There are three aspects in the study of GPS meteorology network in the Wuhan region. The first is the comparison of the GPS precipitable water vapor between final ephemeris and ultra-rapid ephemeris for which the rela...There are three aspects in the study of GPS meteorology network in the Wuhan region. The first is the comparison of the GPS precipitable water vapor between final ephemeris and ultra-rapid ephemeris for which the relative coefficient is 99.97 and the root mean squares is 0.048 mm. It can be concluded that ultra-rapid ephemeris can be used to get the GPS precipitable water vapor for the real-time prediction. The second is the comparison of precipitable water vapor of GPS stations and the distribution of water vapor in the Wuhan region is acquired. The change of GPS precipitable water vapor and rainfall in a rainfall process are compared and analyzed. The change of GPS precipitable water vapor can reflect and predict the process of rainfall.展开更多
The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. A...The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. Among all, the control of ground deformations and variations in sea level has considerable importance. Time series of ground deformation and tidal data in this area have been analysed to highlight these important geophysical features and these results are compared with those obtained from similar data in other time periods. With regard to first mentioned, tiltmetric data have been analysed. These ones come from the tiltmeter network sited in Pozzuoli. Instead, the tidal data come from the tide gauge in Pozzuoli. Data have been analysed by means of a wavelet approach, using a Continuos Wavelet Transform and using, as so-called ＂Wavelet Mother＂, a Gabor-Morlet wavelet. For each time series, the principal harmonic constituents result： lunar semidiurnal （M2）, solar semidiumal （S2） and lunar diurnal （K1）. Other harmonic constituents, having frequencies higher than 1/hour, are present.These last ones could be interpreted as seiches and they could be linked up with generation of discrete plumes of rising magma. Frequencies at which there is the occurrence of these seiches are in agreement with previous studies.展开更多
This paper reports some results of geoscientific investigations of the shallow subsurface beneath the Nazca geoglyphs in the stone desert in southern Peru. A resistivity and georadar survey was accompanied by soil sam...This paper reports some results of geoscientific investigations of the shallow subsurface beneath the Nazca geoglyphs in the stone desert in southern Peru. A resistivity and georadar survey was accompanied by soil sampling at a test site in the Palpa district. The resulting images of the two geophysical methods indicate similar structures. Georadar enables a fast and continuous data acquisition but is restricted in its depth of penetration. Despite the dry surface conditions, the electrical method yielded good results in the desert area. The resulting resistivity images for both vertical and horizontal slices provide structural information that might be interpreted in terms of lithology and water content. A promising correlation between sulfate content and electrical resistivity at shallow depth was observed that might be helpful to provide insight into the migration of chemical constituents. The approach to combine geophysical, mineralogical and geochemical methods proves to be successful to extend the knowledge on the weathering processes in the desert soil.展开更多
In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, ...In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, within the framework of the classical discontinuous deformation analysis(DDA) method, the formulation of three-dimensional spherical DDA(3D SDDA) is deduced; secondly, a bonding and cracking algorithm is constructed and the SDDARF3 D model is proposed; thirdly, corresponding VC++ calculation code is developed and some verification examples are calculated. The simulated results can intuitively reproduce the failure phenomena of rock mass, indicating that the proposed SDDARF3 D numerical model is correct and effective.展开更多
In this paper, we discuss the convergence of the Broyden algorithms withrevised search direction. Under some inexact line searches, we prove that the algorithms areglobally convergent for continuously differentiable f...In this paper, we discuss the convergence of the Broyden algorithms withrevised search direction. Under some inexact line searches, we prove that the algorithms areglobally convergent for continuously differentiable functions and the rate of convergence of thealgorithms is one-step superlinear and n-step second-order for uniformly convex objective functions.展开更多
基金Supported by the National Natural Science Foundation of China （No.NSFC40574009）.
文摘There are three aspects in the study of GPS meteorology network in the Wuhan region. The first is the comparison of the GPS precipitable water vapor between final ephemeris and ultra-rapid ephemeris for which the relative coefficient is 99.97 and the root mean squares is 0.048 mm. It can be concluded that ultra-rapid ephemeris can be used to get the GPS precipitable water vapor for the real-time prediction. The second is the comparison of precipitable water vapor of GPS stations and the distribution of water vapor in the Wuhan region is acquired. The change of GPS precipitable water vapor and rainfall in a rainfall process are compared and analyzed. The change of GPS precipitable water vapor can reflect and predict the process of rainfall.
文摘The Phlegrean Fields are an area in the west of Naples （Italy）, with a huge interest in geophysical community being a volcanic caldera among the most dangerous in the world. Various techniques of monitoring exist. Among all, the control of ground deformations and variations in sea level has considerable importance. Time series of ground deformation and tidal data in this area have been analysed to highlight these important geophysical features and these results are compared with those obtained from similar data in other time periods. With regard to first mentioned, tiltmetric data have been analysed. These ones come from the tiltmeter network sited in Pozzuoli. Instead, the tidal data come from the tide gauge in Pozzuoli. Data have been analysed by means of a wavelet approach, using a Continuos Wavelet Transform and using, as so-called ＂Wavelet Mother＂, a Gabor-Morlet wavelet. For each time series, the principal harmonic constituents result： lunar semidiurnal （M2）, solar semidiumal （S2） and lunar diurnal （K1）. Other harmonic constituents, having frequencies higher than 1/hour, are present.These last ones could be interpreted as seiches and they could be linked up with generation of discrete plumes of rising magma. Frequencies at which there is the occurrence of these seiches are in agreement with previous studies.
文摘This paper reports some results of geoscientific investigations of the shallow subsurface beneath the Nazca geoglyphs in the stone desert in southern Peru. A resistivity and georadar survey was accompanied by soil sampling at a test site in the Palpa district. The resulting images of the two geophysical methods indicate similar structures. Georadar enables a fast and continuous data acquisition but is restricted in its depth of penetration. Despite the dry surface conditions, the electrical method yielded good results in the desert area. The resulting resistivity images for both vertical and horizontal slices provide structural information that might be interpreted in terms of lithology and water content. A promising correlation between sulfate content and electrical resistivity at shallow depth was observed that might be helpful to provide insight into the migration of chemical constituents. The approach to combine geophysical, mineralogical and geochemical methods proves to be successful to extend the knowledge on the weathering processes in the desert soil.
基金supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.KZZD-EW-05-03)the National Basic Research Program of China("973"Project)(Grant No.2011CB710602)the National Natural Science Foundation of China(Grant Nos.51139004&40972201)
文摘In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, within the framework of the classical discontinuous deformation analysis(DDA) method, the formulation of three-dimensional spherical DDA(3D SDDA) is deduced; secondly, a bonding and cracking algorithm is constructed and the SDDARF3 D model is proposed; thirdly, corresponding VC++ calculation code is developed and some verification examples are calculated. The simulated results can intuitively reproduce the failure phenomena of rock mass, indicating that the proposed SDDARF3 D numerical model is correct and effective.
基金This research is supported by Ministry of Education P. R. C.
文摘In this paper, we discuss the convergence of the Broyden algorithms withrevised search direction. Under some inexact line searches, we prove that the algorithms areglobally convergent for continuously differentiable functions and the rate of convergence of thealgorithms is one-step superlinear and n-step second-order for uniformly convex objective functions.
