论文标题
在机械波中的负能量流
Negative flow of energy in a mechanical wave
论文作者
论文摘要
提出了一种类似于具有概率回流的量子系统的经典系统。该系统由弹簧相互关联的一系列群体组成，并由其他弹簧连接到固定支撑。多亏了最后一个弹簧，截止频率和分散体就会出现在沿链条传播的波频谱中。结果表明，这种色散有助于能量回流的出现。在两个波的干扰的情况下，此回流的幅度比上述量子问题中的概率回流值高的数量级。考虑了绿色功能的方程式，并且表明当系统被两个连续的短脉冲激发时，能量的回流也可以。这种经典的回流现象是通过能量流到局部模式的分支来解释的，这是强制阻尼振荡器的结果所证实的。结果表明，即使在如此简单的系统中，能量的回流也发生了（瞬时和平均），并且能量又回到了外力。
A classical system, which is analogous to the quantum one with a backflow of probability, is proposed. The system consists of a chain of masses interconnected by springs, as well attached by other springs to fixed supports. Thanks to the last springs the cutoff frequency and dispersion appears in the spectrum of waves propagating along the chain. It is shown that this dispersion contributes to the appearance of a backflow of energy. In the case of the interference of the two waves, the magnitude of this backflow is an order of magnitude higher than the value of the probability backflow in the mentioned quantum problem. The equation of Green's function is considered, and it is shown that the backflow of energy is also possible when the system is excited by two consecutive short pulses. This classical backflow phenomenon is explained by the branching of energy flow to local modes, what is confirmed by the results for the forced damped oscillator. It is shown that even in such a simple system the backflow of energy takes place (both an instantaneous and on average) and the energy comes back to external force.
