Search

Many UAVs today have an S-bend inlet for the sake of stealth; however, the majority of them have a relatively gentle transition of the flow channel. This study presents an experimental investigation of the aerodynamic performance and swirl flow characteristics of a UAV inlet with double 90° bends, which is also integrated with an aircraft fuselage as well as a volute. The influences of angle of attack, sideslip angle, AIP Mach number and freestream speed are explored in detail. The influences of the deflectors installed ahead of the first 90° bend of the inlet and the baffle installed at the bottom of the volute are revealed. It is found that both the deflectors and the baffle are beneficial in enhancing the aerodynamic performance of the inlet and alleviating the intensity of the swirl flow inside the volute. [ABSTRACT FROM AUTHOR]

Japanese farms currently occur on a small but expanding average physical scale and annual sales, in a decreasing and aging labor force, increasingly abandoned farmland and massive access of corporations powerful in capital and management. The government has proposed to accelerate agricultural growth through adopting high‐level smart technologies in large‐scale farms, with a series of favorite policies and measures. This paper reviews the connotations, characteristics and technologies of smart agriculture in the views of Japanese scholars, the practice of smart agriculture in Japan, followed by a case study on the smart rice production model 'NoshoNavi1000'. The results show that Japanese scholars have conducted in‐depth and massive studies in smart agriculture, with regional characteristics in the orientations on labor‐saving, precise management, disaster reduction and inheriting traditional farming skills. The government's ambitious objective is supported by its all‐round policy package, including project demonstration, supporting services, environmental improvement, education and training, and overseas outreaching. Closely combined with the planting structure of Japanese agriculture, rice production is an important sector for the R&D and application of smart farming in the form of either individual technologies or models. The policies and technologies have achieved benefits in saving labor and production costs, and improving the profit margin. Through years of on‐farm application, 'NoshoNavi1000' has been developed to involve the major technological components of smart agriculture. It has contributed to improving rice yield, production efficiency and profitability of large‐scale farms, through real‐time data collection, comprehensive and professional data mining, and specific and practical feedbacks. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

External organic nitrogen (N) inputs can contrastingly affect the transformation and availability of N in forest soils, which is an important potential N resource and is possibly vulnerable to soil properties. Little is known about the transformation and availability of external small molecule organic N in forest soils and the underlying microbial mechanisms. Soil samples from Changbai Mountain at different altitudes (from 750 m to 2200 m) that ranged widely in soil properties were incubated with 13C, 15N-labeled glycine. The fate of 15N-glycine and the incorporation of 13C into different phospholipid fatty acids (PLFAs) were measured at the same time. The addition of glycine promoted gross N mineralization and microbial N immobilization significantly. Mineralization of glycine N accounted for 6.2–22.5% of the added glycine and can be explicable in the light of a readily mineralizable substrate by soil microorganisms. Assimilation of glycine N into microbial biomass by the mineralization-immobilization-turnover (MIT) route accounted for 24.7–52.1% of the added label and was most mightily affected by the soil C/N ratio. We also found that the direct utilization of glycine is important to fulfill microorganism growth under the lack of available carbon (C) at upper elevations. The labeled glycine was rapidly incorporated into the PLFAs and was primarily assimilated by bacteria, indicating that different groups of the microbial community were answerable to external organic N. G+ bacteria were the main competitors for the exogenous glycine. Increased intact incorporation of glycine into microbial biomass and the concentration of PLFAs in general, particularly in G+ bacteria, suggest a diversified arrangement to response changes in substrate availability. [ABSTRACT FROM AUTHOR]