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21.
D. Ya. Tsvankin V. S. Papkov V. P. Zhukov Yu. K. Godovsky V. S. Svistunov A. A. Zhdanov 《Journal of polymer science. Part A, Polymer chemistry》1985,23(4):1043-1056
The structure changes accompanying phase transitions in poly(diethylsiloxane) (PDES) have been studied by WAXS and SAXS techniques using oriented and isotropic samples. PDES may exist in two low-temperature modifications (the monoclinic α1-form and presumably the “tetragonal” β1-form) and two high-temperature modifications (the monoclinic α2-form and the “tetragonal” β2-form). In linear PDES the crystal - crystal transitions α1–α2 and β1–β2 occur near 214 and 206 K, respectively. At higher temperatures α2 (280 K) and β2 (290 K) forms transform into the mesomorphic phase αm that gradually melts at 280–300 K giving an amorphous phase. According to x-ray and density data, αm phase is also characterized by monoclinic structure slightly different from hexagonal packing. 相似文献
22.
T. I. Osipova A. V. Belyankin A. R. Khomutov Yu. N. Zhukov E. N. Khurs R. M. Khomutov 《Russian Chemical Bulletin》1996,45(11):2588-2591
The reaction of ketoximes with hypophosphorous acid resulted in previously unknown -substituted--aminophosphinic acids, which were oxidized into the corresponding -substituted--aminophosphonic acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2729–2732, November, 1996. 相似文献
23.
Daniel Erne Daniel Ammann Alex F. Zhukov Felix Behm Ern Pretsch Wilthelm Simon 《Helvetica chimica acta》1982,65(2):538-545
A series of lipophilic N, N, N′,N′-tetrasubstituted diamides were prepared and their selectivity in solvent polymeric membranes was studied, cis-N, N, N′, N′-Tetraisobutylcyclohexane-1,2-dicarboxamide induces a selectivity in membranes for Li+over alkaline earth metal cations and other alkali metal cations by a factor of about 1000 and 100 respectively. The ionophore N, N′-diheptyl-N,N′-dimethylethylmalonamide is an attractive candidate for the use in microelectrodes for the determination of intracellular Mg2+-activities. 相似文献
24.
T. V. Magdesieva I. V. Zhukov L. G. Tomilova E. V. Chernykh K. P. Butin 《Russian Chemical Bulletin》1997,46(12):2036-2043
The electrochemical potentials of seven redox transitions for green forms and eight redox transitions for blue forms of neutral
octa-tert-butylsubstituted diphthalocyanine cornplexes of lanthanides Pct
2Ln (Ln=Pr, Sm, Dy, and Lu) in solutions were measured by cyclic voltammetry and rotating disc electrode techniques. The spectroelectrochemical
investigation of the products of two-electron oxidation and reduction of the green form of Pct
2Lu was performed. The frontier molecular orbitals, total charge densities, total spin densities, electrostatic potentials,
and heats of ion formation for (Pc2Y)
m+,n−
(m=0, 1, 2 and 3;n=1, 2, 3 and 4), which can model the products of the redox transitions of the diphthalocyanines under study, were calculated
using the semiempirical ZINDO/1 method. The calculations for (Pc2Y)
m+,n−
and absorption spectra show that the electron changes in all redox transitions of the green forms of Pct
2Ln are mainly localized on the ligands.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya No. 12, pp. 2149–2156, December, 1997. 相似文献
25.
The conductivity of dilute quartz suspensions and electrophoretic mobility of quartz particles in solutions with the concentration C = 10–5–10–2 M XBr (X = H, Cs, Na, and Li) and NaOH, as well as in mixed solutions of 10–4 M XBr (X = Cs, Na, and Li) + 10–4–10–2 M HBr and 10–4 M XBr + 10–4–10–2 M XOH (X = Cs, Na, and Li) in ethanol containing 6 vol % of water were measured using conductometry and microelectrophoresis. The values of surface conductivity of quartz were calculated by the Wagner formula and used to calculate zeta potential by the Henry–Booth formula. The resultant dependences (logC) suggest that the value and sign of zeta potential are determined not only by the adsorption of potential-determining ions + and –, but also by the competitive specific adsorption of all ions of the aforementioned electrolytes, the adsorption values increasing in a cation series Li+ < Na+ < Cs+ < H+ and an anion series Br– < OH–. In particular, it is found that the titration of the above suspensions with XOH bases results in the reversal of zeta potential sign from negative to positive at a concentration depending on the adsorption capacity of alkali cation. 相似文献
26.
K. Laihia A. Valkonen E. Kolehmainen A. Antonov D. Zhukov I. Fedosov V. Nikiforov 《Journal of Molecular Structure》2006,800(1-3):100-105
Three spiro[pyrrolidine-2,3′-oxindoles], 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-phenyl-spiro[3H-indole-3,3′-[3H]-pyrrolizine]-2′-carboxylic acid methyl ester (1), 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-phenyl-spiro[3H-indole-3, 3′-[3H]-pyrrolizine] (2) and 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-(4″-chlorophenyl)-spiro[3H-indole-3,3′-[3H]-pyrrolizine] (3) have been synthesized and their 1H, 13C and 15N spectra assigned. The chemical shift assignments are based on Pulsed Field Gradient (PFG) Double Quantum Filter (DQF) 1H, 1H correlation spectroscopy (COSY), PFG 1H, 13C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG 1H,X (X = 13C and 15N) Heteronuclear Multiple Bond Correlation (HMBC) experiments. The single crystal X-ray structures of 1–3 have been determined. Compounds 1 and 2 crystallized in monoclinic space group C2/c and compound 3 in monoclinic space group P21/c, respectively. Also the ESI-TOF MS data of 1–3 are given. 相似文献
27.
M. E. Prokhorov A. I. Zakharov O. Yu. Stekolshchikov M. S. Tuchin M. K. Abubekerov A. O. Zhukov 《Doklady Physics》2016,61(1):5-7
We propose to introduce a geometric control subsystem into the attitude control systems of space-craft that would allow the current system sensor configuration to be determined in real time. 相似文献
28.
L. V. Sokolov A. A. Zhukov N. M. Parfenov S. O. Igoshin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(1):178-180
The results of studying the formation of the three-dimensional micromechanical structure of an integral tensoconverter are presented. The technological restrictions on contact photolithography over the relief structure formed on the device layer of the silicon-on-insulator wafer are analyzed. The effect of the design parameters (the frame height and the width of the frame slit) are described. 相似文献
29.
D. A. Zhukov 《Russian Mathematics (Iz VUZ)》2017,61(12):13-18
We investigate the infinitesimal MG-deformations of a simply connected surface with positive Gaussian curvature. We choose any symmetric tensor on the surface, variation of the first and the second invariant of this tensor equals given function along a boundary. The study of these boundary-value problems is reduced to the investigation of a solvability of Riemann–Hilbert boundary-value problem and to calculation of its index. As a result we get theorems of existence and uniqueness for the infinitesimal MG-deformation. 相似文献
30.
Alexander V. Zhukov Roland Bouffanais Anastasia V. Pak Mikhail B. Belonenko 《Physics letters. A》2013
In this study we investigate the propagation of extremely short optical pulses in a thin film formed by a graphene grown on a boron nitride substrate. Conduction electrons of the system are described on the basis of the long-wavelength effective Hamiltonian in the case of low temperatures; the electromagnetic field being taken into account within the framework of the classical Maxwell equations. The time evolution of the pulse?s shape for different speeds and maximum amplitudes of an extremely short pulse is analyzed. 相似文献