The physical properties of maize seeds are closely related to food processing and production. To study and evaluate the characteristics of maize seeds, typical maize seeds in a cold region of North China were used as test varieties. A variety of agricultural material test benches were built to measure the maize seeds’ physical parameters, such as thousand-grain weight, moisture content, triaxial arithmetic mean particle size, coefficient of static friction, coefficient of rolling friction, angle of natural repose, coefficient of restitution, and stiffness coefficient. Principal component and cluster comprehensive analyses were used to simplify the characteristic parameter index used to judge the comprehensive score of maize seeds. The results showed that there were significant differences in the main physical characteristics parameters of the typical maize varieties in this cold area, and there were different degrees of correlation among the physical characteristics. Principal component analysis was used to extract the first three principal component factors, whose cumulative contribution rate was over 80%, representing most of the information of the original eight physical characteristic parameters, and had good representativeness and objectivity. According to the test results, the classification standard of the evaluation of the physical characteristics of 15 kinds of maize seeds were determined, and appropriate evaluations were conducted. The 15 kinds of maize seeds were clustered into four groups by cluster analysis, and the physical characteristics of each groups were different. This study provides a new idea for the evaluation and analysis of the physical properties of agricultural materials, and provides a new method for the screening and classification of food processing raw materials.
Threshing device is one of the important parts of combine harvesters, whose function determines the working performance, efficiency, and adaptability of the whole machine directly. Threshing gap refers to the clearance between the threshing elements of the drum and the concave grid. During field harvesting, the actual feeding rate shows a great fluctuation due to various biomechanical characteristics and growth density of different varieties of rice, which will deteriorate the threshing and separation performance of combine harvester (Toshikazu and Tatsuro, 2017;Alizadeh and Bagheri, 2009;Singh and Singh, 1981). Therefore, it is necessary to adjust the threshing gap in time according to various working conditions to ensure the operation stability of combine harvesters and improve its harvesting adaptability.Researchers have conducted a lot of studies on the effect of threshing gap on threshing performance, as well as its regulation mode. Scholars have established some basic models of threshing and separation process through comprehensive consideration of multiple factors that exist during the threshing process. They optimized
In order to realize the mechanical direct seeding of precision rows and hills in rice field, a rotary precision hill direct seed-metering device for rice was designed. Through designing the key components of seed-metering device and analyzing its working principle, the main factors and critical conditions affecting the seed-metering performance were obtained. Using the secondary rotation combination test, taking the rotation speed of seed-metering disc and seed capacity height as the test factors, and the re-broadcasting rate, seed-metering qualified rate and miss-seeding rate as the indexes, the seed-metering performance was experimentally studied by using the JPS-12 seed-metering device tested. Design-Expert 6 0.10 software was used to analyze the test data to obtain the mathematical model between factors and indexes. The test results show that when the speed of the seed-metering plate was 24.60 r/min and the seed capacity height was the radius of the seed-metering disc, the qualified rate of seed-metering was 94.83%, the re-broadcasting rate was 3.43%, and the miss-seeding rate was 1.74%. The seeding performance meets the agronomic requirements of rice seeding, and provides a reference for the design of the whole machine.
Liquid-fertilizer deep-application techniques are techniques for applying fertilizers to the root system of crops, which can effectively improve the utilization rate of fertilizers and reduce application amounts. Due to the soil viscosity of soils in the cold region of Northeast China, the soil return rate of furrow openers for liquid-fertilizer deep applications is low, which can easily cause excessive volatilizations of liquid fertilizers. Therefore, aiming at the operational requirements of low soil disturbance for liquid-fertilizer furrowing and deep applications, an efficient soil-returning liquid-fertilizer deep-application furrow opener was innovatively designed based on soil characteristics during the inter-cultivation period in the cold region of Northeast China. The discrete element method (DEM) was used to analyze the operating performance of the high-efficiency soil-returning liquid-fertilizer deep-application furrow openers, which is determined by key operating parameters including width and slip cutting angle. The DEM Virtual Simulation Experiment results show that the optimal combination is the width of 37.52 mm and a slip cutting angle of 43.27°, and the test results show that the optimal performance of the high-efficiency soil-returning liquid-fertilizer deep-application furrow opener is that the soil disturbance rate is 51.81%, and the soil-returning depth is 52.1 mm. This paper clarifies the relationship between the width and the slip cutting angle in furrowing resistance and soil disturbance and the mechanism by which the width and slip cutting angle affect soil disturbance. Above all, this study provides a theoretical and practical reference for the design of liquid-fertilizer deep-application furrow openers.
Due to the fact that the airflow field cannot solve the accumulations of mixtures on the vibrating screen surface, a conical fan was designed. The CFdesign software was used to numerically simulate the airflow field of the cleaning room.The results showed that compared with the cylindrical fan, the mass of threshed mixture in the main falling area of the vibrating screen surface under the conical fan accounted for 65.4 %. The accumulation central point of the threshed mixture deviated 165 mm from the vibrating screen width to the grass discharge outlet. Under the conical fan, the impurity content of the mixture not screened was 6.8 %, and the cleaning loss rate was 0.2 %.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.