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Siberian Mathematical Journal - Under study is the multidimensional inverse problem of determining the convolutional kernel of the integral term in an integro-differential wave equation.... 相似文献
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The inverse problem of determining 2D spatial part of integral member kernel in integro‐differential wave equation is considered. It is supposed that the unknown function is a trigonometric polynomial with respect to the spatial variable y with coefficients continuous with respect to the variable x. Herein, the direct problem is represented by the initial‐boundary value problem for the half‐space x>0 with the zero initial Cauchy data and Neumann boundary condition as Dirac delta function concentrated on the boundary of the domain . Local existence and uniqueness theorem for the solution to the inverse problem is obtained. 相似文献
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Zhanna A. Krasnaya Vladimir A. Kuz’min Lyubov V. Litvinkova Evgeniya O. Dorofeeva Sergei G. Zlotin 《Mendeleev Communications》2013,23(4):212-214
New bischromophoric dyes (thiacarbocyanine and thiadicarbocyanine) containing coumarin moieties at each of the two benzothiazole systems, as well as monomethinecyanine containing coumarin moiety at only one heterocyclic system, manifest significant batho-chromic shift compared to relative coumarin-free dyes. 相似文献
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Lubov' V. Snegur Yury S. Nekrasov Nataliya S. Sergeeva Zhanna V. Zhilina Vera V Gumenyuk Zoya A. Starikova Alexander A. Simenel Nataliya B. Morozova Irina K. Sviridova Valery N. Babin 《应用有机金属化学》2008,22(2):139-147
The toxicity of ferrocenylethyl benzotriazole ( 1 ) and other ferrocene compounds including ferrocenylmethyl benzimidazoles ( 4,5,6,11 ), ferricenium salts ( 3,9,10 ) and ferrocenylmethyl adenine ( 7 ), was studied. All ferrocene complexes under investigation showed low or medium toxicities. On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of ferrocenylalkyl azoles 1, 8 and ferricenium salts 9, 10 was studied in vivo in the so‐called sub‐capsular test on human tumors. This effectiveness was compared with that of cisplatin. A series of ferrocenylalkyl azoles were synthesized by interacting azoles either with α‐hydroxyalkyl ferrocenes FcC(OH)R1R2 in organic solvent in the presence of aqueous HBF4 in quantitative yields or with trimethyl(aminomethyl)ferrocene iodide in an aqueous‐basic medium in good yields. The X‐ray determinations of molecular and crystal structures of α‐(1‐benzotriazolyl)ethylferrocene ( 1 ) and α‐(1‐naphthatriazolyl)ethylferrocene ( 12 ) were performed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Ludmila V. Chepeleva Alexander Yu. Matsakov Zhanna A. Kondratyuk Fedor G. Yaremenko Andrey O. Doroshenko 《Journal of photochemistry and photobiology. A, Chemistry》2010,209(2-3):163-173
Two isomeric pyrazole derivatives of 3-hydroxychromone (3HC) with and without the possibility of the multiple intramolecular hydrogen bonds formation were compared theoretically and experimentally with the aim to find out whether the excited state intramolecular proton transfer (ESIPT) reaction follows the traditional to the most of 3HCs “flavonol-like” direction towards the CO group oxygen or an “alternative” direction towards the heterocyclic nitrogen atom.Quantum-chemical modeling and comparative study of the experimental spectral parameters of the title compounds indicated the preferential realization of “flavonol-like” ESIPT to oxygen channel.The 3HC systems with the “alternative” intramolecular hydrogen bond to nitrogen were characterized as low fluorescent and practically unable to ESIPT with participation of the nitrogen containing heterocyclic unit. 相似文献
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Albert S. SHABAEV Azamat A. ZHANSITOV Zhanna I. KURDANOVA Leana Kh. KUCHMENOVA Svetlana Yu. KHASHIROVA 《色谱》2018,36(4):395-399
