Transformation of hexagonal Lu to cubic LuH2+x_{2+x} single-crystalline films

With the recent report of near ambient superconductivity at room temperature in the N-doped lutetium hydride (Lu-H-N) system, the understanding of cubic Lu-H compounds has attracted worldwide attention. Generally, compared to polycrystal structures with non-negligible impurities, the single-crystalline form of materials with high purity can provide an opportunity to show their hidden properties. However, the experimental synthesis of single-crystalline cubic Lu-H compounds has not been reported thus far. Here, we developed an easy way to synthesize highly pure LuH$_{2+x}$ single-crystalline films by the post-annealing of Lu single-crystalline films (purity of 99.99%) in the H$_2$ atmosphere. The crystal and electronic structures of films were characterized by X-ray diffraction, Raman spectroscopy, and electrical transport. Interestingly, Lu films are silver-white and metallic, whereas their transformed LuH$_{2+x}$ films become purple-red and insulating, indicating the formation of an unreported electronic state of Lu-H compounds possibly. Our work provides a novel route to synthesize and explore more single-crystalline Lu-H compounds

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

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

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Differential Expression of Urinary Exosomal Small RNAs in Idiopathic Membranous Nephropathy

Background. Idiopathic membranous nephropathy (IMN) is a major cause of adult nephrotic syndromes, and reliable noninvasive biomarkers for diagnosis and monitoring are urgently needed. In this study, we performed small RNA (sRNA) sequencing to explore sRNA profiles of urinary exosomes derived from IMN patients and healthy controls (CON) to provide clues for identifying novel noninvasive sRNA biomarkers for IMN. Methods. Urine samples were collected from five healthy controls and six patients with IMN. High-throughput sequencing was used to screen sRNA expression profiles of urinary exosomes from patients with IMN in two independent cohorts. Results. Urinary exosomes were successfully isolated and used to obtain exosomal sRNAs. We screened 131 differentially expressed miRNAs, including 28 specifically expressed miRNAs, then explored the top 10 specifically expressed miRNAs in all IMN individuals. The specifically expressed miRNAs and differentially expressed miRNAs provide potential biomarkers for IMN. Additionally, we discovered numerous sRNAs derived from genomic repetitive sequences, which could represent an exciting new area of research. Conclusion. Herein, we revealed significant differences in expression profiles of urinary exosomal miRNAs and repetitive region-derived sRNAs between patients with IMN and healthy controls. The findings could facilitate the development of potential molecular targets for membranous nephropathy

Research on the control system of an amphibious transmission line Inspection UAV based on fuzzy PID control

The amphibious UAV combines the advantages of multi rotor UAV and line inspection robot. It can carry out two working modes: air flight and online driving. It can observe the running state of transmission line and improve the quality of patrol. In this paper, a fuzzy PID control algorithm is proposed to make the amphibious UAV flight control more flexible and close to the transmission line, and the simulation and software control process design are carried out

Research on the control system of an amphibious transmission line Inspection UAV based on fuzzy PID control

The amphibious UAV combines the advantages of multi rotor UAV and line inspection robot. It can carry out two working modes: air flight and online driving. It can observe the running state of transmission line and improve the quality of patrol. In this paper, a fuzzy PID control algorithm is proposed to make the amphibious UAV flight control more flexible and close to the transmission line, and the simulation and software control process design are carried out

Investigation of Surface Defects in Optical Components Based on Reflection Mueller Matrix Spectroscopy

Nanoscale defects on the surface of ultra-precision optical elements seriously affect the beam quality in optical systems. In response to the challenge of detecting nanoscale defects on optical component surfaces, we propose a method for the detection and classification of various types of defects on optical component surfaces via reflection Mueller matrix spectroscopy (RMMS). Firstly, an electromagnetic scattering theoretical model for various types of defects on the surface of optical elements and the incident and scattered fields were established by combining the bidirectional reflection distribution function (BRDF) and the Rayleigh–Rice vector scattering theory. Then, the optimal conditions for RMMS measurements were determined by numerically simulating the BRDF. On this basis, the surface roughness and pockmarks of the optical test plate were simulated and analyzed via RMMS, and the results were verified experimentally; then, dirty particles and pockmarks above the surface of the optical element and subsurface bubble defects (SSBD) were simulated and analyzed via RMMS. The results showed that some elements of the Mueller matrix could significantly distinguish defects on the surface of the optical element with dimensions smaller than the visible wavelength, and the dimensions of various types of defects of the element could be inverted using the values of the Mueller matrix elements. This method provides a theoretical basis and reference for the detection and classification of various types of defects in precision optical components