In order to improve the exploration effect of deep non-ferrous mineral resources, multi-channel observation methods for induced polarization （IP） electrical sounding data and their inversion imaging technology are s...In order to improve the exploration effect of deep non-ferrous mineral resources, multi-channel observation methods for induced polarization （IP） electrical sounding data and their inversion imaging technology are studied. First of all, four multi-channel observation methods are developed based on conventional IP electrical method, namely three-electrode and four-electrode arrays of unilateral and bilateral current transmitting. Then the maximum smoothness constrained inversion method of the least squares sense for IP electrical sounding data is proposed, and the inversion software is programmed. Finally, the simulation and inversion results of geo-electrical model for the proposed observation methods are analyzed. And the comparison results show that three-electrode array of bilateral current transmitting gives the best result, but the intensity in field work is larger than others; unilateral three-electrode and four-electrode arrays give the better results. Taking detection results and convenience of field exploration work into consideration, these two methods are more suitable for practical application; bilateral observation method of four-electrode array is not suitable for the detection of the steep ore bodies.展开更多
This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical sou...This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical soundings (VES) and 9 induced polarization soundings (IPS) data were acquired using Schlumberger array technique. Three aquifer units were delineated across the study area. The resistivity of the first, second and third aquifer layers varies from 0.2 to 1569 ohm-m, 0.5 to 904 ohm-m and 0.4 to 665 ohm-m respectively, while depth to the top of first, second and third aquifer varies respectively from 0.7 to 151.5 m, 1.4 to 305.5 m and 12.9 to 452.9 m. The depth to the first aquifer layer is shallow (less than 5 m) in the coastal area which makes this area to be highly vulnerable to anthropogenic pollution while their proximity to Atlantic Ocean makes them susceptible to saline water intrusion. In all the three aquifer units, the coastal area, Agbabu and other few locations in the mainland are characterized by low resistivity values (below 60 ohm-m) indicating possible presence of brackish or saline water. IP sounding results showed that all the low resistive layers in the mainland are characterized by clayey materials. The integration of VES and IPS results enabled the delineation of the saline water lateral extent across the study area. There is a strong direct correlation (r2 = 0.8564) between location distance from the saline water source and depth to saline water in the study area. This can therefore serve as a predictive model to determine depth to saline water at any location within the saline water zone in the study area.展开更多
The study of induced polarization （IP） information extraction from magnetotelluric （MT） sounding data is of great and practical significance to the exploitation of deep mineral, oil and gas resources. The linear i...The study of induced polarization （IP） information extraction from magnetotelluric （MT） sounding data is of great and practical significance to the exploitation of deep mineral, oil and gas resources. The linear inversion method, which has been given priority in previous research on the IP information extraction method, has three main problems as follows： 1） dependency on the initial model, 2） easily falling into the local minimum, and 3） serious non-uniqueness of solutions. Taking the nonlinearity and nonconvexity of IP information extraction into consideration, a two-stage CO-PSO minimum structure inversion method using compute unified distributed architecture （CUDA） is proposed. On one hand, a novel Cauchy oscillation particle swarm optimization （CO-PSO） algorithm is applied to extract nonlinear IP information from MT sounding data, which is implemented as a parallel algorithm within CUDA computing architecture; on the other hand, the impact of the polarizability on the observation data is strengthened by introducing a second stage inversion process, and the regularization parameter is applied in the fitness function of PSO algorithm to solve the problem of multi-solution in inversion. The inversion simulation results of polarization layers in different strata of various geoelectric models show that the smooth models of resistivity and IP parameters can be obtained by the proposed algorithm, the results of which are relatively stable and accurate. The experiment results added with noise indicate that this method is robust to Gaussian white noise. Compared with the traditional PSO and GA algorithm, the proposed algorithm has more efficiency and better inversion results.展开更多
[Objectives]The paper was to analyze the acoustic characteristics of Ips grandicollis larvae by pest acoustic detection technology,and to provide some reference for quarantine identification of pest larvae at ports.[M...[Objectives]The paper was to analyze the acoustic characteristics of Ips grandicollis larvae by pest acoustic detection technology,and to provide some reference for quarantine identification of pest larvae at ports.[Methods]The trial was performed in a self-invented insect sound recording container with good sound insulation effect.I.grandicollis larvae were placed separately on split P.ponderosa logs to observe and record the activities of larvae.AED-2010 was used for signal acquisition and SP-1 probe was used to collect signals at a distance of 5 cm from the larvae.The activity signals of larvae were intercepted,and the signal de-noising was further processed by Goldwave software.Finally,the acoustic signals were carried out correlation analysis by using MATLAB toolbox.[Results]I.grandicollis larvae had more regular feeding acoustic signal characteristics than crawling acoustic signal characteristics,and the two types of acoustic signal characteristics were quite different.The duration of feeding acoustic signal pulse of I.grandicollis larvae was 50-85 ms,the frequency was less than 1 KHz,and the signal frequency was mainly distributed in the range of 510.00-620.20 Hz.There was no obvious law in time domain features of larval crawling acoustic signals and the signal frequency was low,which was below 0.6 KHz and was mainly distributed in the range of 258.00-530.00 Hz.[Conclusions]It is feasible to carry out quarantine identification of I.grandicollis larvae by using feeding acoustic signals.It is suggested to select the feeding acoustic signals with obvious characteristics in the sound monitoring and identification of pests.展开更多
基金Project(41174102)supported by the National Natural Science Foundation of China
文摘In order to improve the exploration effect of deep non-ferrous mineral resources, multi-channel observation methods for induced polarization （IP） electrical sounding data and their inversion imaging technology are studied. First of all, four multi-channel observation methods are developed based on conventional IP electrical method, namely three-electrode and four-electrode arrays of unilateral and bilateral current transmitting. Then the maximum smoothness constrained inversion method of the least squares sense for IP electrical sounding data is proposed, and the inversion software is programmed. Finally, the simulation and inversion results of geo-electrical model for the proposed observation methods are analyzed. And the comparison results show that three-electrode array of bilateral current transmitting gives the best result, but the intensity in field work is larger than others; unilateral three-electrode and four-electrode arrays give the better results. Taking detection results and convenience of field exploration work into consideration, these two methods are more suitable for practical application; bilateral observation method of four-electrode array is not suitable for the detection of the steep ore bodies.
