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281.
Andreotti M Bagnasco S Baldini W Bettoni D Borreani G Buzzo A Calabrese R Cester R Cibinetto G Dalpiaz P Garzoglio G Gollwitzer KE Graham M Hu M Joffe D Kasper J Lasio G Lo Vetere M Luppi E Macrì M Mandelkern M Marchetto F Marinelli M Menichetti E Metreveli Z Mussa R Negrini M Obertino MM Pallavicini M Pastrone N Patrignani C Pedlar TK Pordes S Robutti E Roethel W Rosen JL Rumerio P Rusack R Santroni A Schultz J Seo SH Seth KK Stancari G Stancari M Tomaradze A Uman I Vidnovic T Werkema S 《Physical review letters》2003,91(9):091801
Fermilab experiment E835 has observed (-)pp annihilation production of the charmonium state chi(c0) and its subsequent decay into pi(0)pi(0). Although the resonant amplitude is an order of magnitude smaller than that of the nonresonant continuum production of pi(0)pi(0), an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance (-)pp channel. The product of the input and output branching fractions is determined to be B((-)pp-->chi(c0))xB(chi(c0)-->pi(0)pi(0))=(5.09+/-0.81+/-0.25)x10(-7). 相似文献
282.
E. Kasper 《Applied Physics A: Materials Science & Processing》1982,28(2):129-135
Growth mode, surface morphology, crystal perfection and growth rate of siliconmolecular beam epitaxy films were observed as function of temperature (450°–950°C), silicon flux density (8×1014–8×1015cm2/s) and surface orientation (111, 110, 100). Within the varied parameters growth proceeds by the two-dimensional growth mode via the lateral motion of atomic steps originating from the slight misorientation of commercially available substrates (typically 0.25°). Single crystalline films with high lattice perfection and smooth surfaces result from this growth mode. The growth rate — linearly dependent on Si-flux density and independant of temperature and orientation — indicates a condensation coefficient near unity. An atomic step flow model on the basis of the Burton-Cabrera-Frank theory explains this behaviour by mobile adatoms with low activation energy of diffusion. 相似文献
283.
We have studied dielectric spectra of the glass-forming liquid metafluoroaniline under hydrostatic pressure up to 700 MPa. Its glass transition pressure p(g) increases approximately linearly with temperature. Above p(g)(T), a well pronounced secondary relaxation, the Johari beta peak, is observed showing activated behavior. The activation energy rises proportionally to pressure and, consequently, proportionally to the glass transition temperature T(g)(p). The activation volume is independent of temperature but exhibits different values for pressures higher and lower than the pressure where the liquid left the ergodic regime. The activation volumes are about 1/10 and 1/6 of the molecular volume of fluoroaniline, respectively, suggesting that there are two different species of clusters. 相似文献
284.
Link JM Yager PM Anjos JC Bediaga I Castromonte C Machado AA Magnin J Massafferi A de Miranda JM Pepe IM Polycarpo E dos Reis AC Carrillo S Casimiro E Cuautle E Sánchez-Hernández A Uribe C Vázquez F Agostino L Cinquini L Cumalat JP O'Reilly B Segoni I Stenson K Butler JN Cheung HW Chiodini G Gaines I Garbincius PH Garren LA Gottschalk E Kasper PH Kreymer AE Kutschke R Wang M Benussi L Bertani M Bianco S Fabbri FL Pacetti S Zallo A Reyes M Cawlfield C Kim DY Rahimi A Wiss J Gardner R Kryemadhi A 《Physical review letters》2005,95(5):052003
A high statistics measurement of the D(s)+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, D(s)+ --> phi(1020)pi+ and D(s)+ -->K*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5(stat) +/- 5.1(syst) fs using 8961 +/- 105 D(s)+ --> phi(1020)pi+ and 4680 +/- 90 D(s)+ --> K*(892)0K+ decays. This is a significant improvement over the present world average. 相似文献
285.
