This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located...This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 200 and 1000 - 2500 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.展开更多
The method and basic structure of object─oriented knowledge representation are presented in detail and the hierarchical structurc of object description is explained Based on object─oriented technology.the gear box c...The method and basic structure of object─oriented knowledge representation are presented in detail and the hierarchical structurc of object description is explained Based on object─oriented technology.the gear box concept design expert cistem of NC miller (GBCDLS) has been developed and applied to practical use.Moreover. the design principlc and techniques of GBCDES are discussed and analyzed. and the main functions of GBCDES are described. From the results of applications.it can be seen that GBCDES is effective and successful.展开更多
We have proposed and developed a design method of a freeform surfaces （FFSs） based hyper-numerical-aperture deep ultraviolet （DUV） projection objective （PO） with low aberration. With an aspheric initial configur...We have proposed and developed a design method of a freeform surfaces （FFSs） based hyper-numerical-aperture deep ultraviolet （DUV） projection objective （PO） with low aberration. With an aspheric initial configuration, lens-form parameters were used to determine the best position to remove elements and insert FFSs. The designed FFSs PO reduced two elements without increasing the total thickness of the glass materials. Compared with aspheric initial configuration, the wavefront error of the FFSs PO decreased from 0.006λ to 0.005λ, the distortion reduced from 1 to 0.5 nm, and the aspheric departure decreased from 1.7 to 1.35 mm. The results show that the design method of the FFSs PO is efficient and has improved the imaging performance of PO. The design method of FFSs PO provides potential solutions for DUV lithography with low aberrations at 10–5 nm nodes.展开更多
Efficient data management is crucial to the success of a CAD/CAM system.Traditional database systems,designed to deal with only regular and structural data,cannot efficiently manage design data. In this paper,we prese...Efficient data management is crucial to the success of a CAD/CAM system.Traditional database systems,designed to deal with only regular and structural data,cannot efficiently manage design data. In this paper,we present a data manager called EDBMS/2,which has been developed by our laboratory for engineering support applications.EDBMS/2 has a data model that combines features of both relational and semantic ones and owns flexible abilities for modeling engineering data,such as variable-length data processing,integrated management of structured data and unstructured data,and composite object handling.Mechanisms based on DBV and DBV graph concepts,proposed in EDBMS/2,make EDBMS/2 own powerful abilities for version management and run efficiently.By now,EDBMS/2 has been used successfully in EDCADS(integrated Electronic Devices CAD environ- ment)project and as a lower level support to develop an object-oriented DBMS for mechanical engineering.展开更多
This paper discussed some issues about information system integration and presented a methodology for dealing with it. The IS integration is comprised of information integration, function integration, platform integra...This paper discussed some issues about information system integration and presented a methodology for dealing with it. The IS integration is comprised of information integration, function integration, platform integration and human integration. Among them, Information Integration is the goal of the system integration, while the Human integration is the basis. Based upon the practice of an airline integration information system, a phase based methodology has developed, which combines different methods of development into the integration process.展开更多
基金the 2007 Special Research Project 8-55 of the Department of Finance and the State Science and Technology Support Project 2006BAC13B02
文摘This paper analyzes the seismicity in Bohai Sea,introducing a shape factor K to characterize the seismic risk distribution in sub-regions of the sea. Based on the seismic design ground motions for 46 platforms located in the Bohai Sea,a statistical analysis was performed for different peak ground acceleration (PGA) ratios at two different probability levels. In accordance with the two-stage design method,a scheme of two seismic design levels is proposed,and two seismic design objectives are established respectively for the strength level earthquake and the ductility level earthquake. By analogy with and comparison to the Chinese seismic design code for buildings,it is proposed that the probability level for the strength level earthquake and ductility level earthquake have a return period of 200 and 1000 - 2500 years,respectively. The validity of these proposed values is discussed. Finally,the PGAs corresponding to these two probability levels are calculated for different sub-regions of the Bohai Sea.
文摘The method and basic structure of object─oriented knowledge representation are presented in detail and the hierarchical structurc of object description is explained Based on object─oriented technology.the gear box concept design expert cistem of NC miller (GBCDLS) has been developed and applied to practical use.Moreover. the design principlc and techniques of GBCDES are discussed and analyzed. and the main functions of GBCDES are described. From the results of applications.it can be seen that GBCDES is effective and successful.
基金the Major Scientific Instrument Development Project of the National Natural Science Foundation of China (Nos. 11627808 and 61675026)the National Science and Technology Major Project for their financial support
文摘We have proposed and developed a design method of a freeform surfaces （FFSs） based hyper-numerical-aperture deep ultraviolet （DUV） projection objective （PO） with low aberration. With an aspheric initial configuration, lens-form parameters were used to determine the best position to remove elements and insert FFSs. The designed FFSs PO reduced two elements without increasing the total thickness of the glass materials. Compared with aspheric initial configuration, the wavefront error of the FFSs PO decreased from 0.006λ to 0.005λ, the distortion reduced from 1 to 0.5 nm, and the aspheric departure decreased from 1.7 to 1.35 mm. The results show that the design method of the FFSs PO is efficient and has improved the imaging performance of PO. The design method of FFSs PO provides potential solutions for DUV lithography with low aberrations at 10–5 nm nodes.
文摘Efficient data management is crucial to the success of a CAD/CAM system.Traditional database systems,designed to deal with only regular and structural data,cannot efficiently manage design data. In this paper,we present a data manager called EDBMS/2,which has been developed by our laboratory for engineering support applications.EDBMS/2 has a data model that combines features of both relational and semantic ones and owns flexible abilities for modeling engineering data,such as variable-length data processing,integrated management of structured data and unstructured data,and composite object handling.Mechanisms based on DBV and DBV graph concepts,proposed in EDBMS/2,make EDBMS/2 own powerful abilities for version management and run efficiently.By now,EDBMS/2 has been used successfully in EDCADS(integrated Electronic Devices CAD environ- ment)project and as a lower level support to develop an object-oriented DBMS for mechanical engineering.
文摘This paper discussed some issues about information system integration and presented a methodology for dealing with it. The IS integration is comprised of information integration, function integration, platform integration and human integration. Among them, Information Integration is the goal of the system integration, while the Human integration is the basis. Based upon the practice of an airline integration information system, a phase based methodology has developed, which combines different methods of development into the integration process.
