排序方式: 共有29条查询结果,搜索用时 15 毫秒
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Paul D. Siders 《Journal of statistical physics》2005,119(3-4):861-880
Steady states of the driven lattice gas (DLG) on triangular, hexagonal and square lattices with the field at several fixed orientations to the principal lattice vectors were studied by Monte Carlo simulation. In most cases a strong field suppressed change to a low-temperature ordered phase. On each lattice, one field orientation that caused nonequilibrium ordering was identified. On triangular and hexagonal lattices, dependence of energy and anisotropy on field strength was studied at those orientations. Anisotropic ordering along the field developed at intermediate temperatures under weak fields. Partial ordering along the field persisted to low temperature under strong fields. 相似文献
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A. Cavalleri Ch. Blome P. Forget J.C. Kieffer S. Magnan C.W. Siders 《Phase Transitions》2013,86(7-8):769-777
We summarize recent advancements in the application of femtosecond X-ray scattering to experimental studies of photo-induced, structural phase transitions. Dynamic measurements of atomic rearrangement during solid-liquid and solid-solid transitions, as measured by ultrafast X-ray diffraction using plasma sources of line radiation are reported. 相似文献
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A. Efimov M.D. Moores B. Mei J.L. Krause C.W. Siders D.H. Reitze 《Applied physics. B, Lasers and optics》2000,70(7):S133-S141
Minimizing residual frequency dispersion that accompanies pulse stretching, amplification, and recompression is an important consideration in ultrashort chirped-pulse amplifiers. Here we show how an adaptive learning algorithm can be used in conjunction with a pulse shaper to compensate for higher-order and nonlinear dispersion in a chirped-pulse amplifier. Using spectral blueshifting as a sensitive diagnostic for pulse shape, we implement a 'learning loop' comprised of the pulse shaper, strong field laser ionization, and a genetic algorithm to minimize dispersion through the amplifier. We verify our optimization results using frequency-resolved optical gating (FROG) measurements and also show theoretically and experimentally that spectral blueshifting is indeed a sensitive diagnostic for pulse shape, and specifically, for higher-order dispersion. 相似文献
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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
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Elisabeth CW van Straaten Willem de Haan Hanneke de Waal Philip Scheltens Wiesje M van der Flier Frederik Barkhof Ted Koene Cornelis J Stam 《BMC neuroscience》2012,13(1):1-7