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81.
Mikhail A. Lifshits Werner Linde 《Transactions of the American Mathematical Society》2005,357(5):2059-2079
We investigate the small deviation problem for weighted fractional Brownian motions in -norm, . Let be a fractional Brownian motion with Hurst index . If , then our main result asserts
provided the weight function satisfies a condition slightly stronger than the -integrability. Thus we extend earlier results for Brownian motion, i.e. , to the fractional case. Our basic tools are entropy estimates for fractional integration operators, a non-linear approximation technique for Gaussian processes as well as sharp entropy estimates for -sums of linear operators defined on a Hilbert space.
provided the weight function satisfies a condition slightly stronger than the -integrability. Thus we extend earlier results for Brownian motion, i.e. , to the fractional case. Our basic tools are entropy estimates for fractional integration operators, a non-linear approximation technique for Gaussian processes as well as sharp entropy estimates for -sums of linear operators defined on a Hilbert space.
82.
Gaffney KJ Lindenberg AM Larsson J Sokolowski-Tinten K Blome C Synnergren O Sheppard J Caleman C MacPhee AG Weinstein D Lowney DP Allison T Matthews T Falcone RW Cavalieri AL Fritz DM Lee SH Bucksbaum PH Reis DA Rudati J Macrander AT Fuoss PH Kao CC Siddons DP Pahl R Moffat K Als-Nielsen J Duesterer S Ischebeck R Schlarb H Schulte-Schrepping H Schneider J von der Linde D Hignette O Sette F Chapman HN Lee RW Hansen TN Wark JS Bergh M Huldt G van der Spoel D Timneanu N Hajdu J Akre RA Bong E 《Physical review letters》2005,95(12):125701
The melting dynamics of laser excited InSb have been studied with femtosecond x-ray diffraction. These measurements observe the delayed onset of diffusive atomic motion, signaling the appearance of liquidlike dynamics. They also demonstrate that the root-mean-squared displacement in the [111] direction increases faster than in the [110] direction after the first 500 fs. This structural anisotropy indicates that the initially generated fluid differs significantly from the equilibrium liquid. 相似文献
83.
van Eis MJ van Der Linde BS de Kanter FJ de Wolf WH Bickelhaupt F 《The Journal of organic chemistry》2000,65(14):4348-4354
In contrast to the terminal phosphinidene complex PhPW(CO)(5) (2), which adds to [5]metacyclophane (1) in a 1,4-fashion, dichlorocarbene preferentially adds in a 1,2-fashion to the formal "anti-Bredt" type double bond of the aromatic ring of 1 to afford the norcaradiene 11b, which immediately rearranges to the bridged cycloheptatriene 12b and further by a [1,5] sigmatropic chlorine migration to the isomeric 13b as the first observable product. More slowly, the latter isomerizes via a dissociative mechanism to give 15b. A computational study supports the notion that the [1,5] chlorine migration in the rearrangement 12b --> 13b, for which an activation barrier of 70.2 kJ mol(-)(1) was calculated, is essentially concerted with minor charge separation. In contrast, the analogous [1,5] chlorine migration in the flat model compound 7,7-dichlorocycloheptatriene (12a) displays features of a dissociative pathway. 相似文献
84.
Cavalleri A Siders CW Brown FL Leitner DM Tóth C Squier JA Barty CP Wilson KR Sokolowski-Tinten K Horn Von Hoegen M von der Linde D Kammler M 《Physical review letters》2000,85(3):586-589
Damping of impulsively generated coherent acoustic oscillations in a femtosecond laser-heated thin germanium film is measured as a function of fluence by means of ultrafast x-ray diffraction. By simultaneously measuring picosecond strain dynamics in the film and in the unexcited silicon substrate, we separate anharmonic damping from acoustic transmission through the buried interface. The measured damping rate and its dependence on the calculated temperature of the thermal bath is consistent with estimated four-body, elastic dephasing times (T2) for 7-GHz longitudinal acoustic phonons in germanium. 相似文献
85.
In the present paper, the authors discuss studies carried out for many years dealing particularly with two compounds: benzene and carbon disulphide and compare them with the results obtained by numerous acoustics researchers. These compounds are typical liquids in which acoustic Kneser-type relaxation occurs, caused by an irreversible vibrational and translational (VT) transition. Since magnitudes describing the relaxation process were diverse in many papers, we have undertaken an attempt to clarify these differences and to indicate how to avoid errors resulting from instrumental imperfections and the disregard of the considerable measurement errors when investigating velocity dispersion in the hypersonic (GHz) range. The results of these researches changed the interpretation of previous papers. 相似文献
86.
It is shown that the baryon asymmetry in the inflationary universe under certain constraints on the masses of superheavy bosons can be larger than that in the standard baryosynthesis scenario. An important property of the model considered is that the final baryon asymmetry does not depend on initial conditions in the early universe in contrast to what occurs in the standard scenario based on B?L conserving GUTs. 相似文献
87.
Time resolved luminescence of highly excited GaAs is studied using a streak camera. We observe the Mott transition from the electron-hole plasma to the excitonic state. This transition is smooth and does not show a phase separation. The plasmon sideband of the electron-hole plasma emission is identified. 相似文献
88.
Probability Theory and Related Fields - 相似文献
89.
90.
Steady-state four-level microwave double-resonance experiments are described for pure OCS and OCS diluted with CH3OH, H2, and He. For pure OCS, interactions of higher order than first-order dipole-dipole dominate the behavior of some four-level systems, and the rates of ΔJ = 2 quadrupole-type collision-induced transitions are found to be greater than one-half of the ΔJ = 1 dipolar rates. For OCSCH3OH mixtures, the dipolar rates are significantly enhanced with respect to the pure gas, but ΔJ = 2 transitions are still important. For the mixtures of astrophysical interest, OCSH2 and OCSHe, all four-level systems show ΔJ = 2 collisional preferences. The ΔJ = 2 transition rates are comparable to those of ΔJ = 1 transitions, and there is evidence that ΔJ = 3 transition rates are substantial. 相似文献