To address the problems of high breakage rates, high entrainment losses and many unthreshed kernels when harvesting high moisture content maize seeds, a high moisture content maize seed threshing test was designed based on a multifunctional seed harvester stand designed by this group.In order to determine the optimum operating parameters of the threshing unit, single-factor experiments and orthogonal tests were carried out using the threshing drum speed, concave plate clearance and feed rate as test factors and the crushing rate, unthreshing rate, entrained loss rate and trash content rate as test evaluation indicators.The optimum combination of test factors obtained for the harvesting of maize at 32% to 34% moisture content was a drum speed of 346.55r/min, a concave plate clearance of 44.39mm and a feed rate of 9.739Kg/s.After repeated experiments on the bench, the test results with optimum parameters were 6.311% crushing rate, 0.187% unthreshing rate, 0.912% entrained loss rate and 4.251% impurity rate, at which point the crushing rate was the lowest and the other three met national standards.

Aiming at the problems of the low efficiency of manual pesticide application in the greenhouse, the narrow operating space of plant protection machinery, and the possibility of poisoning the pesticide applicators due to the closed space, a high-pressure atomization spraying equipment for the greenhouse was designed. The spraying equipment adopts two-way communication between PLC and HMI to realize the adjustment of atomization pressure and atomization flow, and the control equipment completes automatic spraying. To determine the best working parameters of the spraying equipment, orthogonal tests were conducted with atomization pressure and atomization nozzle aperture as the test factors and the coefficient of variation of the fog volume distribution as the evaluation index. The optimum combination after parameter optimization was determined to be as follows: atomization pressure of 4 MPa, atomization nozzle aperture of 0.4 mm. The test results under the optimal parameters showed that the spray distribution coefficient of variation was 10.5%, and the uniformity of fog volume distribution was good to meet the requirements of spraying in greenhouses.

With the rapid development of agricultural modernization, the reliability of agricultural machinery had become the key to improving the development level of agricultural machinery and equipment in China. Aiming at the problems of subjectivity, fuzziness, high test cost and difficult data acquisition in the Failure Mode, Effects and Criticality Analysis of grain harvester, an FMECA analysis method based on Data Mining Technology was proposed in this paper. In this study, Python 3.7.8 is used to collect and process the fault data of the header of the grain harvester. According to the data analysis, it is concluded that the fault rate of the cutter component is the highest in the whole system. Then the agreed hierarchy of header was analyzed by Analytic Hierarchy Process, and it was concluded that the blade part failure mode was the most hazardous. The results show that the grain harvester should strengthen the inspection and maintenance of the blade of the cutter in the working process. The research results showed the feasibility of the FMECA method based on Data Mining Technology in agricultural machinery reliability analysis, which opens up a new idea of grain combine harvesters’ reliability analysis and provides the possibility to obtain the reliability level of harvesters with low input.

The properties of akaganeite (β-FeOOH) are affected by the coexisting ions and can be changed by doping various ions. Tin doped β-FeOOH nanorods were prepared using β-FeOOH nanorods as the precursor under hydrothermal conditions. The effect of tin ions on the thermal property of β-FeOOH was investigated. The doping of tin ions was confirmed by X-ray powder diffraction, energy dispersive spectroscopy, and atomic emission spectrometer analysis. The adsorption of tin ions on the surface of β-FeOOH could prevent the transformation from β-FeOOH nanorods to α-Fe2O3 in solution. Thermogravimetric analysis and differential thermal analysis showed they have different thermal decomposition temperatures. β-FeOOH nanorods were transformed into α-Fe2O3 particles at 400 °C. While tin doped β-FeOOH nanorods should be heated to 600 °C. Tin doped β-FeOOH nanorods showed higher thermal stability than that of β-FeOOH nanorods. The presence of tin ions is favor of the formation of rod like shape.