美国科学60秒-SSS 2015-06-25（在线收听）

 Smartphones' battery down to 10 percent. Time to turn down the brightness on the screen. Right? It's a classic strategy to squeeze more juice from the battery and it works. But that trick might be less effective than you think, cause it turns out nearly half the battery drain on the phone happens when the screens not even on. So says the study presented at the meeting of Association for Computing Machinery in Portland O. Researchers eves the job on the activity of more than 1500 Android phones, specifically, the Samsung Galaxy S3 and S4. And they use an app they developed called 'East Star Energy Saver'. The app logs the energy drain of the phone's absent activities as they happen. And you can try out this star energy savor yourself if you have an Android. They found that some 45 percent of the battery drain happened while the screen was off and allow that energy suck was apps updating in the background, downloading headlines and weather while you are not actively using them. And different versions of the same app require different energy supplies. For instance, some versions of the Facebook app were twice energy thirsty as other versions, so app version choice could slow your battery drain. But one of the most hidden energy draws that happen in 12 percent of the battery was just secular pager, that pin from shelter hour every 1.28 seconds that tell your phone if a call or a text is on the way, which was ultimately the price of being connected.