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61.
Monmayrant A Joffre M Oksenhendler T Herzog R Kaplan D Tournois P 《Optics letters》2003,28(4):278-280
We introduce a new approach to the characterization of femtosecond optical pulses based on a remarkably simple setup combining a two-photon detector and a pulse shaper consisting of a longitudinal acousto-optic programmable filter. The operation of this setup is demonstrated through the use of a new version of spectral phase interferometry for direct electric-field reconstruction based on time-domain instead of on frequency-domain interferometry. 相似文献
62.
Berger EL Harris BW Kaplan DE Sullivan Z Tait TM Wagner CE 《Physical review letters》2001,86(19):4231-4234
A long-standing discrepancy between the bottom-quark production cross section and predictions of perturbative quantum chromodynamics is addressed. We show that pair production of light gluinos, of mass 12 to 16 GeV, with two-body decays into bottom quarks and light bottom squarks, yields a bottom-quark production rate in agreement with hadron collider data. We examine constraints on this scenario from low-energy data and make predictions that may be tested at the next run of the Fermilab Tevatron collider. 相似文献
63.
Chung P Ajitanand NN Alexander JM Anderson M Best D Brady FP Case T Caskey W Cebra D Chance JL Cole B Crowe K Das A Draper JE Gilkes ML Gushue S Heffner M Hirsch AS Hjort EL Huo L Justice M Kaplan M Keane D Kintner JC Klay J Krofcheck D Lacey RA Lauret J Lisa MA Liu H Liu YM McGrath R Milosevich Z Odyniec G Olson DL Panitkin SY Pinkenburg C Porile NT Rai G Ritter HG Romero JL Scharenberg R Schroeder L Srivastava B Stone NT Symons TJ Wienold T Witt R Whitfield J Wood L Zhang WN;E Collaboration 《Physical review letters》2001,86(12):2533-2536
Directed flow measurements for Lambda hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2A, 4A, and 6A GeV; b<5-6 fm). The measurements indicate that Lambda hyperons flow consistently in the same direction but with smaller magnitudes. A strong positive flow [for Lambdas] has been predicted in calculations which include the influence of the Lambda-nucleon potential. The experimental flow ratio Lambda/p is in qualitative agreement with expectations (approximately 2/3) from the quark counting rule at 2A GeV but is found to decrease with increasing beam energy. 相似文献
64.
Liu H Ajitanand NN Alexander J Anderson M Best D Brady FP Case T Caskey W Cebra D Chance J Cole B Crowe K Das A Draper J Gilkes M Gushue S Heffner M Hirsch A Hjort E Huo L Justice M Kaplan M Keane D Kintner J Klay J Krofcheck D 《Physical review letters》2000,84(24):5488-5492
Using the large acceptance Time Projection Chamber of experiment E895 at Brookhaven, measurements of collective sideward flow in Au+Au collisions at beam energies of 2A, 4A, 6A, and 8A GeV are presented in the form of in-plane transverse momentum
and the first Fourier coefficient of azimuthal anisotropy v(1). These measurements indicate a smooth variation of sideward flow as a function of beam energy. The data are compared with four nuclear transport models which have an orientation towards this energy range. All four exhibit some qualitative trends similar to those found in the data, although none show a consistent pattern of agreement within experimental uncertainties. 相似文献
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67.
A spectrophotometer system for spectral characterization of materials in the infrared has been built around a bench-top Fourier transform instrument. Its capabilities include the measurement of directional-hemispherical reflectance from 1 to 18 μm. The spectral reflectance measurement is performed with an integrating sphere with an incidence angle of 8°. Both relative and absolute measurements can be made. Several methods can be used to determine the absolute value of the directional-hemispherical reflectance of samples. The primary method used is independent of the integrating sphere theory and the requisite assumptions associated with its use. The calibration of a standard reference material (SRM) is described. This SRM has a reflectance value near 0.9 over the complete calibration range 2–18 μm. As part of the calibration procedure the spatial uniformity of the sphere throughput and the bi-directional reflectance distribution function (BRDF) of the SRM material are evaluated. 相似文献
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A. S. Knox D. I. Kaplan T. G. Hinton 《Journal of Radioanalytical and Nuclear Chemistry》2008,277(1):169-173
We assessed the ability of netted chain fern (Woodwardia areolata) to uptake U and Th from wetland soils on the U.S. Department of Energy’s Savannah River Site in South Carolina. Netted chain
fern had the highest Th and U concentrations of all plants collected from the wetland. Ferns grown in contaminated soil (329
mg·kg−1 Th, 44 mg·kg−1 U) in a greenhouse contained 6.4 mg·kg−1 Th and 5.3 mg·kg−1 U compared with 0.13 mg·kg−1 Th and 0.035 mg·kg−1 U in Bermuda grass (Cynodon dactylon). Netted chain fern has potential for the phytoremediation of soils contaminated with Th and U. 相似文献
70.