The technology of remote transaction mirror image is a feasible, low-investment and well-effect disaster backup scheme in finance business system. The basic idea, construction, working principles and characteristic of...The technology of remote transaction mirror image is a feasible, low-investment and well-effect disaster backup scheme in finance business system. The basic idea, construction, working principles and characteristic of remote transaction mirror image are presented in this paper. We analyze and compare similarities and differences among this disaster backup scheme and others usually used. The technology of remote transaction mirror image have the advantages such as less requiring of software and hardware system platform, low-investment, being able to control and restore lost data, insuring the data consistency and integrity.展开更多
To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component (4C) ocean-bottom seismometer...To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component (4C) ocean-bottom seismometer (OBS) surveys. A case study is presented to show the results of acquiring and processing OBS data for detecting gas hydrates. Key processing steps such as repositioning, reorientation, PZ summation, and mirror imaging are discussed. Repositioning and reorientation find the correct location and direction of nodes. PZ summation matches P- and Z-components and sums them to separate upgoing and downgoing waves. Upgoing waves are used in conventional imaging, whereas downgoing waves are used in mirror imaging. Mirror imaging uses the energy of the receiver ghost reflection to improve the illumination of shallow structures, where gas hydrates and the associated bottom-simulating reflections (BSRs) are located. We developed a new method of velocity analysis using mirror imaging. The proposed method is based on velocity scanning and iterative prestack time migration. The final imaging results are promising. When combined with the derived velocity field, we can characterize the BSR and shallow structures; hence, we conclude that using 4C OBS can reveal the distribution and velocity attributes of gas hydrates.展开更多
In this paper, the principle of mirror image is used to transform the problem of wave diffraction from a circular cylinder in front of orthogonal vertical walls into the problem of diffraction of four symmetric incide...In this paper, the principle of mirror image is used to transform the problem of wave diffraction from a circular cylinder in front of orthogonal vertical walls into the problem of diffraction of four symmetric incident waves from four symmetrically arranged circular cylinders, and then the eigenfunction expansion of velocity potential and Grafs addition theorem are used to give the analytical solution to the wave diffraction problem. The relation of the total wave force on cylinder to the distance between the cylinder and orthogonal vertical walls and the incidence angle of wave is also studied by numerical computation.展开更多
A bimorph deformable mirror (DM) with a large stroke of more than 30 μm using 35 actuators is presented and characterized for an adaptive optics (AO) confocal scanning laser ophthalmoscope application. Facilitate...A bimorph deformable mirror (DM) with a large stroke of more than 30 μm using 35 actuators is presented and characterized for an adaptive optics (AO) confocal scanning laser ophthalmoscope application. Facilitated with a Shack-Hartmann wavefront sensor, the bimorph DM-based AO operates closed-loop AO corrections for hu- man eyes and reduces wavefront aberrations in most eyes to below 0.1 μm rms. Results from living eyes, including one exhibiting ~5D of myopia and ~2D of astigmatism along with notable high-order aberrations, reveal a prac- tical efficient aberration correction and demonstrate a great benefit for retina imaging, including improving resolution, increasing brightness, and enhancing the contrast of images.展开更多
In the case of three-layered(air-seawater-seabed)model,the analytical expressions of the static electric and static magnetic field produced by the static electric dipole located in seawater were derived by using the m...In the case of three-layered(air-seawater-seabed)model,the analytical expressions of the static electric and static magnetic field produced by the static electric dipole located in seawater were derived by using the mirror image theory.Combined with the distribution of the underwater electric potential measured in laboratory,an electric dipole model for physical scale of ship was established and the distribution characteristics of an actual ship' s corrosion related magnetic field were obtained.Based on established models,theoretical analysis and calculation were made to catch out the distribution characteristics of static magnetic field related with corrosion and anticorrosion,which can not be measured directly in seawater.The results show that the static magnetic field related with corrosion and anticorrosion is a kind of noteworthy obstacle signal for degaussed ships.展开更多
