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991.
Shiga T Okawa H Kitagawa S Ohba M 《Journal of the American Chemical Society》2006,128(51):16426-16427
Integration of mononuclear [Cr(CN)6]3- and preorganized trinuclear [Co2Ln(L)2]3+ complexes provides novel trimetallic magnets having a 3-D pillared-layer framework with an alternate array of 2-D layer extended by Cr(III)-CN-Co(II) linkages and Ln(III) ion. The overall magnetic nature can be systematically controlled by Ln(III) ions inserted between the 2-D ferromagnetic layers. 相似文献
992.
In studying ultrafast electron transfer from a dye molecule to a nanosized semiconductor particle, pump-probe experiments are commonly used. In this system the electron transfer (ET) rate is faster than vibrational relaxation so that the ET rate should be described by a single-level rate constant and the probing signal (often in the form of time-resolved spectra) contains the contribution from the dynamics of both population and coherence (i.e., wave packet). In this paper, we shall present the theoretical treatments for femtosecond time-resolved pump-probe experiment and the dynamics of population and coherence by the density matrix method, and the calculation of single-level ET rate constant involved in a pump-probe experiment. As an application, we show the theoretical results using parameters extracted from experiments on a specific dye/semiconductor system. 相似文献
993.
A hydroindation of 1,3-dienes by dichloroindium hydride (HInCl2) generates allylic indiums that react with carbonyl or imine moieties in a one-pot treatment. The former reaction proceeds in a radical manner, and the latter is ionic allylation. Moreover, both reactions require no additives such as radical initiators, Lewis acids, or transition metal catalysts. 相似文献
994.
To clarify the role of diluents in the preparation of molecularly imprinted polymers utilizing only hydrogen bonding, we investigated
the effects of diluents by using different solvents. Melatonin (N-acetyl-5-methoxytryptamine), an amide bond and indole ring-containing hormone was chosen as the target molecule. N-Propionyl-5-methoxytryptamine was used as the pseudo template, methacrylic acid as the functional monomer, and solvents were
used as diluents. Interactions between the template, the functional monomer, melatonin, and the solvents, were observed by
1H NMR spectroscopy. The polymers were evaluated by high-performance liquid chromatography. The results suggest the hydrogen
bonding-acceptor capacity of the solvent is the most important factor in the preparation of molecularly imprinted polymers
for hydrogen bonding-donating molecules. Hydrogen bonding between the template, the functional monomer, and solvent can be
estimated from the chemical shifts in 1H NMR spectra of those molecules in the solvent. 相似文献
995.
The preparation of new thalidomide derivatives 4-methyl-(3S,4R)-3a and 4-phenyl-(3S,4S)-3b starting from pyroglutamic acids (2R,3R)-7a and (2R,3S)-7b, possessing an inappropriate stereochemistry, was successfully realized due to stereochemically complete epimerization at the alpha-stereogenic center upon formation of the corresponding N-phthaloyl anhydrides 9a,b. The demonstrated conformational stability of these new thalidomide derivatives provides solid experimental evidence for practical feasibility of the approach described here to overcome the inherent problem of configurational instability of thalidomide by introducing an alkyl or aryl group in the C4 position. [reaction: see text]. 相似文献
996.
We consider a singular Cauchy problem for the Euler–Poisson–Darboux equation of Fuchsian type in the time variable with ramified Cauchy data. In this paper we establish an expansion of the solutions in a series of hypergeometric functions and then investigate the nature of the singularities of the solutions. 相似文献
997.
Masahito Hayashi 《Annals of the Institute of Statistical Mathematics》2010,62(3):547-569
We calculate the limiting behavior of relative Rényi entropy between adjacent two probability distribution in a non-regular
location-shift family which is generated by a probability distribution whose support is an interval or a half-line. This limit
can be regarded as a generalization of Fisher information, and seems closely related to information geometry and large deviation
theory. 相似文献
998.
Some boundary conditions used to numerically simulate tsunami generation and propagation are studied. Special attention is given to generating boundary conditions thatmake it possible to simulate tsunami waves with desired characteristics (amplitude, time period and, in general, waveform). Since the water flow velocity in a propagating tsunami wave is uniquely defined by its height and ocean depth, one can simulate a wave propagating from the boundary into the simulation area. This can be done by specifying the wave height and water flow velocity on the boundary. This method is used to numerically simulate the propagation of a tsunami from the source to the coast on a sequence of refined grids. In this numerical experiment the wave parameters are transferred from the larger area to the subarea via boundary conditions. This method can also generate a wave that has certain characteristics on a specified line. 相似文献
999.
A new method for the preparation of quaternary chiral aminals has been developed that employs an enamide‐type Overman rearrangement process. This methodology was applied to enantioselective total syntheses of (+)‐dibromophakellin and (+)‐dibromophakellstatin. 相似文献
1000.
Reaction of diarylphosphinobenzene-2-sulfonic acids with tertially amines, followed by addition of [PdMeCl(cod)], provided anionic methylpalladium(II) complexes with bidentate phosphine-sulfonate ligands, which show high activity for copolymerization of ethylene with methyl acrylate. 相似文献