美国科学60秒-SSS 2015-06-26（在线收听）

  Smart phone battery down to ten percent?Time to turn down the brightness on the screen. Right? It's a classic strategy to squize more dues from the battery, and it works. But that trick might be less effetive than you think because it turns out nearly half of the battery drain on the phone happens when the screen is not even on, so says a study presented at a meeting of the Association For Computer Machinery in ?. Researchers eavesdroped on the activities of more than fifteen hundred android phones, specifically Samsang Galaxy S3 and S4. And they used an app they developed called the Eastar Energy Saver. The app logged the energy drain of the phones' absent activities as they happened.And you can try out the energy saver yourself if you have an android. They found about some forty-five percent of the battery drain happened while the screen was off, and a lot of energy suck was apps updating in the background, downloading headlines and weather while you are not actively using it. And different versions of the same app requires different energy supplies, for instance some versions of the facebook app were twice energy thirsty as other versions. So app version choice could slow down your battery drain. But one of the most heated energy draws, it's twelf percent of the battery was just cellular paging, the pins from a sout hour every 1.2 seconds. It tells your phone if a call or text is on the way, which is ultimately the price of being connected.