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一在講熱的传播時,輻射這一概念是很抽象的,同学接受起來是比較困難的。主要是由於我們难於向同学说明這一現象的本質。因此只有通过實驗來加深同学對這一現象的認識和理解。現在介紹幾種熱輻射實驗如下,以供大家的參考。 1.辐射现象的演示實驗 (一)利用“感热紙”的實驗說明热的輻射現象(感熱紙製法見註)。在做這個實驗前應向同学先说明感熱紙受熱變色的情形,以及如何利用感熱紙來說明受熱的情形。感熱紙是淺黄色的,當它受到熱源的輻射時就變為深黄(橙)色,冷却後又改成淺黄色。可以先在火焰旁實驗使同学觀察它的变化,然後做下面的实驗。 將實驗体膨脹的铁球在火上烧紅,掛在鐵架上把感熱紙依次放在鐵球的前、後、左、右、上、下各面(重點是把它放在非對流區域),不
When talking about the spread of heat, the concept of radiation is very abstract, and it is more difficult for students to accept it. Mainly because we find it difficult to explain to students the essence of this phenomenon. Therefore, only by experiment to deepen the students understanding of this phenomenon and understanding. Now introduce several kinds of thermal radiation experiment is as follows, for your reference. 1. Radiation phenomenon demonstration experiment (a) the use of “heat-sensitive paper” experiment shows the phenomenon of thermal radiation (heat-sensitive paper system See Note). Before doing this experiment, students should first explain the situation of heat-sensitive paper under the condition of heat and discoloration, and how to use the heat-sensitive paper to explain the heated situation. The heat-sensitive paper is light yellow, turns dark yellow (orange) when it is radiated by a heat source, and changes to light yellow after cooling. You can experiment next to the flame to make the classmate observe its change, and then do the following experiment. The experimental body expansion of the iron ball on the red-hot fire, hanging in the iron frame on the heat-sensitive paper in turn on the iron ball before, after, left, right, up and down all sides (the focus is to put it in the non-convection area ),Do not