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101.
Murugesan Velayudham Subramanian Singaravadivel Seenivasan Rajagopal Perumal Ramamurthy 《Journal of organometallic chemistry》2009,694(25):4076-4083
Six new homobimetallic and heterobimetallic complexes of rhenium(I) and ruthenium(II) bridged by ethynylene spacer [(CO)3(bpy)Re(BL)Re(bpy)(CO)3]2+ [Cl(bpy)2Ru(BL)Ru(bpy)2Cl]2+ and [(CO)3(bpy)Re(BL)Ru(bpy)2Cl]2+ (bpy = 2,2′-bipyridine, BL = 1,2-bis(4-pyridyl)acetylene (bpa) and 1,4-bis(4-pyridyl)butadiyne (bpb) are synthesized and characterized. The electrochemical and photophysical properties of all the complexes show a weak interaction between two metal centers in heterobimetallic complexes. The excited state lifetime of the complexes is increased upon introduction of ethynylene spacer and the transient spectra show that this is due to delocalization of electron in the bridging ligand. Also, intramolecular energy transfer from *Re(I) to Ru(II) in Re–Ru heterobimetallic complexes occurs with a rate constant 4 × 107 s−1. 相似文献
102.
R. Uthrakumar C. Vesta C. Justin Raj S. Dinakaran Rani Christhu Dhas S. Jerome Das 《Crystal Research and Technology》2008,43(4):428-432
Good quality single crystals of Ni2+, Co2+ ions doped Bisthiourea Cadmium Chloride (BTCC) are some of the excellent and efficient non‐linear optical materials grown from aqueous solution by slow evaporation method. The lattice parameters of the grown crystals are determined by single crystal X‐ray analysis. UV spectral analyses on these samples reveal the improved transparency of the doped crystals ascertaining the inclusion of metal ion in the lattice. FTIR spectral analysis carried out on the materials confirm the presence of functional groups. Dielectric measurements reveal that the dielectric constant of pure and doped crystals decreases with increase of frequency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
103.
The oxidation of ethylenediamine by diperiodatoargentate (III) ion has been studied by stopped‐flow spectrophotometry. Kinetics of this reaction involves two steps. The first step is the complexation of silver (III) with the substrate and is over in about 10 ms. This is followed by a redox reaction in the second step that occurs intramolecularly from the substrate to the silver (III) center. The rate of reduction of silver (III) species by ethylenediamine, ethanolamine, and 1,2‐ethanediol were observed to be 1.2 × 104, 1.1 × 102, and 0.14 dm3 mol−1 s−1, respectively, at 20°C. The reaction rate shows an inverse dependence on [IO] and [OH−] in the low concentration range (≤1 × 10‐3 mol dm−3). At higher [OH−] (>1 × 10−3 mol dm−3) the rate of reaction starts increasing and attains a limiting value at very high [OH−]. The rate of deamination of ethylenediamine is enhanced by its complexation with silver (III). The involvement of [AgIII(H2IO6) (H2O)2] and [AgIII(H2IO6) (OH)2]2− are suggested as the reactive silver (III) species kinetically in mild basic and basic conditions, respectively. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 286–293, 2000 相似文献
104.
105.
Fragment angular distributions in fission is one of the oldest and well understood aspects of fission theory. However, recent
heavy ion-induced fission and fission-like reactions have added a new dimension to this problem. We review here our present
understanding of the fragment angular distribution theory in fission and fission-like reactions. 相似文献
106.
I. M. Navon P. K. H. Phua M. Ramamurthy 《Journal of Optimization Theory and Applications》1990,66(1):71-93
During the last few years, conjugate-gradient methods have been found to be the best available tool for large-scale minimization of nonlinear functions occurring in geophysical applications. While vectorization techniques have been applied to linear conjugate-gradient methods designed to solve symmetric linear systems of algebraic equations, arising mainly from discretization of elliptic partial differential equations, due to their suitability for vector or parallel processing, no such effort was undertaken for the nonlinear conjugate-gradient method for large-scale unconstrained minimization.Computational results are presented here using a robust memoryless quasi-Newton-like conjugate-gradient algorithm by Shanno and Phua applied to a set of large-scale meteorological problems. These results point to the vectorization of the conjugate-gradient code inducing a significant speed-up in the function and gradient evaluation for the nonlinear conjugate-gradient method, resulting in a sizable reduction in the CPU time for minimizing nonlinear functions of 104 to 105 variables. This is particularly true for many real-life problems where the gradient and function evaluation take the bulk of the computational effort.It is concluded that vector computers are advantageous for largescale numerical optimization problems where local minima of nonlinear functions are to be found using the nonlinear conjugate-gradient method.This research was supported by the Florida State University Supercomputer Computations Research Institute, which is partially funded by the US Department of Energy through Contract No. DE-FC05-85ER250000. 相似文献
107.
Gurbaksh Singh R. M. Kothari Rajesh K. Sharma V. Ramamurthy 《Applied biochemistry and biotechnology》1995,50(3):285-290
The effect of a hydrolyzed protein preparation on the growth and biomass yield of the blue-gree algaSpirulina platensis was studied. At the optimum dosage, the hydrolysate enhancedSpirulina productivity by almost 40% when compared to untreated cultures. This increased productivity correlated with an increase in
the level of nitrogen assimilating enzymes, nitrate reductase and glutamine synthetase. 相似文献
108.
The surface diffuseness of deformed and rotating nuclei has been studied using the energy density formalism. It is shown that
the surface diffuseness exhibits an anisotropy. This anisotropy in surface diffuseness can result in an anisotropic charged
particle emission from highly spinning nuclei as has been seen in some recent experiments. 相似文献
109.
Ramamurthy Prabhakaran 《Experimental Mechanics》1982,22(12):462-467
With the interpretation of isochromatic and isoclinic fringes in transparent, birefringent, orthotropic composites established, efforts have been in progress to determine the-individual values of the principal stresses or strains. Several methods have recently been proposed. Some of them utilize the photoelastic results only partially and rely on numerical procedures. Others have attempted to obtain the required information based entirely on experimental data. In this paper, the classical oblique-incidence technique is applied to transversely isotropic-birefringent composites. The proposed extension is verified by applying it to the problem of an orthotropic half-plane subjected to an edge-load. 相似文献
110.
Ramamurthy Chambala Robert W. Sobol Ning Kon Robert J. Suhadolnik Wolfgang Pfleiderer 《Helvetica chimica acta》1991,74(4):892-898
The four protected diastereoisomcrs 7a / 7b and 8a / 8b P-thioadenylyl-(3′–5′)-P-thioadenylyI-(3′–5′)-adenosine were synthesized, separated, and deblocked to the free oligonucleotides (Scheme). Biochemical characterization of these (3′–5′)phosphorothioate analogues of adenyiate trimer indicate that these compounds, and the corresponding 5′-monophosphates, neither bind to nor activate RNase L, and are considered to be valuable control compounds in screening experiments. 相似文献