With microscopic phase-field kinetic model, atomic-scale computer simulation program for the precipitation sequence and microstructure evolution of the ordered intermetallic compound γ' and θ in ternary Ni75AlxV25-...With microscopic phase-field kinetic model, atomic-scale computer simulation program for the precipitation sequence and microstructure evolution of the ordered intermetallic compound γ' and θ in ternary Ni75AlxV25-x alloy were studied. The simulation results show that Al concentration has important effects on the precipitation sequence. When Al concentration in Ni75AlxV25-x alloy is low, 0(Ni3V) ordered phase will be firstly precipitated, followed by γ'(Ni3Al) ordered phase. With Al concentration increasing, θ and γ' ordered phases are simultaneously precipitated. With A1 concentration further increasing, γ' ordered phase is firstly precipitated, followed by θ ordered phase. There is a competition relationship between θ and γ' ordered phases during growth and coarsening process. No matter which first precipitates, θ ordered phase always occupies advantage in the competition process of coarsening, thus, the microstructure with preferred orientation is formed.展开更多
A new (2+1)-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms...A new (2+1)-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms of the singular manifold is obtained. And localized structures are also investigated.展开更多
Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmenta...Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmentation based on the Mumford-Shah model.Compared with the traditional approach for solving the Euler-Lagrange equation we do not need to solve any partial differential equations.Instead,the minimum cut on a special designed graph need to be computed.The method is tested on data with complicated structures.It is rather stable with respect to initial value and the algorithm is nearly parameter free.Experiments show that it can solve large problems much faster than traditional approaches.展开更多
With a more complex pore structure system compared with clastic rocks, carbonate rocks have not yet been well described by existing conventional rock physical models concerning the pore structure vagary as well as the...With a more complex pore structure system compared with clastic rocks, carbonate rocks have not yet been well described by existing conventional rock physical models concerning the pore structure vagary as well as the influence on elastic rock properties. We start with a discussion and an analysis about carbonate rock pore structure utilizing rock slices. Then, given appropriate assumptions, we introduce a new approach to modeling carbonate rocks and construct a pore structure algorithm to identify pore structure mutation with a basis on the Gassmann equation and the Eshelby-Walsh ellipsoid inclusion crack theory. Finally, we compute a single well's porosity using this new approach with full wave log data and make a comparison with the predicted result of traditional method and simultaneously invert for reservoir parameters. The study results reveal that the rock pore structure can significantly influence the rocks' elastic properties and the predicted porosity error of the new modeling approach is merely 0.74%. Therefore, the approach we introduce can effectively decrease the predicted error of reservoir parameters.展开更多
The concepts of floating structure plays a very important role in deepwater projects; and the design of the floating structure is one of the most important tasks in the project. The importance of the floating structur...The concepts of floating structure plays a very important role in deepwater projects; and the design of the floating structure is one of the most important tasks in the project. The importance of the floating structure in offshore projects can be demonstrated in the following several areas: the substantial dynamic structure responses due to wave loading and current loading; the limited motion requirements of risers in deep water; and the increasing difficulty of installation for different components of the system. Three major technical aspects have to be considered, i.e. the strength of structure, the fatigue resistance capacity of the system, and local and global stability of the structure. This paper reviews the current design practice of floating structures, evaluates the main tasks during the design and associated major technical requirements, and addresses the major technical challenges encountered during the design. As a close-out of the paper, the authors discuss some potential future developments in the design of floating structures.展开更多
The paper presents a knowledge-based engineering (KBE) approach for ship node components design. In the ship design process, many design tasks need design experiences to support. Howev- er, a ship design process is ...The paper presents a knowledge-based engineering (KBE) approach for ship node components design. In the ship design process, many design tasks need design experiences to support. Howev- er, a ship design process is a complicated process with many simultaneously repetitive and time-con- suming activities. In this research, the method combines KBE with Tribon system's built-in devel- opment language tools of Vitesse, captures and applies design knowledge for achieving standard com- ponents intelligent design modeling. A case study and industry implementation illustrate the feasibili- ty of the proposed methodology. The KBE technique can provide not only proper references, sug- gests and supports but also knowledge integrated in the ship structure design. Especially, these rules related to the design can avoid lots of design mistakes. During the ship design stage, getting more precise and better designs will not only reduce the time of rework and wasting resources but also shorten the construction time_ imnrov~ clilnl;hz ~nA nrnf;t展开更多
Different from the traditional one dimensional extreme value statistical method, practical design criteria for nearshore structure design are presented based on joint probability theory in this paper. The proposed pro...Different from the traditional one dimensional extreme value statistical method, practical design criteria for nearshore structure design are presented based on joint probability theory in this paper. The proposed procedure considers the combined effect of tide level, huge waves and wind affecting coastal structures. The Importance Sampling Procedure (ISP) is utilized to solve the joint distribution of non Gaussian correlated multivariate distributions. The calculation results show that the ISP is a simulating technique with the advantages of efficiency and high convergency. Finally the environmental conditions are given using this technique for near shore structure design in the Qingdao area.展开更多
基金Projects(51174168,51274167)supported by the National Natural Science Foundation of ChinaProject(2014JM7261)supported by the Natural Science Basic Research Plan in Shaanxi Province of ChinaProject(B08040)supported by "111" Project,China
文摘With microscopic phase-field kinetic model, atomic-scale computer simulation program for the precipitation sequence and microstructure evolution of the ordered intermetallic compound γ' and θ in ternary Ni75AlxV25-x alloy were studied. The simulation results show that Al concentration has important effects on the precipitation sequence. When Al concentration in Ni75AlxV25-x alloy is low, 0(Ni3V) ordered phase will be firstly precipitated, followed by γ'(Ni3Al) ordered phase. With Al concentration increasing, θ and γ' ordered phases are simultaneously precipitated. With A1 concentration further increasing, γ' ordered phase is firstly precipitated, followed by θ ordered phase. There is a competition relationship between θ and γ' ordered phases during growth and coarsening process. No matter which first precipitates, θ ordered phase always occupies advantage in the competition process of coarsening, thus, the microstructure with preferred orientation is formed.
