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1.
TS Bayasgalan 《Integral Equations and Operator Theory》1998,31(2):255-258
For bounded normal operators in Krein spaces we give a necessary and sufficient condition for strong stability. The same result for unitary operators was obtained by M.G.Krein [1] (see also [2]). For selfadjoint operators we refer to the papers of P.Jonas, H.Langer [3] and H.Langer [4]. 相似文献
2.
T. S. Tulyaganov 《Chemistry of Natural Compounds》1993,29(1):26-30
The new alkaloid komavicine has been isolated from the epigeal part ofNitraria komarovii, and its structure has been established on the basis of spectral characteristics and chemical transformations. The products of the dehydrogenation of nitrarine with selenium and sulfur have been studied. A method has been developed for the dehydrogenation of dihydro and tetrahydro derivatives in the quinolinyl--carboline series.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 33–39, January–February, 1993. 相似文献
3.
The quantitative composition of the combined metabolites isolated from the rat organism after the administration of the anticholinesterase preparation deoxypeganine and its analog deoxyvasicinone has been determined by the mass-spectrometric method of integrating the ion current. The results of the determination have been compared with those obtained by UV spectroscopy.Institute of the Chemistry of Plant Substances, Academy of Sciences of the USSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 201–206, March–April, 1981. 相似文献
4.
Two new alkaloids nitraramidine and nitraraidine were isolated from the aerial part of Nitraria sibirica. Their structures were established using spectral data and chemical transformations. 相似文献
5.
V. N. Plugar' N. D. Abdullaev Ya. V. Rashkes M. R. Yagudaev N. Tulyaganov 《Chemistry of Natural Compounds》1984,19(6):720-727
The structures of the main components of the total metabolites of the anticholinesterase drug deoxypeganine (DOP) and its analog deoxyvasicinone (DOV) in the rat organism have been studied. The structures of two metabolites of DOP and DOV — 11-hydroxydeoxyvasicinone and 2-(-ethoxycarbonyl)ethyl-4-quinazoline — have been determined by the PMR method. On the basis of their structures and the results of measurements of the elementary compositions of ions, the fragmentation of the compounds has been elucidated. A minor component of the total metabolites has been isolated by chromato-mass spectrometry and for it the structure of 6-methoxydide-hydrovasicinone is proposed. A scheme of the metabolism of DOP and DOV has been put forward.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 758–766, November–December, 1983. 相似文献
6.
Hugo R. Fernandes Dilshat U. Tulyaganov José M. F. Ferreira 《Journal of Thermal Analysis and Calorimetry》2013,112(3):1359-1368
The crystallisation kinetics of experimental glasses in 3 different systems: (A) Li2O–SiO2, (B) Li2O–Al2O3–SiO2 and (C) Li2O–K2O–Al2O3–SiO2 were studied under non-isothermal conditions. The DTA results revealed a stronger tendency to crystallisation of binary compositions in comparison to the ternary and quaternary compositions comprising Al2O3 and K2O which present the lower crystallisation, i.e. the crystallisation propensity follows the trend A > B > C. The devitrification process in the Li2O–SiO2 and Li2O–Al2O3–SiO2 systems began earlier and the rate was higher in comparison to that of glasses in the quaternary Li2O–K2O–Al2O3–SiO2 system. Thus, addition of Al2O3 and K2O to glasses of Li2O–SiO2 system was demonstrated to promote glass stability against crystallisation. However, the activation energy for crystallisation was shown to depend also on the SiO2/Li2O ratio with the binary system showing a decreasing trend with increasing SiO2/Li2O ratio, while the opposite tendency was being observed for compositions with added Al2O3 and K2O. 相似文献
7.
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9.
R. Ya. Okmanov B. Tashkhodzhaev Z. M. Khakimova T. S. Tulyaganov Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(1):59-61
Crystal structures of the alkaloids vasicinone and peganidine hydrochloride were studied by x-ray structure analysis. The
configurations of asymmetric centers C4 and C9 in peganidine were determined. The hydroxyl and acetonyl groups were mutually
syn-positioned relative to the tricyclic plane. H-bonds involving the Cl ion, which connected molecular cations transformed
by 21 screw axes, were formed in the peganidine hydrochloride crystal. H-bonds between the C4 carbonyl and the C9 hydroxyl transformed
by a glide plane were formed in the vasicinone crystal. The N1 atom was not involved in forming intermolecular H-bonds. 相似文献
10.
Hugo R. Fernandes Dilshat U. Tulyaganov Ashutosh Goel José M. F. Ferreira 《Journal of Thermal Analysis and Calorimetry》2011,103(3):827-834
This article aims to shed some light on the structure and thermo-physical properties of lithium disilicate glasses in the
system Li2O–SiO2–Al2O3–K2O. A glass with nominal composition 23Li2O–77SiO2 (mol%) (labelled as L23S77) and glasses containing Al2O3 and K2O with SiO2/Li2O molar ratios (3.13–4.88) were produced by conventional melt-quenching technique in bulk and frit forms. The glass-ceramics
(GCs) were obtained from nucleation and crystallisation of monolithic bulk glasses as well as via sintering and crystallisation
of glass powder compacts. The structure of glasses as investigated by magic angle spinning-nuclear magnetic resonance (MAS-NMR)
depict the role of Al2O3 as glass network former with four-fold coordination, i.e., Al(IV) species while silicon exists predominantly as a mixture
of Q
3
and Q
4
(Si) structural units. The qualitative as well as quantitative crystalline phase evolution in glasses was followed by differential
thermal analysis (DTA), X-ray diffraction (XRD) adjoined with Rietveld-reference intensity ratio (R.I.R.) method, Fourier
transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The possible correlation amongst structural
features of glasses, phase composition and thermo-physical properties of GCs has been discussed. 相似文献