Hunan Institute of Technology (simplified Chinese: 湖南工学院; traditional Chinese: 湖南工學院; pinyin: Húnán Gōngxuéyuàn) is a university located in Hengyang, Hunan, China.As of fall 2013, the university has two campuses, a combined student body of 19,000 students, 1,000 faculty members.The university consists of 12 colleges, with 30 specialties for undergraduates.
Coal that has undergone pre-oxidation and pyrolysis in the closed fire area(CFA) is prone to reignition upon re-exposure to oxygen. While pre-oxidation and pyrolysis generate active sites and oxygen-containing functional groups(OCG) in the coal, the gas-generation mechanism involving the coexistence of these active sites and functional group(FG) during re-oxygenation remains unclear. The experiments firstly tested the risk of coal reignition, and then used in situ infrared spectroscopy(FTIR) and electron paramagnetic resonance(ESR) to test the variation of FG content and free radical parameters during oxidation of different coals, and finally analyzed the mechanism of the active sites on the FG by combining with DFT simulation. It is found that the CO production of the coal after pyrolysis is notably higher than raw coal’s at the initial stage of reignition. Pre-oxidation results in a higher content of OCG in the coal, and the active sites produced by pyrolysis can maintain stable existence in an inert atmosphere. The active site alkyl radical gives off heat when adsorbing oxygen, which can rapidly activate the aldehyde group to produce CO, and then leads to coal spontaneous combustion chain reaction with the heat accumulation. The study results have a guiding role in unsealing the CFA and environmental management in the mining area.
4H-silicon carbide (SiC)-based metal–oxide–semiconductor (MOS) capacitors have become the top choice for high-power and high-temperature applications, surpassing traditional silicon (Si)-based MOS capacitors due to their superior performance and reliability. However, the challenge of scaling down devices and the limitations of the low dielectric constant (k) of silicon dioxide (SiO2) has made it unsuitable as a passivation layer for both Si and 4H-SiC. Consequently, high k materials, such as cerium oxide (CeO2), have emerged as promising alternatives. This review provides a comprehensive analysis of CeO2-based high k passivation layers for Si and 4H-SiC substrates, highlighting key challenges in their implementation and strategies to enhance passivation characteristics. To the best of our knowledge, this is the first in-depth review dedicated to CeO2-based high k materials for these substrates, offering valuable insights for future device engineering.
Inspired by the signal amplification property of the field-effect transistor (FET) enabled by electric field modulation across the conducting channel, a carbon-based FET hydrogen sulfide (H2S) sensor with ionogel sensing material was fabricated, providing trace-level detection without the need of thermal or optical fields. Under an applied back-gate voltage, the working state of the FET sensor could be regulated to the linear region, significantly boosting the sensor’s sensitivity toward low-concentration analytes. The proposed sensor exhibited a room-temperature detection ability toward 0.1-1 ppm of H2S. Leveraging the hydrophobic nature of the ionogel, the sensor showed a slight response variation (6.8
Multi-principal nitride coatings have received growing attention for their significant potential as protective coatings against solid particle erosion. In this study, the solid particle erosion behavior and associated failure mechanisms of medium-entropy AlCrTiSiN coatings and ternary AlCrN coatings were investigated. The results show that AlCrTiSiN coatings exhibit better erosion resistance than AlCrN coatings due to their higher hardness and greater fracture toughness. The outstanding performance of AlCrTiSiN coatings arises not only from the powerful solid solution strengthening effect and elevated surface energy imparted by their multi-principal elements, but also from the unique microstructures generated by the arc ion plating process. AlCrTiSiN coatings are composed of columnar AlCrTiSiN nitrides and spherical metal-droplets. These columnar AlCrTiSiN nitrides are deposited as a nanolayer structure, consisting of CrN phase solid solutions with periodic fluctuations in elemental composition. During erosion, metal-droplets dissipate impact energy through the formation of dense microcracks, rotations of nanocrystallites, and internal plastic deformations. Simultaneously, the nanolayer structure promotes formation of transverse microcracks and deflects long cracks, thus increasing the driving energy consumed by crack propagation.
The first example of heterogeneous direct benzylation of N -heterocycles (quinoxalin-2(1 H )-ones and quinoxalines) with benzaldehydes has been accomplished via the sequence of a NaDT-photocatalyzed HAT, a single electron transfer reduction and a proton transfer, a spin-center shift and a back-HAT. Utilizing this strategy, a diverse array of benzylated N -heterocycles (29 examples) can be produced with high yields. Importantly, the DT-photocatalyzed direct benzylation with benzaldehydes would be a useful complement to the more extensively studied DT-photocatalyzed acylation and hydroxyalkylation, expanding the scope of DT photocatalysis. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.
