The antielectron , or positron , was discovered in 1932 反电子或正电子,是在1932年被发现。
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And then , metal structure with aspect ratio 30 was obtained in our laboratory . eventually , a few micro parts with high aspect ratio were fabricated by liga process under the optimum condition . there were key parts of micro thruster , netlike nickel antielectron modulator , micro copper radiator , stainless steel micro components and many filter mediums with different shapes and dimensions 最后，我们利用liga技术加工的独特优点，以发展其高深宽比技术的实际应用，先后制作了狭缝阵列镍结构微推进器关键部件、薄壁网状多孔镍结构正电子慢化体、微型铜结构换热气和多种材料不同、尺寸各异的过滤介质，还结合利用liga技术和微细电火花技术的加工优点，制作出了不锈钢微结构