Non-superimposable mirror image crystals of both enantiomers(S/R) of cyclicγ-alkenyl alcohol(2) have been recognized and remarkably identified by the naked eye.More interestingly,both crystals are an outcome of m...Non-superimposable mirror image crystals of both enantiomers(S/R) of cyclicγ-alkenyl alcohol(2) have been recognized and remarkably identified by the naked eye.More interestingly,both crystals are an outcome of most astonishingly H-bond and intermolecularσ/π-πinteractions.They accounted for the relatively rare and less predictable spontaneous resolution with optical purity 〉99%ee from the racemic mixture.The chiral discrimination mechanism of this spontaneous resolution has also been proposed.展开更多
A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distributio...A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distribution and the interaction force between two spheres can be calculated accurately even for very small gap between two spheres.Our results show that the magnitude of the product of the gap between two spheres and the local electric field in the center of the gap is approximately in the same order and the interaction between two spheres increases very fast as the two spheres are close to each other.We also show that the interaction force between two conductor spheres is almost same with that between two dielectric spheres with high permittivity.展开更多
LIGO/Virgo S190814 bv is the first high-probability neutron star–black hole(NSBH)merger candidate,whose gravitational waves(GWs)triggered LIGO/Virgo detectors at21:10:39.012957 UT,14 August 2019.It has a probability&...LIGO/Virgo S190814 bv is the first high-probability neutron star–black hole(NSBH)merger candidate,whose gravitational waves(GWs)triggered LIGO/Virgo detectors at21:10:39.012957 UT,14 August 2019.It has a probability>99%of being an NSBH merger,with a low false alarm rate(FAR)of one per 1.559 e+25 years.For an NSBH merger,electromagnetic counterparts(especially short gamma-ray bursts(GRBs))are generally expected.However,no electromagnetic counterpart has been found in the extensive follow-up observing campaign.In the present work,we propose a novel explanation for this null result.In our scenario,LIGO/Virgo S190814 bv is just a GW mirror image of the real NSBH merger which should have been detected before 14 September 2015,but at that time we had no ability to detect its GW signals.The electromagnetic counterparts associated with the real NSBH merger should be found in the archive data before 14 September 2015.In this work,we indeed find nine short GRBs that are possibly electromagnetic counterparts.展开更多
基金This work was supported by"Shu Guang"project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation (No.2002SG53) and was also supported by Science and Technology Foundation of Shanghai Higher Education (No.CL200222).
文摘The technology of remote transaction mirror image is a feasible, low-investment and well-effect disaster backup scheme in finance business system. The basic idea, construction, working principles and characteristic of remote transaction mirror image are presented in this paper. We analyze and compare similarities and differences among this disaster backup scheme and others usually used. The technology of remote transaction mirror image have the advantages such as less requiring of software and hardware system platform, low-investment, being able to control and restore lost data, insuring the data consistency and integrity.
基金supported by the National Hi-tech Research and Development Program of China(863 Program)(Grant No.2013AA092501)the China Geological Survey Projects(Grant Nos.GZH201100303 and GZH201100305)
文摘To investigate the distribution and velocity attributes of gas hydrates in the northern continental slope of South China Sea, Guangzhou Marine Geological Survey conducted four-component (4C) ocean-bottom seismometer (OBS) surveys. A case study is presented to show the results of acquiring and processing OBS data for detecting gas hydrates. Key processing steps such as repositioning, reorientation, PZ summation, and mirror imaging are discussed. Repositioning and reorientation find the correct location and direction of nodes. PZ summation matches P- and Z-components and sums them to separate upgoing and downgoing waves. Upgoing waves are used in conventional imaging, whereas downgoing waves are used in mirror imaging. Mirror imaging uses the energy of the receiver ghost reflection to improve the illumination of shallow structures, where gas hydrates and the associated bottom-simulating reflections (BSRs) are located. We developed a new method of velocity analysis using mirror imaging. The proposed method is based on velocity scanning and iterative prestack time migration. The final imaging results are promising. When combined with the derived velocity field, we can characterize the BSR and shallow structures; hence, we conclude that using 4C OBS can reveal the distribution and velocity attributes of gas hydrates.
基金financially supported by the National Natural Science Foundation of China(Grant No.50025924).
文摘In this paper, the principle of mirror image is used to transform the problem of wave diffraction from a circular cylinder in front of orthogonal vertical walls into the problem of diffraction of four symmetric incident waves from four symmetrically arranged circular cylinders, and then the eigenfunction expansion of velocity potential and Grafs addition theorem are used to give the analytical solution to the wave diffraction problem. The relation of the total wave force on cylinder to the distance between the cylinder and orthogonal vertical walls and the incidence angle of wave is also studied by numerical computation.