基金Supported by Research Fund for the Doctoral Program of Higher Education of China under Grant No.20070486094
文摘A new (2+1)-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms of the singular manifold is obtained. And localized structures are also investigated.
基金support from the Centre for Integrated Petroleum Research(CIPR),University of Bergen, Norway,and Singapore MOE Grant T207B2202NRF2007IDMIDM002-010
文摘Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmentation based on the Mumford-Shah model.Compared with the traditional approach for solving the Euler-Lagrange equation we do not need to solve any partial differential equations.Instead,the minimum cut on a special designed graph need to be computed.The method is tested on data with complicated structures.It is rather stable with respect to initial value and the algorithm is nearly parameter free.Experiments show that it can solve large problems much faster than traditional approaches.
基金sponsored by the National Nature Science Foundation of China (Grant No.40904034 and 40839905)
文摘With a more complex pore structure system compared with clastic rocks, carbonate rocks have not yet been well described by existing conventional rock physical models concerning the pore structure vagary as well as the influence on elastic rock properties. We start with a discussion and an analysis about carbonate rock pore structure utilizing rock slices. Then, given appropriate assumptions, we introduce a new approach to modeling carbonate rocks and construct a pore structure algorithm to identify pore structure mutation with a basis on the Gassmann equation and the Eshelby-Walsh ellipsoid inclusion crack theory. Finally, we compute a single well's porosity using this new approach with full wave log data and make a comparison with the predicted result of traditional method and simultaneously invert for reservoir parameters. The study results reveal that the rock pore structure can significantly influence the rocks' elastic properties and the predicted porosity error of the new modeling approach is merely 0.74%. Therefore, the approach we introduce can effectively decrease the predicted error of reservoir parameters.
基金Supported by China National 111 Project Under Grant No.B07109
文摘The concepts of floating structure plays a very important role in deepwater projects; and the design of the floating structure is one of the most important tasks in the project. The importance of the floating structure in offshore projects can be demonstrated in the following several areas: the substantial dynamic structure responses due to wave loading and current loading; the limited motion requirements of risers in deep water; and the increasing difficulty of installation for different components of the system. Three major technical aspects have to be considered, i.e. the strength of structure, the fatigue resistance capacity of the system, and local and global stability of the structure. This paper reviews the current design practice of floating structures, evaluates the main tasks during the design and associated major technical requirements, and addresses the major technical challenges encountered during the design. As a close-out of the paper, the authors discuss some potential future developments in the design of floating structures.
基金Supported by the'Knowledge-based Ship-design Hyper-integrated Platform(KSHIP)'of Ministry of Education and Finance of P.R.China(No.200512)the National Natural Science Foundation of China(No.51009093)
文摘The paper presents a knowledge-based engineering (KBE) approach for ship node components design. In the ship design process, many design tasks need design experiences to support. Howev- er, a ship design process is a complicated process with many simultaneously repetitive and time-con- suming activities. In this research, the method combines KBE with Tribon system's built-in devel- opment language tools of Vitesse, captures and applies design knowledge for achieving standard com- ponents intelligent design modeling. A case study and industry implementation illustrate the feasibili- ty of the proposed methodology. The KBE technique can provide not only proper references, sug- gests and supports but also knowledge integrated in the ship structure design. Especially, these rules related to the design can avoid lots of design mistakes. During the ship design stage, getting more precise and better designs will not only reduce the time of rework and wasting resources but also shorten the construction time_ imnrov~ clilnl;hz ~nA nrnf;t
基金supported by China State Education Ministry’s Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe Scientific Research Foundation for Young Scholars of Ocean University of China.
文摘Different from the traditional one dimensional extreme value statistical method, practical design criteria for nearshore structure design are presented based on joint probability theory in this paper. The proposed procedure considers the combined effect of tide level, huge waves and wind affecting coastal structures. The Importance Sampling Procedure (ISP) is utilized to solve the joint distribution of non Gaussian correlated multivariate distributions. The calculation results show that the ISP is a simulating technique with the advantages of efficiency and high convergency. Finally the environmental conditions are given using this technique for near shore structure design in the Qingdao area.