A visible red light beam can be positioned for easy setup and target alignment.

清晰可见的红色光束可为简单的设置和目标保持一致进行定位。

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Central filamentsof the dusty clouds glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light.

在尘埃云中心的细丝发出微弱的红色荧光，这是由于一些尘埃微粒能有效地将恒星发出的不可见紫外线转换成可见的红光。

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He then set out to make a new type of semiconductor crystal that would be able to emit visible, red light.

之后他就开始着手研制一种新型的可以发出可见红光的晶态半导体。

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The astronomers overcame this by using cameras that pick up infra-red rather than visible light (like the thermal imaging cameras used for seeing in the dark).

ECONOMIST: Dusty genesis

For example, iron-gall ink, commonly used on ancient documents, is transparent to infra-red light and most visible in the ultraviolet region of the spectrum.

ECONOMIST: Monitor

This part of the infra-red spectrum, with wavelengths close to that of visible light, carries heat energy.

ECONOMIST: Archaeology: What lies beneath | The