Beside having similar properties to mollusc shell nuclei, the new pearl nuclei possess some advantages such as white color, strong luster, round shape and cheap cost.

这种珠核物化性质与现有贝、蚌壳珠核相近，具有颜色白、光泽强、外形圆和价格低廉等特点。

youdao

Under the laws of quantum mechanics, the nuclei of atoms have shell-like structures analogous to the spheres in which given numbers of electrons exist in certain orbits around the nucleus.

ECONOMIST: Nuclear physics