http://vashu11.livejournal.com/ ([identity profile] vashu11.livejournal.com) wrote in [personal profile] vashu11 2023-04-06 05:36 am (UTC)

Излучательная способность поверхности легко снижается до едениц процентов (1 — абсолютно черное тело), возможно на 2-3 порядка для частных случаев



Закон_Стефана_—_Больцмана


где ε — интегральная поглощательная способность тела. Для абсолютно чёрного тела ε = 1 выражение имеет специальное название: закон Стефана — Больцмана. Для многих температур металлы имеют ε = 0,1…0,4, а для окислов металлов ε = 0,5…0,9


ε \varepsilon = 0,612 эффективной светимости Земли.


...


https://mash-xxl.info/info/10332/


Способность излучательная 323, 337 -- максимальная 329


https://mash-xxl.info/page/018012019046154255161038046137244239099177051079/


...


https://en.wikipedia.org/wiki/Emissivity


emits thermal radiation at the rate of approximately 448 watts per square metre at room temperature (25 °C, 298.15 K). All real objects have emissivities less than 1.0, and emit radiation at correspondingly lower rates.[1]


.


Emissivities of common surfaces


Silver, polished 0.02


Aluminium foil 0.03


...


https://sci-hub.ee/10.1016/j.cryogenics.2008.07.007


...


https://en.wikipedia.org/wiki/Low_emissivity


...


https://www.nasa.gov/feature/cryogenic-selective-surfaces-0/


Solar White” that, when used in deep space, is predicted to reflect more than 99.9% of the sun’s energy.


...


only about 0.01 % of


the sun’s peak


energy is absorbed.


https://ntrs.nasa.gov/api/citations/20160010567/downloads/20160010567.pdf


...


https://en.wikipedia.org/wiki/Selective_surface


Thermal emissivities as low as 0.02 have been obtained in laboratories


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