中层大气中脉冲点源产生的声重力波
ON ACOUSTIC-GRAVITY WAVES GENERATED BY AN IMPULSIVE POINT SOURCE IN THE MIDDLE ATMOSPHERE
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摘要: 本文从脉冲点源出发,利用广义函数的理论,将象函数作高频近似和低频近似,求得了早时响应和长时响应,从而将目前已有的结果由特殊推广到一般。再巧妙地引入含参变量的积分,可以得到(1/ωct0)n的因子,此因子有极其重要的物理意义。本文的结果是:1.Row1是在特殊情况下作近似,只能得到J_c\left(\omega_c \sqrtt^2-t_0^2\right),本文不作近似而是在一般情况下就可得到结果。此结果除了包含特殊情况下的J_0\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right)外,还得到了一个修正项J_1\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right),t-α-t0越小,修正效应越大。2.Row1的(12)式中J_0\left(\omega_c \sqrtt^2-t_0^2\right) H\left(t-t_0\right)的应改为J_0\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right)\cdot H\left(t-\alpha-t_0\right)，α表示一向后的推迟时间。3.(1/ω0t0)n表示离源越远,t0越大,修正效应越小。而ωc越小周期Tc越长,修正效应越强,越低频率声重力波衰减愈慢而愈容易观察。4.从推导过程可以看到Row1文章的(20)式不是长周期近似,而是高频近似。5.实验与理论一致。Abstract: In this paper the Row's1 results are extanded from the special condition to the general condition. Besides the J_0\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right) H\left(t-\alpha-t_0\right), the corrective factorJ_1\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right) H\left(t-\alpha-t_0\right) is gained. The J_0\left(\omega_c \sqrtt^2-t_0^2\right) H\left(t-t_0\right) of formula (12) in row (1967)1 must be changed into J_0\left(\omega_c \sqrt(t-\alpha)^2-t_0^2\right) H\left(t-\alpha-t_0\right) where α is a retarded time. The (1ωct0)n indicates that: when to is greater, the corrective effect is less; when Tc is longer, the corrective effect is more.
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