163 research outputs found

    Respublika mechei ili torgovaia respublika ?

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    Les auteurs analysent la représentation qui est faite de la toute puissante république de Novgorod dans les écrits historiques et politiques russes du xviiie – début du xixe siècle. Dans la tradition européenne, la république classique est une république militaire, qui s’appuie sur le modèle de la république romaine militairement puissante. En opposition, la république commerciale est considérée comme un petit État, inférieure militairement aux grandes monarchies. La pensée sociale russe, à commencer par celle développée par A.I. Mankiev, identifie Novgorod à une république mais demeure ambivalente dans l’évaluation de sa puissance militaire. Sous l’influence de l’imagerie romaine et du discours général « de gloire et de grandeur » de la fin du xviiie siècle, un canon s’est mis en place, qui fait de l’ancienne Novgorod « une république militaire » tout en conservant la république commerciale comme outil conceptuel pour l’analyse de l’histoire ultérieure de la ville. La reconnaissance d’un pouvoir militaire à la république de Novgorod sape l’un des arguments clés en faveur de la monarchie, selon lequel seule une monarchie est capable de contrôler et défendre efficacement un large territoire. De ce fait, l’évaluation de Novgorod en tant que république militaire marque une étape importante dans l’apparition dans la société russe du xixe siècle d’une alternative républicaine à un monarchisme apparemment inébranlable.The authors analyze how the powerful Republic of Novgorod was represented in Russian historical and political writing between the eighteenth and early nineteenth centuries. In the European tradition, a republic typically was military and modeled on the Roman Republic and its military strength. In contrast, the trading republic was considered a small state, militarily inferior to great monarchies. Russian social thought, starting with A.I. Mankiev’s, identified Novgorod with a military republic while remaining ambivalent in assessing its military might. The influence of Roman imagery and the general discourse on “glory and grandeur” of the late eighteenth century brought about the emergence of a model of old Novgorod as a military republic and set aside the trading republic as a conceptual toolkit for studying the town’s future historical development. Recognition of military power in the Republic of Novgorod undermined one of the key arguments in favor of monarchy – the claim that monarchy alone is able to effectively control and protect a vast territory. Thus, viewing Novgorod as a military republic was an important step towards the rise, in early‑nineteenth‑century Russian society, of a republican alternative to a seemingly immutable monarchy

    Bound-state beta-decay of a neutron in a strong magnetic field

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    The beta-decay of a neutron into a bound (pe)(pe^-) state and an antineutrino in the presence of a strong uniform magnetic field (B1013B \gtrsim 10^{13} G) is considered. The beta-decay process is treated within the framework of the standard model of weak interactions. A Bethe-Salpeter formalism is employed for description of the bound (pe)(pe^-) system in a strong magnetic field. For the field strengths 101310^{13} GB1018 \lesssim B \lesssim10^{18} G the estimate for the ratio of the bound-state decay rate wbw_b and the usual (continuum-state) decay rate wcw_c is derived. It is found that in such strong magnetic fields wb/wc0.10.4w_b/w_c \sim 0.1-0.4. This is in contrast to the field-free case, where wb/wc4.2×106w_b/w_c \simeq 4.2 \times 10^{-6} [J. N. Bahcall, Phys. Rev. {\bf 124}, 495 (1961); L. L. Nemenov, Sov. J. Nucl. Phys. {\bf 15}, 582 (1972); X. Song, J. Phys. G: Nucl. Phys. {\bf 13}, 1023 (1987)]. The dependence of the ratio wb/wcw_b/w_c on the magnetic field strength BB exhibits a logarithmic-like behavior. The obtained results can be important for applications in astrophysics and cosmology.Comment: 22 pages (revtex4), 1 figure; v2: more detailed discussion on astrophysical applications in conclusion section, accepted for publication in Phys. Rev.

    Cryphonectria nitschkei chrysovirus 1 with unique molecular features and a very narrow host range

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    Cryphonectria nitschkei chrysovirus 1 (CnCV1), was described earlier from an ascomycetous fungus, Cryphonectria nitschkei strain OB5/11, collected in Japan; its partial sequence was reported a decade ago. Complete sequencing of the four genomic dsRNA segments revealed molecular features similar to but distinct from previously reported members of the family Chrysoviridae. Unique features include the presence of a mini-cistron preceding the major large open reading frame in each genomic segment. Common features include the presence of CAA repeats in the 5′-untranslated regions and conserved terminal sequences. CnCV1-OB5/11 could be laterally transferred to C. nitschkei and its relatives C. radicalis and C. naterciae via coculturing, virion transfection and protoplast fusion, but not to fungal species other than the three species mentioned above, even within the genus Cryphonectria, suggesting a very narrow host range. Phenotypic comparison of a few sets of CnCV1-infected and -free isogenic strains showed symptomless infection in new hosts

    Quasimonoenergetic electron beams with relativistic energies and ultrashort duration from laser-solid interactions at 0.5 kHz

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    International audienceWe investigate the production of electron beams from the interaction of relativistically-intense laser pulses with a solid-density SiO2 target in a regime where the laser pulse energy is -mJ and the repetition rate -kHz. The electron beam spatial distribution and spectrum were investigated as a function of the plasma scale length, which was varied by deliberately introducing a moderate-intensity prepulse. At the optimum scale length of λ/2, the electrons are emitted in a collimated beam having a quasimonoenergetic distribution that peaked at -0.8MeV. A highly reproducible structure in the spatial distribution exhibits an evacuation of electrons along the laser specular direction and suggests that the electron beam duration is comparable to that of the laser pulse. Particle-in-cell simulations which are in good agreement with the experimental results offer insights on the acceleration mechanism by the laser field. © 2009 The American Physical Society

    Feshbach projection-operator formalism to resonance scattering on Bargmann-type potentials

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    The projection-operator formalism of Feshbach is applied to resonance scattering in a single-channel case. The method is based on the division of the full function space into two segments, internal (localized) and external (infinitely extended). The spectroscopic information on the resonances is obtained from the non-Hermitian effective Hamilton operator HeffH_{\rm eff} appearing in the internal part due to the coupling to the external part. As well known, additional so-called cut-off poles of the SS-matrix appear, generally, due to the truncation of the potential. We study the question of spurious SS matrix poles in the framework of the Feshbach formalism. The numerical analysis is performed for exactly solvable potentials with a finite number of resonance states. These potentials represent a generalization of Bargmann-type potentials to accept resonance states. Our calculations demonstrate that the poles of the SS matrix obtained by using the Feshbach projection-operator formalism coincide with both the complex energies of the physical resonances and the cut-off poles of the SS-matrix.Comment: 12 pages, 9 figure

    Octahedral molybdenum cluster complexes with aromatic sulfonate ligands

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    This article describes the synthesis, structures and systematic study of the spectroscopic and redox properties of a series of octahedral molybdenum metal cluster complexes with aromatic sulfonate ligands (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] (where X- is Cl-, Br- or I-; OTs- is p-toluenesulfonate and PhSO3 - is benzenesulfonate). All the complexes demonstrated photoluminescence in the red region and an ability to generate singlet oxygen. Notably, the highest quantum yields (>0.6) and narrowest emission bands were found for complexes with a {Mo6I8}4+ cluster core. Moreover, cyclic voltammetric studies revealed that (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] confer enhanced stability towards electrochemical oxidation relative to corresponding starting complexes (nBu4N)2[{Mo6X8}X6]

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30MM_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Non-Standard Errors

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    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
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