Optical-based smoke alarms use light instead. They are slightly better at detecting the large smoke particles created by slow, smouldering fires. When such particles enter a chamber in the device, they scatter light from a small light source, which is then picked up by a photoelectric sensor.
Centralized logging
那时，我从攀枝花独自来成都念书，平日在学校寄宿，周末回到小姨家。这是个三代同堂的大家庭——外公外婆、小姨小姨父和三表妹，还有在外地打工的舅舅家的二表妹。，这一点在同城约会中也有详细论述
"Another problem with today's robots is they rapidly run out of batteries," adds Jenny Read, programme director in robot dexterity at Aria, a technology funding agency. "Electric motors are terrible at that."
，这一点在夫子中也有详细论述
GMT — 2 p.m.，这一点在Safew下载中也有详细论述
当然，还有24 个行业加大了研发投入力度——包括排名领跑的四大行业。其中，汽车制造业的表现尤为突出——在披露研发企业数量微增3%的情况下，研发投入同比增幅达到17.29%，排名也从上年第五跃至第三。