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Seven fatty acids were detected by GC-MS in Xanthoceras sorbifolium Bunge seed oil extracted at different temperatures, including Palmitic acid C16:0, Stearic acid C18:0, Oleic acid C18:1, Eicosenoic acid C20:1, Docosenoic acid C22:1, Tetracosenoic acid C24:1, and Linoleic acid C18:2. The highest content of nervonic acid (NA) was found in Xanthoceras sorbifolium Bunge seed oil extracted at 70 °C. Three methods were selected to analyze the extraction rate of nervonic acid in Xanthoceras sorbifolium Bunge seed oil, including urea complexation, low-temperature solvent crystallization, and a combined treatment using these two methods. The final content of nervonic acid obtained was 14.07%, 19.66%, and 40.17%, respectively. The combined treatment method increased the purity of nervonic acid in Xanthoceras sorbifolium Bunge seed oil by 12.62 times. Meanwhile, thermogravimetric behavior analysis of samples extracted using different methods was conducted by thermogravimetric analyzer, which suggested that the thermal stability of the samples extracted by the combined treatment was enhanced. These results can provide a new process parameter and scientific basis for the extraction of NA. At the same time, FTIR and NMR were also used to characterize the combined extraction sample, and the structure of the samples was proved. [ABSTRACT FROM AUTHOR]

Prickly ash peel oleoresin (PPO) is a highly concentrated oil of Prickly ash essential oil and has a stronger aroma. However, its low water solubility, high volatility, difficulty in transport and storage, and decomposition by light, heat, and oxygen limit its wider application. To solve this problem, this study used freeze-drying or spray-drying, with soybean protein isolate (SPI) or gum Arabic (GA), combined with aqueous maltodextrin (MD) as the encapsulating agents to prepare four types of PPO microcapsules (POMs). Spray-dried microcapsules with GA as the encapsulating agent achieved a high encapsulation efficiency (EE) of 92.31 ± 0.31%, improved the thermal stability of the PPO, and had spherical morphology. (Headspace solid-phase microextraction/gas chromatography–mass spectrometry) HS-SPME/GC-MS detected 41 volatile compounds in PPO; of these, linalool, β-myrcene, sabinene, and D-limonene were identified as key flavor components. Principal component analysis (PCA) effectively distinguished the significant differences in flavor between PPO, spray-dried SPI/MD microcapsules (SS), and spray-dried GA/MD microcapsules (SG). During 15 days of air-exposure, the loss of flavor from SG (54.62 ± 0.54%) was significantly lower than PPO (79.45 ± 1.45%) and SS (57.55 ± 0.36%). During the air-exposure period, SG consistently had the highest antioxidant capacity, making it desirable for PPO packaging, and expanding its potential applications within the food industry. [ABSTRACT FROM AUTHOR]

In this paper we consider the long time well-posedness of solutions to two-dimensional compressible magnetohydrodynamic (MHD) boundary layer equations. When the initial data is a small perturbation of a steady solution with size of $ \varepsilon $, then the lifespan of solutions in Sobolev spaces is proved to be greater than $ \varepsilon^{-\frac43} $. And such a result can be extended to the case that both initial data and far-field state are small perturbations around the steady states. Moreover, it holds true for both isentropic and non-isentropic magnetohydrodynamic boundary layer equations. [ABSTRACT FROM AUTHOR]

To optimize the control effect of nitrogen injection fire-fighting technology, the No.8401 working face in Madaotou Coal Industry Company of Datong Coal Mine Group is taken as the research object. The numerical simulation method is used to study the influence of ventilation and advancing degree of working face on the scope of spontaneous combustion oxidation zone in goaf under nitrogen injection and non-nitrogen injection. The results show that whether nitrogen injection or not, the larger the air volume in the working face is, the wider the oxidation temperature rise zone is, and the greater the spontaneous combustion risk of goaf is. From the view point of preventing the goaf from spontaneous combustion, the air volume of the working face should be reduced as much as possible, i.e. the reasonable ventilation technology should be adopted. The reasonable range of air supply in No.8401 fully mechanized caving face is 1 400~1 755 m3/min. At the same time, it is concluded that the nitrogen injection measures must be taken in No.8401 fully mechanized caving face, and the monthly advancing degree of the working face should be no less than 36 m. Under the above conditions, the application effect of nitrogen injection fire-fighting technology is the best.

[Objectives] In order to solve the problem of inertial navigation systems(INS)and doppler velocity logs(DVL) on multiple autonomous underwater vehicles(AUV) failing or having no sensors, combined with the traditional extended Kalman filter estimation,a cooperative positioning method based on dual-model is proposed.[Methods] A relative motion model and two-leader state space model are established. The velocity information of the following AUV is estimated using the relative motion model in underwater acoustic communication,and then the multi-AUV coordinated positioning state space model with the two-leader model is applied to further improve the robustness and accuracy of the coordinated positioning system. Semi-real simulation experiments are then carried out using sea test data.[Results] The results show that the leader-follower multi-AUV cooperative localization method based on the dual-model can estimate the position of the following AUV in real time without INS or DVL on the AUV.[Conclusions] This method can ensure that the positioning accuracy of the cooperative localization system is within the allowable range,and reduce the cost of the multi-AUV cooperative localization system.

This study uses the method of literature and logical analysis to discuss the concept of sustainable development of United Nations and its theoretical significance in the sustainable development of the Beijing Winter Olympics legacy, and on this basis, explores the connotation of sustainable development of the Beijing Winter Olympics legacy and the principles of post-game development. As a result, the concept of sustainable development of United Nations provides useful references for the sustainable development of the Beijing Winter Olympics legacy, and also has certain reference significance for the Beijing Winter Olympics legacy to clarify its systematic development nature, balance development direction, unify development vision and related development effects of economy, society and environment. Based on that, this study summarizes the connotation of the sustainable development of Beijing Winter Olympic legacy as "compatibility with the ecological environment", "combination with social development", and "co-prosperity with economic development". At the same time, four post-game sustainable development principles such as people-oriented, coordinated and co-governance, co-construction and sharing, and gradual progress are proposed, in order to provide theoretical references for the post-game inheritance and sustainable development of the legacy for the Beijing Winter Olympics. [ABSTRACT FROM AUTHOR]