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31.
We show that a potential difference is generated across a semiconductor sample containing free carriers when the sample is in a magnetic field gradient in the direction of the field. A measurement of the potential difference can give direct information concerning the effective mass and effective g-factor of the free carriers. 相似文献
32.
Nutrient uptake and control of animal cell proliferation. 总被引:3,自引:0,他引:3
33.
Cho SH Kärtner FX Morgner U Ippen EP Fujimoto JG Cunningham JE Knox WH 《Optics letters》2001,26(8):560-562
We demonstrate the generation of high-energy pulses by using a low-repetition-rate Kerr-lens mode-locked laser. Repetition rates as low as 4 MHz were achieved with a long, multiple-pass cavity and a semiconductor saturable Bragg reflector. The laser generated pulses of 55-fs duration with a pulse energy of 48 nJ when it was mode locked in the net negative dispersion regime. Mode locking in the positive dispersion regime reduces instabilities and enables pulses to have durations of 80 fs and energies as high as 90 nJ. This is, to our knowledge, the highest pulse energy and the lowest repetition rate ever generated directly from a femtosecond laser resonator without cavity dumping. 相似文献
34.
Superconductivity in dense MgB2 wires 总被引:11,自引:0,他引:11
Canfield PC Finnemore DK Bud'ko SL Ostenson JE Lapertot G Cunningham CE Petrovic C 《Physical review letters》2001,86(11):2423-2426
MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet. 相似文献
35.
Other Index
Index abstracts 相似文献36.
H. B. Knowles L. H. James Th. R. Cunningham H. L. Hamner W. Brüggemann C. M. Johnson E. Bertrand H. C. Weirick C. H. Mc Collam J. V. Tamchyna C. Montelucci M. Gambioli L. Spiegel Th. M. Maas E. Montignie H. Hauptmann M. Balconi E. Carriére R. Lautié Z. Raichinstein N. Korobow J. F. Sacher 《Analytical and bioanalytical chemistry》1934,98(9-10):362-374
37.
E. Maurer F. Hartmann F. Mylius F. Foerster G. Schoene H. Schenck Alexander Fischer G. T. Dougherty M. Dittrich A. Leonhard O. L. Barnebey J. V. Mc Crae R. L. Dowdell L. Jordan J. G. Thompson J. S. Acken J. H. S. Dickenson P. Herasymenko G. Pondélik Th. R. Cunningham R. J. Price C. H. Herty G. R. Fitterer J. E. Eckel J. J. Egan W. Crafts und A. B. Kinzel 《Fresenius' Journal of Analytical Chemistry》1935,101(1-2):50-53
Ohne Zusammenfassung 相似文献
38.
39.
Th. R. Cunningham R. J. Price St. G. Simpson W. C. Schumb P. Klinger O. Schliessmann D. R. Nijk H. Bart G. v. Hevesy R. Hobbie A. Asmanow P. H. M. P. Brinton R. B. Ellestad G. Scagliarini P. Pratesi I. M. Kolthoff J. J. Lingane J. Volmar Mathis J. Perrin E. Bayle R. Fabre H. George H. Gräven G. Canneri und L. Fernandes 《Fresenius' Journal of Analytical Chemistry》1934,99(3-4):113-129
Ohne Zusammenfassung 相似文献
40.
Niels M. B. Smeets Johan P. A. Heuts Jan Meuldijk Michael F. Cunningham Alex M. Van Herk 《Journal of polymer science. Part A, Polymer chemistry》2009,47(19):5078-5089
The effect the catalytic chain transfer agent, bis[(difluoroboryl) dimethylglyoximato] cobalt(II) (COBF), on the course of the ab initio emulsion polymerization of methyl methacrylate, and the product properties in terms of the molecular weight distribution were investigated. The emulsion polymerization kinetics have been studied with varying surfactant, initiator, and COBF concentrations. The experimentally determined average number of radicals per particle strongly depends on the concentration of COBF and proves to be in good agreement with the results of model calculations. The apparent chain transfer constant, determined up to high conversion, is in excellent agreement with the predicted value based on a mathematical model based on COBF partitioning and the Mayo equation. The results of this work enhance the fundamental understanding of the influence a catalytic chain transfer agent has on the course of the emulsion polymerization and the control of the molecular weight distribution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5078–5089, 2009 相似文献