This is work generally done by a person who recently earned a PhD, or doctor of philosophy degree.

VOA: special.2009.01.15

All right, July, 1913, blow this up, so On the Constitution of Atoms and Molecules by N. Bohr, Doctor of Philosophy, Copenhagen, asterisk here, and I've blown up the bottom of the page, communicated by Professor Ernest Rutherford, F.R.S., Fellow of the Royal Society.

913年，六月，发表了，波尔博士,建立了原子分子模型，哥本哈根，星号这儿，我通过和恩内斯特卢瑟福的交流，被这页底部的所震惊了，英国皇家学会会员。

麻省理工公开课 - 固态化学导论课程节选