因为测量的引发是由脉冲的前导沿控制的，除非设置一定的预触发延迟，否则会丢失部分脉冲、造成频谱失真。

Since the measurement initiation is controlled by the leading slope of the pulse, part of the pulse is lost and the resulting spectrum is distorted unless some pretrigger delay is specified.

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先前基于宏观电磁波(包含大量光子)的实验已经证明，光前驱是光脉冲在传播过程中最快的部分。

Previous experiments based on macroscopic electromagnetic wave propagation (involving lots of photons) have shown that the optical precursor is the fastest part in the propagation of an optical pulse.

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有一种仪器被称为“引导者”(pacemaker)植入大脑主干，它能够发送电子脉冲到大脑特定的部分。

A device called a brain pacemaker implanted in the brain stem can send electrical impulses to specific parts of the brain.

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