An ink stick for use in a solid ink feed system of a phase change ink jet printer includes at least first and second three dimensional ink stick body portions. Each ink stick body portion includes a perimeter section that is substantially the same as a corresponding section of a keyed insert...
回望过去,中国人民经历过沧桑巨变,但在困难面前从不低头.孙家栋说:"通过第一颗卫星,我们证明,就是我们能把卫星送上去,我们能做一颗卫星在天上生存."在那个物质匮乏,百废待兴的年代,孙家栋等老一辈航天人向世界证明了中国有能力搞航天事业.已经90岁高龄的孙家栋院士虽已获得共和国勋章,目前却还活跃在北斗卫星导航系统...