Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a ...Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.展开更多
Marine controlled source electromagnetic signal could be used in mineral resource exploration,reservoir appraisal and communicative technique in ocean. It's necessary to study the electromagnetic generated by MCSE...Marine controlled source electromagnetic signal could be used in mineral resource exploration,reservoir appraisal and communicative technique in ocean. It's necessary to study the electromagnetic generated by MCSEM. The propagation of the electromagnetic fields from a controlled source in the marine environment was studied with virtual interface method combined with discrete complex image method. Transmitter of finite length current source is approximated by dipole (HED) . A three-layered model is accepted,with sea water as intermediate conductive layer under air and a relatively high resistive seabed as basement,possibly containing a hydrogen layer of higher resistivity. The electromagnetic fields in whole space thus computed show that: (1) the spatial distribution of field component depends on its type; (2) inline Ex component is more sensitive to reservoir layer than that in broadside; (3) The airwave affects marine electromagnetic (MEM) exploration when sea water is relatively shallow; in the case of deep water MEM exploration,the airwave influence could be neglected; and (4) an appropriate frequency should be selected in order to balance the signal strength and electromagnetic induction effect.展开更多
The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization b...The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization become one of the most important geological engineering problems. At the same time, it is also crucial to select a safe and economic excavation gradient for the construction. We studied the problem of how to select a safe and economic slope ratio by analyzing the geological condition of the high slope, including the lithology, slope structure, structural surface and their combinations, rock weathering and unloading, hydrology, and the natural gradient. The study results showed that the use of an excavation gradient larger than the gradient observed during site investigation and the gradient recommended in standards and field practice manuals is feasible. Then, we used the finite element method and rigid limit equilibrium method to evaluate the stability of the excavation slope under natural, rainstorm and earthquake conditions. The calculated results showed that the excavated slope only has limited failure, but its stability is greatly satisfactory. The research findings can be useful in excavation and slope stabilization projects.展开更多
The low-lying states of 200-205Hg nuclei have been studied by using the nucleon pair approximation (NPA) of the shell model. We calculate low-excited energy levels, electric quadrupole moments, and magnetic dipole mom...The low-lying states of 200-205Hg nuclei have been studied by using the nucleon pair approximation (NPA) of the shell model. We calculate low-excited energy levels, electric quadrupole moments, and magnetic dipole moments, and investigate dominant configurations of low-lying states in the nucleon pair basis. Our calculations reasonably reproduce the available experimental data. We also tabulate our predicted results of low-lying states, including excitation energies, electric quadrupole moments and magnetic moments.展开更多
A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicat...A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicate that with the increase in the anode inclined angle,the maximum bubble thickness is increased gradually.Furthermore,compared with the conventional anode,the inclined and chamfered anodes are conductive to the bubble length reduction and the bubble velocity improvement.Meanwhile,the bubble-induced electrolyte motion in the electrolysis cell can improve the distribution and transport process of oxyfluorides,thereby enhancing the current efficiency.Finally,a novel feeding method based on the electrolyte flow is proposed.展开更多
基金funded by the National Natural Science Foundation of China (41130420)the State High-Tech Development Plan of China (2012AA09A20101)
文摘Simulation and interpretation of marine controlled-source electromagnetic(CSEM) data often approximate the transmitter source as an ideal horizontal electric dipole(HED) and assume that the receivers are located on a flat seabed.Actually,however,the transmitter dipole source will be rotated,tilted and deviated from the survey profile due to ocean currents.And free-fall receivers may be also rotated to some arbitrary horizontal orientation and located on sloping seafloor.In this paper,we investigate the effects of uncertainties in the transmitter tilt,transmitter rotation and transmitter deviation from the survey profile as well as in the receiver's location and orientation on marine CSEM data.The model study shows that the uncertainties of all position and orientation parameters of both the transmitter and receivers can propagate into observed data uncertainties,but to a different extent.In interpreting marine data,field data uncertainties caused by the position and orientation uncertainties of both the transmitter and receivers need to be taken into account.
基金Supperted by project of the National Science Foundation of China(No.40874050)
文摘Marine controlled source electromagnetic signal could be used in mineral resource exploration,reservoir appraisal and communicative technique in ocean. It's necessary to study the electromagnetic generated by MCSEM. The propagation of the electromagnetic fields from a controlled source in the marine environment was studied with virtual interface method combined with discrete complex image method. Transmitter of finite length current source is approximated by dipole (HED) . A three-layered model is accepted,with sea water as intermediate conductive layer under air and a relatively high resistive seabed as basement,possibly containing a hydrogen layer of higher resistivity. The electromagnetic fields in whole space thus computed show that: (1) the spatial distribution of field component depends on its type; (2) inline Ex component is more sensitive to reservoir layer than that in broadside; (3) The airwave affects marine electromagnetic (MEM) exploration when sea water is relatively shallow; in the case of deep water MEM exploration,the airwave influence could be neglected; and (4) an appropriate frequency should be selected in order to balance the signal strength and electromagnetic induction effect.
基金financially supported by Chinese National Natural Science Foundation (Grant No. 41072229)State Key Laboratory of Hydraulics and Mountain River Engineering (Sichuan University) open fund (Grant No. 201110)Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education and National Engineering Research Center for Inland Waterway Regulation (Chongqing Jiaotong University) open fund (Grant No. SLK2011B04)
文摘The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization become one of the most important geological engineering problems. At the same time, it is also crucial to select a safe and economic excavation gradient for the construction. We studied the problem of how to select a safe and economic slope ratio by analyzing the geological condition of the high slope, including the lithology, slope structure, structural surface and their combinations, rock weathering and unloading, hydrology, and the natural gradient. The study results showed that the use of an excavation gradient larger than the gradient observed during site investigation and the gradient recommended in standards and field practice manuals is feasible. Then, we used the finite element method and rigid limit equilibrium method to evaluate the stability of the excavation slope under natural, rainstorm and earthquake conditions. The calculated results showed that the excavated slope only has limited failure, but its stability is greatly satisfactory. The research findings can be useful in excavation and slope stabilization projects.
基金supported by the Science & Technology Program of Shanghai Maritime University (Grant No. 20100086)
文摘The low-lying states of 200-205Hg nuclei have been studied by using the nucleon pair approximation (NPA) of the shell model. We calculate low-excited energy levels, electric quadrupole moments, and magnetic dipole moments, and investigate dominant configurations of low-lying states in the nucleon pair basis. Our calculations reasonably reproduce the available experimental data. We also tabulate our predicted results of low-lying states, including excitation energies, electric quadrupole moments and magnetic moments.
基金National Natural Science Foundation of China(52101165)Inner Mongolia Science and Technology Major Project(2020ZD0010)Key Research Program of the Chinese Academy of Sciences(ZDRW-CN-2021-3)。
文摘A 2D transient mathematical model was established to separately describe the anode bubble dynamics and the bubbleinduced electrolyte motion in the rare earth electrolysis cell with horizontal electrode.Results indicate that with the increase in the anode inclined angle,the maximum bubble thickness is increased gradually.Furthermore,compared with the conventional anode,the inclined and chamfered anodes are conductive to the bubble length reduction and the bubble velocity improvement.Meanwhile,the bubble-induced electrolyte motion in the electrolysis cell can improve the distribution and transport process of oxyfluorides,thereby enhancing the current efficiency.Finally,a novel feeding method based on the electrolyte flow is proposed.