Poly(ether ether ketone)(PEEK)was synthesized via polycondensation of hydroquinone with 4,4′-difluorobenzophenone at 320℃for 5 h.Thermal and thermo-oxidative degradation of PEEK was studied over a wide range of temperatures.In an inert medium,decomposition of the polymer occurred in one stage,with the formation of a coke residue accounting for approximately 50%of the original polymer mass.In air,the mass loss curve exhibited two distinct stages.The first stage involved breakdown of the main polymer chain,the speed of which indicated a radical chain failure mechanism.In the second stage,the rate of mass loss clearly decreased,indicating a transition from the radical chain failure mechanism to simple combustion reactions(wherein the polymer combusted completely).To further investigate the nature of the processes occurring during the pyrolysis of PEEK,the investigations were carried out using gas chromatograph under isothermal conditions.It was concluded that during thermal degradation,the decomposition of the polymer starts with the rupture of ketone and ether bonds and proceeds to destruction of the benzene ring at higher temperatures,which is accompanied by the formation of H2O and CH4.Above 500℃,the polymer degradation further involved thermohydrolysis.The thermo-oxidation of PEEK,which was accompanied mainly by the formation ofH2,was noticeable beginning at 325℃.The total yield of the latter indicated oxidation of fragments of the benzene ring. 相似文献
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Dorofeeva VN Kolotilov SV Kiskin MA Polunin RA Dobrokhotova ZV Cador O Golhen S Ouahab L Eremenko IL Novotortsev VM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(16):5006-5012
Trinuclear building block {Fe(2)NiO(Piv)(6)} (Piv = pivalate), which possessed pseudo-D(3h) symmetry, was linked by two ligands, pseudo-D(3h) ligand tris-(4-pyridyl)pyridine (L1) and C(2v) ligand 4-(N,N-dimethylamino)phenyl-2,6-bis(4-pyridyl)pyridine (L2) into two products with different topologies: 2D coordination polymer [Fe(2)NiO(Piv)(6)(L1)](n) (1), and discrete molecule [{Fe(2)NiO(Piv)(6)}(8) {L2}(12)], which had a nanocube structure (2). In compound 1, trinuclear {Fe(2)NiO(Piv)(6)} blocks were linked through ligand L1 into layers with honeycomb topology. In compound 2, eight trinuclear blocks were located in the vertices of the nanocube, with each L2 ligand linked to two {Fe(2)NiO(Piv)(6)} units. In the crystal structure, these nanocubes formed infinite catenated chains. Analysis of possible structures that could be assembled from these building blocks showed that compounds 1 and 2 corresponded to their respective predicted topologies. Compound [1?solvent] possessed a porous structure, in which the voids were filled by solvent molecules (DMF or DMSO). This structure was retained following desolvation, and compound 1 absorbed significant quantities of N(2) and H(2) at 78?K (S(BET) = 730?m(2) g(-1), H(2) sorption capacity: 0.9?% by weight at 865?Torr). Desolvation of [2?solvent] led to disorder of its crystal structure, and compound 2 only adsorbed negligible quantities of N(2) but adsorbed 0.27?% H(2) (by weight) at 855?Torr and 78?K. The magnetic properties of these complexes (temperature dependence of molar magnetic susceptibility) were governed by the magnetic properties of the trinuclear "building block". 相似文献
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Alexander O. Terent’ev Igor B. Krylov Vera A. Vil’ Zhanna Yu. Pastukhova Sergey A. Fastov Gennady I. Nikishin 《Central European Journal of Chemistry》2012,10(2):360-367
It was found that oximes undergo deoximation in the presence of the H2O2aq-HBraq system to form ketones and bromo ketones. This reaction provided the basis for the synthesis of dibromo ketones in yields
varying from 40% to 94%. This method is environmentally friendly, sustainable, and easy to perform. The results of this investigation
extend the potential of the use of oximes for the protection of carbonyl group, thus offering the ability to perform not only
conventional deoximation but also the subsequent bromination of ketones. The reaction is easily scaled up and dibromo ketones
can be prepared in gram amounts.
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