请教关于贝塞尔函数的应用

BESSEL Bessel functions of various kinds.
Bessel functions are solutions to Bessel's differential
equation of order NU:
2 2 2
x * y'' + x * y' + (x - nu ) * y = 0

There are several functions available to produce solutions to
Bessel's equations. These are:

BESSELJ(NU,Z) Bessel function of the first kind
BESSELY(NU,Z) Bessel function of the second kind
BESSELI(NU,Z) Modified Bessel function of the first kind
BESSELK(NU,Z) Modified Bessel function of the second kind
BESSELH(NU,K,Z) Hankel function
AIRY(K,Z) Airy function