英语翻译材料化学方面的 Briefly the catalyst charge was ca.2 g with an a

英语翻译
材料化学方面的 Briefly the catalyst charge was ca.2 g with an average particle size from 16 to 32 mesh.这句话盖怎么翻译,谁能帮下.
原段落是 The catalysts were tested in a fixed-bed flow microreactor.Briefly the catalyst charge was ca.2 g with an average particle size from 16 to 32 mesh.The catalyst was activated for 1 h at 550 ◦Cunder nitrogen and then cooled in nitrogen to the reaction temperature.Catalytic tests were carried out at 120 ◦C under 1MPa.The reaction products were analyzed by a GC-8A gas chromatograph with an FID detector.The conversion of ethylene and 2-butylene was calculated on the basis of carbon number.