A black body maintained at a constant temperature is a full radiator at that temperature because the radiation reaching and leaving it must be in equilibrium.
黑色物体在恒温条件下是温度的完全辐射器，因为到达和离开该物体的辐射量必须保持平衡。
2
The thermal balance equation of spatial object is established and solved. The light radiation characteristic is obtained by calculating the thermal equilibrium temperature of spatial object.
通过建立和求解空间目标热平衡方程，计算了空间目标的平衡温度，讨论了空间目标的光辐射特性。
3
The equilibrium thermal radiation in a curved space-time shows Planco black body spectrum given by coordinate quanties.