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

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 30$M_{\odot}$ 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

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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

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

Regional Variability in Microphysical Characteristics of Precipitation Features with Lightning across China: Observations from GPM

The statistical characteristics of precipitation microphysics in lightning clouds are not yet fully understood, as a result of the limitations of traditional observational methods. Using the latest observations from the dual-frequency radar and microwave imager onboard the Global Precipitation Mission (GPM) and ground-based lightning observations, the precipitation microphysics of precipitation features with and without lightning (LPFs and NLPFs) was investigated across four typical regions of China in summer during the time period of 2014–2021. The statistical results show that the LPFs are characterized by smaller concentration and larger mass-weighted mean diameter (Dm) for rain and ice hydrometeors than those of NLPFs. Below the melting layer, the radar reflectivity (Ze) for both the LPFs and NLPFs generally decreases toward the surface, indicating the evaporation or strong break-up of rain hydrometeors. Above the melting layer, the Ze values mainly increase as the altitudes decrease for both LPFs and NLPFs, indicating the rimming, aggregation, or deposition processes. However, the change in slope is much smaller for the LPFs than for the NLPFs, which suggests a more uniform distribution of large ice hydrometeors at high altitudes, probably as a result of the stronger updrafts within the LPFs. The microphysical structures of the LPFs show great regional differences among the four regions of China, which is characterized by the low concentration of large-sized rain hydrometeors over Northeast China, and a high concentration of small-sized rain hydrometeors near the surface over the Yangtze-Huaihe River basin

离子液体/羊毛纤维/凝固剂三元相图的构建 : [The construction of phase diagram for ionic liquid/wool fiber/coagulator ternary systems]

三元相图是研究羊毛角蛋白再生过程热力学行为的有效工具。通过浊度测试和Boom经验方程构建离子液体(IL)/羊毛纤维/凝固剂浊点线性关系(LCP)曲线和三元相图，进一步系统地研究了凝固剂种类、再生温度和离子液体结构对羊毛角蛋白再生性能的影响规律。结果表明，羊毛角蛋白最优再生体系是1-乙基-3-甲基咪唑磷酸二乙酯([Emim]Dep)/羊毛纤维/水(25℃)。对羊毛纤维原料和不同再生条件获得的再生羊毛角蛋白进行FT-IR和XRD表征，结果表明再生羊毛角蛋白的结构和羊毛纤维原料基本保持一致，但相对结晶度有所下降。实验温度为25℃时，以水为凝固剂制备的再生羊毛角蛋白相对结晶度最高。Keratin is one of the natural polymers with abundant reserves, wool fiber consists 95wt% of keratin, which is an important source of natural keratin and has excellent mechanical and biological properties. However, due to the numerous complex inter- and intra-molecular hydrogen bonds, disulfide bonds and other chemical bonds, wool fiber is insoluble in water and common organic solvents. As an emerging green solvent, ionic liquid (IL) shows outstanding performance in dissolving natural polymers such as wool fiber, cellulose, chitin, etc. due to their tunable structure, non-volatile, thermal stability, as well as high solubility for biopolymer. According to the reports, the current researches of ionic liquids on wool fiber are mainly focused on the solubility properties of wool fiber. The studies on the regeneration properties of wool keratin are still limited. There are three components involved in the regeneration process of wool fiber, and thus the thermodynamic behavior of polymer regeneration can be investigated by the ternary phase diagram. In this study, the linearized cloud point (LCP) correlation and ternary phase diagram of IL/wool fiber/coagulator (T) system were constructed by the turbidity method. The effects of coagulator types, coagulation temperatures, and structures of ILs on the properties of wool keratin regeneration were investigated systematically. The regenerated wool keratin was obtained using [Emim]Dep as the solvent with the coagulation temperature of 25℃. In different coagulator systems, the order of wool keratin regeneration capacity is water&gt;ethanol&gt;iso-propanol. The regenerated wool keratin was obtained using [Emim]Dep as the solvent, and water as the coagulator. In different coagulation temperature systems, as the coagulation temperature increased, the regeneration capacity of wool keratin gradually decreased. The regenerated wool keratin was obtained using water as the coagulator with a coagulation temperature of 25℃. In different IL structure systems, the order of wool keratin regeneration capacity was [Emim]Dep&gt;[DBNE]Dep&gt;[DBNH]OAc. The characterization of raw wool fiber and regenerated wool keratin under different regeneration conditions were obtained by FT-IR and XRD, the characterization of the structures and properties showed that the main structure of the regenerated wool keratin basically agreed with the raw wool fiber, and the crystallinity of the regenerated wool keratin had decreased than raw wool keratin. The highest crystallinity of the regenerated wool keratin was obtained from the system of [Emim]Dep/wool fiber/water system at the coagulation temperature of 25℃.Godkänd;2021;Nivå 0;2021-04-09 (alebob)</p

Study on the regularity of cellulose degradation in ionic liquids

Ionic liquids (ILs) show the superiority in dissolving and spinning of cellulose. In this work, wood pulp and microcrystalline cellulose were dissolved respectively in two ILs, 1-allyl-3-methylimidazolium chloride ([Amim] Cl) and 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP), to investigate the regularity of cellulose degradation in ILs. A novelmethod for determining degree of polymerization of cellulose employed ILs was proposed and its accuracy was compared with the traditional method. The results indicated that cellulose depolymerized seriouslywith the increase of time and temperature in [Amim]Cl than in [Emim]DEP. In addition, after cellulose dissolving for 72 h, none of the reducing sugar remained in the recycled [Emim]DEP, however, more than 2% reducing sugar can be measured in the recycled [Amim]Cl. These results are consistent with FTIR investigation, i.e., [Amim]Cl shows greater dissolution capability for cellulose than [Emim]DEP. Therefore, [Emim]DEP shows great prospects in the continuous industrial spinning process under the determined temperature of 90-100 degrees C. (C) 2020 Elsevier B.V. All rights reserved

