Dendritic fibrous nano-silica & titania (DFNST) spheres as novel cataluminescence sensing materials for the detection of diethyl ether

A Strategy for Studying Environmental Engineering: Simple Hydrothermal Synthesis of Flower-Shaped Stannous Sulfide Nanomaterials for Efficient Cataluminescence Sensing of Diethyl Ether

In this work, flower-like stannous sulfide (SnS) nanomaterials are synthesized using a hydrothermal method and used as sensitive materials for cataluminescence (CTL)-based detection of diethyl ether. Gas sensors based on SnS nanomaterials are prepared, and the SnS nanomaterials exhibit excellent gas-sensitive behavior towards ether. High sensitivity to ether is achieved at a relatively low operating temperature (153 °C) compared to other common sensors. The response time is 3 s and the recovery time is 8 s. The CTL intensity shows a good linear relationship (R2 = 0.9931) with a detection limit of 0.15 ppm and the concentration of ether in the range of 1.5-60 ppm. The proposed CTL sensor shows good selectivity towards ether. In addition, a highly stable signal is obtained with a relative standard deviation of 1.5%. This study indicates that the SnS-based sensor has excellent gas-sensitive performance and shows potential for applications in the detection of ether.

Calculation and Analysis of Nonlinear Algorithm for Stability of Nanosilica Powder Soft Soil Pile Foundation

In order to reasonably evaluate the stability of the embankment supported by the rigid pile composite foundation, a nonlinear algorithm calculation and analysis method for the stability of the nanosilica powder soft soil pile foundation is proposed. First, the soft soil foundation reinforced by the composite structure of "piles (prestressed pipe piles, (cement fly-ash gravel, CFG) piles)-pile caps-geotextile pads" is analyzed through the soft soil embankment test section of the Wenfu high-speed railway. Second, the compressive modulus under one-dimensional confining compression is calculated using the layered summation method. Finally, the deep lateral deformation of the pile foundation soil is measured by an inclinometer to evaluate the actual displacement of the pile foundation soil. In the standard method, the empirical coefficient 1.1-1.7 is multiplied on the basis of the calculation result of this method to correct the calculation error. Combined with the test results, it is shown that nanosilica powder can give full play to its excellent characteristics: promoting hydration speed and hydration degree through the reaction of pozzolan refining and consuming Ca(OH)2 crystals produced by cement hydration. Soft soils and modified soft soils: a certain amount of nanosilica powder can significantly improve the strength of soft soil at different ages.

Novel Diethyl Ether Gas Sensor Based on Cataluminescence on Nano-Pd/ZnNi3Al2O7

A sensitive diethyl ether gas sensor based on cataluminescence on nano-Pd/ZnNi3Al2O7 at a temperature lower than 150 °C was reported. The composition of the sensitive material was determined by energy-dispersive spectrometry, and a particle size of less than 50 nm was shown by transmission electron microscopy. When the atomic percentage of Pd in the sensing material is 0.8-1.3%, it is beneficial to the low-temperature and high-selective cataluminescence of diethyl ether. The signal response and recovery of diethyl ether on the sensitive material can be completed quickly in 0.5 s, and the relative standard deviation of the signal within 500 h of continuous operation is not more than 2.5%. There is good linear relationship between the luminescence intensity and the concentration of diethyl ether in the range of 0.08-75 mg/m3. The detection limit (3σ) is 0.04 mg/m3. The working conditions optimized by the response surface methodology were an analytical wavelength of 548.86 nm, a reaction temperature of 109.18 °C, and a carrier gas velocity of 125.88 mL/min. The sensitivity of the method can be increased by 4.5% under the optimized working conditions. The optimization method is universal for many multi-parameter processes.