71 research outputs found

    Direct measurement of non-linear properties of bipartite quantum states

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    Non-linear properties of quantum states, such as entropy or entanglement, quantify important physical resources and are frequently used in quantum information science. They are usually calculated from a full description of a quantum state, even though they depend only on a small number parameters that specify the state. Here we extract a non-local and a non-linear quantity, namely the Renyi entropy, from local measurements on two pairs of polarization entangled photons. We also introduce a "phase marking" technique which allows to select uncorrupted outcomes even with non-deterministic sources of entangled photons. We use our experimental data to demonstrate the violation of entropic inequalities. They are examples of a non-linear entanglement witnesses and their power exceeds all linear tests for quantum entanglement based on all possible Bell-CHSH inequalities.Comment: To appear on PRL with minor change

    STUDY OF THE INFLUENCE OF THE RIPENESS DEGREE OF PARSNIP ROOTS AND STORAGE METHOD ON THEIR PRESERVATION

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    Sowing parsnip is recommended to be harvested in the stage of technical ripeness that takes place in 120–150 days after sprouts. A ripeness degree cannot be determined by a root size, because in this case planting conditions and agrotechnique play an important role. The aim of the research was to analyze the influence of a vegetation period duration of different sorts of sowing parsnip on formation of chemical composition components and roots preservation to determine the dependence between the content of dry soluble substances and one of dry substances, sugars, saccharose, reducing sugars, ascorbic acid. The research gives a possibility to get roots with the maximal content of chemical composition components and long storage period. There has been studied the influence of a vegetation period duration of different sorts of sowing parsnip on formation of chemical composition components and roots preservation. The dependence between the content of dry soluble substances and one of dry substances, sugars, saccharose, reducing sugars, ascorbic acid has been determined. The research has been conducted with parsnip roots of sowing sort Petrik, Student, Boris. There has been studied the influence of a ripeness degree (vegetation period duration) on a quality and preservation of parsnip roots. Parsnip roots of the sowing sorts Student and Boris are characterized by the most content of the dry substance 27,1–25,4 %, and content of the total sugar 5,7–5,4 %, high content of vitamin С 10,2–10,1 mg/100 g. It has been established, that the studied sorts are not inclined to nitrates accumulation, their content varies from 60 to 80 mg/kg and is lower than the maximally permitted level (MPL 250 mg/kg). There has been established the direct strong connection between the content of the dry substance and sugars content (r=0,98), nitrates content (r=0,80) and the middle content with the testing mark (r=–0,54) and vitamin С (r=0,57). The dry soluble substance content has the direct strong connection with the sugars content (r=0,99), nitrates content (r=0,78) and middle connection with the content of vitamin С (r=0,46) and reverse middle connection with the testing mark (r=–0,52). The reverse middle connection exists between the sugars content and the testing mark (r=–0,52) and the direct strong connection with nitrates content (r=0,84), middle connection with the content of vitamin C (r=0,48). At storage of roots the loss of the mass of dry substances is from 11,5 % at storage in an open box to 6,2 – in a polyethylene film. The most changes take place in saccharose and monosaccharides, 36,6 and 33,0 % respectively. The content of vitamin C decreases by 30 % at storage in an open box and by 10 % in a polyethylene film. The vegetation period duration as 150 days is characterized by the lower sugars content, but at that the ratio saccharose: monosacharides – the most. There has been offered the method of determining the ripeness degree of parsnip roots by the saccharose content. At the technical ripeness the amount of saccharose is 72–75 % of the total amount of sugars. The optimal ripeness is characterized by deceleration of growing processes, decrease of saccharose accumulation rates, the most ratio of the roots mass to the one of leaves and saccharose to monosugars. The method of roots storage with p. e. film decreases losses of nutrients of roots and increases the storage duration

    Higher borides and oxygen-enriched Mg-B-O inclusions as possible pinning centers in nanostructural magnesium diboride and the influence of additives on their formation

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    The study of high pressure (2 GPa) synthesized MgB2-based materials allows us to conclude that higher borides (with near MgB12 stoichiometry) and oxygen-enriched Mg-B-O inclusions can be pinning centers in nanostructural magnesium diboride matrix (with average grain sizes of 15-37 nm). It has been established that additions of Ti or SiC as well as manufacturing temperature can affect the size, amount and distribution of these inclusions in the material structure and thus, influence critical current density. The superconducting behavior of materials with near MgB12 stoichiometry of matrix is discussed.Comment: 4 pages, 1 figues, presented at VORTEX VI-2009, accepted for Physica

    MASTER Optical Polarization Variability Detection in the Microquasar V404 Cyg/GS 2023+33

