However, it is unclear whether these positrons can escape from the stellar debris in sufficient quantity to explain the size of the observed cloud.
然而，尚不清楚是否有足够数量的正电子能够逃离恒星残骸以解释观察得到云团的大小。
2
With the field model, the electrostatic field distribution were observed and the magnitude of the charged quantity is determined by electron holography.
采用这个模型，能用电子全息法观测由该点电荷所形成的静电场分布及荷电量的大小。
3
A number of studies have observed that a product's production costs decline by some quantity about each time cumulative output doubles.