【摘要】 仅考察降雨对棉蚜的机械杀伤作用时,一日降雨量（R）与棉蚜死亡率（D）之间呈“S”型曲线关系。利用正态分布的积分面积与正态等差的关系,可将死亡率换算为机率值（p）,便有p=a+bR线性方程。再将单位脉冲函数δ_t)及t时刻棉蚜种群M_t引入方程,并对p与D的关系换算,可得降雨杀死棉蚜的动态模型 （t）=δ_t.M_t.（1-D）更多还原

【Abstract】 Only through examining the effect of rainfall inflicting casialty upon the cotton aphid population, there exists an S-shapsd curve between rainfall per day (R) and the mortality (D) of cotton aphids. And then the mortality (D) of cotton aphids can be converted into the value of probability (P) using the relationship between intsgral area of normal distribution and normal equivalent deviation, thus, obtaining the linear equation. P = a + bR.And then the pulse function, δ (t) per uiit area and cotton aphid po-oulation M(t)at t time can be introduced into the equation,and the values of P and D can be converted. Thus far, a dynamic model of rainfall inflicting caSuaty on cotton aphid population is deduced as follows.更多还原