文摘This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical soundings (VES) and 9 induced polarization soundings (IPS) data were acquired using Schlumberger array technique. Three aquifer units were delineated across the study area. The resistivity of the first, second and third aquifer layers varies from 0.2 to 1569 ohm-m, 0.5 to 904 ohm-m and 0.4 to 665 ohm-m respectively, while depth to the top of first, second and third aquifer varies respectively from 0.7 to 151.5 m, 1.4 to 305.5 m and 12.9 to 452.9 m. The depth to the first aquifer layer is shallow (less than 5 m) in the coastal area which makes this area to be highly vulnerable to anthropogenic pollution while their proximity to Atlantic Ocean makes them susceptible to saline water intrusion. In all the three aquifer units, the coastal area, Agbabu and other few locations in the mainland are characterized by low resistivity values (below 60 ohm-m) indicating possible presence of brackish or saline water. IP sounding results showed that all the low resistive layers in the mainland are characterized by clayey materials. The integration of VES and IPS results enabled the delineation of the saline water lateral extent across the study area. There is a strong direct correlation (r2 = 0.8564) between location distance from the saline water source and depth to saline water in the study area. This can therefore serve as a predictive model to determine depth to saline water at any location within the saline water zone in the study area.
基金Projects(41604117,41204054)supported by the National Natural Science Foundation of ChinaProjects(20110490149,2015M580700)supported by the Research Fund for the Doctoral Program of Higher Education,China+1 种基金Project(2015zzts064)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(16B147)supported by the Scientific Research Fund of Hunan Provincial Education Department,China
文摘The study of induced polarization （IP） information extraction from magnetotelluric （MT） sounding data is of great and practical significance to the exploitation of deep mineral, oil and gas resources. The linear inversion method, which has been given priority in previous research on the IP information extraction method, has three main problems as follows： 1） dependency on the initial model, 2） easily falling into the local minimum, and 3） serious non-uniqueness of solutions. Taking the nonlinearity and nonconvexity of IP information extraction into consideration, a two-stage CO-PSO minimum structure inversion method using compute unified distributed architecture （CUDA） is proposed. On one hand, a novel Cauchy oscillation particle swarm optimization （CO-PSO） algorithm is applied to extract nonlinear IP information from MT sounding data, which is implemented as a parallel algorithm within CUDA computing architecture; on the other hand, the impact of the polarizability on the observation data is strengthened by introducing a second stage inversion process, and the regularization parameter is applied in the fitness function of PSO algorithm to solve the problem of multi-solution in inversion. The inversion simulation results of polarization layers in different strata of various geoelectric models show that the smooth models of resistivity and IP parameters can be obtained by the proposed algorithm, the results of which are relatively stable and accurate. The experiment results added with noise indicate that this method is robust to Gaussian white noise. Compared with the traditional PSO and GA algorithm, the proposed algorithm has more efficiency and better inversion results.
基金Supported by Project of Lianyungang Science and Technology Association(Lkxqt2125)。
文摘[Objectives]The paper was to analyze the acoustic characteristics of Ips grandicollis larvae by pest acoustic detection technology,and to provide some reference for quarantine identification of pest larvae at ports.[Methods]The trial was performed in a self-invented insect sound recording container with good sound insulation effect.I.grandicollis larvae were placed separately on split P.ponderosa logs to observe and record the activities of larvae.AED-2010 was used for signal acquisition and SP-1 probe was used to collect signals at a distance of 5 cm from the larvae.The activity signals of larvae were intercepted,and the signal de-noising was further processed by Goldwave software.Finally,the acoustic signals were carried out correlation analysis by using MATLAB toolbox.[Results]I.grandicollis larvae had more regular feeding acoustic signal characteristics than crawling acoustic signal characteristics,and the two types of acoustic signal characteristics were quite different.The duration of feeding acoustic signal pulse of I.grandicollis larvae was 50-85 ms,the frequency was less than 1 KHz,and the signal frequency was mainly distributed in the range of 510.00-620.20 Hz.There was no obvious law in time domain features of larval crawling acoustic signals and the signal frequency was low,which was below 0.6 KHz and was mainly distributed in the range of 258.00-530.00 Hz.[Conclusions]It is feasible to carry out quarantine identification of I.grandicollis larvae by using feeding acoustic signals.It is suggested to select the feeding acoustic signals with obvious characteristics in the sound monitoring and identification of pests.
