In order to absolutely measure the radioactivity of β-γ decay radionuclides, we have developed a calculation software for 4πβ-γ coincidence counting. The combination of software and hardware systems constitutes an absolute radioactivity measurement system. The hardware uses a NaI (Tl) γ-ray detector and 4πβ proportional counter as front detectors. The software uses a 4πβ-γ coincidence efficiency e...Show More
In order to prospect deep geological structure, low natural frequency geophone is needed. Traditionally, low natural frequency (less than 10Hz) of geophone is acquired by increasing its volume of coil or magnetic body. But that makes it too heavy to be widely used in oil seismic exploration. This manuscript introduces a new method to broaden the low frequency of geophone without changing its struc...Show More
