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coolcd joined: 2008-01-21 posted: 2601 promoted: 348 bookmarked: 95 |
How to make graphene with a pencil and sticky tape (w/ Videos) 沒想到,原來鉛筆就是石墨,小時候學的都還給老師了 XD edited: 1
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winlin joined: 2007-09-25 posted: 1859 promoted: 111 bookmarked: 33 |
離題一下,小時候以為鉛筆含有鉛,吃到了鉛筆削下來的粉末會中毒,原來不是這樣鉛筆不是鉛做的--晶體結構如何影響晶體特性------------------------------------------------------------------- | |||||||
eliu joined: 2007-08-09 posted: 11480 promoted: 617 bookmarked: 187 新竹, 台灣 |
石墨(碳 Carbon) 會導電,但是電阻很大。愛迪生第一代的燈泡就是用碳當燈泡發光的電阻絲。 我們在把自動鉛筆心(石墨)接上電池,可以看到筆心變紅發熱,隔一段時間就燒掉了,因為沒有抽成真空。 |
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