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1.
Priti Hansia Saraswathi Vishveshwara Samir Kumar Pal 《Chemical physics letters》2006,420(4-6):512-517
Femtosecond spectroscopy carried out earlier on Monellin and some other systems has given insights into the hydration dynamics of the proteins. In the present work, molecular dynamics simulations have been performed on Monellin to study the hydration dynamics. A method has been described to follow up the molecular events of the protein–water interactions in detail. The time constants of the survival correlation function match well with the reported experimental values. This validates the procedure, adapted here for Monellin, to investigate the hydration dynamics in general. 相似文献
2.
K. V. Dinesha Suman B. Iyer Saraswathi Vishveshwara 《International journal of quantum chemistry》1986,30(6):783-790
The matrix elements of the spin-free Hamiltonian between two atomic configuration state functions (CSF 'S ) in the L–S coupling scheme are expressed in terms of the atomic integrals Fk's and Gk's. Using these general expressions, the matrix elements have been obtained for all the atomic configurations with three valence electrons that have not been solved so far by earlier methods. The scope for applying this new approach to obtain the Auger line energies and the promotion energies of metals that involve more than two partially filled shells is indicated. The energy expressions for some of the relevant configurations are tabulated. 相似文献
3.
The reaction of acidhydrazides with α-substituted carbonyl compounds in the presence of metal acetates gives substituted 1,2,4-triazines. These cyclisations could be effected without any added acetate by refluxing in dimethyl formamide, pyridine/acetic acid or dimethyl sulfoxide Sixty five 3,5,6-tri-3,6-di and 6 monosubstituted-1,2,4-triazines (in 50–90% yields) with a wide variation in the C3 substituent (alkyl, aryl or heteryl) and the C6-substituent (aryl or heteryl) are reported. The mechanistic path followed in the formation of these compounds is discussed. 相似文献
4.
Ga and In co‐doped ZnO (GIZO) thin films together with ZnO, In‐doped ZnO (IZO), Ga‐doped ZnO (GZO), and IZO/GZO multilayer for comparison, were grown on corning glass and boron doped Si substrates by PLD. The photoluminescence spectra of GIZO showed a strong white light emission and the current–voltage characteristics showed relatively lower turn‐on voltage and larger forward current. The CIE coordinates for GIZO were observed to be (0.31, 0.33) with a correlated colour temperature of 6650 K, indicating a cool white light, and establishing a possibility of white light emitting diodes. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
K. Saraswathi 《Proceedings Mathematical Sciences》1977,85(6):514-523
Polarograpbic studies of potassium ethylxanthate (RSH or xantbate) at the dropping mercury electrode (DME) reveal that the product of the anodic reaction is strongly adsorbed at the mercury drop as indicated by a prewave. The adsorbed film (0·15 mM to 1·0 mM xanthate solution) greatly affects the characteristics of the anodic wave of xanthate in aqueous medium. The current of main wave is proportional to the concentration of xanthate up to 2·5 mM in aqueous medium at DME. This electrode is used as an indicator electrode for amperometric titrations of metal ions with xanthate. Proper buffer composition and pH are developed for the accurate determination of metal ions. The combined use of the cathodic current of metal ions and the anodic current of xanthate under controlled pH conditions makes possible the amperometric titration of two metal ions in a mixture. 相似文献
6.
Saraswathi Vishveshwara 《Chemical physics letters》1978,59(1):26-29
CH…X hydrogen bonded systems are studied by the STO-3G method. The proton donor ability of carbon is analysed in terms of its hybridization states and the substituents. 相似文献
7.
Mandapati Saraswathi Jack M. Miller 《Journal of the American Society for Mass Spectrometry》1996,7(1):42-49
Fast-atom bombardment (FAB) mass spectrometry was used to investigate the interaction of proton and alkali metal ions with dinucleotide analogs such as T-n-T (T = thymine moiety, n = polyether chain, e.g., triethylene, tetraethylene, pentaethylene, and hexaethylene ether 1–4), A-n-T (A = adenine unit 5–8), and T-n-OMe (9–12) in 3-nitrobenzyl alcohol matrix. The [M + H]+ ion is the most abundant ion for the A-n-T series, whereas in 1–4 and 9–12 the (TC2H4)+ ion is the most abundant. Formation of [M + H -C2H4O]+ ions, a characteristic fragmentation of crown ethers under electron ionization, is observed for compounds 1–12 and is more pronounced in 6 and 7. An abundant [M ? H]? ion is observed for all the compounds studied under negative ion FAB due to the presence of the (-CO-NH-CO-) group of thymine, an indication of existence of intramolecular H bonding. The FAB mass spectra of 1–12 with alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) showed formation of abundant metal-coordinated ions ([M + Met]+ and [TC2H4 + Met]+). Compounds 3, 4, 6, 7, and 10–12 showed ions due to the substitution of the thymine moiety by a hydroxyl group ([M + Met ? 108]+, Met = metal ion). For compound 3 alone, substitution of two thymine groups ([M + Met - 216]+) was observed. Metastable ion studies were used to elucidate the structures of these potentially significant ions, and the ion formule were confirmed with high resolution measurements. Selectivity toward metal complexation with ligand size was seen in the T-n-T and A-n-T series and was even more pronounced in A-n-T series. These dinucleotide analogs fall in the following order of chelation of alkali metal ions, acyclic glymes < dinucleotide analogs (acyclic glymes substituted with nitrogen bases) < crown ethers, which places them in perspective as receptor models. 相似文献
8.
Saraswathi Vishveshwara 《Chemical physics letters》1978,59(1):30-32
The 4-31G basis set is used to study the bond length variations as functions of dihedral angels in methanediol. This study is compared with OCO bond angle optimization studies by Gorenstein and Kar and the possible reason for bond length shorteing in the transtrans configuration is analysed. 相似文献
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10.
In contrast to other chemical reducing agents, it has been found that sodium trimethoxyborohydride will selectively reduce 1-chloro-2-iodoperfluorocycloalkenes to give good yields of 1-hydro-2-chloroperfluorocycloalkenes. The selective displacement of iodine by hydrogen is discussed in terms of HSAB principles. 相似文献