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101.
Gas-separation membranes based on interpolymer complexes of sulfonate-containing aromatic polyamides
The gas-separation properties of membranes prepared from sulfonate-containing aromatic polyamide and aliphatic polyamines
are studied. With the use of potentiometry, IR spectroscopy, and elemental analysis, it is shown that interpolymer complexes
arising in these systems are primarily stabilized by electrostatic forces, while the degree of transformation in them is dependent
on the basicity of polyamine and the conditions of the interpolymer reaction. The relationship between the nature of polyamine,
the composition of the interpolymer complex, and the degree of transformation in it and the gas-separation characteristics
of the membranes is established. 相似文献
102.
N. L. Smirnova 《Crystallography Reports》2010,55(7):1174-1176
It is established that one of the 12 Kepler nets (R, 3366 + 3636) belongs to Krötenheerdt nets. However, the number of Kepler nets remains 12, because one of them (L, 33336) is enantiomorphic. Along with 20 Krötenheerdt nets, there may be many other polytypes which enter infinite sequences of the O, OD, DO, D types. 相似文献
103.
E. V. Suvorov I. A. Smirnova 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(6):1189-1192
X-ray diffraction patterns in a thin crystal are investigated by numerical simulation and experimental section topography
for the case when the screw dislocation axis is parallel to the dislocation vector. The strongly distorted region near the
dislocation core is found to operate like an X-ray mirror wheninteracting with an X-ray wave field in a scattering triangle;
i.e., new wave fields appear in the new scattering triangles in the strong distortion region where the crystal departs from
the reflecting position, and the coherent interaction of the new fields with the old leads to the formation of a complex X-ray
image. Superposition of these waves, taking into account their phases, is found to result in a large variety of defect images. 相似文献
104.
We formulate and solve certain problems of the optimal amplitude-phase tuning of antenna complexes that emit and receive acoustic
signals in inhomogeneous ocean-type waveguides. 相似文献
105.
We studied polymerizable nanocomposites for obtaining polymer-nanoparticle periodic structures by a holographic method. A general approach to choosing components of composites is developed that ensures a maximal contrast and high efficiency of structures for different types of nanoparticles. We found that the optimal monomeric component of a nanocomposite is a combination of single- and multifunctional monomers with substantially different reactivities. In this case, the low-reactivity monomer should posses a low viscosity, be a good solvent for nanoparticles, and have a low thermodynamic affinity to the polymer network formed upon the polymerization of the high-reactivity monomer. We developed a holographic composition based on known commercially produced monomers that ensures the formation of highly efficient periodic structures for nanoparticles of different types. We described the holographic properties of obtained nanocomposites, as well as parameters of bulk gratings recorded in them. 相似文献
106.
I. V. Zavarzin N. G. Smirnova V. N. Yarovenko M. M. Krayushkin 《Russian Journal of Organic Chemistry》2006,42(2):273-274
A convenient procedure was developed for preparation of thiazolo[5,4-b]pyridine-2-carboxamides by oxidation of monothiooxamides synthesized from 3-aminopyridine. 相似文献
107.
By high-precision dynamic calorimetry the temperature dependences of heat capacity of dimethylene urethane (DMU) between 320 and 370 K and partially crystalline poly(dimethylene urethane) (PDMU) in the range 326-490 K at standard pressure have been determined within ±1.5%. The thermodynamic characteristics of fusion of the substances, namely the temperature interval of melting, temperature, enthalpy and entropy of fusion, as well as the characteristics of devitrification and glassy state for poly(dimethylene urethane) have been estimated. The first and the second cryoscopic constants have been calculated for dimethylene urethane. The experimental data obtained in the present work and literature findings on the heat capacity of the substances were used to calculate their thermodynamic functions: the heat capacity C°p (T), enthalpy H°(T)−H°(0), entropy S°(T) and Gibbs function G°(T)−H°(0) over the range from T→0 to (370-480) K. Based on the data, the thermodynamic characteristics of polymerization process with five-membered ring opening ΔpolH°, ΔpolS° and ΔpolG° of dimethylene urethane with the formation of linear partially crystalline poly(dimethylene urethane) have been evaluated. 相似文献
108.
M. K. Mirzakhmedova L. S. Smirnova S. Mukhamedova Kh. A. Abduazimov 《Chemistry of Natural Compounds》1986,21(6):784-786
A comparative study of the dioxane lignins isolated from healthy and wilt-affected cotton plant stems has shown thatFusarium fungi demethylate lignin and make it more oxidized than the lignin from healthy stems.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 825–827, November–December, 1985. 相似文献
109.
Zavarzin I. V. Smirnova N. G. Chernoburova E. I. Yarovenko V. N. Krayushkin M. M. 《Russian Chemical Bulletin》2004,53(6):1257-1260
A method for syntheses of previously unknown derivatives of thieno[2,3-d]pyrimidines and quinazolines from monothiooxamides was proposed. 相似文献
110.
E. P. Smirnova A. V. Sotnikov N. V. Zaitseva H. Schmidt M. Weihnacht 《Physics of the Solid State》2014,56(5):996-1001
The dielectric and acoustic properties of (1 ? x)SrTiO3?xBiFeO3 solid solutions (0 ≤ x ≤ 1) have been studied in the temperature range from 4.2 to 850 K. Evolution of the antiferrodistortive transition and its suppression in the concentration range 0.1 < x < 0.2 have been revealed. X-ray diffraction data obtained at room temperature, as well as the observed acoustic anomalies combined with dielectric measurements, have been used to estimate the concentration range of the existence of the relaxor state, as well as of the formation and coexistence of the antiferromagnetic and ferroelectric phases at high BiFeO3 concentrations. 相似文献