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Infant botulism is caused by ingesting Clostridium botulinum spores and characterized by symmetric descending paralysis, which can progress to respiratory failure in severe cases (1). Specific therapies include intravenous administration [...]

Accurately predicting the departure aircraft slip out time can effectively improve the airport surface operation efficiency and reduce the operation cost. A prediction model of departure and departure time based on BP neural network is established. The key factors influencing the actual slip out time are analyzed,and the correlation is tested. The model is verified by two weeks' actual operation data of an airport in central and southern China,and the root mean square error(RMSE),mean absolute error(MAE)and MAE percentage are analyzed. The results show that there is a strong correlation between the number of aircraft launched in the same period,the number of aircraft taking off in the same period,the number of aircraft in the same period,the average taxiing time within one hour and the taxiing time of departing aircraft. The taxiing distance,the number of turns and the delay time are related to the taxiing time,but not significant. The time period at which the aircraft takes off is not related to the slip out time. The average slip out time within 1 hour plays an important role in improving the prediction accuracy of the model. The introduction of relevant but insignificant influencing factors plays a certain role in improving the accuracy of prediction results. After the introduction of irrelevant factors,the prediction accuracy of the model will decrease significantly.

Poor fracture toughness and calcium–magnesium–aluminum–silicate (CMAS) corrosion resistance adversely affect environmental barrier coatings (EBCs) during prolonged service. Herein, an in-situ nanostructured Lu 2 O 3 /Lu 2 SiO 5 composite EBC was successfully prepared using nanostructured Lu 2 SiO 5 feedstocks. The morphologies and phase structures of the Lu 2 SiO 5 feedstocks and the corresponding coating were thoroughly characterized. Additionally, the mechanism of the in suit reaction of the Lu 2 O 3 /Lu 2 SiO 5 composite EBC was examined. The results indicate that the nanostructured as-deposited EBC exhibits a bimodal and dual-phase structure. The nanostructured Lu 2 SiO 5 coating comprises melted lamellae and unmelted or partially melted particles. The phase structure of these unmelted or partially melted particles includes Lu 2 O 3 and X2-Lu 2 SiO 5. The Lu 2 O 3 nanoparticles are formed by the decomposition of Lu 2 SiO 5 during spraying, and their content can be controlled to <15 %, which can enhance the fracture toughness and CMAS corrosion resistance of the EBCs to some extent. [ABSTRACT FROM AUTHOR]

Aiming at the problem of delayed repair of cracks in the airtight wall of the goaf, a method to initiate crack repair using microcapsules in the initial stage of crack evolution of the airtight wall (cracking period) is proposed. This method makes use of the stress at the crack tip. The microcapsule wall is torn to allow the repair agent wrapped in the wall of the capsule to flow out and fill the gap. After the curing reaction, crack repair is completed. During the crack repair process of the airtight wall, the particle size of the microcapsule affects the strength of the capsule wall and directly affects the repair effect. In order to study the influence of particle size on the strength of microcapsules, eight kinds of microcapsules with different particle diameters and the same wall thickness were prepared by orthogonal experiments. The particle size and wall thickness were characterized by SEM, and the strength of the capsule wall was measured using nanoindentation technology. The quadratic function relationship that the strength of the capsule wall decreases with the increase of the particle size is obtained.

In this study, a new type of highly efficient and recyclable magnetic-fluorine-containing polyether composite demulsifier (Fe3O4@G-F) was synthesized by the solvothermal method to solve the demulsification problem of oil–water emulsion. Fe3O4@G-F was successfully prepared by grafting fluorinated polyether onto Fe3O4 and graphene-oxide composites. Fe3O4@G-F was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Taking the self-made crude-oil emulsion as the experimental object, the demulsification mechanism of the demulsifier and the influence of external factors, such as the temperature and pH value, on the demulsification performance of the demulsifier are discussed. The results show that the demulsification efficiency of the Fe3O4@G-F emulsion can reach 91.38% within 30 min at a demulsifier dosage of 750 mg/L, pH of 6, and a demulsification temperature of 60 °C. In neutral and acidic environments, the demulsification rate of the demulsifier is more than 90%. In addition, Fe3O4@G-F has been proven to have good magnetic effects. Under the action of an external magnetic field, Fe3O4@G-F can be recycled and reused in a two-phase system four times, and the demulsification efficiency is higher than 70%. This magnetic nanoparticle demulsifier has broad application prospects for various industrial and environmental processes in an energy-saving manner. [ABSTRACT FROM AUTHOR]

