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991.
G. F. Prozorova I. V. Mazyar V. V. Nosyreva S. A. Korzhova T. I. Vakul’skaya B. A. Trofimov 《Russian Journal of General Chemistry》2014,84(5):892-900
Interaction of trichloroethene with sodium tetra- and pentasulfide (prepared in turn from sodium sulfide and elemental sulfur) has lead to new family of polyvinylenepolysulfides containing up to 94% of sulfur. The polymers were found highly electrochemically active when applied as active cathode for lithium batteries. 相似文献
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995.
Spartak S. Khutsishvili Marina V. Lesnichaya Tamara I. Vakul’skaya Gania Dolmaa Galina P. Aleksandrova Aleksandr L. Rakevich 《光谱学快报》2018,51(4):169-173
Structural peculiarities and supramolecular organization of medicinally promising nanocomposites, synthesized from humic substances, which essentially differ depending on decomposition degree, have been studied using electron spin resonance, transmission electron, and confocal laser scanning microscopy techniques and some other modern physical–chemical methods. It is shown that stable zero-valent gold nanoparticle of about 10–17?nm in size are formed in a natural macromolecular matrix. The nanocomposites obtained turn out to be stable in aggregative state for a long time and preserve their properties that are extremely important for prospective medicinal substances. 相似文献
996.
V. N. Barvinchenko N. A. Lipkovskaya T. V. Fedyanina A. A. Rugal’ 《Colloid Journal》2014,76(2):139-145
The effect of the cationic surfactants decamethoxine and miramistin on the physicochemical properties of the natural flavonoids quercetin and rutin is studied spectrophotometrically in the range of physiological pH values. It is established that the interaction with these cationic surfactants changes the spectral characteristics of the flavonoids in solutions and essentially increases their adsorption on the surface of highly dispersed silica as compared with their aqueous solutions. It is shown that the efficiency of flavonoid adsorption from decamethoxine and miramistin solutions is governed by solution pH, flavonoid hydrophobicity, and the nature of a cationic surfactant. 相似文献
997.
With the consideration of mechanism of prevention and control for the spread of viral diseases, in this paper, we propose two novel virus dynamics models where state feedback control strategies are introduced. The first model incorporates the density of infected cells (or free virus) as control threshold value; we analytically show the existence and orbit stability of positive periodic solution. Theoretical results imply that the density of infected cells (or free virus) can be controlled within an adequate level. The other model determines the control strategies by monitoring the density of uninfected cells when it reaches a risk threshold value. We analytically prove the existence and orbit stability of semi-trivial periodic solution, which show that the viral disease dies out. Numerical simulations are carried out to illustrate the main results. 相似文献
998.
Steva Lević Nina Obradović Vladimir Pavlović Bojana Isailović Ivana Kostić Miodrag Mitrić Branko Bugarski Viktor Nedović 《Journal of Thermal Analysis and Calorimetry》2014,118(2):661-668
In this study, polyvinyl alcohol (PVA) nanofibers with ethyl vanillin as an active compound were prepared using electrospinning technique. The final products of electrospinning process were in the form of nanofibers films. PVA/ethyl vanillin nanofibers, having fibers diameters in the range 100–1700 nm, were successfully electrospun from ethanol/water mixture of PVA and ethyl vanillin. The effects of immobilization process on ethyl vanillin thermal properties were investigated by differential scanning calorimetry (DSC). The results of DSC showed significant influence of immobilization process on thermal properties of ethyl vanillin. It was noticed that melting point of immobilized ethyl vanillin was lower (~55 °C) compared to free flavor (~77 °C). Our results showed that films based on PVA/ethyl vanillin nanofibers are mechanically stable. 相似文献
999.
Irina E. Kononova Vyatcheslav A. Moshnikov Grażyna Olchowik Alexandr S. Len’shin Kamil G. Gareev Ekaterina A. Soboleva Vladimir V. Kuznetsov Jan M. Olchowik 《Journal of Sol-Gel Science and Technology》2014,71(2):234-240
This paper discusses the preparation and properties of gas detectors based on “porous silicon–nickel ferrite” nanocomposites. Impedance spectroscopy was used to measure sensitivity to ethanol and isopropanol vapours in the presence of an alternating electric field. The results were interpreted with the help of an equivalent electrical circuit. In the analysis of the resistive–capacitive properties in the equivalent circuit a constant phase element was used. 相似文献
1000.
N. N. Rozanov S. V. Fedorov R. S. Savel’ev A. A. Sukhorukov Yu. S. Kivshar 《Journal of Experimental and Theoretical Physics》2012,114(5):782-791
The frequency dependence of the gain required to compensate for absorption is determined for a layered structure consisting of alternating absorbing and amplifying layers. It is shown that the fulfillment of the same conditions is required for the existence of a band structure consisting of alternating bands allowed and forbidden for optical radiation propagation in the frequency-wave vector parametric region. Conditions are found under which the gain required for compensation is smaller than thresholds for absolute (parasitic lasing) and convective (waveguide amplification of radiation) instabilities. 相似文献