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排序方式: 共有193条查询结果,搜索用时 15 毫秒
91.
Felix D. Sokolov Maria G. Babashkina Damir A. Safin Axel Klein 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1815-1822
The complexation and extraction properties of RC(S)NHP(X)(OiPr)2 [X = S, R = PhNH (HLI); X = O, R = PhNH (HLII), Ph (HLIII)] towards cobalt cations were studied. The nitrocellulose membrane was used as a carrier for HLI?III. The maximal degree of extraction of cobalt cations from an aqueous solution is observed at pH = 7.8–8.4. It was established that complexes formed are kept in a water solution on a surface of the carrier and washed away in 96% aqueous ethanol. The membrane modified by HLI allows extraction and concentration of Co(II) selectively, while the modification by HLIII leads to the selective extraction of Co(III). 相似文献
92.
Damir Z. Arov 《Journal of Functional Analysis》2009,256(12):3892-3327
Let Z be a maximal nonnegative subspace of a Kre?n space X, and let X/Z be the quotient of X modulo Z. Define
H(Z)={h∈X/Z|sup{−X[x,x]|x∈h}<∞}. 相似文献
93.
Damir R. Tadjiev 《Journal of Non》2010,356(2):102-6145
The near-surface mechanical properties of glasses and differences in mechanical behaviour between high and low durability silicate glasses are investigated. Nanoindentation is used to examine the effect of hydration on the near-surface mechanical properties of silicate glasses with varying degrees of chemical durability. It is shown that hydration has little if any effect on high durability glasses even at long immersion times, whereas in low durable glasses hydration reduces the near-surface mechanical properties significantly and the thickness of hydrated layer may exceed the indentation depth. In addition an attempt is made to measure the thickness and mechanical properties of hydrated layer in low durability glasses where influence of the substrate is negligible. 相似文献
94.
Safin DA Babashkina MG Robeyns K Garcia Y 《Dalton transactions (Cambridge, England : 2003)》2012,41(15):4324-4327
Reaction of the potassium salt of N-thiophosphorylated thiourea 6-MeO(O)CC(6)H(4)NHC(S)NHP(S)(OiPr)(2) (HL) with PdX(2) (X = Cl(-), Br(-), I(-)) leads to the dark red binuclear complexes [(PdLX)(2)], while the same reaction with PdY(2) (Y = NO(3)(-), CN(-), CH(3)COO(-)) leads to the light red mononuclear complex [PdL(2)]. [PdL(2)] exhibits reversible photoinduced cis-isomerization upon irradiation at 365 or 450 nm, reverting back to the trans-isomer in darkness or upon irradiation at 546 nm. 相似文献
95.
Babashkina MG Safin DA Robeyns K Garcia Y 《Dalton transactions (Cambridge, England : 2003)》2012,41(5):1451-1453
Reaction of the deprotonated N-thiophosphorylated thiourea (4'-benzo-15-crown-5)NHC(S)NHP(S)(OiPr)(2) (HL) with NiCl(2) in aqueous EtOH leads to dark green [Ni(L-1,5-S,S')(2)]·2H(2)O crystals that were isolated by recrystallization from a mixture of CH(2)Cl(2) and n-hexane. 相似文献
96.
Bitangential input scattering problems are formulated and analyzed for canonical integral systems. Special attention is paid to the case when the input scattering matrix is ap×q matrix valued function of Wiener class. Formulas for the solution of the inverse input scattering problem are obtained by reproducing kernel Hilbert space methods. A number of illustrative examples are presented. Additional examples for the case when the input scattering matrix is of Wiener class/rational will be presented in a future publication. 相似文献
97.
Damir Vukicevic Milan Randic Alexandru T. Balaban 《Journal of mathematical chemistry》2004,36(3):271-279
A rigorous proof is provided for the theorem on the necessary and sufficient conditions for the algebraic Kekulé structure of a peri-condensed or corona-condensed benzenoid hydrocarbon to correspond to more than one geometric Kekulé structure. 相似文献
98.
Nadezhda M. Vitkovskaya Vladimir B. Orel Vladimir B. Kobychev Alexander S. Bobkov Damir Z. Absalyamov Boris A. Trofimov 《International journal of quantum chemistry》2020,120(9):e26158
The mechanisms of fundamental base-promoted acetylene reactions, namely, nucleophilic addition to the triple C ≡ C bond (vinylation) and nucleophilic addition of acetylenic carbanion to a carbonyl group (ethynylation), are addressed using three models of different complexity—pentasolvate, monosolvate, and anionic—which describe the catalytic superbasic systems MOH(OBut)/DMSO (suspensions of alkali hydroxides or tert-butoxides in dimethyl sulfoxide). The above acetylene reactions and sequential transformations of reagents arranged by the superbasic center are modeled within the framework of the most complete pentasolvate model, in which the superbase is represented by the KOH·5DMSO (KOBut·5DMSO) complexes. We have developed approaches to the construction of simplified models (monosolvate and anionic) to describe transformations in complex systems. The mechanisms of cascade assemblies of 6,8-dioxabicyclo[3.2.1]octanes, cyclopentenones, and furan cycles from ketones and acetylenes in the superbasic environment are investigated using a uniform B2PLYP/6-311+G**//B3LYP/6-31+G* approach, and the energy profiles of these different carbo- and heterocycles are analyzed. 相似文献
99.
Damir Madjarević 《PAMM》2015,15(1):403-404
The present study deals with the shock wave profiles in the macroscopic multi-temperature (MT) model of binary gaseous mixtures. For that purpose we have adopted the hyperbolic model developed within the framework of extended thermodynamics [1] in which we include viscosity and thermal conductivity to eliminate restriction on parameters. This allows us to compare our results with more sophisticated kinetic solutions, which were computed for hypothetic mixtures of gases [2]. Numerical implementation of the MT model is considerably simpler than the one for Boltzmann equations for mixtures or the direct simulation Monte Carlo method (DSMC). (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
100.
Maria G. Babashkina Damir A. Safin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1437-1444
Reaction of O,O′-diisopropylphosphoric acid isothiocyanate (iPrO)2P(O)NCS with NH2(CH2)nNH2 (n = 3, 2) leads to the N-phosphorylated bis-thioureas [(iPrO)2C(S)NHP(O) NH]2Z (Z = —(CH2)3—, H2LI ; —(CH2)2—, H2LII ). Reaction of the potassium salt of H2LI with Co(II) and Zn(II) in aqueous EtOH leads to complexes of formula M2(L-O,S)2. The metal cation in both complexes is coordinated by two deprotonated ligands through the sulfur atoms of the thiocarbonyl groups and the oxygen atoms of the phosphoryl groups. Reaction of K2LI with Ni(II) and Pd(II) in the same conditions leads to M2(L-N,S)2 complexes. In both compounds, the metal center is found in a square-planar N2S2 environment formed by the C=S sulfur atoms and the P—N nitrogen atoms of two deprotonated ligands LI . Reaction of H2LII with KOH leads to a product of heterocyclization, in which one of the thiourea fragments is retained. Compounds obtained were investigated by IR, UV-Vis, 1H and 31P NMR spectroscopy, and microanalysis. 相似文献