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11.
Selvamuthu Dharmaraja Puneet Pasricha Paola Tardelli 《Journal of statistical physics》2017,169(4):876-888
This article deals with the problem of probabilistic prediction of the time distance to default for a firm. To model the credit risk, the dynamics of an asset is described as a function of a homogeneous discrete time Markov chain subject to a catastrophe, the default. The behaviour of the Markov chain is investigated and the mean time to the default is expressed in a closed form. The methodology to estimate the parameters is given. Numerical results are provided to illustrate the applicability of the proposed model on real data and their analysis is discussed. 相似文献
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Journal of Fluorescence - In the present work, fluorescence anisotropy studies of BODIPY (pyrromethene 546 or C14H17BF2N2) dye have been performed and found that it has a potential to be used as a... 相似文献
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Riddhiman Sarkar Puneet Ahuja Detlef Moskau Dr. Paul R. Vasos Dr. Geoffrey Bodenhausen Prof. Dr. 《Chemphyschem》2007,8(18):2652-2656
Different decoupling sequences are tested—using various shaped radio‐frequency (RF) pulses—to achieve the longest possible lifetimes of singlet‐state populations over the widest possible bandwidths, that is, ranges of offsets and relative chemical shifts of the nuclei involved in the singlet states. The use of sinc or refocusing broadband universal rotation pulses (RE‐BURP) for decoupling during the intervals where singlet‐state populations are preserved allows one to extend the useful bandwidth with respect to prior state‐of‐the‐art methods based on composite‐pulse WALTZ decoupling. The improved sinc decoupling sequences afford a more reliable and sensitive measure of the lifetimes of singlet states in pairs of spins that have widely different chemical shifts, such as the two aromatic protons H5 and H6 in uracil. Similar advantages are expected for nucleotides in RNA and DNA. Alternative approaches, in particular frequency‐modulated decoupling sequences, also appear to be effective in preserving singlet‐state populations, even though the profiles of the apparent relaxation rate constants as a function of the offset are somewhat perturbed. The best decoupling sequences prove their utility in sustaining longer lifetimes of singlet states than previously achieved for the side‐chain tyrosine protons in bovine pancreatic trypsin inhibitor (BPTI) at 600 MHz (14.1 T), where the differences of chemical shifts between coupled protons are a challenge. 相似文献
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Pascal Miéville Puneet Ahuja Dr. Riddhiman Sarkar Dr. Sami Jannin Dr. Paul R. Vasos Dr. Sandrine Gerber‐Lemaire Dr. Mor Mishkovsky Dr. Arnaud Comment Prof. Rolf Gruetter Dr. Olivier Ouari Prof. Paul Tordo Prof. Geoffrey Bodenhausen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2010,122(43):8004-8004
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Puneet Srivastava 《Tetrahedron letters》2010,51(8):1149-9061
A novel route to cyclic imines based on 5-exo radical cyclization is explored. The radical precursors are imines prepared from allylamine and readily available α-phenylselenenyl ketones. 相似文献
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Pascal Miéville Puneet Ahuja Dr. Riddhiman Sarkar Dr. Sami Jannin Dr. Paul R. Vasos Dr. Sandrine Gerber‐Lemaire Dr. Mor Mishkovsky Dr. Arnaud Comment Prof. Rolf Gruetter Dr. Olivier Ouari Prof. Paul Tordo Prof. Geoffrey Bodenhausen 《Angewandte Chemie (International ed. in English)》2010,49(43):7834-7834
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Mukherjee TK Ahuja P Koner AL Datta A 《The journal of physical chemistry. B》2005,109(25):12567-12573
The effect of micellar environment on the excited state proton transfer (ESPT) of 2-(2'-pyridyl)benzimidazole (2PBI) has been investigated by steady state and time resolved fluorescence spectroscopy. The ESPT, which occurs to a rather small extent at pH 7, is found to be enhanced remarkably at the interface of sodium dodecyl sulfate (SDS) micelles and water. Such an enhancement is not observed for the cationic cetyl trimethyl ammonium bromide (CTAB) or neutral Triton X-100 micelles. This selective enhancement is explained in the light of a modification of pK(a) and a more acidic local pH in the micelle-water interface. A rise time of about 890 ps is observed in the region of tautomer emission. The origin of this rise time is explored, considering three factors, namely, diffusion controlled protonation of the normal form of 2PBI, slow and possibly incomplete solvation of the transition state, leading to a slowing down of the proton transfer process and a similar slow dynamics of the tautomeric excited state. 相似文献
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A simple, geometrical construction is given for three-dimensional spacetimes with negative cosmological constant that contain
two particles colliding head-on. Depending on parameters like particle masses and distance, the combined geometry will be
that of a particle, or of a black hole. In the black hole case the horizon is calculated. It is found that the horizon typically
starts at a point and spreads into a closed curve with corners, which propagate along spacelike caustics and disappear as
the horizon passes the particles.
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