【摘要】 观察了保温瓶瓶胆在动态真空系统中热损失与抽气压强P之间的关系。 实验发现瓶胆保温度T-T₀随时间t呈指数衰减。从对数坐标图中求出该衰减系数或温度下降率α,得出α随P的变化规律。结果指出: （1）当压强P大于 10^-2乇时,α与 P关系不大; （2）当压强P在10^-3乇数量级时,α随P成正比减小; （3）当压强P小于10^-3乇时,α与P基本无关。 结合气体分子热传导公式,讨论了实验结果。更多还原

【Abstract】 The correlation of the heat-loss of thermos refills under dynamic vaccuum conditions with respect to the pressure P of vaceuum air pump has been observed.It is found that the heat-retension T - T0 decreases exponentially as the time t increases. By plotting the data in logarithmic coordinates, the attenuation coefficient or temperature decreasing rate a is obtained.It is shown by the α-P relation curve that:(1) there is little correlation between a and P as the pressure P>10-2 torr;(2) the value of a varies linearly with P when the pressure P is in the order of 10-3 torr(3) the value of a almost keeps unchanged as the pressure P<10-3 torr.The results have been discussed in connection with, the heat conduction formula of gas molecules更多还原