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为了研究地震电磁辐射前兆信号不同步现象的物理机制，我们对岩样施加双轴压力，使岩样产生剪切破裂和摩擦滑动，以模拟地震孕震区构造断裂带的活动．在断裂缝周围放置各类频率的天线，采用自动快速连续观测系统，记录各类岩样在剪切破裂和滑动摩擦过程中不同方位、不同频率的电磁辐射和声发射信号．实验结果表明：①岩样在双轴压力作用下发生剪切破裂和滑动摩擦过程中出现大量的电磁信号，信号的频率从几百赫兹～几千赫兹；②不同方位、不同频率的天线接收的信号到时不同步、信号幅度也有差异，位于裂缝处的天线接收的信号最大；③电信号和磁信号不同步出现，其中电信号出现的频率次数多，而且幅度大．笔者认为，产生电信号（Ｅ）和磁信号（Ｍ）的机理不同．岩样内部的电信号是由于岩石晶体的压电效应和破裂的新生表面的净电荷产生的，而磁信号是岩石带电碎片的高速运动和岩石破裂时向外发射电子激励周围空气电离产生．分析几次中强地震的电磁前兆信号，也存在电和磁信号的不同步现象，而且电信号早于磁信号．如果同一个台站同时观测电场（地下）和磁场（大气），能有效提高地震预报的效能．
In order to study the physical mechanism of the unsynchronized phenomenon of seismic precursors of electromagnetic radiation, we apply biaxial pressure to the rock samples to cause shear fractures and frictional slips in the rock samples to simulate the activities of the fault zones in the seismic seismogenic zone. Antennas of various frequencies are placed around the fracture. An automatic rapid continuous observation system is used to record the electromagnetic radiation and acoustic emission signals of different azimuths and frequencies at various fractures in the process of shear fracture and sliding friction. The experimental results show that: (1) A large number of electromagnetic signals appear during the shear fracture and sliding friction of rock specimens under biaxial pressure. The frequencies of the signals range from a few hundred hertz to several thousands of hertz. (2) The frequencies received by antennas with different azimuths and frequencies Signal is not synchronized, the signal amplitude is also different, the antenna located in the crack at the maximum signal received; ③ electrical signals and magnetic signals do not appear simultaneously, where the frequency of electrical signals appear more frequently, and the magnitude of large. The author believes that the electrical signal (E) and magnetic signal (M) mechanism is different. The electrical signal inside the rock sample is due to the piezoelectric effect of the rock crystal and the net charge of the ruptured nascent surface, while the magnetic signal is generated by the high-velocity motion of charged rock fragments and the ionization of the surrounding air by outward-emitting electron excitations when the rock ruptures. After analyzing several electromagnetic precursors of moderately strong earthquakes, there is also the phenomenon that electrical and magnetic signals are not synchronized, and the electrical signals are earlier than the magnetic signals. If the same station simultaneously observes electric field (underground) and magnetic field (atmosphere), the effectiveness of earthquake prediction can be effectively improved.