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51.
Abdullah Alqudami S. Annapoorni Govind S. M. Shivaprasad 《Journal of nanoparticle research》2008,10(6):1027-1036
Homogenous Ag–Au alloy nanoparticles having an average size of 12 ± 2 nm were successfully prepared by the exploding wire
technique comprising of a wire–plate system and using 12 V batteries. The X-ray photoelectron spectroscopy data reveal the
formation of alloy nanoparticles with Ag80-Au20 composition, which agrees with the absorption data, obtained using UV-Visible
spectroscopy. XPS also reveals a thin metal-oxide shell on the metallic alloy core. These alloy nanoparticles show visible
fluorescence emission that was compared with the observed fluorescence from pure Ag nanoparticles. A mechanism for the observed
fluorescence is also provided. 相似文献
52.
Govind P. Agrawal 《Optics Communications》1981,39(4):272-276
The theory of nondegenerate four-wave mixing is described for the case wherein the counter-propagating pump waves are in two-photon resonance with the nonlinear medium. In contrast to the one-photon case, the reflection bandpass is found to be mainly determined by the phase-matching requirement. The variation of the phase-conjugate reflectivity with the pump intensity and pump detuning is considered. The effect of the intensity-dependent Stark shift on the phase-conjugation efficiency is discussed in some detail. 相似文献
53.
Thiols react with diimidazolylsulfide under mild conditions to give symmetrical trisulfides in good yield and high purity. 相似文献
54.
55.
Patil Sandip K. Bhise Sagar C. Awale Deepak V. Vadiyar Madagonda M. Patil Suryakant A. Gunjal Dattatray B. Kolekar Govind B. Ghorpade Uma V. Kim Jin H. Kolekar Sanjay S. 《Research on Chemical Intermediates》2018,44(10):6267-6282
Research on Chemical Intermediates - We explored a geminal dicationic ionic liquid (DCIL), 1′-(propane-1,3-diyl)bis(4-aminopyridin-1-ium) dibromide, [C3(Amp)2][Br]2, as a fluorescent probe... 相似文献
56.
We study a discrete attachment model for the self-assembly of polyhedra called the building game. We investigate two distinct aspects of the model: (i) enumerative combinatorics of the intermediate states and (ii) a notion of Brownian motion for the polyhedral linkage defined by each intermediate that we term conformational diffusion. The combinatorial configuration space of the model is computed for the Platonic, Archimedean, and Catalan solids of up to 30 faces, and several novel enumerative results are generated. These represent the most exhaustive computations of this nature to date. We further extend the building game to include geometric information. The combinatorial structure of each intermediate yields a systems of constraints specifying a polyhedral linkage and its moduli space. We use a random walk to simulate a reflected Brownian motion in each moduli space. Empirical statistics of the random walk may be used to define the rates of transition for a Markov process modeling the process of self-assembly. 相似文献
57.
This report details a photoelectron spectroscopy (PES) and theoretical investigation of electron affinities (EAs) and electronic structures of several atmospherically relevant higher bromine and iodine oxide molecules in the gas phase. PES spectra of BrO(2)(-) and IO(2)(-) were recorded at 12 K and four photon energies--355 nm/3.496 eV, 266 nm/4.661 eV, 193 nm/6.424 eV, and 157 nm/7.867 eV--while BrO(3)(-), IO(3)(-), and IO(4)(-) were only studied at 193 and 157 nm due to their expected high electron binding energies. Spectral features corresponding to transitions from the anionic ground state to the ground and excited states of the neutral are unraveled and resolved for each species. The EAs of these bromine and iodine oxides are experimentally determined for the first time (except for IO(2)) to be 2.515 ± 0.010 (BrO(2)), 2.575 ± 0.010 (IO(2)), 4.60 ± 0.05 (BrO(3)), 4.70 ± 0.05 (IO(3)), and 6.05 ± 0.05 eV (IO(4)). Three low-lying excited states along with their respective excitation energies are obtained for BrO(2) [1.69 (A (2)B(2)), 1.79 (B (2)A(1)), 1.99 eV (C (2)A(2))], BrO(3) [0.7 (A (2)A(2)), 1.6 (B (2)E), 3.1 eV (C (2)E)], and IO(3) [0.60 (A (2)A(2)), 1.20 (B (2)E), ~3.0 eV (C (2)E)], whereas six excited states of IO(2) are determined along with their respective excitation energies of 1.63 (A (2)B(2)), 1.73 (B (2)A(1)), 1.83 (C (2)A(2)), 4.23 (D (2)A(1)), 4.63 (E (2)B(2)), and 5.23 eV (F (2)B(1)). Periodate (IO(4)(-)) possesses a very high electron binding energy. Only one excited state feature with 0.95 eV excitation energy is shown in the 157 nm spectrum. Accompanying theoretical calculations reveal structural changes from the anions to the neutrals, and the calculated EAs are in good agreement with experimentally determined values. Franck-Condon factors simulations nicely reproduce the observed vibrational progressions for BrO(2) and IO(2). The low-lying excited state information is compared with theoretical calculations and discussed with their atmospheric implications. 相似文献
58.
We have studied the effect of chain topology on the structural properties and diffusion of polymers in a dilute solution in a good solvent. Specifically, we have used three different simulation techniques to compare the chain size and diffusion coefficient of linear and ring polymers in solution. The polymer chain is modeled using a bead-spring representation. The solvent is modeled using three different techniques: molecular dynamics (MD) simulations with a particulate solvent in which hydrodynamic interactions are accounted through the intermolecular interactions, multiparticle collision dynamics (MPCD) with a point particle solvent which has stochastic interactions with the polymer, and the lattice Boltzmann method in which the polymer chains are coupled to the lattice fluid through friction. Our results show that the three methods give quantitatively similar results for the effect of chain topology on the conformation and diffusion behavior of the polymer chain in a good solvent. The ratio of diffusivities of ring and linear polymers is observed to be close to that predicted by perturbation calculations based on the Kirkwood hydrodynamic theory. 相似文献
59.
Nandu Baban Bhise Dhananjay Govind Sathe Tarur Radhakrishanan Raviraj Deore 《合成通讯》2013,43(9):1516-1526
Bicalutamide is an oral nonsteroidal, anti-androgen drug used for prostate cancer. It binds to the androgen receptor. During the bulk synthesis of bicalutamide, various impurities are formed. The present work details the development of simple processes for the preparation of impurities of bicalutamide, viz bical-sulfoxides (6), bical-deshydroxy (10), bical-desfluoro (10a), bical-2-fluoro (10b), and bical-3-fluoro (10c). 相似文献
60.
In the present work, we report the interplay of single particle and Cooper pair tunnelings on the superconducting state of
layered high-T
c cuprate superconductors. For this we have considered a model Hamiltonian incorporating the intra-planar interactions and
the contributions arising due to the coupling between the planes. The interplanar interactions include the single particle
tunneling as well as the Josephson tunneling of Cooper pairs between the two layers. The expression of the out-of-plane correlation
parameter which describes the hopping of a particle from one layer to another layer in the superconducting state is obtained
within a Bardeen-Cooper-Schriefer (BCS) formalism using the Green’s function technique. This correlation is found to be sensitive
to the various parameter of the model Hamiltonian. We have calculated the out-of-plane contribution to the superconducting
condensation energy. The calculated values of condensation energy are in agreement with those obtained from the specific heat
and the c-axis penetration depth measurements on bilayer cuprates. 相似文献