966 research outputs found
Solar wind dependence of the electron flux variation at geostationary orbit observed by ETS-V
In this study we have examined the relationship between the energetic electron flux at geostationary orbit and the solar wind speed. We have compared the electron flux ( >0.4MeV) observed by the Engineering Test Satellite V (ETS-V) with solar wind speed measurements in the OMNI data set obtained from the National Space Science Data Center (NSSDC). The tendency has been observed for the logarithm of the electron flux to be proportional to the solar wind speed at solar minimum, but scattered at solar maximum. We have found that during the main and recovery phases of magnetic storms occurring at solar minimum, the logarithm of the electron flux is roughly proportional to the solar wind speed. At solar maximum, however, there is no apparent correlation between both these parameters. Moreover, in quiet periods there is also no observable correlation at both solar minimum and maximum. The dependence of the electron flux at geostationary orbit on the solar wind speed is related to recurrent storms caused by high-speed solar wind streams
Hierarchy of the Selberg zeta functions
We introduce a Selberg type zeta function of two variables which interpolates
several higher Selberg zeta functions. The analytic continuation, the
functional equation and the determinant expression of this function via the
Laplacian on a Riemann surface are obtained.Comment: 14 page
Применение криптографических методов шифрования информации
Необходимость технических средств защиты диктуется тем, что Интернет – это источник информации, за который никто не несет ответственности, и вероятность получения из него недостоверной, оскорбительной, пиратской или запрещенной по другим причинам информации весьма велика.The need for technological protection measures dictated by the fact that the Internet - a source of information for which no one is responsible, and the probability of getting out of it inaccurate, abusive, pirated or illegal for other reasons information is very high
Solvable model of a phase oscillator network on a circle with infinite-range Mexican-hat-type interaction
We describe a solvable model of a phase oscillator network on a circle with
infinite-range Mexican-hat-type interaction. We derive self-consistent
equations of the order parameters and obtain three non-trivial solutions
characterized by the rotation number. We also derive relevant characteristics
such as the location-dependent distributions of the resultant frequencies of
desynchronized oscillators. Simulation results closely agree with the
theoretical ones
Electron-spin-resonance and electrically detected-magnetic-resonance characterization on P bC center in various 4H-SiC(0001)/SiO2 interfaces
We characterized an intrinsic interface defect, called the "PbC center," formed at 4H-SiC(0001)/SiO2 interfaces by means of electron-spin-resonance (ESR) and electrically detected-magnetic-resonance (EDMR) spectroscopies. The formation of the PbC center was observed with a spin density of 3-4 × 1012 cm-2 after standard thermal oxidation. This center could be effectively removed by the NO post-oxidation-anneal (POA) process or ultra-high-temperature oxidation and could be passivated by H atoms via the H2 POA process. There was a clear correlation between the PbC center and field-effect mobility (μFE) of 4H-SiC(0001) metal-oxide-semiconductor field effect transistors (MOSFETs). The PbC center decreased μFE because this center acts as electron traps, reducing the free-carrier density in the inversion channel of 4H-SiC(0001) MOSFET. We also examined the counter doping effect of NO POA by introducing 15N impurities; however, the counter doping of 15N donors was not detectable by ESR (much lower than 2 × 1011cm-2). Highly sensitive EDMR measurements revealed that the PbC center has two isotropic hyperfine (HF) interactions at 1.3 and 6.8 mT and suggested that its main 13C HF interaction should be larger than 14 mT. Based on the present experimental data, the origin of the PbC center was ascribed as a carbon-related interface defect that forms a C-H bond after hydrogen passivation. This feature is similar to that of the porous-PbC centers (carbon dangling-bond centers) found in porous-SiC/SiO2 systems. However, their HF signatures indicated that the PbC center at 4H-SiC(0001)/SiO2 interfaces and the porous-PbC centers in porous-SiC should be different centers associated with different wave functions.Umeda T., Nakano Y., Higa E., et al. Electron-spin-resonance and electrically detected-magnetic-resonance characterization on P bC center in various 4H-SiC(0001)/SiO2 interfaces. Journal of Applied Physics, 127, 14, 145301. https://doi.org/10.1063/1.5134648
Layer-by-layer fabrication of highly transparent polymer based piezoelectric transducers
