亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

Application uniformity is an essential aspect of the performance of a variable-rate fertilization (VRF) applicator. In order to study the relationship between fertilization uniformity and control sequence such as active feed-roll length (L) and rotational speed of the drive shaft (n) for a spiral fluted-roll fertilizer distributer for a bivariate fertilization applicator, the discrete element simulation model was established and the fertilization uniformity was studied by conducting discrete element simulation tests via the discrete element method (DEM) software. Firstly, a calibration was conducted at different active-feed roll length (L) and rotational speed of the drive shaft (n), and then the fertilization model was formed by general regression neural network (GRNN). To test model prediction accuracy, another 20 samples were utilized as test set, the validation result showed that the correlation coefficient (R2) was up to 0.9994 and the mean relative error (MRE) was 3.56%. In addition, three target fertilization, including Q1=1067.37g/min，Q2=2323.04g/min，Q3=4206.56g/min，were chosen according to the equal discharge curve of spiral fluted-roll fertilizer distributer and control index (L,n) at the same target fertilization rate were found by differential evolution algorithm (DE) and formed GRNN model. Finally, the fertilization simulation tests at different control indexes for three different target rates were conducted via EDEM 2.8 software. The coefficient of variation σ was calculated as criteria to evaluate the fertilization uniformity. The result showed that, at target rate of Q1, the minimized σ occurred at the control index of (25mm，17.78r/min), which was 5.27%. At target rate of Q2, the minimized σ was occurred at control index of (65mm，17.12r/min), which was 3.46%. At target rate of Q3, σwas below 4% at all control index. The minimized σoccurred at control index of (65mm，32.85r/min), which was 2.08%. In conclusion, at the small target fertilization rate, the selection of the control sequence had a significant impact on fertilization performance. In fertilization, the opening length and rotational speed boundaries should be avoided. At the large target fertilization rate, the selection of the control sequence had little effect on the fertilization uniformity of spiral fluted-roll fertilizer distributer.