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81.
Examining the possibility that the enhancement of Tc in the tungsten bronzes arises from interband coupling, we find that a single density of states provides reasonable quantitative agreement with the Tc enhancement, the heat capacity and the magnetic susceptibility. 相似文献
82.
Three new Fe-defect complexes have been identified by ESR in Fe doped crystals of SrTiO3. These are an Fe3+ center with rhombic fine structure in the “as-grown” crystals, and the vacancy associated complexes Fe2+ -Vo and Fe1+ -Vo in “reduced” crystals. Photo-excited charge transfer effects are observed for these centers. 相似文献
83.
We investigate the direct effects of phonon softening on Tc in Nb3Sn. It is inadequate to explain the high Tc, which arises instead from an unusually large electron- phonon coupling to the two Γ'12 optical phonon modes. 相似文献
84.
J. Amirzadeh R.E. Ansorge M. Baubillier I.J. Bloodworth G.J. Bossen A. Burns J.N. Carney J.R. Carter C.A. Cowan G.F. Cox U. Dore Ph. Gavillet J.K. Hassall J.B. Kinson K. Knudson F. Levy P.F. Loverre R. Zitoun 《Physics letters. [Part B]》1979,89(1):125-130
We present evidence for a narrow Y1 with a mass of 3.17 GeV and a width ? 20 MeV decaying to ΣKK? + pions, ΛKK? + pions and ΞK + pions. The data come from two high statistics K?p bubble chamber experiments with a sensitivity of ≈100 eV/μbat 8.25 GeV/c and ≈ 45 eV/μbat 6.5 GeV/c. 相似文献
85.
A mechanism is proposed to explain the double phase transitions found in K2PbCu(NO2)6 and Tl2PbCu(NO2)6. The higher temperature transition is caused by the cooperative Jahn-Teller effect. The lower temperature transition occurs as the fourth order anharmonic interaction restabilizes the lattice against instabilities caused by static distortions in the third order anharmonic interaction. Calculated curves of the order parameter and heat capacity reproduce all the features in the experimental curves. 相似文献
86.
Vicic DA Anderson TJ Cowan JA Schultz AJ 《Journal of the American Chemical Society》2004,126(26):8132-8133
Reaction of two equiv of 1-adamantylzinc bromide with (dippm)NiBr2 (dippm = bis(di-isopropylphosphino)methane) led to a dinuclear metal complex containing a unique linear bridging hydride ligand. The hydride was characterized by neutron diffraction methods, which confirmed a linear bonding mode. Preliminary reactivity studies of this unusual dimer are reported. 相似文献
87.
Abe K Abe K Abe T Adam I Akimoto H Aston D Baird KG Baltay C Band HR Barklow TL Bauer JM Bellodi G Berger R Blaylock G Bogart JR Bower GR Brau JE Breidenbach M Bugg WM Burke D Burnett TH Burrows PN Calcaterra A Cassell R Chou A Cohn HO Coller JA Convery MR Cook V Cowan RF Crawford G Damerell CJ Daoudi M de Groot N de Sangro R Dong DN Doser M Dubois R Erofeeva I Eschenburg V Fahey S Falciai D Fernandez JP Flood K Frey R Hart EL Hasuko K Hertzbach SS Huffer ME Huynh X Iwasaki M Jackson DJ 《Physical review letters》2002,88(15):151801
The parity violation parameters A(b) and A(c) of the Zb(b) and Zc(c) couplings have been measured directly, using the polar angle dependence of the polarized cross sections at the Z(0) pole. Bottom and charmed hadrons were tagged via their semileptonic decays. Both the electron and muon analyses take advantage of new multivariate techniques to increase the analyzing power. Based on the 1993-1998 SLD sample of 550,000 Z(0) decays produced with highly polarized electron beams, we measure A(b) = 0.919+/-0.030(stat)+/-0.024(syst), and A(c) = 0.583+/-0.055(stat)+/-0.055(syst). 相似文献
88.
Ahmad QR Allen RC Andersen TC Anglin JD Barton JC Beier EW Bercovitch M Bigu J Biller SD Black RA Blevis I Boardman RJ Boger J Bonvin E Boulay MG Bowler MG Bowles TJ Brice SJ Browne MC Bullard TV Bühler G Cameron J Chan YD Chen HH Chen M Chen X Cleveland BT Clifford ET Cowan JH Cowen DF Cox GA Dai X Dalnoki-Veress F Davidson WF Doe PJ Doucas G Dragowsky MR Duba CA Duncan FA Dunford M Dunmore JA Earle ED Elliott SR Evans HC Ewan GT Farine J Fergani H Ferraris AP Ford RJ Formaggio JA Fowler MM 《Physical review letters》2002,89(1):011302
The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution. 相似文献
89.
Ahmad QR Allen RC Andersen TC D Anglin J Barton JC Beier EW Bercovitch M Bigu J Biller SD Black RA Blevis I Boardman RJ Boger J Bonvin E Boulay MG Bowler MG Bowles TJ Brice SJ Browne MC Bullard TV Bühler G Cameron J Chan YD Chen HH Chen M Chen X Cleveland BT Clifford ET Cowan JH Cowen DF Cox GA Dai X Dalnoki-Veress F Davidson WF Doe PJ Doucas G Dragowsky MR Duba CA Duncan FA Dunford M Dunmore JA Earle ED Elliott SR Evans HC Ewan GT Farine J Fergani H Ferraris AP Ford RJ Formaggio JA Fowler MM 《Physical review letters》2002,89(1):011301
Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models. 相似文献
90.