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Near-infrared spectroscopy (NIRS) combined with chemometrics analysis was used in this study to qualitatively and quantitatively determine the adulterated Camellia oil. A binary model was constructed for determining both the authenticity and the number of adulterated contents. NIRS combined with support vector machine classification was used to establish a full spectral model and a selected spectral model via competitive adaptive heavy-weighted sampling and backward interval partial least squares. Notably, both of them were proved to be suitable for determining the authenticity of Camellia oil. NIRS combined with support vector machine regression may be used to predict the amount of adulterated content in Camellia oil because of the high model correlation coefficient (R was higher than 99%, and the maximum mean square error was 0.0605).

This study investigates the influence of various heat treatment processes on the microstructure and properties of laser cladding Fe314 coatings. The microstructure, phases, and impact fracture morphology of the cladding layer were observed using X-ray diffraction and scanning electron microscopy, among other methods. The hardness and impact performance of the cladding layer were also tested. The results indicated that there was compositional segregation and non-equilibrium microstructure in the untreated cladding layer, with an average microhardness of 368.67 HV and an impact toughness of 27 J, exhibiting quasi-cleavage fracture. The stress-relief annealing treatment resulted in a uniform distribution of M23C6 carbides inside the cladding layer. The pinning effect generated by M23C6 reduced the microhardness by 16.26% and increased the impact toughness to 54 J. The impact fracture surface exhibited ductile fracture. After secondary normalizing and annealing, the microstructure of the cladding layer transformed into a fine single-phase austenite structure, and fine M7C3 carbides precipitated at the grain boundaries. Under the effects of fine grain strengthening and dispersion strengthening, the microhardness of the cladding layer decreased by 38.14%, and the average impact absorbed energy of the specimen was 64 J, showing complete ductile fracture. [ABSTRACT FROM AUTHOR]

In this study, LaFeO3 nanotubes were created using the electrostatic spinning method and then calcined at various temperatures. Investigations into the impact of calcined temperatures on the morphological properties of LaFeO3 nanotubes used a variety of methods. The results show that the surface of LaFeO3 nanotubes gradually became rougher when the calcination temperature was above 700 °C, which could enhance the gas-sensitive properties of n-butanol. The response of LaFeO3 nanotubes is 45.3–100 ppm n-butanol at 150 °C, and the low detection limit is 0.3 ppm. In addition, LaFeO3 nanotubes calcined at 700 °C were found to have excellent selectivity for n-butanol. The mechanism of calcination temperature on the improvement of gas-sensitive properties of LaFeO3 nanotubes was also proposed. [ABSTRACT FROM AUTHOR]

The efficient and reliable monitoring of trimethylamine (TMA) is significant to environmental protection and human healthcare. The Molybdenum trioxide (MoO3) nanofibers can be regarded as a promising sensing material with a low-detection limit for trimethylamine. MoO3 nanofibers with controlled morphology were synthesized by adjusting electrospinning and calcination conditions. MoO3 with the second-step calcination time is 90 s, which shows excellent trimethylamine sensing properties. The response of sensors based on M-90 nanofibers to 50 ppm acetone is 82.3 at 175 °C. And it has excellent selectivity to TMA. The sensors show good selectivity to TMA, compared to other gases to be measured. Finally, a detailed study of the sensing mechanism of MoO3 is conducted to analyze the reasons for exhibiting high response to TMA. [ABSTRACT FROM AUTHOR]