czyu008:
[图片]500){this.resized=true;this.width=500;this.alt='这是一张缩略图,点击可放大。\n按住CTRL,滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}"onclick="if(!this.resized){returntrue;}else{window.open('http://u.dianyuan.com/bbs/u/43/1152935490.gif');}"onmousewheel="returnimgzoom(this);">为什么电路LM317和电阻会发热呢?