This paper extends CAATI （Computed Angle-of-Arrival Transient Imaging） technique of Multi-angle Swath Bathymetry Sidesean Sonar （MSBSS） into Multi-Beam Bathymetry Sonar （MBBS） and presents a new Multiple Sub-arr...This paper extends CAATI （Computed Angle-of-Arrival Transient Imaging） technique of Multi-angle Swath Bathymetry Sidesean Sonar （MSBSS） into Multi-Beam Bathymetry Sonar （MBBS） and presents a new Multiple Sub-array Beamspaee - CAATI （MSB-CAATI） algorithm. The method not only can achieve high resolution seafloor mapping in the whole wide swath, but also can work well in complex acoustic environments or geometries. Simulation results and processing results of sea-experiment data prove the validity and superiority of the algorithm.展开更多
Fracture-fissure systems found at mid-ocean ridges are dominating conduits for the circulation of metallogenic fluid.Ascertaining the distribution area of active faults on both sides of mid-ocean ridges will provide a...Fracture-fissure systems found at mid-ocean ridges are dominating conduits for the circulation of metallogenic fluid.Ascertaining the distribution area of active faults on both sides of mid-ocean ridges will provide a useful tool in the search for potential hydrothermal vents,thus guiding the exploration of modern seafloor sulfides.Considering the MidAtlantic Ridge 20°N–24°N(NMAR)and North Chile Rise(NCR)as examples,fault elements such as Fault Spacing(?S)and Fault Heave(?X)can be identified and quantitatively measured.The methods used include Fourier filtering of the multi-beam bathymetry data,in combination with measurements of the topographic slope,curvature,and slope aspect patterns.According to the Sequential Faulting Model of mid-ocean ridges,the maximal migration distance of an active fault on either side of mid-ocean ridges—that is,the distribution range of active faults—can be measured.Results show that the maximal migration distance of active faults at the NMAR is 0.76–1.01 km(the distance is larger at the center than at the ends of this segment),and at the NCR,the distribution range of active faults is 0.38–1.6 km.The migration distance of active faults on the two study areas is positively related to the axial variation of magma supply.In the NCR study area,where there is an abundant magma input,the number of faults within a certain distance is mainly affected by the variation of lithospheric thickness.Here a large range of faulting clearly corresponds to a high proportion of magmatism to seafloor spreading near mid-ocean ridges(M)value,and in the study area of the NMAR,there is insufficient magmatism,and the number of faults may be controlled by both lithospheric thickness and magma supply,leading to a less obvious positive correlation between the distribution range of active faults and M.展开更多
In order to improve the manufacturing quality of electron beam welding,some technologies are developed by using the special features of electron beam.Comparing with the conventional electron beam welding,the usage of ...In order to improve the manufacturing quality of electron beam welding,some technologies are developed by using the special features of electron beam.Comparing with the conventional electron beam welding,the usage of multi-beam technology and micro-beam technology are introduced.In addition.the development of beam diagnostic system is also presented.展开更多
Since its first introduction to the industry the control systems of electron beam machines have gone through an enormous evolution.With the availability of fast amplifier components and digital beam controllers the ad...Since its first introduction to the industry the control systems of electron beam machines have gone through an enormous evolution.With the availability of fast amplifier components and digital beam controllers the advantages of the electron beam have further increased making it a truly software controlled thermal processing tool.Modern beam controllers enable multi-beam and multi-focus technologies,where the beam is split in up to 60 individual beams.These technologies can reduce the processing time by parallel processing or improve the quality by optimized thermal expansion of the part.Multi-process technologies,where several processes are performed in one run (e.g.welding and cosmetic treatment) further extend the application range of the electron beam process.Fast beam deflection in conjunction with electron-optical monitoring is the fundamental component for advanced seam tracking systems.They allow automating the EB application in order to optimize the process costs and improve the quality of the re-sults in a reproducible manner.Basis for a high quality of the EB process is the condition of the tool,the electron beam itself.By in-troducing the beam parameter product to the electron beam,reliable information about the quality of the beam can be derived.Im-plemented into automatic beam alignment systems repeatable results with high quality are achieved.展开更多
基金Supported by the Foundation of the Chinese Doctoral Science Grant No. 20050217010the Foundation of the Chinese Postdoctoral Science Grant No. LRB0025the Foundation of Underwater Acoustic Technology National Key Lab Grant No. 9140C200501060C20.
