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81.
Coan TE Gao YS Liu F Maravin Y Stroynowski R Artuso M Boulahouache C Blusk S Bukin K Dambasuren E Moneti GC Mountain R Muramatsu H Nandakumar R Skwarnicki T Stone S Wang JC Mahmood AH Csorna SE Danko I Bonvicini G Cinabro D Dubrovin M McGee S Bornheim A Lipeles E Pappas SP Shapiro A Sun WM Weinstein AJ Briere RA Chen GP Ferguson T Tatishvili G Vogel H Adam NE Alexander JP Berkelman K Boisvert V Cassel DG Drell PS Duboscq JE Ecklund KM Ehrlich R Galik RS Gibbons L Gittelman B Gray SW Hartill DL 《Physical review letters》2003,90(10):101801
Using 13.8 fb(-1) of data collected at or just below the Upsilon(4S) with the CLEO detector, we report the result of a search for the flavor changing neutral current process D0-->gammagamma. We observe no significant signal for this decay mode and determine 90% confidence level upper limits on the branching fractions B(D0-->gammagamma)/B(D0-->pi(0)pi(0))<0.033 and B(D0-->gammagamma)<2.9 x 10(-5). 相似文献
82.
Shapiro IR Jenkins DM Thomas JC Day MW Peters JC 《Chemical communications (Cambridge, England)》2001,(20):2152-2153
A homoleptic phosphine adduct of thallium(I) supported by a tris(phosphino)borate ligand has been isolated and structurally characterized. 相似文献
83.
Caixing Gu Jonathan E. Shapiro 《Proceedings of the American Mathematical Society》2003,131(9):2779-2789
We find some extreme points in the unit ball of the set of Hankel operators and show that the unit ball of the set of compact Hankel operators is strictly convex. We use this result to show that the collection of lower triangular Toeplitz contractions is strictly convex. We also find some extreme points in certain reduced Cowen sets and discuss cases in which they are or are not strictly convex.
84.
Shapiro EM Borthakur A Bansal N Leigh JS Reddy R 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2000,143(1):213-216
We describe the characterization of a (23)Na temperature-dependent chemical shift and relaxation rates in the complex, Na(4)HTm[DOTP]. This is the first characterization of a (23)Na temperature-dependent chemical shift in a nonmetallic sample. The (23)Na temperature-dependent chemical shift coefficient is approximately -0. 5 PPM/ degrees C for both an aqueous solution and a 6% agarose gel of this compound. This is 50 times the magnitude of the temperature-dependent chemical shift coefficient of water protons. The relaxation times, T(1), T(2f), and T(2s) increased by 0.1, 0.01, and 0.05 ms/ degrees C, respectively. Applications of these unique properties for designing an MRI technique for monitoring heat deposition in tissue and tissue phantoms are discussed. 相似文献
85.
86.
M. M. Shapiro S. M. Parsadanyan Yu. V. Tabachnik I. A. Furgel N. S. Golosov 《等离子体物理论文集》1989,29(6):589-597
A regular truncation scheme in which the divergencies characteristic of the Debye truncation are removed by taking into account the shall-range correlations. As a result, the two radii of screening the Debye radius D and √2 D appear in plasma which is not symmetrical as to its particle charges. The criterion of the applicability of this approach relates the plasma parameter to the potential depth of unlike-charged particles interaction. 相似文献
87.
88.
We study double Hurwitz numbers in genus zero counting the number of covers CP1→CP1 with two branching points with a given branching behavior. By the recent result due to Goulden, Jackson and Vakil, these numbers are piecewise polynomials in the multiplicities of the preimages of the branching points. We describe the partition of the parameter space into polynomiality domains, called chambers, and provide an expression for the difference of two such polynomials for two neighboring chambers. Besides, we provide an explicit formula for the polynomial in a certain chamber called totally negative, which enables us to calculate double Hurwitz numbers in any given chamber as the polynomial for the totally negative chamber plus the sum of the differences between the neighboring polynomials along a path connecting the totally negative chamber with the given one. 相似文献
89.
D. Shaltiel H.-A. Krug von Nidda B.Ya. Shapiro B. Bogoslavsky B. Rosenstein I. Shapiro T. Tamegai 《Physica C: Superconductivity and its Applications》2010,470(21):1937-1942
Following the discovery of high Tc superconductors, many researchers have applied EPR spectrometers to investigate their properties using the regular instructions to operate the spectrometer. As no substantial information was obtained it was soon practically abandoned. Investigations performed recently with the EPR technique, using a different operating method than the conventional one and the introduction of a detailed theoretical study related to the interaction of the JV with the microwave magnetic field lead to new and important results related to properties of high anisotropy superconductors indicating that the EPR spectrometer can be used to investigate properties of high anisotropy superconductors. The failures when using conventional operating method to obtain meaningful results and the method used in the present work to carry out the measurements in a proper manner are presented. Some important results obtained in investigating high anisotropy superconductors by the EPR technique are presented. 相似文献
90.
Jack M. Shapiro 《代数通讯》2013,41(6):1879-1898
For a field F with trivial involution we have the Karoubi L-groups ±1Ln(F). For 0≤n≤2 these groups are intimately related to subgroups of the classical Witt ring of quadratic forms. -1L 2(F) also has a presentation by symbols due to Matsumoto. In terms of this data we make explicit calculations for two cup product maps that appear in the L-theory of fields. 相似文献