438 research outputs found

    Purity-bounded uncertainty relations in multidimensional space -- generalized purity

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    Uncertainty relations for mixed quantum states (precisely, purity-bounded position-momentum relations, developed by Bastiaans and then by Man'ko and Dodonov) are studied in general multi-dimensional case. An expression for family of mixed states at the lower bound of uncertainty relation is obtained. It is shown, that in case of entropy-bounded uncertainty relations, lower-bound state is thermal, and a transition from one-dimensional problem to multi-dimensional one is trivial. Results of numerical calculation of the relation lower bound for different types of generalized purity are presented. Analytical expressions for general purity-bounded relations for highly mixed states are obtained.Comment: 12 pages, 2 figures. draft version, to appear in J. Phys. A Partially based on a poster "Multidimensional uncertainty relations for states with given generalized purity" presented on X Intl. Conf. on Quantum Optics'2004 (Minsk, Belarus, May 30 -- June 3, 2004) More actual report is to be presented on ICSSUR-2005, Besan\c{c}on, France and on EQEC'05, Munich. V. 5: amended article after referees' remark

    New uncertainty relations for tomographic entropy: Application to squeezed states and solitons

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    Using the tomographic probability distribution (symplectic tomogram) describing the quantum state (instead of the wave function or density matrix) and properties of recently introduced tomographic entropy associated with the probability distribution, the new uncertainty relation for the tomographic entropy is obtained. Examples of the entropic uncertainty relation for squeezed states and solitons of the Bose--Einstein condensate are considered.Comment: 18 pages, 2 figures, to be published in European Physical Journal

    Dysarthria as a Cause of Hypotonic Dysphonia in Adolescents

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    В статье рассматривается патология голосового аппарата и причины развития гипотонусной дисфонии у подростков.The main tool of a person in society is a voice that makes communicative activity and social interaction possible. Dysphonia is a disorder of voice production, which impairs the quality of voice. Therefore, the responsibility for the formation of the voice function in adolescents with speech pathology falls on logopedists as specialists in the field of speech and voice production, and the prevention and treatment of voice disorders is carried out by a doctor-otorhinolaryngologist and/or phoniatrist

    Time dependence of the electron and positron components of the cosmic radiation measured by the PAMELA experiment between July 2006 and December 2015

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    Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) till the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.Comment: 11 pages, 2 figure

    Комплексное лечение больных с локализованными и местнораспространенными формами почечно-клеточного рака с применением предоперационной эмболизации

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    Background: Treatment of localized and locally advanced renal cancer is still of current importance. Subjects and methods: 100 cases of pT2, pT3a renal cell carcinoma were compared in 2 groups according to the treatment strategy: 1) patients who had received complex treatment (renal artery embolization and surgical treatment) (a study group) and 2) those who had been surgically treated (a control group). The criterion for efficiency was the median duration of relapse- free survival. Results: the median duration of relapse-free survival was 37 months in study group patients with pT2 disease and 39.5 months in the control group. The relapse-free survival varies greatly: 30.5 months in patients with pT3a in the study group and 16.5 months in the control group. Conclusion: The findings have led to the conclusion that it is necessary to make preoperative renal artery embolization in the complex treatment of patients with pT3a renal cell carcinoma.

    Trapped proton fluxes at low Earth orbits measured by the PAMELA experiment

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    We report an accurate measurement of the geomagnetically trapped proton fluxes for kinetic energy above > 70 MeV performed by the PAMELA mission at low Earth orbits (350-610 km). Data were analyzed in the frame of the adiabatic theory of charged particle motion in the geomagnetic field. Flux properties were investigated in detail, providing a full characterization of the particle radiation in the South Atlantic Anomaly region, including locations, energy spectra and pitch angle distributions. PAMELA results significantly improve the description of the Earth's radiation environment at low altitudes placing important constraints on the trapping and interaction processes, and can be used to validate current trapped particle radiation models.Comment: 22 pages, 5 figure

    Measurement of boron and carbon fluxes in cosmic rays with the PAMELA experiment

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    The propagation of cosmic rays inside our galaxy plays a fundamental role in shaping their injection spectra into those observed at Earth. One of the best tools to investigate this issue is the ratio of fluxes for secondary and primary species. The boron-to-carbon (B/C) ratio, in particular, is a sensitive probe to investigate propagation mechanisms. This paper presents new measurements of the absolute fluxes of boron and carbon nuclei, as well as the B/C ratio, from the PAMELA space experiment. The results span the range 0.44 - 129 GeV/n in kinetic energy for data taken in the period July 2006 - March 2008
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