文摘This paper extends CAATI （Computed Angle-of-Arrival Transient Imaging） technique of Multi-angle Swath Bathymetry Sidesean Sonar （MSBSS） into Multi-Beam Bathymetry Sonar （MBBS） and presents a new Multiple Sub-array Beamspaee - CAATI （MSB-CAATI） algorithm. The method not only can achieve high resolution seafloor mapping in the whole wide swath, but also can work well in complex acoustic environments or geometries. Simulation results and processing results of sea-experiment data prove the validity and superiority of the algorithm.
基金supported by the grant of China Ocean Mineral Resources R&D Association(DY135-S2-1-01)
文摘Fracture-fissure systems found at mid-ocean ridges are dominating conduits for the circulation of metallogenic fluid.Ascertaining the distribution area of active faults on both sides of mid-ocean ridges will provide a useful tool in the search for potential hydrothermal vents,thus guiding the exploration of modern seafloor sulfides.Considering the MidAtlantic Ridge 20°N–24°N(NMAR)and North Chile Rise(NCR)as examples,fault elements such as Fault Spacing(?S)and Fault Heave(?X)can be identified and quantitatively measured.The methods used include Fourier filtering of the multi-beam bathymetry data,in combination with measurements of the topographic slope,curvature,and slope aspect patterns.According to the Sequential Faulting Model of mid-ocean ridges,the maximal migration distance of an active fault on either side of mid-ocean ridges—that is,the distribution range of active faults—can be measured.Results show that the maximal migration distance of active faults at the NMAR is 0.76–1.01 km(the distance is larger at the center than at the ends of this segment),and at the NCR,the distribution range of active faults is 0.38–1.6 km.The migration distance of active faults on the two study areas is positively related to the axial variation of magma supply.In the NCR study area,where there is an abundant magma input,the number of faults within a certain distance is mainly affected by the variation of lithospheric thickness.Here a large range of faulting clearly corresponds to a high proportion of magmatism to seafloor spreading near mid-ocean ridges(M)value,and in the study area of the NMAR,there is insufficient magmatism,and the number of faults may be controlled by both lithospheric thickness and magma supply,leading to a less obvious positive correlation between the distribution range of active faults and M.
基金Project (50505019) supported by Natural Science Foundation of China.
文摘In order to improve the manufacturing quality of electron beam welding,some technologies are developed by using the special features of electron beam.Comparing with the conventional electron beam welding,the usage of multi-beam technology and micro-beam technology are introduced.In addition.the development of beam diagnostic system is also presented.
文摘Since its first introduction to the industry the control systems of electron beam machines have gone through an enormous evolution.With the availability of fast amplifier components and digital beam controllers the advantages of the electron beam have further increased making it a truly software controlled thermal processing tool.Modern beam controllers enable multi-beam and multi-focus technologies,where the beam is split in up to 60 individual beams.These technologies can reduce the processing time by parallel processing or improve the quality by optimized thermal expansion of the part.Multi-process technologies,where several processes are performed in one run (e.g.welding and cosmetic treatment) further extend the application range of the electron beam process.Fast beam deflection in conjunction with electron-optical monitoring is the fundamental component for advanced seam tracking systems.They allow automating the EB application in order to optimize the process costs and improve the quality of the re-sults in a reproducible manner.Basis for a high quality of the EB process is the condition of the tool,the electron beam itself.By in-troducing the beam parameter product to the electron beam,reliable information about the quality of the beam can be derived.Im-plemented into automatic beam alignment systems repeatable results with high quality are achieved.