基金supported by the National Science Foundation of China(No.61605210)the National Instrumentation Program(NIP)(No.2012YQ120080)+4 种基金the National Key Research and Development Program of China(No.2016YFC0102500)the Jiangsu Province Science Fund for Distinguished Young Scholars(No.BK20060010)the Frontier Science Research Project of the Chinese Academy of Sciences(No.QYZDB-SSWJSC03)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB02060000)the Zhejiang Province Technology Program(No.2013C33170)
文摘A bimorph deformable mirror (DM) with a large stroke of more than 30 μm using 35 actuators is presented and characterized for an adaptive optics (AO) confocal scanning laser ophthalmoscope application. Facilitated with a Shack-Hartmann wavefront sensor, the bimorph DM-based AO operates closed-loop AO corrections for hu- man eyes and reduces wavefront aberrations in most eyes to below 0.1 μm rms. Results from living eyes, including one exhibiting ~5D of myopia and ~2D of astigmatism along with notable high-order aberrations, reveal a prac- tical efficient aberration correction and demonstrate a great benefit for retina imaging, including improving resolution, increasing brightness, and enhancing the contrast of images.
基金Sponsored by National Defense Pre-research Foundation(51444070105JB11)
文摘In the case of three-layered(air-seawater-seabed)model,the analytical expressions of the static electric and static magnetic field produced by the static electric dipole located in seawater were derived by using the mirror image theory.Combined with the distribution of the underwater electric potential measured in laboratory,an electric dipole model for physical scale of ship was established and the distribution characteristics of an actual ship' s corrosion related magnetic field were obtained.Based on established models,theoretical analysis and calculation were made to catch out the distribution characteristics of static magnetic field related with corrosion and anticorrosion,which can not be measured directly in seawater.The results show that the static magnetic field related with corrosion and anticorrosion is a kind of noteworthy obstacle signal for degaussed ships.
基金Financial support from Beijing Institute of Technology(No. 2011CX01008 and others)partially from NSFC(No.20972016)Chinese Scholarship Council(M.Sohail)
文摘Non-superimposable mirror image crystals of both enantiomers(S/R) of cyclicγ-alkenyl alcohol(2) have been recognized and remarkably identified by the naked eye.More interestingly,both crystals are an outcome of most astonishingly H-bond and intermolecularσ/π-πinteractions.They accounted for the relatively rare and less predictable spontaneous resolution with optical purity 〉99%ee from the racemic mixture.The chiral discrimination mechanism of this spontaneous resolution has also been proposed.
基金Supported by Guizhou Provincial Science and Technology Foundation (Z103167)Youth Foundation of Guizhou University (X092012)+1 种基金the National Basic Research Program of China under Grant No. 2009CB930800National Natural Science Foundation of China under Grant Nos. 10674157 and 10875166
文摘A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distribution and the interaction force between two spheres can be calculated accurately even for very small gap between two spheres.Our results show that the magnitude of the product of the gap between two spheres and the local electric field in the center of the gap is approximately in the same order and the interaction between two spheres increases very fast as the two spheres are close to each other.We also show that the interaction force between two conductor spheres is almost same with that between two dielectric spheres with high permittivity.
基金supported in part by NSFC under Grants No.11975046 and No.11575022。
文摘LIGO/Virgo S190814 bv is the first high-probability neutron star–black hole(NSBH)merger candidate,whose gravitational waves(GWs)triggered LIGO/Virgo detectors at21:10:39.012957 UT,14 August 2019.It has a probability>99%of being an NSBH merger,with a low false alarm rate(FAR)of one per 1.559 e+25 years.For an NSBH merger,electromagnetic counterparts(especially short gamma-ray bursts(GRBs))are generally expected.However,no electromagnetic counterpart has been found in the extensive follow-up observing campaign.In the present work,we propose a novel explanation for this null result.In our scenario,LIGO/Virgo S190814 bv is just a GW mirror image of the real NSBH merger which should have been detected before 14 September 2015,but at that time we had no ability to detect its GW signals.The electromagnetic counterparts associated with the real NSBH merger should be found in the archive data before 14 September 2015.In this work,we indeed find nine short GRBs that are possibly electromagnetic counterparts.