体蒸发可降温,气体液化可供热.试举例说明__________________________________________________________________________________________________
问题描述:
体蒸发可降温,气体液化可供热.试举例说明__________________________________________________________________________________________________
答
中暑常在头额上涂酒精,利用蒸发制冷;
冬天常哈气暖和暖和手,就是利用气体液化放热.