排序方式: 共有72条查询结果,搜索用时 15 毫秒
31.
S. Cecchini M. Cozzi D. Di Ferdinando M. Errico F. Fabbri G. Giacomelli R. Giacomelli M. Giorgini A. Kumar J. McDonald G. Mandrioli S. Manzoor A. Margiotta E. Medinaceli L. Patrizii J. Pinfold V. Popa I. E. Qureshi O. Saavedra Z. Sahnoun G. Sirri M. Spurio V. Togo C. Valieri A. Velarde A. Zanini 《The European Physical Journal C - Particles and Fields》2008,57(3):525-533
The SLIM experiment at the Chacaltaya high altitude laboratory was sensitive to nuclearites and Q-balls which could be present
in the cosmic radiation as possible Dark Matter components. It was sensitive also to strangelets, i.e. small lumps of Strange
Quark Matter predicted at such altitudes by various phenomenological models. The analysis of 427 m2 of Nuclear Track Detectors exposed for 4.22 years showed no candidate event. New upper limits on the flux of downgoing nuclearites
and Q-balls at the 90% C.L. were established. The null result also restricts models for strangelets propagation through the
Earth atmosphere. 相似文献
32.
33.
Paolo Bruni Liberato Cardellini Carla Conti Elisabetta Giorgini Giorgio Tosi 《Monatshefte für Chemie / Chemical Monthly》1990,121(2-3):165-171
Summary The reaction of isomeric arylazopyridines with 1-hydroxy-2-phenylindole leads to molecular associations between the pyridine derivative and the 1-hydroxy-2-phenylindole itself or its dimer. The role of hydrogen bonding in the formation of the complex is also discussed in the light of conductivity measurements.
Molekulare Wechselwirkungen zwischen Arylazopyridinen und N-Hydroxyindolen
Zusammenfassung Die Reaktion isomerer Arylazopyridine mit 1-Hydroxy-2-phenylindol führt zu molekularen Associaten zwischen den Pyridin-Derivaten und 1-Hydroxy-2-phenylindol oder seinem Dimer. Die Rolle der Hydrogenbindung bei der Bildung der Komplexverbindung wird mittels Leitfähigkeitsmessungen geprüft.相似文献
34.
Renata Longo Adelma Giorgini Silvia Magnaldi Lorenzo Pascazio Claudio Ricci 《Magnetic resonance imaging》1993,11(8):1209-1215
Two patients affected by severe Alzheimer's disease (AD) were investigated by MRI and image-guided 31P MRS. In one case, 1H MRS was additionally performed. In both cases the diagnosis of AD was confirmed, post mortem, by the pathologist. The spectral parameters of the 31P MR spectra were estimated by fitting the 31P MR signals in the time domain. Our 31P MRS results suggest that it is possible to detect the membrane catabolism, as indexed with the level of PDE resonances visible in in vivo 31P MRS, at least in severe AD cases. The 1H spectrum from AD brain showed a marked decrease of NAA signal respect to choline. 相似文献
35.
Nascimbène S Navon N Pilati S Chevy F Giorgini S Georges A Salomon C 《Physical review letters》2011,106(21):215303
We measure the magnetic susceptibility of a Fermi gas with tunable interactions in the low-temperature limit and compare it to quantum Monte Carlo calculations. Experiment and theory are in excellent agreement and fully compatible with the Landau theory of Fermi liquids. We show that these measurements shed new light on the nature of the excitations of the normal phase of a strongly interacting Fermi gas. 相似文献
36.
Francesco?Di?PlinioEmail authorView authors OrcID profile Andrea?Giorgini Vittorino?Pata Roger?Temam 《Journal of Nonlinear Science》2018,28(2):653-686
We consider a Navier–Stokes–Voigt fluid model where the instantaneous kinematic viscosity has been completely replaced by a memory term incorporating hereditary effects, in presence of Ekman damping. Unlike the classical Navier–Stokes–Voigt system, the energy balance involves the spatial gradient of the past history of the velocity rather than providing an instantaneous control on the high modes. In spite of this difficulty, we show that our system is dissipative in the dynamical systems sense and even possesses regular global and exponential attractors of finite fractal dimension. Such features of asymptotic well-posedness in absence of instantaneous high modes dissipation appear to be unique within the realm of dynamical systems arising from fluid models. 相似文献
37.
We study the Fermi gas at unitarity and at T=0 by assuming that, at high polarizations, it is a normal Fermi liquid composed of weakly interacting quasiparticles associated with the minority spin atoms. With a quantum Monte Carlo approach we calculate their effective mass and binding energy, as well as the full equation of state of the normal phase as a function of the concentration x=n downward arrow/n upward arrow of minority atoms. We predict a first order phase transition from normal to superfluid at x(c)=0.44 corresponding, in the presence of harmonic trapping, to a critical polarization P(c)=(N upward arrow - N downward arrow/(N upward arrow + N downward arrow)=77%. We calculate the radii and the density profiles in the trap and predict that the frequency of the spin dipole mode will be increased by a factor of 1.23 due to interactions. 相似文献
38.
We investigate the phase diagram of asymmetric two-component Fermi gases at zero temperature as a function of polarization and interaction strength. The equations of state of the uniform superfluid and normal phase are determined using quantum Monte Carlo simulations. We find three different mixed states, where the superfluid and the normal phase coexist in equilibrium, corresponding to phase separation between (a) the polarized superfluid and the fully polarized normal gas, (b) the polarized superfluid and the partially polarized normal gas, and (c) the unpolarized superfluid and the partially polarized normal gas. 相似文献
39.
Paolo Bruni Carla Conti Elisabetta Giorgini Eziana Maurelli Giorgio Tosi 《Journal of heterocyclic chemistry》1992,29(5):1331-1336
Complexes of hydrazones of heterocyclic compounds with organic acceptors are investigated through the evaluation of spectroscopic and thermodynamic properties. Values of the formation constants and comparison between uv-visible and ft-ir determinations on liquid and solid phases indicate these systems are weak complexes. Contributions from hydrogen bonding and the effects of π?π* or n?π* transitions on the spectroscopic and thermodynamic properties of the complexes are discussed. 相似文献
40.
S. Balestra S. Cecchini M. Cozzi M. Errico F. Fabbri G. Giacomelli R. Giacomelli M. Giorgini A. Kumar S. Manzoor J. McDonald G. Mandrioli S. Marcellini A. Margiotta E. Medinaceli L. Patrizii J. Pinfold V. Popa I.E. Qureshi O. Saavedra Z. Sahnoun G. Sirri M. Spurio V. Togo A. Velarde A. Zanini 《The European Physical Journal C - Particles and Fields》2008,55(1):57-63
The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m
a.s.l.). The detector was in particular sensitive to intermediate mass magnetic monopoles, with masses 105 GeV <MM< 1012 GeV. From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3×10-15 cm-2 s-1 sr-1 for downgoing fast intermediate mass monopoles was established at the 90% C.L.
PACS 14.80.Hv; 29.40.Wk; 29.90.+r 相似文献