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    On 2015 June 15, the Swift space observatory discovered that the Galactic black hole candidate V404 Cyg was undergoing another active X-ray phase, after 25 years of inactivity. The 12 telescopes of the MASTER Global Robotic Net located at six sites across four continents were the first ground-based observatories to start optical monitoring of the microquasar after its gamma-ray wake up at 18h 34m 09s U.T. on 2015 June 15. In this paper, we report, for the first time, the discovery of variable optical linear polarization, changing by 4%-6% over a timescale of ∼1 hr, on two different epochs. We can conclude that the additional variable polarization arises from the relativistic jet generated by the black hole in V404 Cyg. The polarization variability correlates with optical brightness changes, increasing when the flux decreases.Fil: Lipunov, V.. M.V.Lomonosov Moscow State University. Physics Department; RusiaFil: Gorbovskoy, E.. M.V.Lomonosov Moscow State University, Sternberg Astronomical Institute; RusiaFil: Krushinskiy, V.. Kourovka Astronomical Observatory, Ural Federal University; RusiaFil: Vlasenko, D.. M.V.Lomonosov Moscow State University, Sternberg Astronomical Institute; RusiaFil: Tiurina, N.. M.V.Lomonosov Moscow State University, Sternberg Astronomical Institute; RusiaFil: Balanutsa, P.. M.V.Lomonosov Moscow State University, Sternberg Astronomical Institute; RusiaFil: Kuznetsov, A.. M.V.Lomonosov Moscow State University, Sternberg Astronomical Institute; RusiaFil: Budnev, N.. Applied Physics Institute. Irkutsk State University; RusiaFil: Gress, O.. Applied Physics Institute, Irkutsk State University; RusiaFil: Tlatov, A.. Kislovodsk Solar Station of the Main (Pulkovo) Observatory RAS; RusiaFil: Rebolo Lopez, L.. Instituto de Astrofsica de Canarias; EspañaFil: Serra-Ricart, M.. Instituto de Astrofsica de Canarias; EspañaFil: Buckley, D. A. H.. South African Astronomical Observatory; SudáfricaFil: Israelyan, G.. Instituto de Astrofsica de Canarias; EspañaFil: Lodieu, N.. Instituto de Astrofisica de Canarias; EspañaFil: Ivanov, K.. Applied Physics Institute. Irkutsk State University; RusiaFil: Yazev, S.. Applied Physics Institute, Irkutsk State University; RusiaFil: Sergienko, Y.. Blagoveschensk State Pedagogical University; RusiaFil: Gabovich, A.. Blagoveschensk State Pedagogical University; RusiaFil: Yurkov, V.. Blagoveschensk State Pedagogical University; RusiaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Podesta, R.. Observatorio "Felix Aguiklar". Universidad Nacional de San Juan; ArgentinaFil: Lopez, C.. Observatorio "Felix Aguilar". Universidad nacional de San juan; Argentin

    International Impact of COVID-19 on the Diagnosis of Heart Disease

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    BACKGROUND The coronavirus disease 2019 (COVID-19) pandemic has adversely affected diagnosis and treatment of noncommunicable diseases. Its effects on delivery of diagnostic care for cardiovascular disease, which remains the leading cause of death worldwide, have not been quantified. OBJECTIVES The study sought to assess COVID-19's impact on global cardiovascular diagnostic procedural volumes and safety practices. METHODS The International Atomic Energy Agency conducted a worldwide survey assessing alterations in cardiovascular procedure volumes and safety practices resulting from COVID-19. Noninvasive and invasive cardiac testing volumes were obtained from participating sites for March and April 2020 and compared with those from March 2019. Availability of personal protective equipment and pandemic-related testing practice changes were ascertained. RESULTS Surveys were submitted from 909 inpatient and outpatient centers performing cardiac diagnostic procedures, in 108 countries. Procedure volumes decreased 42% from March 2019 to March 2020, and 64% from March 2019 to April 2020. Transthoracic echocardiography decreased by 59%, transesophageal echocardiography 76%, and stress tests 78%, which varied between stress modalities. Coronary angiography (invasive or computed tomography) decreased 55% (p < 0.001 for each procedure). In multivariable regression, significantly greater reduction in procedures occurred for centers in countries with lower gross domestic product. Location in a low-income and lower-middle-income country was associated with an additional 22% reduction in cardiac procedures and less availability of personal protective equipment and telehealth. CONCLUSIONS COVID-19 was associated with a significant and abrupt reduction in cardiovascular diagnostic testing across the globe, especially affecting the world's economically challenged. Further study of cardiovascular outcomes and COVID-19-related changes in care delivery is warranted
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