BlogHide Resteemsapocalypse1 (26)in cn • 9 months ago圆珠笔的发展历程简单的圆珠笔涉及到的物理原理可不少，它的内部其核心部件是笔尖的金属球，这个直径约1毫米的小球通常由不锈钢、钨合金等材料制成，表面经过精密抛光能在笔尖内腔中自如滚动。 当我们书写时，小球在纸面和笔尖间旋转，不断从墨水储存器中带出墨水，均匀地涂抹在纸面上形成流畅美观的字迹， 但这时出现了一个问题，圆珠笔的钢珠如果太紧墨水就会堵住而写不出字，如果太松墨水就会漏出而弄脏纸张，…apocalypse1 (26)in cn • 9 months agoHow to make yourself betterFirst of all, we have to learn self-discipline and defeat procrastination. Daily Goals: Make goals for yourself in advance every day, and then follow the goal list. If there is no goal or focus…
