初三物理第48页,演示热的对流实验,可采用投影的方法,把液体的对流情况清晰地投影在银幕上,其效果非常明显。用透明胶片做一个长约4厘米、高约3厘米、宽约1毫米的扁形容器,开口向上地放在显微投影光源的切片支架上。取一小滴墨汁滴入适量清水中,摇匀,然后注入扁形容器。接通显微投影光源的电源电路,光源中竖一 The third physics page 48, the demonstration of convection heat test, the projection method can be used to the liquid convection situation clearly projected on the screen, the effect is very obvious. Using transparencies, a flat container about 4 cm long, about 3 cm high, and about 1 mm wide was placed with the opening up on the microtome support for the microlight projection light source. Take a small drop of ink drip into the amount of water, shake, and then into the flat container. Turn on the micro-projection light source power circuit, the light source vertical one