Dressel M Kasper N Petukhov K Gorshunov B Grüner G Huth M Adrian H 《Physical review letters》2002,88(18):186404
The optical conductivity of the heavy fermions UPd(2)Al(3) and UPt(3) has been measured in the energy range from 0.04 to 5 meV. In both compounds a well pronounced pseudogap of less than 1 meV develops in the optical response at low temperatures; we relate this to the antiferromagnetic ordering. From the energy dependence of the effective mass and scattering rate we conclude that the enhancement of the mass mainly occurs below the energy which is related to magnetic correlations between the local magnetic moments and the itinerant electrons. This implies that the magnetic order in these compounds is the prerequisite to the formation of the heavy quasiparticles and eventually to superconductivity. 相似文献
286.
Aderholz M Aggarwal MM Akbari H Allport PP Baba PV Badyal SK Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell RC Cence R Chatterjee TK Clayton EF Corrigan G Coutures C De Prospo D Devanand De Wolf E Faulkner PJ Fretter WB Gupta VK Guy J Hanlon J Harigel G Harris F Jabiol MA Jacques P Jain V Jones GT Jones MD Jones RW Kafka T Kalelkar M Kasper P Kaul GL Kaur M Kohli JM Koller EL Krawiec RJ Lauko M Lys J Mann WA Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J 《Physical review letters》1989,63(21):2349-2352
287.
Jain V Harris FA Aderholz M Aggarwal MM Akbari H Allport PP Baba PV Badyal SK Barth M Baton JP Bingham HH Brucker EB Burnstein RA Campbell JR Cence RJ Chatterjee TK Clayton EF Corrigan G Coutures C Deprospo D Devanand De Wolf E Faulkner PJ Fretter WB Gupta VK Guy J Hanlon J Harigel GG Jabiol MA Jacques P Jones GT Jones MD Kafka T Kalelkar M Kasper P Kaul GL Kaur M Kohli JM Koller EL Krawiec RJ Lauko M Lys J Marage P Milburn RH Miller DB Mittra IS Mobayyen MM Moreels J Morrison DR Myatt G 《Physical review D: Particles and fields》1990,41(7):2057-2073
288.
Adams D Ahmad S Akchurin N Birmingham P Breuer H Chang CC Cihangir S Corcoran MD Davis WL Gustafson HR Holmgren H Kasper P Kruk J Lincoln D Longo MJ Marraffino J McPherson J Miettinen HE Morrow G Mutchler GS Naples D Onel Y Skeens J Thomas GP Traynor MM Waters JW Webster MS Xu JP Zhu Q 《Physical review letters》1994,72(15):2337-2340
289.
290.
Horst Kasper 《Monatshefte für Chemie / Chemical Monthly》1967,98(4):1206-1216
Zusammenfassung Im System ZnO–Sb2O5 existieren zwei Spinellphasen (I) und (III) gleicher Zusammensetzung Zn7Sb2O12. Außerdem konnte noch eine weitere Modifikation (II) mit einer niedrigsymmetrischen Struktur aufgefunden werden.In (II) und (III) wurden Cu2+, Ni2+ und Co2+ als farbgebende Kationen eingebaut. Die spektralphotometrische Untersuchung ergab, daß Zn2+ in (II) sowohl oktaedrisch als auch tetraedrisch koordiniert ist. Im Spinell (III) wird Cu2+ sowohl in Tetraeder-und Oktaederlücken, Ni2+ nur in Oktaeder- und Co2+ vorwiegend in Oktaederlücken eingebaut.In the system ZnO–Sb2O5 exist two phases (I) and (III) with the spinel structure and the same composition Zn7Sb2O12. Besides these another modification (II) with a structure of lower symmetry could be found.The colouring cations Cu2+, Ni2+, Co2+ have been incorporated in (II) and (III). The spectrophotometrical investigation shows that Zn2+ occupies in (II) octahedral and tetrahedral sites. In the spinel (III) Cu2+ is incorporated tetrahedrally and octahedrally, Ni2+ only octahedrally and Co2+ predominantly octahedrally.Mit 4 Abbildungen1. Mitt.:H. Kasper, Z. anorg. allgem. Chem. (im Druck). 相似文献