Whenever possible, use the speaker-phone mode or a wireless Bluetooth headset, which has less than 1/100th of the electromagnetic emission of a normal cell phone.
可能的话，尽量使用扬声器模式或者无线蓝牙耳机，它将会小于标准手机辐射的百分之一。
2
Nanometer scale semiconductor materials have been studied extensively in recent years because of their important applications in photovoltaic cell, sensing, optical emission and photocatalysis.