90 research outputs found

    Performance assessment for the integrated green-gray-blue infrastructure under extreme rainfall scenarios

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    Synergistic allocation of urban stormwater infrastructure is critical to flood risk prevention and control under extreme rainfall events. This study focuses on the interaction regularity of green, gray, and blue infrastructure in the process of runoff retention and discharge under extreme rainfall scenarios. Three strategies, namely, gray infrastructure, green-gray infrastructure, and green-gray-blue infrastructure, are proposed to analyze the effectiveness of different scenarios on flood risk control capabilities of urban drainage systems and to determine the key influencing factors of the three strategies. The results show that green-gray-blue infrastructure demonstrates synergy in improving the efficiency of urban drainage systems. Under gravity drainage conditions, the backwater jacking caused by high river water levels has a certain impact on the smooth discharge of stormwater runoff in urban drainage systems. This case study identified a sensitive range in the influence of water level on runoff control and drainage function and an adaptive range in which the flood increases slightly with the water level increase. These present notable rules in improving the synergistic effect of blue infrastructure in the integrated urban green-gray-blue infrastructure system

    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 30M⊙M_{\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

    Research on High Speed Cutting Parameter Optimization and Fault Diagnosis Technology

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    High speed cutting process is a very complicated process; cutting parameters have a significant effect on cutting process and play a key role in the process of product manufacturing. The overall scheme of high speed cutting parameter optimization and its fault diagnosis have been introduced. The mathematical model of the selected cutting parameters was established and the optimized parameters were obtained by combining the experimental design with the technology of data processing. The statistical description of high speed cutting process control was introduced and the fault diagnosis model of cutting parameter optimization by using the neural network was proposed. Finally, the mathematical model in the present study is validated with a numerical example. The results show that the present method solved the problem of poor universality of high speed cutting data effectively and avoided the inaccuracy of physical and chemical mechanism research. Meanwhile, the present study prevents the passive checks of the cutting and gets better diagnosis of the complicated cutting fault type

    <b>Datasets of phylogenetic relationships </b><b>within</b><b> the core eudicots based on multi-copy SOGs and </b><b>single-copy SOGs</b>.

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    gene trees on multi-copy SOGs and single-copy SOGs, and alignments on multi-copy SOGs and single-copy SOGs</p

    Comparative study of nanomaterials activated recycled powders from demolition and decoration wastes as supplementary cementitious material

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    Powdered particles can significantly affect the technical performance of recycled aggregates and recycled concrete. Therefore, there has been a considerable focus on the disposal and utilization of recycled powder (RP) with high value. This study applied nano-CaCO3 (NC), nano–graphene oxide (GO) and nano–SiO2 (NS) to activate RP from demolition and decoration waste (RP1 and RP2, respectively). The results indicated that the nanomaterials had an activation effect on RP, but the effect was more pronounced for RP2. In addition, NC had the best activation effect on the RP among the three nanomaterials. Comparing to cement pastes with 30% RP2, compressive strength of cement paste activated by NC, GO, and NS were increased by 43.4%, 33.3% and 23.7% at 28d, respectively. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), Scanning electronic microscopy (SEM), and mercury intrusion porosity (MIP) were utilized to further explore the activation mechanism. Results presented that nanomaterial activated RP could promote hydration degree to produce more Ca(OH)2 (CH), meanwhile, the nanomaterials activated RP refine and modified the orientation index of CH. This paper implies a useful activation method for RP, which is expected to fully stimulate the potential of RP to form new kinds of supplementary cementitious material

    Characterization of the complete chloroplast genome of Clematoclethra scandens subsp. actinidioides (Actinidiaceae)

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    Clematoclethra scandens subsp. actinidioides (Actinidiaceae) is an endemic medicinal species in China. Here, we first sequenced and characterized the complete chloroplast genome of C. scandens subsp. actinidioides. The chloroplast genome was 159,341 bp in length, containing a large single-copy of 88,351 bp and a small single-copy of 21,580 bp separated by a pair of identical inverted repeat regions of 24,705 bp each. A total of 131 genes were identified, including 84 protein-coding genes, 39 tRNA, and eight rRNA genes. The phylogenetic analysis of C. scandens subsp. actinidioides showed a relatively close relationship with Clematoclethra scandens subsp. hemsleyi
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