Design and optimization of the seed conveying system for belt-type highspeed corn seed guiding device

Seeding is an important part of improving corn yield.Currently,seed guide tubes are mostly used as transport devices.But the existing seed guide tubes cannot meet the requirements or achieve the goal of fixing the seed falling trajectory.A seed collision phenomenon occurs occasionally.So,in response to the problems that the seeds and seed guide tube collide or bounce under high speed operation,which results in a lower sowing qualification rate and poor spacing uniformity,a seed receiving and conveying system comprising a belt-type high-speed corn seed guiding device was designed and optimized,to meet the needs of high-speed precision sowing operations and improve the spacing uniformity.The factors affecting the seed conveying performance were obtained by analyzing the mechanical properties of the seeds at various movement stages.These factors were the number of seed cavities between adjacent seeds,the forward speed,the height from the ground,and the installation angle.Single factor simulation experiments were conducted by selecting the paddle spacing as the test factor and using the pass rate,reseeding rate,omission rate and coefficient of variation as the evaluation indexes to investigate the influence of the paddle spacing on the seed guide performance of the device and further determine the structural parameters of the paddle belt.Orthogonal rotation combination tests of three factors and five levels were also conducted through bench testing.Then the test outcomes were optimized.The results indicated that the best results were obtained when the number of seed cavity intervals between adjacent seeds was 5.16,the installation angle was 79.40°,and the height from the ground was 31.84 mm.At this time,the qualified rate was 98.49%,the repeated sowing rate was 0.48%,the missed sowing rate was 1.03%,and the coefficient of variation was 6.80%.Experiments were used to validate the optimization results,and all of the obtained index data satisfied the criteria for accurate and quick corn sowing.The study’s findings can serve as a theoretical foundation for a belt-type high-speed corn seed guiding device optimization test.

High efficiency photothermal cyclic self-healing antibacterial coating based on in-situ dual-functional BiOI@Bi_(2)S_(3)

Although extremely challenging,it is highly desirable to develop self-healing materials that exhibit high efficiency under environmental conditions for marine protection applications.In this work,polyurethane elastomers with hydrogen bond and dimethylglyoxime-urethane(DOU)coordination complex were combined with in-situ dual-functional BiOI@Bi_(2)S_(3) to synthesize high-efficiency photothermal cyclic self-healing antibacterial coating.The photothermal efficiency of BiOI@Bi_(2)S_(3) is improved by 38% through interfacial regulation.BiOI@Bi_(2)S_(3)/PU rapidly rises by 50.2℃ within 300 s under near-infrared(NIR)light,which can trigger the hydrogen bond of polyurethane coating and recover the barrier properties of the coating through self-healing.Density functional theory was used to simulate and analyze the generation of multiple electron transfer paths after the vulcanization of BiOI,which improves the interfacial mobility of photogenerated carriers and generates more heat.Importantly,molecular dynamics verified the self-healing mechanism of hydrogen bond and the photothermal lifting mechanism of the coating.After 5th scratches and self-healing cycle tests,the coating has a self-healing efficiency of more than 80%,which can ensure the self-healing and anticorrosion protection performance of the coating for multiple cycles.The photocatalytic and photothermal properties of BiOI@Bi_(2)S_(3) enhance the antibacterial rate of the coating up to 99%.This work provides heuristic perspectives for the design of coatings with anti-corrosion,antibacterial and self-healing properties.