“thermal conductivity”的概念、定义、翻译、参考文献-科学参考

thermal conductivity

Physics

See conductivity.

Chemical Engineering

The measure of the movement of heat through a body by kinetic molecular activity. It is used in Fourier’s law, which states that the thermal conductivity is independent of the temperature gradient but not necessarily of temperature itself. The thermal conductivity is the proportionality constant between heat flux and temperature gradient. That is, the rate of flow of heat (dQ/dt) through a surface of area A in a medium is given by:
$\frac{d Q}{d t} = - k A \frac{d T}{d t}$

where dT/dt is the temperature gradient measured in the direction normal to the surface. Values for the thermal conductivity vary widely for substances, with metals having the highest and finely powdered materials the lowest. The SI units are W m⁻¹ K⁻¹.

Geology and Earth Sciences

A parameter used as a measure of how well a material conducts heat (for example, for copper K = 385 W/m/K, for air K = 0.02 W/m/K). K forms the constant of proportionality in the heat-conduction-rate equation: dQ/dt = −KA dθ‎/dl, where dQ/dt is the heat conduction rate (in joules per second), A is the cross-sectional area of a uniform sample (in square metres), and dθ‎/dl is the temperature gradient along the sample (in kelvin per metre). Compare thermal resistivity.

单词	thermal conductivity
释义	thermal conductivity Physics See conductivity. Chemical Engineering The measure of the movement of heat through a body by kinetic molecular activity. It is used in Fourier’s law, which states that the thermal conductivity is independent of the temperature gradient but not necessarily of temperature itself. The thermal conductivity is the proportionality constant between heat flux and temperature gradient. That is, the rate of flow of heat (dQ/dt) through a surface of area A in a medium is given by: $\frac{d Q}{d t} = - k A \frac{d T}{d t}$ where dT/dt is the temperature gradient measured in the direction normal to the surface. Values for the thermal conductivity vary widely for substances, with metals having the highest and finely powdered materials the lowest. The SI units are W m⁻¹ K⁻¹. Geology and Earth Sciences A parameter used as a measure of how well a material conducts heat (for example, for copper K = 385 W/m/K, for air K = 0.02 W/m/K). K forms the constant of proportionality in the heat-conduction-rate equation: dQ/dt = −KA dθ‎/dl, where dQ/dt is the heat conduction rate (in joules per second), A is the cross-sectional area of a uniform sample (in square metres), and dθ‎/dl is the temperature gradient along the sample (in kelvin per metre). Compare thermal resistivity.
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