But the acquisition of radioactive material for a so-called 'dirty bomb,' which is radioactive material that is dispersed with a conventional explosive device, that is not that challenging.

VOA: standard.2009.05.01

So with the problems, that is where you really will get your hands dirty and truly immerse yourself in this world of computer science and programming.

带着这些问题，你就能深入研究,这真的可以使你沉浸到计算机科学,和编程世界中。

哈佛公开课 - 计算机科学课程节选

As I said at the beginning, in the philosophical literature, this has become known as the problem of dirty hands so named after a famous play written by the French philosopher Jean-Paul Sartre.

正如我一开始所说的，在哲学作品中,这已经作为脏手问题而闻名,自从法国哲学家萨特写下,一部非常有名的戏剧之后。

耶鲁公开课 - 政治哲学导论课程节选

Experts say terrorist groups are seeking materials for a crude nuclear device - a so-called "dirty bomb" - that would have limited blast potential but could spread radiation in a major urban area.

VOA: standard.2010.04.11

It goes out to the outside world, interacts,gets its hand and mind dirty, does work outside and then applies its work and learns from "the dirty experiences" and brings it back to the lab and so on and so on in an upward spiral.

而是走到外面的世界，与外界互动，接触那些“肮脏“事物，在外面工作，并吸取经验,从“肮脏经验“中学习“,将得到的经验带回实验室,诸如此类，就像一个上升的螺旋。

哈佛公开课 - 幸福课课程节选