In late December of 1991, observation of three component geomagnetic short period variations was carried out in Chengmai county of Hainan province, along a short measurement profile with small spatial intervals of d...In late December of 1991, observation of three component geomagnetic short period variations was carried out in Chengmai county of Hainan province, along a short measurement profile with small spatial intervals of detection points. Within the period range of 20 s to 500 s, we have discovered that the vertical variations are basically correlated with the horizontal variations in north direction in all measurement points, the real parts of complex transfer functions demonstrate that an asymmetric spatial variation of short wavelength superimposed on regional monotonic tendencious spatial variation. Inversion of the observed data along the small profile was carried out by using the invention method of generalized inverse matrix of finite element forward calculation for the electromagnetic induction of the 2 D conductivity model to investigate the conductivity structure of the profile. We conclude that the anomaly of geomagnetic short periodic variation in the small area originated from the Wangwu Wenjiao fault in the northern part of Hainan island .展开更多
A measuring profile was set up in both sides of the Qiongzhou strait to carry out the simultaneous observation of three component geomagnetic variation. The observed synchronous geomagnetic vertical variations of shor...A measuring profile was set up in both sides of the Qiongzhou strait to carry out the simultaneous observation of three component geomagnetic variation. The observed synchronous geomagnetic vertical variations of short periods were reversed on the both sides of the strait. It means that there is a abnormal concentration of electric current in the area. Spatial wave number domain analysis was performed by Sompi spectral analysis for the spatial distribution and the internal and the external parts of the geomagnetic variation field were separated. Inversion of the internal field was carried out by generalized inverse matrix inversion based on singular value decomposition and the distribution of undergrond current density was obtained. The discussion suggests that this abnormal current concentration comes from current channelling effect in the Quaternary sediment in this region.展开更多
The U-matrlx theory in quantum mechanics recently developed has been appliedto study a superconductor system described by the BCS pairing Hamiltonian . It is shown that in general the -operator in our theory specifies...The U-matrlx theory in quantum mechanics recently developed has been appliedto study a superconductor system described by the BCS pairing Hamiltonian . It is shown that in general the -operator in our theory specifies a canonical transformation. Using the to describe the system, it is proved that if the Hartrec type approximation is adopted, or the c-number approach is used, the Bogoliubov transformation can be derived via the U-matrix theory if the perturbing Hamiltonian is turned on ’suddenly’. It is also shown that based on the U-matrix, the BCS ground state wave function of a superconducting system can be deduced under the sudden switching condition.展开更多
The monthly means of north component X of geomagnetic field from 16 observatories during 1984-1988 were analyzed using the Sompi spectral analysis technique. Most of these observatories are located in China. The analy...The monthly means of north component X of geomagnetic field from 16 observatories during 1984-1988 were analyzed using the Sompi spectral analysis technique. Most of these observatories are located in China. The analysis of the semiannual variations indicates that the latitude has no apparent effect on the X component. This clearly implies that the source field mode of semiannual variations cannot simply be described by using the P°1 mode. Using the P°1 mode to estimate the inductive scale length C in the semiannual period, the value of C at each observatory would be biased significantly. The purpose of this study is to find which kind of modes is optimal for estimating the values of C corresponding to the semiannual variations. The results show that a composite mode, involving five terms P°n(n = 1,....,5), might be a reasonable and acceptable one.展开更多
基金sponsored by the Quality Education Fund,Hong Kong,bearing the project title'Utitlisation of Neuro-cognitive Science for the Improvement of Language Education in Hong Kong',participated by staff of four institutions:the Chinese University of Hong Kong,University of Hong Kong,City University of Hong Kong,Polytechnic University of Hong Kongsponsored by the Department of Medicine,University of Hong Kongsponsored by the Electrical and Electronic Engineering Department,University of Hong Kong
文摘In late December of 1991, observation of three component geomagnetic short period variations was carried out in Chengmai county of Hainan province, along a short measurement profile with small spatial intervals of detection points. Within the period range of 20 s to 500 s, we have discovered that the vertical variations are basically correlated with the horizontal variations in north direction in all measurement points, the real parts of complex transfer functions demonstrate that an asymmetric spatial variation of short wavelength superimposed on regional monotonic tendencious spatial variation. Inversion of the observed data along the small profile was carried out by using the invention method of generalized inverse matrix of finite element forward calculation for the electromagnetic induction of the 2 D conductivity model to investigate the conductivity structure of the profile. We conclude that the anomaly of geomagnetic short periodic variation in the small area originated from the Wangwu Wenjiao fault in the northern part of Hainan island .
文摘A measuring profile was set up in both sides of the Qiongzhou strait to carry out the simultaneous observation of three component geomagnetic variation. The observed synchronous geomagnetic vertical variations of short periods were reversed on the both sides of the strait. It means that there is a abnormal concentration of electric current in the area. Spatial wave number domain analysis was performed by Sompi spectral analysis for the spatial distribution and the internal and the external parts of the geomagnetic variation field were separated. Inversion of the internal field was carried out by generalized inverse matrix inversion based on singular value decomposition and the distribution of undergrond current density was obtained. The discussion suggests that this abnormal current concentration comes from current channelling effect in the Quaternary sediment in this region.
文摘The U-matrlx theory in quantum mechanics recently developed has been appliedto study a superconductor system described by the BCS pairing Hamiltonian . It is shown that in general the -operator in our theory specifies a canonical transformation. Using the to describe the system, it is proved that if the Hartrec type approximation is adopted, or the c-number approach is used, the Bogoliubov transformation can be derived via the U-matrix theory if the perturbing Hamiltonian is turned on ’suddenly’. It is also shown that based on the U-matrix, the BCS ground state wave function of a superconducting system can be deduced under the sudden switching condition.
文摘The monthly means of north component X of geomagnetic field from 16 observatories during 1984-1988 were analyzed using the Sompi spectral analysis technique. Most of these observatories are located in China. The analysis of the semiannual variations indicates that the latitude has no apparent effect on the X component. This clearly implies that the source field mode of semiannual variations cannot simply be described by using the P°1 mode. Using the P°1 mode to estimate the inductive scale length C in the semiannual period, the value of C at each observatory would be biased significantly. The purpose of this study is to find which kind of modes is optimal for estimating the values of C corresponding to the semiannual variations. The results show that a composite mode, involving five terms P°n(n = 1,....,5), might be a reasonable and acceptable one.
