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91.
Bibhas Ranjan Majhi 《General Relativity and Gravitation》2013,45(2):345-357
A derivation of entropy from the expressions for two dimensional gravitation anomalies is given. Starting from the near horizon anomalous energy–momentum tensors corresponding to particular anomalies, the Virasoro algebra with central extension is obtained. The central charge is identified by comparing with the standard form of the algebra. Then the conserved charge in the ground state is computed. Finally, using the Cardy formula the entropy is obtained. Here both the vector and chiral theories are discussed. 相似文献
92.
During the last years, one had to combine the proposal about how quasinormal frequencies are related with black holes and the proposal about the adiabatic invariance of black holes in order to derive the quantized entropy spectrum and its minimum change for several black holes. In this Letter we exclusively utilize the statement that the black hole horizon area is an adiabatic invariant and derive an equally spaced entropy spectrum of a black hole with its quantum to be equal to the one given by Bekenstein. Interestingly, in our approach no concept of quasi-normal mode is needed. 相似文献
93.
We present a complete next to next to leading order QCD corrections to the resonant production of sneutrino and charged slepton at the Tevatron and the Large Hadron Collider within the context of R-parity violating supersymmetric model. We have demonstrated the role of NNLO QCD corrections in reducing uncertainties resulting from renormalisation and factorisation scales and thereby making our predictions reliable. We have incorporated soft gluon effects at N3LO level in order to study the stability of our results under perturbation. The results obtained in this article are also applicable to resonance production of any color-neutral scalar coupled to fermions through Yukawa interaction. 相似文献
94.
Ortony JH Chatterjee T Garner LE Chworos A Mikhailovsky A Kramer EJ Bazan GC 《Journal of the American Chemical Society》2011,133(21):8380-8387
Conjugated oligoelectrolytes are of emerging technological interest due to their recent function in the fabrication of optoelectronic devices, application in biosensors, and as species that facilitate transmembrane charge migration. Solubility in aqueous, or highly polar, solvents is important for many of these applications; however, there are few studies on how the self-assembly of conjugated oligoelectrolytes into multichromophore species influences linear and nonlinear optical properties. Here, we examine 1,4-bis(4'-(N,N-bis(6'-(N,N,N-trimethylammonium)hexyl)amino)-styryl)benzene tetraiodide (DSBNI) in water, a conjugated oligoelectrolyte based on the distyrylbenzene framework. We find that DSBNI aggregation leads to increased fluorescence lifetimes, coupled with hypsochromic shifts, and larger two-photon absorption cross sections. Liquid atomic force microscopy (AFM) and cryogenic transmission electron microscopy (cryo-TEM) were used to image DSBNI aggregates and to confirm that the planar molecules stack to form nanocylinders above a critical aggregation concentration. Finally, small-angle neutron scattering (SANS) was used to quantify the aggregate dimensions in situ. Comparison of the results highlights that the hydrophilic mica surface used to image via liquid AFM and the high concentrations required for cryo-TEM facilitate the propagation of the cylinders into long fibers. SANS experiments are consistent with equivalent molecular packing geometry but lower aspect ratios. It is therefore possible to understand the evolution of optical properties as a function of concentration and aggregation and the general geometric features of the resulting supramolecular structures. 相似文献
95.
Prakash Mathews Rahul Basu D. Indumathi E. Laenen Swapan Majhi Anuradha Misra Asmita Mukherjee W. Vogelsang 《Pramana》2004,63(6):1367-1379
This is the report of the QCD working sub-group at WHEPP-8 which was part of the QCD and QGP working group. Discussion and
work on some aspects of resummation and parton distribution are reported. 相似文献
96.
Direct conversion of methane to higher hydrocarbons is an effective process to solve the problem of natural gas utilization. Although remarkable progress has been achieved on the dehydro-aromatization of methane (DAM), low conversion caused by severe thermodynamic limitations,coke formation, and catalysis deactivation remain important drawbacks to the direct conversion process. Molybdenum catalysts supported on HZSM-5 type zeolite support are among the most promising catalysts. This review focuses on the aspects of direct methane conversion, in terms of catalysts containing metal and support, reaction conditions, and conversion in different types of reactors. The reaction mechanism for this catalytic process is also discussed. 相似文献
97.
Dr. Yingguo Liu Pankaj Kumar Majhi Runjiang Song Dr. Chengli Mou Dr. Lin Hao Prof. Huifang Chai Prof. Zhichao Jin Prof. Yonggui Robin Chi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):3887-3891
A catalytic dynamic kinetic resolution and asymmetric acylation reaction of hydroxyphthalides is developed. The reaction involves formation of a carbene catalyst derived chiral acyl azolium intermediate that effectively differentiates the two enantiomers of racemic hydroxyphthalides. The method allows quick access to enantiomerically enriched phthalidyl esters with proven applications in medicine. It also enables asymmetric modification of natural products and other functional molecules that contain acetal/ketal groups, such as corollosporine and fimbricalyxlactone C. 相似文献
98.
99.
100.
Dichroic Nd3+:Au–antimony glass (K2O–B2O3–Sb2O3) nanocomposites (NCs) have been synthesized by single-step melt-quench thermochemical reduction process. The UV–Vis–NIR spectra show surface plasmon resonance (SPR) band of Au0 nanoparticles (NPs) and absorption peaks of Nd3+ ions. XRD and SAED results indicate growth of Au0 NPs along (200) plane. TEM image reveals elliptical Au0 NPs having sizes 12–21 nm (aspect ratio ~1.2) responsible for the dichroic behavior. Photoluminescent upconversion under excitation at 805 nm exhibit two emission bands of Nd3+ ions at 540 (green) and 650 (red) nm due to 4G7/2 → 4I9/2 and 4G7/2 → 4I13/2 transitions respectively. Both bands undergo maximum 8 and 11 fold intensity enhancements respectively at 0.03 wt% Au0 (4.1 × 1018 atoms/cm3). Local field enhancement (LFE) induced by Au0 SPR and energy transfer (ET) from Au0 → Nd3+ is found to be responsible for enhancement while ET from Nd3+ → Au0 and optical re-absorption due to Au0 SPR for quenching. 相似文献