施氮量和留叶数互作对烤烟NC297产量和质量的影响

以促进NC297产量和质量协调和最优化为目的，研究施氮量和留叶数互作对NC297的物理特性、化学成分、经济性状的影响。结果表明：在施氮量7.5～60 kg/hm2、留叶数17～26片时，NC297叶长、叶宽、叶面积、叶厚、单叶重均随施氮量的增加而增加；含梗率、叶质重随施氮量的增加先降低后升高；烟碱和总氮含量随着施氮量的增加而上升显著，随着留叶数的增加而显著下降；产量持续上升，产值、均价、中上等烟比例随着施氮量和留叶数的增加先增大后减小；在物理性状、化学成分、经济性状上，除还原糖和糖碱比外，施氮量对其余各指标的影响均最大，留叶数的影响次之，二者交互作用产生的影响最小。NC297的适宜施氮量为30 kg/hm2，适宜留叶数为20～23片。

Effects of nitrogen application and remaining leaves and their interactionson yield and quality of flue-cured tobacco NC297

The mechanical resonance caused by flexible connection is a constraint of servo system performance. With expounding the mechanism of mechanical resonance, two reasons causing vibration are analyzed. The mechanical resonance can be suppressed by acceleration feedback which can increase the motor equivalent inertia. In this paper, an adjustable inertia ratio method of load torque feedback based on Kalman filter is presented, and the coefficient of load torque feedback can be calculated by the optimal inertia ratio. After that, a load torque observer is designed by Kalman filter, then the observed torque is feedback to the reference of current loop. The performances of the observer and the mechanical resonance suppressed by load torque feedback are verified by matlab simulation.