遗憾的是，一秒钟的标准定义依赖于原子在绝对零度的条件，而实际的时钟需要在室温下运行，室温条件下电子壳层膨胀了。

Unfortunately, the standard definition of a second relies on what the atom does at a temperature of absolute zero. Real clocks need to run at room temperature, where the shell of electrons puffs up.

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模型由一系列部件模型组成，包括压缩机、经济器、膨胀阀、壳管式冷凝器以及满液式蒸发器。

The model includes sub models for key components, such as non economized compressor, economized compressor, economizer, expansion valve, shell and tube condenser, and flooded evaporator.

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黑洞喷流或许产生了不断膨胀的壳层，这一点最近得到了证实，因为天鹅座x - 1周围已经发现了壳层。

Confirmation that black hole jets may create expanding shells has come recently from the discovery of shells surrounding Cygnus X-1.

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