Ionic liquid assisted fabrication of cellulose-based conductive films for Li-ion battery

An imidazolium-based ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP) was used to dispense graphene nanoplates (GN) and multiwalled carbon nanotubes (MWCNTs) as well as dissolve cellulose for fabricating composite conductive films. The effects of GN, MWCNTs, and cellulose mass ratios on the electrical conductivity and morphology of the films were investigated. The interaction between GN, MWCNTs, and cellulose was analyzed by SEM, X-ray diffraction (XRD), TGA, and Raman spectroscopy. The results indicate that [Emim]DEP plays a vital and irreplaceable role in GN and MWCNTs dispersion, cellulose dissolution, and porous formation during the regeneration and drying processes. MWCNTs linked flaky GN and a hybrid structure was constructed elaborately to form a better conductive path and improve the conductivity as well as increase the film stability. For the XRD result, the carbonized GN-MWCNTs-cellulose films exhibited the graphitic peaks, showing that the films still retained the structure of carbon atoms or molecules. Besides, the maximum conductivity of carbonized GN-MWCNTs-cellulose (7:3:2) composite film was up to 9,009 S m(-1), due to the small carbon clusters formation and the high degree of graphitization. Further, the carbonized films were applied as anodes in Li-ion battery and showed good electrochemical performance. The best cyclic stability (i.e., discharge/charge capacity) of 438/429 mA h g(-1) and coulomb efficiency of 50.2% were obtained. This novel and sustainable design is a promising approach to obtain cellulose-based conductive films and anodes for Li-ion battery applications

A simplified log creep model for describing triaxial creep of mélange rocks

This study aims to develop a simplified log creep model (LgCM) for predicting the triaxial three-stage creep behaviors of mélange rocks. The model was deduced from the creep deformation mechanism by considering the competition of strain rate hardening and damage during the steady and accelerating creep stages and was described by two simplified fractal functions. The model was then compared with the previous creep models on the uniaxial three-stage creep data of mortar, rock salt, and sandy shale, as well as the triaxial low-stress creep data of claystone. Afterward, the triaxial creep experimental results of the mélange rock samples were introduced to illustrate the process of calibrating the model in predicting the triaxial three-stage creep behaviors of mélange rocks. It was found the developed LgCM model showed good performance in predicting both the uniaxial and triaxial three-stage creep behaviors of rocks. The investigation reveals that the trend of the parameter β can indicate three thresholds of the hardening and damaging effects, and provide the equation to reproduce the creep behavior of the mélange rock. The work contributes to understanding the time-dependent failure of underground rock mass in mélange rock formations

Shack&ndash;Hartmann Wavefront Sensing Based on Four-Quadrant Binary Phase Modulation

Aiming at the problem that it is difficult for the conventional Shack&ndash;Hartmann wavefront sensor to achieve high-precision wavefront reconstruction with low spatial sampling, a kind of Shack&ndash;Hartmann wavefront sensing technology based on four-quadrant binary phase modulation is proposed in this paper. By introducing four-quadrant binary phase modulation into each subaperture, the technology is able to use an optimization algorithm to reconstruct wavefronts with high precision. The feasibility and effectiveness of this method are verified at extreme low spatial frequency by a series of numerical simulations, which show that the proposed method can reliably reconstruct wavefronts with high accuracy with rather low spatial sampling. In addition, the experiment demonstrates that with a 2 &times; 2 microlens array, the four-quadrant binary phase-modulated Shack&ndash;Hartmann wavefront sensor is able to achieve approximately 54% reduction in wavefront reconstitution error over the conventional Shack&ndash;Hartmann wavefront sensor

Fatty Acid Modification of the Anticancer Peptide LVTX-9 to Enhance Its Cytotoxicity against Malignant Melanoma Cells

Spider venom is a valuable resource for the development of novel anticancer drugs. In this study, we focused on novel linear amphipathic &alpha;-helical anticancer peptide LVTX-9, which was derived from the cDNA library of the venom gland of the spider Lycosa vittata. The cytotoxicity of LVTX-9 against murine melanoma cells in the range of 1.56&ndash;200 &mu;M was tested and found to be significantly lower than those of most anticancer peptides reported. Its IC50 was determined to be 59.2 &plusmn; 19.8 &mu;M in a serum or 76.3 &plusmn; 12.7 &mu;M in serum-free medium. Fatty acid modification is a promising strategy for improving peptide performance. Therefore, to enhance the cytotoxic activity of LVTX-9, fatty acid modification of this peptide was performed, and five different carbon chain length lipopeptides named LVTX-9-C12-C20 were produced. Among them, the lipopeptide LVTX-9-C18 showed the highest cytotoxic activity in relation to B16-F10 cells, whether in a serum or serum-free medium. Most importantly, the cytotoxic activity of LVTX-9-C18 was improved by about 12.9 times in a serum medium or 19.3 times in a serum-free medium compared to that of LVTX-9. Subsequently, assays including scanning electron microscopy, trypan blue staining, lactate dehydrogenase leakage assay, and hemolytic activity could indicate that the potential direct cell membrane disruption is the main mechanism of LVTX-9-C18 to induce cancer cell death. Furthermore, the LVTX-9-C18 also showed strong cytotoxicity in relation to 3D B16-F10 spheroids, which indicates it might be a promising lead for developing anticancer drugs