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1.
S. Albeverio S. N. Lakaev J. I. Abdullaev 《Functional Analysis and Its Applications》2002,36(3):212-216
A Hamiltonian describing four bosons that move on a lattice and interact by means of pair zero-range attractive potentials is considered. A stronger version of the Hunziker–Van Vinter–Zhislin theorem on the essential spectrum is established. It is proved that the set of eigenvalues lying to the left of the essential spectrum is finite for any interaction energy of two bosons and is empty if this energy is sufficiently small. 相似文献
2.
This paper reports on the results of experimental investigations into the thermal conductivity of GaS and GaSe layered semiconductor crystals in directions parallel and perpendicular to the crystal layers in the temperature range 5–300 K. Specific features of the thermal conductivity of these crystals are analyzed. 相似文献
3.
A. A. Ibragimov Z. Osmanov B. Tashkhodzhaev N. D. Abdullaev M. R. Yagudaev S. Yu. Yunusov 《Chemistry of Natural Compounds》1981,17(5):458-463
The proof of the structures of two isomeric alkaloids — nitramine and isonitramine — from two species of plants of the genusNitraria is given. Their diastereoisomerism with respect to the C7 asymmetric atom has been established. This is the first time that alkaloids with the structure of 2-azaspiro[5,5]undecan-7-ol have been found. 相似文献
4.
5.
Ya. V. Rashkes A. M. Rashkes U. A. Abdullaev M. M. Kiktev N. K. Khidyrova V. N. Plugar Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》1994,30(2):254-260
The qualitative and quantitive compositions of fractions from the leaves of two self-pinching-out lines of cotton plant and
of the standard variety 108-F have been determined in parallel by mass chromatography, and differences in their contents of
the main metabolites have been determined. A fraction of the secondary metabolites (SMs) obtained from mature leaves of a
cotton plant of the self-pinching-out line L-49 has shown a retardant activity in treatment of the growth points of plants
of the Tashkent-1 variety.
Deceased. 相似文献
6.
In the quark-parton model we obtain an expression for the effective cross section of the process of direct photon generation in the annihilation of an antineutrino and an electron into hadrons (e + e + X). The angular and energy dependences of the photons are investigated. It is shown that for large photon energies, the contribution from hadronic radiation dominates that from leptonic radiation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 98–103, November, 1987. 相似文献
7.
8.
Tulyasheva M Rasulev BF Tojiboev AG Turgunov KK Tashkhodjaev B Abdullaev ND Shakhidoyatov KM 《Molecules (Basel, Switzerland)》2005,10(9):1209-1217
The new compounds (Z)-ethyl 2-cyano-2-(3H- and 2-methyl-3H-quinazoline-4-ylidene) acetate (1 and 2, respectively) were synthesized by multi-step reactions. The structures in a solution have been determined by (1)H-NMR spectroscopy and in the crystal form by X-ray analysis. Molecule 1 crystallized in a primitive monoclinic cell, space group capital ER, P2(1/c). The cell dimensions are a=7.970(6) A, b=7.061(2) A, c=20.537(7) A, beta=97.69(5) degrees , V=1145.3(10) A(3). Molecule 2 crystallized in a triclinic cell, space group P-1, the cell dimensions are a=8.196(5) A, b=8.997(6) A, c=9.435(4) A, alpha=74.22(4) degrees, beta=89.75(4) degrees , gamma=74.07(5) degrees , V=641.9(6) A(3). In both compounds the presence of intra-molecular NH---O=C hydrogen bonding between the nitrogen atom in position 3 of the quinazoline ring and a carbonyl group of the ethyl cyanoacetate residue was proven by quantum-chemical, (1)H-NMR and X-ray methods. 相似文献
9.
K. L. Lutfullin M. M. Tadzhibaev V. M. Malikov U. A. Abdullaev U. Rakhmankulov 《Chemistry of Natural Compounds》1977,12(6):696-699
Summary The biosynthesis of the alkaloids ofAmmothamnus lehmannii Bge. have been studied by supplying the plants with [1,5-14C2] cadaverine. It has been shown that cadaverine is a precursor of sophocarpidine, sophocarpine, and pachycarpine. Possible routes of interconversions have been studied by supplying the plants with the tritium-labelled alkaloids [3H] sophocarpine, [3H] matrine, and [3H] pachycarpine.V. I. Lenin Tashkent State University. Institute of Plant Biochemistry, Academy of Sciences of the German Democratic Republic, Halle. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 776–780, November–December, 1976. 相似文献
10.