China＇s continental deposition basins are characterized by complex geological structures and various reservoir lithologies. Therefore, high precision exploration methods are needed. High density spatial sampling is a...China＇s continental deposition basins are characterized by complex geological structures and various reservoir lithologies. Therefore, high precision exploration methods are needed. High density spatial sampling is a new technology to increase the accuracy of seismic exploration. We briefly discuss point source and receiver technology, analyze the high density spatial sampling in situ method, introduce the symmetric sampling principles presented by Gijs J. O. Vermeer, and discuss high density spatial sampling technology from the point of view of wave field continuity. We emphasize the analysis of the high density spatial sampling characteristics, including the high density first break advantages for investigation of near surface structure, improving static correction precision, the use of dense receiver spacing at short offsets to increase the effective coverage at shallow depth, and the accuracy of reflection imaging. Coherent noise is not aliased and the noise analysis precision and suppression increases as a result. High density spatial sampling enhances wave field continuity and the accuracy of various mathematical transforms, which benefits wave field separation. Finally, we point out that the difficult part of high density spatial sampling technology is the data processing. More research needs to be done on the methods of analyzing and processing huge amounts of seismic data.展开更多
Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.unifo...Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.uniform fields,have not been investigated in diabetics.Here,we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients(>10 T/m vs.0-10 T/m)on type 1 diabetic(T1D) and type 2 diabetic(T2D) mice.We found that 14 h of prolonged treatment of gradient(as high as 55.5 T/m) high SMFs(1.0-8.6 T) had negative effects on T1D and T2D mice,including spleen,hepatic,and renal tissue impairment and elevated glycosylated serum protein,blood glucose,inflammation,and anxiety,while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects.In regular T1D mice(blood glucose>16.7 mmol/L),the>10 T/m gradient high SMFs increased malondialdehyde(P<0.01) and decreased superoxide dismutase(P<0.05).However,in the severe T1D mice(blood glucose≥30.0 mmol/L),the>10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate.In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation.Therefore,this study showed that prolonged exposure to high-field(1.0-8.6 T)>10 T/m gradient SMFs(35-1 380 times higher than that of current clinical MRI)can have negative effects on diabetic mice,especially mice with severe T1D,whereas 9.4 T high SMFs at 0-10T/m did not produce the same effects,providing important information for the future development and clinical application of SMFs,especially high-field MRI.展开更多
Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature...Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.展开更多
This paper studies blast-induced wing crack behavior in a dynamic–static superimposed stress field using high-speed photography in combination with the optical method of caustics. With a static–dynamic loading setup...This paper studies blast-induced wing crack behavior in a dynamic–static superimposed stress field using high-speed photography in combination with the optical method of caustics. With a static–dynamic loading setup, four PMMA plate specimens with pre-existing cracks under different static loading and the same dynamic loading were tested to observe the mechanical characteristics and the kinematic characteristics of blast-induced wing cracks during the propagation process, including crack length, crack velocity and dynamic stress intensity factor(SIF) at the crack tip. The results show that the behavior of the blast-induced wing crack is affected by the explosion stress wave and initial static stress, and the initial static stress with the direction being perpendicular to the wing crack propagation direction hinders crack propagation. Furthermore, the boundary constraint condition of the specimen plays an important role on the behavior of the crack propagation in the experiment.展开更多
Statics are big challenges for the processing of deep reflection seismic data. In this paper several different statics solutions have been implemented in the processing of deep reflection seismic data in South China a...Statics are big challenges for the processing of deep reflection seismic data. In this paper several different statics solutions have been implemented in the processing of deep reflection seismic data in South China and their corresponding results have been compared in order to find proper statics solutions. Either statics solutions based on tomographic principle or combining the low-frequency components of field statics with the high-frequency ones of refraction statics can provide reasonable statics solutions for deep reflection seismic data in South China with very rugged surface topography, and the two statics solutions can correct the statics anomalies of both long spatial wavelengths and short ones. The surface-consistent residual static corrections can serve as the good compensations to the several kinds of the first statics solutions. Proper statics solutions can improve both qualities and reso- lutions of seismic sections, especially for the reflections of Moho in the upmost mantle.展开更多
