You start with the square of an electron's charge, divide it by the speed of light and Planck's constant, then multiply the whole lot by two PI.

一开始将电子电荷平方，再除以光速和普朗克常数，然后将总数乘以2个圆周率。

youdao

The angle actually goes from minus pi over two to pi over two.

实际上，角度取值范围是从-π/2到π

youdao

Two years ago, Tammet became famous for reciting pi to 22, 514 decimal places with the same ease that the rest of us can reel off 3.142.

两年前，Tammet因为背诵 π 至小数点后22514位而出名，而且他背起来就像我们背到3.142那么容易。

youdao

So, what we end up having is three of these pi -- 2 p y 2 p y bonds, we can have one between these two carbons here.

我们剩下的有三个π键-,2py2py键，在这两个碳原子之间会有一个。

麻省理工公开课 - 化学原理课程节选

The two-month long competition was run by the foundation behind the Raspberry Pi and intended to find the best young programmers working with the bare-bones computer.

BBC: Time-lapse code wins Raspberry Pi contest

Ang Lee's 3D epic Life of Pi - which went into the awards with nine nominations - picked up two awards for cinematography and special visual effects.

BBC: Baftas: Argo wins best film award

After two years of building and tweaking, the folks at Party Robotics have finally polished their Raspberry Pi-powered cocktail-making rig and have posted it to Kickstarter.

ENGADGET