The difficulties in the reconstruction of Zhang Heng’s Seismoscope come mainly from the lack of understanding of its mechanical principles. Such a discrepancy affects the rational reconstruction of the external form ...The difficulties in the reconstruction of Zhang Heng’s Seismoscope come mainly from the lack of understanding of its mechanical principles. Such a discrepancy affects the rational reconstruction of the external form of the seismoscope and the fair assessment of its position in science. In connection with the two basic conjectures on its basic principles over the past hundred years: namely, the suspended pendulum and the upright rod, the authors have conducted a comprehensive study from the viewpoint of modern seismology. In this study, various aspects are involved, such as the properties of the seismoscope, its description in the “History of the Latter Han Dynasty", the structure and movement of the central pillar, historical earthquakes in the Longxi region, earthquake intensity in Luoyang, and modern seismograms from the Luoyang seismic station. The result shows that Zhang Heng’s seismoscope works following a suspended pendulum principle; it is triggered to move by seismic Rayleigh waves; and resonance plays the role of amplification. The long-prevailing conjecture of the upright rod, which was mistakenly called the “inverted pendulum" for a time, is believed to be improper. Both theory and practice show that it cannot be used in a seismoscope and will lead to an irrational reconstruction of the external form.展开更多
Although the CTBT (Comprehensive Nuclear Test Ban Treaty) was passed in 1996, it is still necessary to develop new and highly efficient methods (Wu Zhongliang, Chen Yuntai, et al., 1993; Xu Shaoxie, et al.1994; Richar...Although the CTBT (Comprehensive Nuclear Test Ban Treaty) was passed in 1996, it is still necessary to develop new and highly efficient methods (Wu Zhongliang, Chen Yuntai, et al., 1993; Xu Shaoxie, et al.1994; Richard L. Garwin, 1994) to monitor possible events. Many discrimination criteria (Xu Shaoxie, et al.,1994; Institute of Geophysics, Chinese Academy of Sciences, 1976; Richard L. Garwin, 1994) have been put forward since the 1950s. The results show that each of the existing criteria has its own limitation, but the seismological method is an important and efficient method in the discrimination between nuclear explosion and earthquake. Especially in recent years, because of the little and little equivalent as well as the increasing hiding steps used in the test, a number of more efficient seismological methods have been worked out. In this paper, a new discrimination method, the Wavelet Packet Component Ratio (WPCR) method, is put forward. This method makes full use of the difference in variation with time between the spectra of nuclear explosions and earthquakes. Its discrimination efficiency is rather high.展开更多
文摘The difficulties in the reconstruction of Zhang Heng’s Seismoscope come mainly from the lack of understanding of its mechanical principles. Such a discrepancy affects the rational reconstruction of the external form of the seismoscope and the fair assessment of its position in science. In connection with the two basic conjectures on its basic principles over the past hundred years: namely, the suspended pendulum and the upright rod, the authors have conducted a comprehensive study from the viewpoint of modern seismology. In this study, various aspects are involved, such as the properties of the seismoscope, its description in the “History of the Latter Han Dynasty", the structure and movement of the central pillar, historical earthquakes in the Longxi region, earthquake intensity in Luoyang, and modern seismograms from the Luoyang seismic station. The result shows that Zhang Heng’s seismoscope works following a suspended pendulum principle; it is triggered to move by seismic Rayleigh waves; and resonance plays the role of amplification. The long-prevailing conjecture of the upright rod, which was mistakenly called the “inverted pendulum" for a time, is believed to be improper. Both theory and practice show that it cannot be used in a seismoscope and will lead to an irrational reconstruction of the external form.
文摘Although the CTBT (Comprehensive Nuclear Test Ban Treaty) was passed in 1996, it is still necessary to develop new and highly efficient methods (Wu Zhongliang, Chen Yuntai, et al., 1993; Xu Shaoxie, et al.1994; Richard L. Garwin, 1994) to monitor possible events. Many discrimination criteria (Xu Shaoxie, et al.,1994; Institute of Geophysics, Chinese Academy of Sciences, 1976; Richard L. Garwin, 1994) have been put forward since the 1950s. The results show that each of the existing criteria has its own limitation, but the seismological method is an important and efficient method in the discrimination between nuclear explosion and earthquake. Especially in recent years, because of the little and little equivalent as well as the increasing hiding steps used in the test, a number of more efficient seismological methods have been worked out. In this paper, a new discrimination method, the Wavelet Packet Component Ratio (WPCR) method, is put forward. This method makes full use of the difference in variation with time between the spectra of nuclear explosions and earthquakes. Its discrimination efficiency is rather high.
