红三叶种子丸粒化工作参数多目标优化

针对红三叶种子丸粒化包衣存在丸化合格率低、丸化设备参数优选困难等问题,以单籽丸化合格率与单籽抗压强度作为丸粒化包衣性能指标,利用多目标优化方法对红三叶种子丸粒化包衣工作参数进行优选。采用二次正交试验获取不同包衣锅工作参数下的丸粒化包衣性能指标值,通过Design-Expert软件建立相应的二阶回归方程并进行回归模型单目标优化。结果显示红三叶种子单籽丸化合格率及单籽抗压强度模型用于种子丸化包衣性能预测分析的准确性,单籽丸化合格率预测值与物理试验值相对误差为0.15%,单籽抗压强度预测值与物理试验值相对误差为5.85%;通过多目标优化分析,确定红三叶种子最佳工作参数为包衣锅振动频率15 Hz、包衣锅转速59 r/min、包衣锅倾角35°。

红三叶种子离散元仿真参数的标定与试验

为了提高红三叶种子丸粒化包衣过程离散元仿真试验所用参数的准确性,通过休止角测定物理试验和仿真试验相结合的方法对仿真参数进行标定。首先,通过物理试验获得红三叶种子的基本物性参数和接触参数,并将其作为仿真试验参数选择范围的依据。采用Plackett-Burman试验对仿真试验参数进行显著性筛选,试验结果表明:红三叶种子-红三叶种子静摩擦系数和滚动摩擦系数、红三叶种子-钢板静摩擦系数对仿真休止角有显著性影响。进一步通过最陡爬坡试验确定显著性参数的最优区间范围,并根据Central composite design设计试验得到仿真试验休止角与物理试验休止角相对误差的二次回归模型,以相对误差的最小值为优化目标得到最优参数组合:红三叶种子-红三叶种子静摩擦系数和滚动摩擦系数分别为0.605和0.637、红三叶种子-钢板静摩擦系数为0.388。在最优参数组合下仿真试验休止角结果24.43°与物理试验休止角结果24.57°的相对误差为0.57%,验证了仿真试验的可靠性。研究结果表明标定所得的最优参数可用于红三叶种子包衣过程的离散元仿真试验。

Effect of Phosphorus and Potassium Foliar Treatment on Seed Yield and Yield Components of Red Clover （ Trifolium pratense L.） Cultivars

Proper mineral nutrition of red clover especially on the acid soils is a prerequisite for the realization of maximum potential for seed yield. The field experiment with four cultivars of red clover were established on soil having a pH （in H2O） of 4.8, in order to in conditions of dense planting （20 cm inter row） analyzes the effect of foliar application of phosphorus and potassium （PK） on yield and yield components （number of stems/m2, number of inflorescences/m2, number of inflorescences/stem, number of flowers/inflorescence, number of seeds/inflorescence and one thousand grain weight）. Regardless of foliar treatment with PK, varieties differed in the number of inflorescences/m2, number of flowers/inflorescence, number of seeds/inflorescence and seed yield. Foliar application of PK in the phase of intensive growth of red clover had a positive impact on number of stem/m2, number of inflorescences/m2 and seed yield in all varieties, as well as on the number of flowers/inflorescence, number of seeds/inflorescence in cultivar Viola.