热力学：第一定律，内能，工作，热。

Thermodynamics: first law, internal energy, work, heat.

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热塑料性塑料是指在特定温度范围内能反复加热软化和冷却硬化的塑料，如聚乙烯、聚四氟乙烯等。

Thermal plastic and plastic is defined as a specific temperature range can be repeated heating and cooling to soften hardened plastic such as polyethylene, PTFE and so on.

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热的物体比类似的较冷物体具有更多的内能，但一大浴缸的冷水比一杯开水可能有更多的内能。

A hot body has more thermal energy than a similar cold body, but a large tub of cold water may have more thermal energy than a cup of boiling water.

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We have discovered that this partial derivative that appears in the definition, the abstract definition of the differential for internal energy, is just equal to the constant volume heat capacity.

我们还发现,这个偏微分出现在了，内能的偏微分,定义式中，它也就是热容。

麻省理工公开课 - 热力学与动力学课程节选

And because there is an explicit relationship between u, delta u, q and w, you can always find the easy way to derive the change in internal energy or the heat or the work.

因为Δu，q和w之间,有明确的关系，一般来说,内能或热或功的变化,易于计算。

麻省理工公开课 - 热力学与动力学课程节选