By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary c...By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.展开更多
Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-sta- tic micro bubb...Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-sta- tic micro bubble flotation column. The simulation results visually show the interior flow and illustrate mix- ing of the different flows within the apparatus. An analysis of the distribution in velocity and vorticity was used to analyze the separation mechanism and the synergism of the component parts and to strengthen the design of each unit. The conclusions are that axial back mixing and vortexes still exist in the separation unit even in the presence of packing media. The inverted cone structure near the tangential inlet （cone 1 ） within the cyclonic unit is the main reason for this. The cone 1 structure enhances swirling and focuses energy within the inner area of the cone where there are abundant bubbles. As a result slowly floating minerals are forcibly recovered and railings are effectively separated within this unit. However, cone 1 also reduces the vorticity downstream from it, which reduces the efficiency of railings separation within this part. Therefore, the design of cone 1 should be based on the principles of lessening disturbances to the column unit while strengthening the separation effect of the cyclonic unit. Also, the axial distance between the paired cyclonic structures at the bottom of the column （cone 2） and cone 1 poses tough requirements because of an interaction between separation of the middlings and railings.展开更多
文摘China＇s continental deposition basins are characterized by complex geological structures and various reservoir lithologies. Therefore, high precision exploration methods are needed. High density spatial sampling is a new technology to increase the accuracy of seismic exploration. We briefly discuss point source and receiver technology, analyze the high density spatial sampling in situ method, introduce the symmetric sampling principles presented by Gijs J. O. Vermeer, and discuss high density spatial sampling technology from the point of view of wave field continuity. We emphasize the analysis of the high density spatial sampling characteristics, including the high density first break advantages for investigation of near surface structure, improving static correction precision, the use of dense receiver spacing at short offsets to increase the effective coverage at shallow depth, and the accuracy of reflection imaging. Coherent noise is not aliased and the noise analysis precision and suppression increases as a result. High density spatial sampling enhances wave field continuity and the accuracy of various mathematical transforms, which benefits wave field separation. Finally, we point out that the difficult part of high density spatial sampling technology is the data processing. More research needs to be done on the methods of analyzing and processing huge amounts of seismic data.
基金supported by the National Natural Science Foundation of China (U21A20148, 31900506, 52007185)International Partnership Program of the Chinese Academy of Sciences(116134KYSB20210052)+2 种基金Heye Health Technology Chong Ming Project(HYCMP2021010)CAS President’s International Fellowship Initiative Grant(2022VMA0009)CASHIPS Director’s Fund (BJPY2021A06,2021YZGH04, YZJJ2020QN26, YZJJZX202014, YZJJ2021QN32,YZJJ2023QN43)。
文摘Although 9.4 T magnetic resonance imaging(MRI) has been tested in healthy volunteers,its safety in diabetic patients is unclear.Furthermore,the effects of high static magnetic fields(SMFs),especially gradient vs.uniform fields,have not been investigated in diabetics.Here,we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients(>10 T/m vs.0-10 T/m)on type 1 diabetic(T1D) and type 2 diabetic(T2D) mice.We found that 14 h of prolonged treatment of gradient(as high as 55.5 T/m) high SMFs(1.0-8.6 T) had negative effects on T1D and T2D mice,including spleen,hepatic,and renal tissue impairment and elevated glycosylated serum protein,blood glucose,inflammation,and anxiety,while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects.In regular T1D mice(blood glucose>16.7 mmol/L),the>10 T/m gradient high SMFs increased malondialdehyde(P<0.01) and decreased superoxide dismutase(P<0.05).However,in the severe T1D mice(blood glucose≥30.0 mmol/L),the>10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate.In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation.Therefore,this study showed that prolonged exposure to high-field(1.0-8.6 T)>10 T/m gradient SMFs(35-1 380 times higher than that of current clinical MRI)can have negative effects on diabetic mice,especially mice with severe T1D,whereas 9.4 T high SMFs at 0-10T/m did not produce the same effects,providing important information for the future development and clinical application of SMFs,especially high-field MRI.
