It was a very difficult first step to accept the positron .

接受正电子是艰难的第一步。

Some of these gamma rays pass near atomic nuclei , in the process transforming into an electron and a positron , researchers said .

某些伽马射线在靠近原子核的附近经过，进入到转化为个电子和正电子的过程，研究人员说。

The result is that the electron shadow and the positron shadow are separated .

这样的结果就是电子带和正电子带将被分开。

Positron and electron ( particle and anti-particle ) can annihilate in collision turning into electromagnetic radiation .

正电子和电子（粒子和反粒子）在对撞中会发生湮灭，并产生电磁辐射。

Pet , or positron emission tomography , is an imaging study that allows doctors to evaluate the use of certain substances by the brain .

pet，即正电子放射断层摄影术，是一项成像研究，它能使医生评价大脑对某些物质的使用。