state of this probe is directly observed by EPR spectroscopy. For tiopronin-protected Au nanoparticles, we observed an increase in pKa of up to ca. 1.1 pH units that was affected by the position of the reporter moiety with respect to the monolayer interface. 相似文献
10.
The eigen frequencies of radial pulsations of neutron stars are calculated in a strong magnetic field. At low densities we
use the magnetic BPS equation of state (EOS) similar to that obtained by Lai and Shapiro while at high densities the EOS obtained
from the relativistic nuclear mean field theory is taken and extended to include strong magnetic field. It is found that magnetized
neutron stars support higher maximum mass whereas the effect of magnetic field on radial stability for observed neutron star
masses is minimal. 相似文献