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281.
Camacho CM Camsonne A Mazouz M Ferdi C Gavalian G Kuchina E Amarian M Aniol KA Beaumel M Benaoum H Bertin P Brossard M Chen JP Chudakov E Craver B Cusanno F de Jager CW Deur A Feuerbach R Fieschi JM Frullani S Garçon M Garibaldi F Gayou O Gilman R Gomez J Gueye P Guichon PA Guillon B Hansen O Hayes D Higinbotham D Holmstrom T Hyde-Wright CE Ibrahim H Igarashi R Jiang X Jo HS Kaufman LJ Kelleher A Kolarkar A Kumbartzki G Laveissière G Lerose JJ Lindgren R Liyanage N Lu HJ Margaziotis DJ 《Physical review letters》2006,97(26):262002
We present the first measurements of the e[over -->]p-->epgamma cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q(2) dependence (from 1.5 to 2.3 GeV(2)) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q(2). The helicity-independent cross section is also measured at Q(2)=2.3 GeV(2). We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation. 相似文献
282.
End-labeled free solution electrophoresis (ELFSE) provides a means of separating DNA with free-solution CE, eliminating the need for gels and polymer solutions which increase the run time and can be difficult to load into a capillary. In free-solution electrophoresis, DNA is normally free-draining and all fragments reach the detector at the same time, whereas ELFSE uses an uncharged label molecule attached to each DNA fragment in order to render the electrophoretic mobility size-dependent. With ELFSE, however, the larger molecules are not separated enough (limiting the read length in the case of ssDNA sequencing) while the smaller ones are overseparated; the larger ones are too fast while the shorter ones are too slow, which is the opposite of traditional gel-based methods. In this article, we show how an EOF could be used to overcome these problems and extend the DNA sequencing read length of ELFSE. This counterflow would allow the larger, previously unresolved molecules more time to separate and thereby increase the read length. Through our theoretical investigation, we predict that an EOF mobility of approximately the same magnitude as that of unlabeled DNA would provide the best results for the regime where all molecules move in the same direction. Even better resolution would be possible for smaller values of EOF which allow different directions of migration; however, the migration times then would become too large. The flow would need to be well controlled since the gain in read length decreases as the magnitude of the counterflow increases; an EOF mobility double that of unlabeled DNA would no longer increase the read length, although ELFSE would still benefit from a reduction in migration time. 相似文献
283.
Babich R Brannick J Brower RC Clark MA Manteuffel TA McCormick SF Osborn JC Rebbi C 《Physical review letters》2010,105(20):201602
We present an adaptive multigrid solver for application to the non-Hermitian Wilson-Dirac system of QCD. The key components leading to the success of our proposed algorithm are the use of an adaptive projection onto coarse grids that preserves the near null space of the system matrix together with a simplified form of the correction based on the so-called γ5-Hermitian symmetry of the Dirac operator. We demonstrate that the algorithm nearly eliminates critical slowing down in the chiral limit and that it has weak dependence on the lattice volume. 相似文献
284.
We prove some heavy-traffic limit theorems for processes which encompass the fractionally integrated random walk as well as some FARIMA processes, when the innovations are in the domain of attraction of a non-Gaussian stable distribution. 相似文献
285.
We prove some heavy-traffic limit theorems for some nonstationary linear processes which encompass the fractionally differentiated random walk as well as some FARIMA processes, when the innovations are in the domain of attraction of a non-Gaussian stable distribution. The results are based on an extension of the point process methodology to linear processes with nonsummable coefficients and make use of a new maximal type inequality. 相似文献
286.
Xiang D Colby E Dunning M Gilevich S Hast C Jobe K McCormick D Nelson J Raubenheimer TO Soong K Stupakov G Szalata Z Walz D Weathersby S Woodley M 《Physical review letters》2012,108(2):024802
Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science. 相似文献
287.
Cramér’s theorem provides an estimate for the tail probability of the maximum of a random walk with negative drift and increments having a moment generating function finite in a neighborhood of the origin. The class of (g,F)-processes generalizes in a natural way random walks and fractional ARIMA models used in time series analysis. For those (g,F)-processes with negative drift, we obtain a logarithmic estimate of the tail probability of their maximum, under conditions comparable to Cramér’s. Furthermore, we exhibit the most likely paths as well as the most likely behavior of the innovations leading to a large maximum. 相似文献
288.
289.
290.
Garth P. McCormick 《Mathematical Programming》1976,10(1):147-175
For nonlinear programming problems which are factorable, a computable procedure for obtaining tight underestimating convex programs is presented. This is used to exclude from consideration regions where the global minimizer cannot exist.This work was supported by Contract AFORS-73-2504, U.S. Air Force, Office of Scientific Research. 相似文献