锕类任何化学性质相似, 原子序数在89 ( 锕 ) 与103 ( 铹 ) 之间变化的放射性元素. Any of a series of chemically similar, radioactive elements with atomic numbers ranging from 89 ( actinium ) through 103 ( lawrencium ).
在所有的实验室里测量质量的工具是砝码和天平.Scales and balances are the tools of mass measurementin all laboratories.需要一套经过校准的砝码.A set of calibrated weights will be needed.对于小模型,可用装满铅丸的容器作为砝码.For small models we can use as weights containers ...
This gaseous impurity is able to bring about metal corrosion and contaminating.这些气相杂质的存在会造成金属材料腐蚀,并污染环境.Untrammelled industrialisation, particularly in poor countries, is contaminating rivers and aquifers.不节制的工业化, 尤其是在穷国...
Aim To probe the effects of lamellar keratoplasty implantation and epithelium of limbus implantation for pterygium.目的探讨板层角膜移植联合角膜缘上皮移植术治疗翼状胬肉的疗效.The epithelium of the smaller bronchi was fragmented and partially desquama...