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781.
Paul S. Haradem Bertrand L. Chamberland Lewis Katz Alain Gleizes 《Journal of solid state chemistry》1977,21(3):217-223
A single crystal study of Ba3Pt2O7 shows that the structure tolerates a variable composition which can be written Ba3Pt2+xO7+2x. The crystal studied has a hexagonal cell of dimensions a = 10.108 ± 0.006 Å and c = 8.638 ± 0.009 Å, and a probable space group . The density determined by water displacement is 7.99 g/cm3; the theoretical density for Ba3Pt2O7 is 7.94 g/cm3. The structure was determined from the set of 401 observed independent reflections obtained from 5189 reflections measured by automated counter methods. Refinement on F was carried to a conventional R of 8.0%. The structure has barium-oxygen layers with an essentially four-layer stacking sequence of the double hexagonal (ABAB) type. Platinum is found mainly in face-sharing octahedra, but is also distributed over some sites in which the coordination is nearly square planar and other sites in which the coordination is trigonal prismatic with three PtO bond lengths of 2.00 Å and three long PtO distances of 2.65 Å. The platinum with planar coordination is 0.08 Å from the plane of the four oxygen atoms. 相似文献
782.
Efficient resonant frequency doubling of a cw Nd:YAG laser in bulk periodically poled KTiOPO(4) 总被引:1,自引:0,他引:1
A cw Nd:YAG laser was quasi-phase-matched frequency doubled by a bulk periodically poled flux-grown KTiOPO(4) crystal in an external resonant cavity. The conversion efficiency and the second-harmonic power with a pump of 225 mW were 55% and 123.5 mW, respectively. The loss of the 1-cm-long crystal, which operated near room temperature, was 1.3% and was dominated by scatter from the cleaved facets of the crystal. No damage, photorefractive or other, was observed at intensites of 370Wmm(-2) , but beam size had to be optimized to eliminate thermal-induced instabilities in the doubling cavity. 相似文献
783.
M. Berggren J. Guy P. -O. Hulth G. T. Jones U. F. Katz P. Marage E. Matsinos S. W. O'Neale E. Simopoulou K. E. Varvell A. Vayaki W. Venus W. Wittek 《Zeitschrift fur Physik C Particles and Fields》1991,50(3):427-440
TheW andQ
2 dependence of the transverse momentum of the forward-going hadrons in deep inelastic neutrino charged current interactions on neon is studied. The data were obtained by exposing BEBC filled with a Ne/H2 mixture to the CERN SPS wide-band neutrino beam. The data on average transverse momentum are compared to a model which includes first order QCD, intrinsic quark momentum in the nucleon and Fermi motion, as well as a simple model for hadronization. The model is found to describe the data well. Values of
s
=0.16±0.02(stat)±0.02(syst.)±0.03(frag.) at an averageQ
2 of 15.4±0.4 GeV2/c2 and
(stat.)
–90
+100
(syst.)
–90
+130
, (frag.) MeV/v for three flavours are extracted. 相似文献
784.
A novel method is proposed that reduces the bit error rate (BER) in an optically amplified system by using a Mach-Zender interferometer coherence manipulation at the receiver. Exact analysis is presented, which shows that the signal-to-noise ratio can be improved by 3 dB. Resulting BER improvements are presented. 相似文献
785.
S. Stepanjan J. J. Strishewski W. H. Jackson S. A. Katz N. S. Arontschikowa W. Åström T. P. Hoar E. D. Koepping F. P. Dwyer und R. K. Murphy 《Fresenius' Journal of Analytical Chemistry》1939,117(3-4):132-136
Ohne Zusammenfassung 相似文献
786.
787.
Oisin Tong Yushi Yanagita Shaun Harris Aaron Katz Doug Hunsaker 《International Journal of Computational Fluid Dynamics》2013,27(4-5):203-217
ABSTRACTIn this work, we examine the flux correction method for three-dimensional transonic turbulent flows on strand grids. Building upon previous work, we treat flux derivatives along strands with high-order summation-by-parts operators and penalty-based boundary conditions. A finite-volume like limiting strategy is implemented in the flux correction algorithm in order to sharply capture shocks. To achieve turbulence closure in the Reynolds-Averaged Navier–Stokes equations, a robust version of the Spalart–Allmaras turbulence model is employed that accommodates negative values of the turbulence working variable. Validation studies are considered which demonstrate the flux correction method achieves a high degree of accuracy for turbulent shock interaction flows. 相似文献
788.
Ultrahigh energy neutrinos (UHEnu) scatter on relic neutrinos (Rnu) producing Z bosons, which can decay hadronically producing protons (Z burst). We compare the predicted proton spectrum with the observed ultrahigh energy cosmic ray (UHECR) spectrum and determine the mass of the heaviest Rnu via a maximum likelihood analysis. Our prediction depends on the origin of the powerlike part of the UHECR spectrum: m(nu) = 2.75(+1.28)(-0.97) eV for Galactic halo and 0.26(+0.20)(-0.14) eV for extragalactic origin. The necessary UHEnu flux should be detected in the near future. 相似文献
789.
We report a measurement of the suppression of collisions of quasiparticles with ground state atoms within a Bose-Einstein condensate at low momentum. These collisions correspond to Beliaev damping of the excitations, in the previously unexplored regime of the continuous quasiparticle energy spectrum. We use a hydrodynamic simulation of the expansion dynamics, with the Beliaev damping cross section, in order to confirm the assumptions of our analysis. 相似文献
790.
Ichia LS Katz E Wasserman J Willner I 《Chemical communications (Cambridge, England)》2002,(2):158-159
Magnetic-field-stimulated 'ON' and 'OFF' biochemiluminescence is accomplished by electrocatalyzed reduction of naphthoquinone-functionalized magnetic particles in the presence of a biocatalytic peroxidase/luminol system. 相似文献