426 research outputs found

    Parametric attosecond pulse amplification far from the ionization threshold from high order harmonic generation in He+^+

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    Parametric amplification of attosecond coherent pulses around 100 eV at the single-atom level is demonstrated for the first time by using the 3D time-dependent Schr{\"o}dinger equation in high-harmonic generation processes from excited states of He+^+. We present the attosecond dynamics of the amplification process far from the ionization threshold and resolve the physics behind it. The amplification of a particular central photon energy requires the seed XUV pulses to be perfectly synchronized in time with the driving laser field for stimulated recombination to the He+^+ ground state and is only produced in a few specific laser cycles in agreement with the experimental measurements. Our simulations show that the amplified photon energy region can be controlled by varying the peak intensity of the laser field. Our results pave the way to the realization of compact attosecond pulse intense XUV lasers with broad applications

    Rediscovery of Parazuphium chevrolatii praepannonicum in Hungary (Coleoptera: Carabidae)

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    Parazuphium (Parazuphium) chevrolatii praepannonicum (Endrődy-Younga, 1958) was found in 2014, 61 years aft er its discovery (1953) in Hungary. Three specimens were collected in the Pilis Mts under a large boulder embedded in loessy soil above andesite bedrock. Zuphium hungaricum J. Frivaldszky, 1877 is deleted from the list of Carabidae of present-day Hungary. With 2 figures

    Amplification of high harmonic generation signal by double gas jet scheme

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    Tumour necrosis factor-α and adenosine in endotoxin shockleading related cardiovascular symptoms

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    We have observed uncontrollable cardiogenic shock as a cardiovascular manifestation of systemic inflammatory response syndrome (SIRS) leading to death in a 62-year-old woman. The diagnosis of SIRS was based on the demonstration of endotoxinaemia, and highly elevated plasma levels of tumour necrosis factor (TNF)-α, and interleukin (IL)-10. We suggest that these cytokines may contribute to the terminal SIRS-related arrythmias, impaired myocardial contractility, as well as increased vascular permeability. In addition, the increased production of adenosine, a counter-regulatory mediator of inflammation, may also play a role in cardiodepression. We suggest a relationship between the action of TNF-α , IL-10 and adenosine in the pathogenesis of circulatory symptoms described above

    Geology of the historical Bodrogköz

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    Abstract The Bodrogköz is predominantly a flat area surrounded by the rivers Tisza, Bodrog and Latorica. The Hungarian-Slovakian border cuts it into two parts; consequently, the geologic data in the two countries are different in terms of scale and in approach. The authors harmonized the different data on the two sides and created a unified geologic database for the entire area. The Bodrogköz is part of the depression at the northeastern part of the Great Hungarian Plain. It is covered mostly by Quaternary formations but in the Slovakian part there are smaller outcrops of Permian formations and Miocene volcanics

    Space-time coupling of shaped ultrafast ultraviolet pulses from an acousto-optic programmable dispersive filter

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    A comprehensive experimental analysis of spatio-temporal coupling effects inherent to the acousto-optic programmable dispersive filter (AOPDF) is presented. Phase and amplitude measurements of the AOPDF transfer function are performed using spatially and spectrally resolved interferometry. Spatio-temporal and spatio-spectral coupling effects are presented for a range of shaped pulses that are commonly used in quantum control experiments. These effects are shown to be attributable to a single mechanism: a group-delay--dependent displacement of the shaped pulse. The physical mechanism is explained and excellent quantitative agreement between the measured and calculated coupling speed is obtained. The implications for quantum control experiments are discussed.Comment: 8 pages, 6 figures; accepted for publication within JOSA
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