Airy disk brilliance (the brightness of a point-source stellar image) is proportional to the fourth power of aperture.
艾里斑的亮度(点光源恒星的图像亮度)正比于孔径尺寸的四次方。
2
With a large, bright screen and inability to remove the battery in the iPhone 4, getting a secondary powersource is inevitable if you can't guarantee a powerpoint on your travels.
旅行时没法充电，iPhone 4屏幕硕大闪亮，再加上内置电池无法取出，是时候准备一个备用电源了。
3
To set up a sync point coincide with a natural commutation point in OTC products, and will be able to improve reliability and stability of the phase shifting trigger and output of the powersource.