文摘Aim To analyse the static temperature field ofthe solid rubber tire(SRT).Methods The mechanical and thermal FE models were developed and analyzed respectively with the FE software ANSYS.Results The maximum temperature becomes higher with the higher with the higher velocity of tire and scales down slightly with the higher convection coefficients.The mixed models are reasonable.Conclusion The study on static temperature field is important and reasonable.It gives the fundament for life analysis of SRT.
基金the financial support received from the PhD Programs Foundation of Ministry of Education of China (No. 20120023120020)the National Natural Science Foundation of China (No. 51134025)
文摘This paper studies blast-induced wing crack behavior in a dynamic–static superimposed stress field using high-speed photography in combination with the optical method of caustics. With a static–dynamic loading setup, four PMMA plate specimens with pre-existing cracks under different static loading and the same dynamic loading were tested to observe the mechanical characteristics and the kinematic characteristics of blast-induced wing cracks during the propagation process, including crack length, crack velocity and dynamic stress intensity factor(SIF) at the crack tip. The results show that the behavior of the blast-induced wing crack is affected by the explosion stress wave and initial static stress, and the initial static stress with the direction being perpendicular to the wing crack propagation direction hinders crack propagation. Furthermore, the boundary constraint condition of the specimen plays an important role on the behavior of the crack propagation in the experiment.
基金supported by the Foundation of Institute of Geology,Chinese Academy of Geological Sciences (No. J1315)the 3D Geological Mapping Project (No. D1204)the SinoProbe-02 project of China
文摘Statics are big challenges for the processing of deep reflection seismic data. In this paper several different statics solutions have been implemented in the processing of deep reflection seismic data in South China and their corresponding results have been compared in order to find proper statics solutions. Either statics solutions based on tomographic principle or combining the low-frequency components of field statics with the high-frequency ones of refraction statics can provide reasonable statics solutions for deep reflection seismic data in South China with very rugged surface topography, and the two statics solutions can correct the statics anomalies of both long spatial wavelengths and short ones. The surface-consistent residual static corrections can serve as the good compensations to the several kinds of the first statics solutions. Proper statics solutions can improve both qualities and reso- lutions of seismic sections, especially for the reflections of Moho in the upmost mantle.
文摘By solving the magneto-transport equation for excess minority charge carriers in the base of the series vertical-junction silicon cell, the phenomenological parameters of the cell can be determined from the boundary conditions. Photocurrent density and photovoltage are determined for each value of applied magnetic field and corresponding optimum thickness, to establish the current-voltage characteristic (Jph(Sf, Sb, z, B, Hop)-Vph(Sf, Sb, z, B, Hop) of the silicon cell under polychromatic illumination. This study will make it possible to reduce the material used (by reducing the optimum thickness), which will help to lower prices. It will also enable us to reduce betting effects (lower series resistance), thereby boosting solar cell efficiency.
基金supported by the National Natural Science Foundation of China (No. 51074157)the Foundation of China University of Mining and Technology (No. 2011QNA08)
文摘Improved fluid dynamics can enhance the separation efficiency of flotation methods. A Computational Fluid Dynamics simulation using FLUENT was performed to model the fluid environment of a cyclonic-sta- tic micro bubble flotation column. The simulation results visually show the interior flow and illustrate mix- ing of the different flows within the apparatus. An analysis of the distribution in velocity and vorticity was used to analyze the separation mechanism and the synergism of the component parts and to strengthen the design of each unit. The conclusions are that axial back mixing and vortexes still exist in the separation unit even in the presence of packing media. The inverted cone structure near the tangential inlet （cone 1 ） within the cyclonic unit is the main reason for this. The cone 1 structure enhances swirling and focuses energy within the inner area of the cone where there are abundant bubbles. As a result slowly floating minerals are forcibly recovered and railings are effectively separated within this unit. However, cone 1 also reduces the vorticity downstream from it, which reduces the efficiency of railings separation within this part. Therefore, the design of cone 1 should be based on the principles of lessening disturbances to the column unit while strengthening the separation effect of the cyclonic unit. Also, the axial distance between the paired cyclonic structures at the bottom of the column （cone 2） and cone 1 poses tough requirements because of an interaction between separation of the middlings and railings.
