优彩
<tr id='r3tmgS'><strong id='r3tmgS'></strong><small id='r3tmgS'></small><button id='r3tmgS'></button><li id='r3tmgS'><noscript id='r3tmgS'><big id='r3tmgS'></big><dt id='r3tmgS'></dt></noscript></li></tr><ol id='r3tmgS'><option id='r3tmgS'><table id='r3tmgS'><blockquote id='r3tmgS'><tbody id='r3tmgS'></tbody></blockquote></table></option></ol><u id='r3tmgS'></u><kbd id='r3tmgS'><kbd id='r3tmgS'></kbd></kbd>
数据采集直观准确，并具有内测和外测二种功能，无需另配电源和仪表即可开设四组实验。
1、电子束的电偏转 2、电子束的电聚焦
3、电子束的磁偏①转 4、电子束的磁聚焦
