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Electron beam (EB) irradiation is an efficient method for avoiding microbial contamination affecting food quality. To explore the properties of Litopenaeus vannamei after EB sterilization, samples were irradiated at an absorbed dose of 0-12 kGy using a 10-MeV backward wave linear accelerator and tested for protein, fat, and amino acid content; pH; volatile saline nitrogen; textural features; microbiology; and organoleptic satisfaction. The results showed that the protein content and fat content were in the normal range. In the optimal absorbed dose range (6-8 kGy), TVB-N, which characterizes the freshness of shrimp, was apparently lower. Further, most of the amino acids peaked; textural features such as chewiness and cohesiveness were significantly enhanced; no microbial colonies were detected; and both color and taste were relatively better. These results suggest that EB irradiation sterilization is an effective method for microbiological control of food, and it results in greater freshness without degradation of the properties of frozen Litopenaeus vannamei in terms of nutrient content and other properties.

Anhydride-cured epoxy is a common insulating material used in electrical equipment, but recycling it effectively is difficult, which results in the overall abandonment of the equipment after decommissioning and serious environmental pollution. In order to make anhydride cured epoxy degradable while maintaining its electrical performance, we synthesized a high-performance epoxy insulating material that can be recycled and reused using triethanolamine as a transesterification catalyst co-accelerator. Results show that the new epoxy has the lowest dielectric loss of 0.0012, the highest breakdown strength of 42.26 kV mm−1, and the highest tensile strength of 93.7 MPa. The degradable epoxy can be recovered via mechanical hot pressing and regenerated through chemical degradation. Degradation products can be directly used as curing accelerators to complete the re-preparation of the insulating material. Even after recovery, the properties of the epoxy resin meet the application requirements of insulating materials. [ABSTRACT FROM AUTHOR]

SF6 equipment internal insulation faults generate trace amounts of characteristic gases, mainly SO2 and SO2F2. Accurately tracing such small amounts of gas at a low temperature is rather necessary for SF6 equipment status monitoring and fault diagnosis to ensure safe and stable operation of the power system. In this work, we present a gas sensor with ultrahigh sensitivity, excellent low-temperature performance, low detection limits, fast response, and superior recovery performance for detecting SO2 and SO2F2, employing molybdenum carbide nanowires with an oxygen content of 13.60% (Mo2C-500) as the sensing material. Gas-sensing test results show that the sensing performance of Mo2C enhances with the increase of the oxygen content, and that Mo2C-500 shows the most outstanding sensing performance for SO2 and SO2F2 among all three oxygenated Mo2C (oxygen contents of 0, 5.80, and 13.60%). In addition, at the optimum operating temperatures of 250 °C (SO2) and 150 °C (SO2F2), the response value (response time) of Mo2C-500 is 2.75-(24 s) and 3.61-(26 s) toward 300 ppm of SO2 and SO2F2, and the detection limits for SO2 and SO2F2 are 0.83 and 1.01 ppm, respectively. Moreover, the potential adsorption mechanism upon SO2 and SO2F2 by oxygenated Mo2C nanowires is further explored by density functional theory (DFT) calculations that the introduction of oxygen promotes the generation of more free electrons and the formation of a deeper electron depletion layer, giving rise to the enhanced sensing response to SO2 and SO2F2. This study demonstrates that the Mo2C-500 gas sensor with excellent performance and low cost has superior application prospects in detecting SF6 decomposition species, which serves as a basis for the development of nanogas sensors. [ABSTRACT FROM AUTHOR]

Recently, Dai proved new infinite families of congruences modulo 2 for broken 11-diamond partition functions by using Hecke operators. In this note, we establish new parity results for broken 11-diamond partition functions. In particular, we generalize the congruences due to Dai by utilizing an identity due to Newman. Furthermore, we prove some strange congruences modulo 2 for broken 11-diamond partition functions. For example, we prove that if p is a prime with p ≠ 23 and Δ11(2p + 1) ≡ 1 (mod 2), then for any k ≥ 0, Δ11(2p3k+3 + 1) ≡ 1 (mod 2), where Δ11(n) is the number of broken 11-diamond partitions of n.

In this work, a novel nanostructure of gold nanosheets (NSs)-decorated TiO2 nanocolumns (NCs) coated on carbon fiber (Au NSs-TiO2 NCs/CF) is designed and fabricated. The structure and morphology can be adjusted from Tanghulu-like to sausage-shaped with the final concentration of chloroauric ions in the reaction solution. Au NSs-TiO2 NCs/CF have been proven to be an excellent SERS substrate with a high analytical enhancement factor, good uniformity, and great stability. Most importantly, SERS experiments can be carried out on one strand of Au NSs-TiO2 NCs/CF with the aid of a Raman confocal microscope. These Tanghulu-like and sausage-shaped Au NSs-TiO2 NCs/CF have great potential in SERS analysis of trace samples. [ABSTRACT FROM AUTHOR]