The crystal morphology of high energetic materials plays a crucial role in aspects of their safety performance such as impact sensitivity. In order to reveal the crystal morphology of ammonium dinitramide/pyrazine-1,4-dioxide (ADN/PDO) cocrystal at different temperatures, the modified attachment energy model (MAE) was used at 298, 303, 308, and 313 K to predict the morphology of the ADN/PDO cocrystal under vacuum and ethanol. The results showed that under vacuum conditions, five growth planes of the ADN/PDO cocrystal were given, which were (1 0 0), (0 1 1), (1 1 0), (1 1 −1), and (2 0 −2). Among them, the ratios of the (1 0 0) and (0 1 1) planes were 40.744% and 26.208%, respectively. In the (0 1 1) crystal plane, the value of S was 1.513. The (0 1 1) crystal plane was more conducive to the adsorption of ethanol molecules. The order of binding energy between the ADN/PDO cocrystal and ethanol solvent was (0 1 1) > (1 1 −1) > (2 0 −2) > (1 1 0) > (1 0 0). The radial distribution function analysis revealed that there were hydrogen bonds between the ethanol and the ADN cations, van der Waals interactions with the ADN anions. As the temperature increased, the aspect ratio of the ADN/PDO cocrystal was reduced, making the crystal more spherical, which helped to further reduce the sensitivity of this explosive. [ABSTRACT FROM AUTHOR]

In order to solve the problem of oily wastewater treatment in Shengli Oilfield, tert‐butyl phenol (TP) series nonionic polyether water clarifiers were synthesized by polymerization with p‐tert‐butyl phenol (PTBP) as the initiator. The water clarifiers were characterized by Fourier‐transform infrared spectroscopy (FT‐IR) and the interfacial tension test was carried out. The TP series of water clarifiers effect were evaluated by the oil content and suspension content in the clean water experiments. In addition, the effects of dosage and temperature on the water effect were discussed through the control variable method. The experimental results showed that the oil removal rate of TP6 can reach 95% and the suspension removal rate can reach 92% when the dosage of water clarifier was 40 mg/L, the cleaning water temperature was 55°C, and the cleaning water time was 30 min. The oily wastewater colour after cleaning was clear and transparent with the TP series of water clarifiers, and the effect was better than with commercial water clarifiers. [ABSTRACT FROM AUTHOR]

Sodium borohydride (NaBH4), with a high theoretical hydrogen content (10.8 wt%) and safe characteristics, has been widely employed to produce hydrogen based on hydrolysis reactions. In this work, a porous titanium oxide cage (PTOC) has been synthesized by a one-step hydrothermal method using NH2-MIL-125 as the template and L-alanine as the coordination agent. Due to the evenly distributed PtNi alloy particles with more catalytically active sites, and the synergistic effect between the PTOC and PtNi alloy particles, the PtNi/PTOC catalyst presents a high hydrogen generation rate (10,164.3 mL∙min−1∙g−1) and low activation energy (28.7 kJ∙mol−1). Furthermore, the robust porous structure of PTOC effectively suppresses the agglomeration issue; thus, the PtNi/PTOC catalyst retains 87.8% of the initial catalytic activity after eight cycles. These results indicate that the PtNi/PTOC catalyst has broad applications for the hydrolysis of borohydride. [ABSTRACT FROM AUTHOR]