变中子源 fission neutrons: 核分裂中子; 裂变中子fission product of neutrons: 裂变时的中子释放neutrons per fission: 每次裂变所放出的中子数neutrons yield per fission: 每次裂变后的中子产额infinite plane source of neutrons: 中子无限平面源下载手机词典可随时随地查词查翻译