kω ^2=-Jdω/dtk/Jdt=-dω/ω^2kt/J十C=1/ωω=1/[kt/J十C]=J/(kt十JC)t=0,ω=ω0ω0=1/CC=1/ω0回代：ω=J/(kt十J/ω0)=Jω0/(kω0t十J)
