To reduce the vibration of the coaxial helicopter main transmission system considering both level and vertical flight conditions, a vibration evaluation and optimization model was built. A vibration simulation model and a vibration evaluation method was established. A hybrid Gravitational Search Algorithm-Simulated Annealing (GSA-SA) algorithm was combined to balance convergence speed and searching accuracy. The principle test was conducted to prove the accuracy of theoretical method. The optional results show that the vibration of the optimized transmission system decreases significantly, in which the maximum reduction of key vibration indicators reaches more than 20%. The proposed method could be extended to other fields.

Aero-engine hot-end components face grinding challenges due to superalloys' low thermal conductivity, causing high heat, energy consumption, and reliance on unsustainable cooling. Ultrasonic vibration-assisted grinding (UVAG), heat pipe grinding wheels (HPGW), and minimum quantity lubrication (MQL) have been proposed to integrate to reduce heat generation, enhance heat dissipation, and minimize coolant use. In this case, the high-efficiency and sustainable grinding can be achieved with improved surface integrity.

A novel Y₄Al₂O₉/Y₂O₃ composite exhibits substantial resistance to CMAS infiltration at both temperatures at 1300 ℃ and 1500 ℃, without notable grain-boundary penetration by CMAS glass. More importantly, the incorporation of reaction active compositions in the composite accelerated the consumption of molten CMAS constituents and reduced its corrosive activity, which is recognized as the crucial principle for composition design of anti-CMAS materials. This work provides valuable insights that guide the design of composition and advancement of superior CMAS-resistant materials.

Hypersonic vehicles face critical aerodynamic heating during flight, demanding advanced thermal protection systems (TPS). A team of Chinese researchers has developed a novel carbon-bonded carbon fiber (CBCF) composite modified with SiBCN ceramics (CBCF/SiBCN), enabling efficient in-plane heat dissipation while maintaining thermal insulation. The composite exhibits exceptional anisotropic thermal properties and mechanical strength, addressing long-standing limitations in traditional CBCF materials for aerospace TPS.

The combustion chamber temperature of the new generation aircraft engines can reach an ultra-high temperature of 1800 °C, making temperature monitoring of key components crucial. Thin-film thermocouples (TFTCs) are highly sensitive and have rapid response time; however, their upper temperature limit remains below 1800 °C. This study proposes an ultra-high temperature film thermocouple, enhanced by yttria-stabilized zirconia (YSZ) for positive film, indium oxide (In₂O₃) for negative film, aluminium oxide (Al₂O₃) for protect film. The thermocouple is designed based on temperature measurement principles, First-principles, and simulations, and it is manufactured via screen-printing. The results indicate that the maximum working temperature is 1850 ℃. In experiments with different doping ratios at 1800 ℃, the thermocouple achieves a maximum temperature electromotive force (TEMF) of 258.5 mV and a maximum Seebeck coefficient of 180.9 μV/°C, with an In₂O₃:YSZ92(ZrO2:Y₂O₃ = 92:8 wt%) ratio of 9:1 wt%. Using the lumped heat capacity method, the response time is measured at 2.8 ms, demonstrating good dynamic response characteristics. The film thermocouple is successfully utilized to measure the gas temperature of 1090 °C at the outlet of air turbine rocket engine, confirming its high-temperature operational capability. To improve the repeatability of the TFTCs without affecting their thermoelectric outputs, a CNN-LSTM-attention neural network is implemented to mitigate repeatability errors, achieving a high repeatability of 99.53%. Additionally, the compensated temperature data are compared with those obtained from a standard B-type thermocouple, showing a full-scale error of ±0.73% FS. This study provides a feasible solution for ultra-high temperature measurements.

A new study in Forest Ecosystems reveals how fire history, vegetation type, and soil features jointly influence carbon storage in boreal forests. Researchers in Norway compared pine and spruce forests across regions with different fire legacies, and they found that pine forests store nearly twice as much organic carbon as spruce forests, with charcoal carbon stocks varying by region due to fire frequency, terrain microtopography, and organic layer depth. The study highlights the importance of localized forest management strategies for sustaining carbon storage in the face of climate change.

Excessive Malassezia yeast colonization in lesional skin has been found to cause psoriasis exacerbations. This paper published in Mycology found that oxymatrine inhibits Malassezia biofilm formation and ameliorates Malassezia-associated psoriasis by modulating oxidative stress, inflammation, and apoptosis.

China’s national carbon market has become the world’s largest carbon market and is expected to be a crucial policy instrument for achieving the country’s “dual carbon” goals. The design of China’s national carbon market integrates economic theory and international experiences, and more importantly, it fully considers China’s actual situation. This is reflected in key areas such as sectoral coverage, allowance allocation, cap setting, and the MRV (Monitoring, Reporting and Verification) system. Currently, China’s national carbon market has made effective progress in several aspects, but it also faces challenges.