412 research outputs found

    cloudbandPy 1.0: an automated algorithm for the detection of tropical–extratropical cloud bands

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    Persistent and organized convective cloud systems that arise in convergence zones can lead to the formation of synoptic cloud bands extending from the tropics to the extratropics. These cloud bands are responsible for heavy precipitation and are often a combination of tropical intrusions of extratropical Rossby waves and processes originating from the tropics. Detecting these cloud bands presents a valuable opportunity to enhance our understanding of the variability of these systems and the underlying processes that govern their behavior and that connect the tropics and the extratropics. This paper presents a new atmospheric cloud band detection method based on outgoing longwave radiation using computer vision techniques, which offers enhanced capabilities to identify long cloud bands across diverse gridded datasets and variables. The method is specifically designed to detect extended tropical–extratropical convective cloud bands, ensuring accurate identification and analysis of these dynamic atmospheric features in convergence zones. The code allows for easy configuration and adaptation of the algorithm to meet specific research needs. The method handles cloud band merging and splitting, which allows for an understanding of the life cycle of cloud bands and their climatology. This algorithm lays the groundwork for improving our understanding of the large-scale processes that are involved in the formation and life cycle of cloud bands and the connections between tropical and extratropical regions as well as evaluating the differences in cloud band types between different ocean basins.</p

    Trion induced negative photoconductivity in monolayer MoS2

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    Optical excitation typically enhances electrical conduction and low-frequency radiation absorption in semiconductors. We have, however, observed a pronounced transient decrease of conductivity in doped monolayer molybdenum disulfide (MoS2), a two-dimensional (2D) semiconductor, under femtosecond laser excitation. In particular, the conductivity is reduced dramatically down to only 30% of its equilibrium value with high pump fluence. This anomalous phenomenon arises from the strong many-body interactions in the system, where photoexcited electron-hole pairs join the doping-induced charges to form trions, bound states of two electrons and one hole. The resultant increase of the carrier effective mass substantially diminishes the carrier conductivity

    Discovering New Strong Gravitational Lenses in the DESI Legacy Imaging Surveys

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    We have conducted a search for new strong gravitational lensing systems in the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys’ Data Release 8. We use deep residual neural networks, building on previous work presented in Huang et al. (2020). These surveys together cover approximately one third of the sky visible from the northern hemisphere, reaching a z-band AB magnitude of ∼ 22.5. We compile a training sample that consists of known lensing systems as well as non-lenses in the Legacy Surveys and the Dark Energy Survey. After applying our trained neural networks to the survey data, we visually inspect and rank images with probabilities above a threshold. Here we present 1210 new strong lens candidates

    Qualidade microbiológica de alface fertirrigada por gotejamento com fertilizantes orgânicos ou mineral.

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    O objetivo desse trabalho foi comparar a qualidade microbiológica de alfaces 'Laurel' produzidas em cultivo protegido, fertilirrigadas por gotejamento com biofertilizante Horbio®, biofertilizante comercial e fertilizante mineral, bem como a qualidade microbiológica desses fertilizantes.bitstream/item/198134/1/BPD-179.pd

    The QCD/SM Working Group: Summary Report

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    This Report documents the results obtained by the Working Group on Quantum ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV Colliders'', Les Houches, France, 21 May - 1 June 2001. The account of uncertainties in Parton Distribution Functions is reviewed. Progresses in the description of multiparton final states at Next-to-Leading Order and the extension of calculations for precision QCD observables beyond this order are summarized. Various issues concerning the relevance of resummation for observables at TeV colliders is examined. Improvements to algorithms of jet reconstruction are discussed and predictions for diphoton and photon pi-zero production at the LHC are made for kinematic variables of interest regarding searches for a Higgs boson decaying into two photons. Finally, several improvements implemented in Monte-Carlo event generators are documented
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