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941.
The Einstein–Podolsky–Rosen–Bohm (EPRB) experiment performed with random variable and spatially separated analyzers is a milestone
test in the controversy between Objective Local Theories (OLT) and Quantum Mechanics (QM). Only a few OLT are still possible.
Some of the surviving OLT (specifically, the so called non-ergodic theories) would be undetectable in the averaged statistical
values, but they may leave their trace in the time dynamics. For, while QM predicts random processes, the OLT of this kind
predict the existence of regularities that may be revealed as a low dimensional object in the phase space. We perform a numerical
analysis of the time-resolved data recorded in that experiment to unveil any hypothetical low dimensional dynamics that may
be present. We find no consistent indication of such dynamics except for one data file, the longest of all in the real time.
The possible causes of these dynamics are discussed.
相似文献
942.
Vineet Kumar Rai 《Applied physics. B, Lasers and optics》2007,88(2):297-303
The dependence of temperature on the fluorescence lifetime and fluorescence intensity ratio using Stark sublevels and thermally
coupled (close lying) levels in triply ionized rare earth ions, doped into a variety of glasses and fibers, have been reviewed.
Also, it is claimed that not only for the two closely lying levels of triply ionized rare earth ion of the same kind, but
also for two different triply ionized rare earth ions, having their excited levels very close to each other, may be used to
monitor the temperature.
PACS 42.70.Ce 相似文献
943.
Mechanical Characterization Measurement of Polymer Material under Stress by Birefringence Microscope
Some polymer materials under tensile stress provide us interesting information. Internal structure changes of polymer materials
must be observed by external stress. Birefringence shows the orientation characteristic in molecular orientation. A microscopic
measurement system for birefringence distribution is proposed to analyze the relation between applied stress and birefringence
distribution of an internal structure. Birefringence distributions of gelatin such as phase difference and azimuthal angle
are shown in cases of loading and unloading stress as a demonstration. The phase difference increased nonlinearly with each
process, and change of birefringence in the elastic domain was different from that in the plastic domain. 相似文献
944.
Yong-Xu Yang Jin-Li Zhou Qing-Run Li 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):35-41
Based on an α-particle model of 12C, an optical potential for intermediate-energy proton- 12C scattering is presented in the framework of the KMT theory. The parameterized proton- 4He amplitude, the required basic input for constructing the optical potential, is obtained by fitting the proton- 4He scattering data. The differential cross-sections and analyzing powers of the proton- 12C elastic scattering at incident energies ranging from 0.2 to 1.0GeV have been calculated by using the obtained optical potential.
The main features of the measured angular distributions of the cross-section and the analyzing power can be satisfactorily
described. The proton- 12C total cross-sections have also been calculated, and the results are in good agreement with the experimental data at energies
below 0.6GeV but underestimate the data about 6% at higher energies. 相似文献
945.
We consider a quantum system in contact with a heat bath consisting in an infinite chain of identical sub-systems at thermal
equilibrium at inverse temperature β. The time evolution is discrete and such that over each time step of duration τ, the
reference system is coupled to one new element of the chain only, by means of an interaction of strength λ. We consider three
asymptotic regimes of the parameters λ and τ for which the effective evolution of observables on the small system becomes
continuous over suitable macroscopic time scales T and whose generator can be computed: the weak coupling limit regime λ → 0, τ = 1, the regime τ → 0, λ2τ → 0 and the critical case λ2τ = 1, τ → 0. The first two regimes are perturbative in nature and the effective generators they determine is such that a
non-trivial invariant sub-algebra of observables naturally emerges. The third asymptotic regime goes beyond the perturbative
regime and provides an effective dynamics governed by a general Lindblad generator naturally constructed from the interaction
Hamiltonian. Conversely, this result shows that one can attach to any Lindblad generator a repeated quantum interactions model
whose asymptotic effective evolution is generated by this Lindblad operator. 相似文献
946.
The effect of light noise on a Neurospora circadian clock system in the steady states is investigated. It is found that the circadian oscillations could be induced
by light noise, leading to various resonance phenomena including internal signal stochastic resonance (ISSR) and ISSR without
tuning in the system. The strength of ISSR could be significantly reinforced with the decrease of the distance of the control
parameter to the Hopf bifurcation point of the system. The fundamental frequency of noise-induced circadian oscillations almost
does not change with the increment of light noise intensity, which implies that the Neurospora system could sustain intrinsic circadian rhythms. In addition, the ISSR and ISSR without tuning could be both amplified,
suppressed or destroyed by tuning the frequency or amplitude of external signal. 相似文献
947.
We consider the question of the existence of stationary solutions for the Navier Stokes equations describing the flow of a
incompressible fluid past a semi-infinite flat plate at zero incidence angle. By using ideas from the theory of dynamical
systems we analyze the vorticity equation for this problem and show that a symmetry-breaking term fits naturally into the
downstream asymptotic expansion of a solution. Finally, in order to check that our asymptotic expressions can be completed
to a symmetry-breaking solution of the Navier–Stokes equations we solve the problem numerically by using our asymptotic results
to prescribe artificial boundary conditions for a sequence of truncated domains. The results of these numerical computations
a clearly compatible with the existence of such a solution.
Mathematics Subject Classification (2000). 76D05, 76D25, 76M10, 41A60, 35Q35
Supported in part by the Fonds National Suisse. 相似文献
948.
Cédric Boutillier 《Communications in Mathematical Physics》2007,271(1):55-91
In this paper, we introduce a family of observables for the dimer model on a bi-periodic bipartite planar graph, called pattern density fields. We study the scaling limit of these objects for non-frozen Gibbs measures of the dimer model, and prove that they converge
to a linear combination of a derivative of the Gaussian massless free field and an independent white noise. 相似文献
949.
Anita Topkar S. Praveenkumar Bharti Aggarwal S. K. Kataria M. D. Ghodgaonkar 《Pramana》2007,69(6):1085-1088
A specific research and development program has been carried out by BARC in India to develop the technology for large area
silicon strip detectors for application in nuclear and high energy physics experiments. These strip detectors will be used
as pre-shower detector in the CMS experiment at LHC, CERN for π
0/λ rejection. The fabrication technology to produce silicon strip detectors with very good uniformity over a large area of ∼40
cm2, low leakage currents of the order of 10 nA/cm2 per strip and high breakdown voltage of >500 V has been developed by BARC. The production of detectors is already under way
to deliver 1000 detector modules for the CMS and 90% production is completed. In this paper, research and development work
carried out to develop the detector fabrication technology is briefly described. The performance of the silicon strip detectors
produced in India is presented. The present status of the detector technology is discussed.
相似文献
950.
Hakim Boumaza 《Mathematical Physics, Analysis and Geometry》2007,10(2):97-122
We study a continuous matrix-valued Anderson-type model. Both leading Lyapunov exponents of this model are proved to be positive
and distinct for all energies in (2, +∞) except those in a discrete set, which leads to absence of absolutely continuous spectrum
in (2, +∞). This result is an improvement of a previous result with Stolz. The methods, based upon a result by Breuillard
and Gelander on dense subgroups in semisimple Lie groups, and a criterion by Goldsheid and Margulis, allow for singular Bernoulli
distributions.
相似文献