一般情况下我不能这么写,因为这一项会包含pdV和，但是我们已经假定压强为常数，所以包含dp的部分等于零。
Normally I couldn't do that Vdp because this term would have p dV plus V dp, but we've specified the pressure is constant, so the dp part is zero.
这些边界条件用以决定一般解中的积分常数。
Boundary conditions are used to determine the integral constants in the general solution.
所得结果表明，在一般情况下耦合系数并非是常数，而是与波的传播距离有关的函数。
The obtained expression indicates that in the general condition the coupling coefficient is not a constant, but is a function associated with the travelling distances of the waves.
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