Study on leakage and explosion law of buried gas pipeline based on scenario construction.

Based on the Jilin Songyuan gas pipeline accident, FLACS software was used to numerically simulate its leakage and explosion process in order to study the change law of the equivalent gas cloud volume of gas leakage diffusion under various influencing factors. The simulation results were compared and analyzed with the accident investigation report in order to ensure the accuracy of the simulation results. On this premise, the three primary influencing factors-the obstacle distribution technique, the ambient wind speed magnitude, and the ambient temperature-are varied in order to study the equivalent gas cloud volume variation features of the leaking gas cloud. The findings indicate a positive association between the maximum equivalent gas cloud volume of the leaking gas cloud and the density of the obstacle distribution. There is a positive correlation between ambient wind speed and the equivalent gas cloud volume when the ambient wind speed is less than 5.0 m/s, and a negative correlation between ambient wind speed and the equivalent gas cloud volume when the ambient wind speed is greater than or equal to 5.0 m/s. A drop in Q8 is proportionately increased by around 5% for every 10 °C increase in ambient temperature when the temperature is below room temperature. There is a positive association between ambient temperature and the equivalent gas cloud volume Q8. When the temperature is higher than room temperature, the drop in Q8 is correspondingly increased by about 3% for every 10 °C increase in ambient temperature.

A Novel Ruthenium(II) Polypyridyl Complex Bearing 1,8-Naphthyridine as a High Selectivity and Sensitivity Fluorescent Chemosensor for Cu2+ and Fe3+ Ions.

A novel ruthenium(II) polypyridyl complex bearing 1,8-naphthyridine was successfully designed and synthesized. This complex was fully characterized by EI-HRMS, NMR, and elemental analyses. The recognition properties of the complex for various metal ions were investigated. The results suggested that the complex displayed high selectivity and sensitivity for Cu2+ and Fe3+ ions with good anti-interference in the CH3CN/H2O (1:1, v/v) solution. The fluorescent chemosensor showed obvious fluorescence quenching when the Cu2+ and Fe3+ ions were added. The detection limits of Cu2+ and Fe3+ were 39.9 nmol/L and 6.68 nmol/L, respectively. This study suggested that this Ru(II) polypyridyl complex can be used as a high selectivity and sensitivity fluorescent chemosensor for Cu2+ and Fe3+ ions.