The fabrication of highly transparent piezoelectric transducers is of increasing interest in the scientific and technological community. In this work, polymer based piezoelectric transducers were fabricated by the direct deposition of each layer forming the transducer on the desired substrate, avoiding the use of coupling layers. Transparent conductive oxide (TCO) electrodes were deposited by magnetron sputtering and piezoelectric films based on the copolymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) were deposited by spin-coating. All layers were processed and characterized to obtain a highly transparent piezoelectric P(VDF-TrFE) transducer with a strong adhesion between layers and preserving the piezoelectric response of the copolymer film. Indium tin oxide (ITO), gallium-doped zinc oxide (GZO) and aluminium-doped zinc oxide (AZO) were evaluated, and the best performance was obtained with AZO. The optimized transducer features an optical transmittance higher than 75% in the visible spectral range and a piezoelectric coefficient vertical bar d(33)vertical bar of 34 pC.N-1.The authors thank the FCT-Fundacao para a Ciencia e Tecnologia-for financial support under framework of the Strategic Funding UID/FIS/04650/2013, project PTDC/EEI-SII/5582/2014 and project UID/EEA/04436/2013 by FEDER funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI) with the reference project POCI-01-0145-FEDER-006941. Funds provided by FCT in the framework of EuroNanoMed 2016 call, Project LungChek ENMed/0049/2016 are also gratefully acknowledged. VFC also thanks the FCT for the grant SFRH/BPD/98109/2013. Finally, the authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs.info:eu-repo/semantics/publishedVersio
2022 Proposed base case model for eastern Atlantic and Mediterranean bluefin tuna assessment using stock synthesis.
This document presents the proposed base case for the assessment of Eastern Atlantic and Mediterranean population of bluefin tuna using Stock Synthesis in 2022. The model runs from 1950 to 2020 and was fitted to length composition data, conditional age-at-length (otolith and spines–length-age pairs), 16 fishing fleets and 11 indices of abundance. Growth is modeled by a Richards function with Linf fixed at 271 cm, K fixed at 0.23387, and the shape parameter is estimated by the model. A Beverton-Holt stock recruitment relationship was estimated in the model with the steepness and sigmaR fixed at 0.9 and 0.6, respectively. R0 is freely estimated. Although the diagnostics indicate an acceptable stability of the model, there are important conflicts between the catch information, length composition and index data. The model fits to length compositions were not good, but the model followed most of the indices fairly fine. The model results showed that the SSB decreased since 1950 until 1970s, remaining relatively stable at low values during the 1980-2009 period, and showing a sharp and steady increased since 2010. Model diagnostics indicated that the different source of data provides contradicting information about the stock, resulting in biases in the results
The Decadal Climate Prediction Project (DCPP) contribution to CMIP6
The Decadal Climate Prediction Project (DCPP) is a coordinated multi-model investigation into decadal climate prediction, predictability, and variability. The DCPP makes use of past experience in simulating and predicting decadal variability and forced climate change gained from the fifth Coupled Model Intercomparison Project (CMIP5) and elsewhere. It builds on recent improvements in models, in the reanalysis of climate data, in methods of initialization and ensemble generation, and in data treatment and analysis to propose an extended comprehensive decadal prediction investigation as a contribution to CMIP6 (Eyring et al., 2016) and to the WCRP Grand Challenge on Near Term Climate Prediction (Kushnir et al., 2016). The DCPP consists of three components. Component A comprises the production and analysis of an extensive archive of retrospective forecasts to be used to assess and understand historical decadal prediction skill, as a basis for improvements in all aspects of end-to-end decadal prediction, and as a basis for forecasting on annual to decadal timescales. Component B undertakes ongoing production, analysis and dissemination of experimental quasi-real-time multi-model forecasts as a basis for potential operational forecast production. Component C involves the organization and coordination of case studies of particular climate shifts and variations, both natural and naturally forced (e.g. the "hiatus", volcanoes), including the study of the mechanisms that determine these behaviours. Groups are invited to participate in as many or as few of the components of the DCPP, each of which are separately prioritized, as are of interest to them.The Decadal Climate Prediction Project addresses a range of scientific issues involving the ability of the climate system to be predicted on annual to decadal timescales, the skill that is currently and potentially available, the mechanisms involved in long timescale variability, and the production of forecasts of benefit to both science and society
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