A novel technique of three-dimensional (3D) reconstruction, segmentation, display and analysis of series slices of images including microscopic wide field optical sectioning by deconvolution method, cryo-electron micr...A novel technique of three-dimensional (3D) reconstruction, segmentation, display and analysis of series slices of images including microscopic wide field optical sectioning by deconvolution method, cryo-electron microscope slices by Fou-rier-Bessel synthesis and electron tomography (ET), and a series of computed tomography (CT) was developed to perform si-multaneous measurement on the structure and function of biomedical samples. The paper presents the 3D reconstruction seg-mentation display and analysis results of pollen spore, chaperonin, virus, head, cervical bone, tibia and carpus. At the same time, it also puts forward some potential applications of the new technique in the biomedical realm.展开更多
An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the ma...An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the main stress trajectories as the representation of force flows on a free-form surface,an automatic grid generation approach is proposed for the architectural design.The algorithm automatically plots the main stress trajectories on a 3D free-form surface,and adopts a modified advancing front meshing technique to generate the structural grid.Based on the proposed algorithm,an automatic grid generator named "St-Surmesh" is developed for the practical architectural design of free-form surface structure.The surface geometry of one of the Sun Valleys in Expo Axis for the Expo Shanghai 2010 is selected as a numerical example for validating the proposed approach.Comparative studies are performed to demonstrate how different structural grids affect the design of a free-form surface structure.展开更多
Observations indicate that global radiation reaching the Earth's surface has gradually decreased over the past several decades(i.e.,the "global dimming" phenomenon),while the fraction of diffuse radiatio...Observations indicate that global radiation reaching the Earth's surface has gradually decreased over the past several decades(i.e.,the "global dimming" phenomenon),while the fraction of diffuse radiation in global radiation has increased.It has been found that the increase in diffuse fraction significantly increases photosynthetic production in the canopy,but the mechanism has not been clarified.A three-dimensional light distribution model considering the geometry of incident radiation was employed in this study.This model was used to simulate the light distribution and potential photosynthetic production of rice canopy.The results indicate that the potential photosynthetic production of rice significantly increases in response to an increase in the diffuse fraction as long as global radiation does not decline greatly.The "fertilization effect" of diffuse radiation results from the reduction of leaf area with photosynthetic photon flux density(PPFD) below the light compensation point in response to an increasing diffuse fraction,and an increase in the leaf area with PPFD on the linear part of the light response curve.The increase in the diffuse fraction results in a significant increase in the photosynthetic rate of the upper canopy.High-performance computation is an easy-to-use and economic approach to overcome the computational constraints of the model.展开更多
文摘A novel technique of three-dimensional (3D) reconstruction, segmentation, display and analysis of series slices of images including microscopic wide field optical sectioning by deconvolution method, cryo-electron microscope slices by Fou-rier-Bessel synthesis and electron tomography (ET), and a series of computed tomography (CT) was developed to perform si-multaneous measurement on the structure and function of biomedical samples. The paper presents the 3D reconstruction seg-mentation display and analysis results of pollen spore, chaperonin, virus, head, cervical bone, tibia and carpus. At the same time, it also puts forward some potential applications of the new technique in the biomedical realm.
基金Project(51378457)supported by the National Natural Science Foundation of China
文摘An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the main stress trajectories as the representation of force flows on a free-form surface,an automatic grid generation approach is proposed for the architectural design.The algorithm automatically plots the main stress trajectories on a 3D free-form surface,and adopts a modified advancing front meshing technique to generate the structural grid.Based on the proposed algorithm,an automatic grid generator named "St-Surmesh" is developed for the practical architectural design of free-form surface structure.The surface geometry of one of the Sun Valleys in Expo Axis for the Expo Shanghai 2010 is selected as a numerical example for validating the proposed approach.Comparative studies are performed to demonstrate how different structural grids affect the design of a free-form surface structure.
基金supported by National High Technology Research and Development Program of China (Grant No. 2006AA10Z231)National Key Technologies R & D Program (Grant No. 2007BAD87B08)Chinese Universities Scientific Fund (Grant No. 2009-3-14)
文摘Observations indicate that global radiation reaching the Earth's surface has gradually decreased over the past several decades(i.e.,the "global dimming" phenomenon),while the fraction of diffuse radiation in global radiation has increased.It has been found that the increase in diffuse fraction significantly increases photosynthetic production in the canopy,but the mechanism has not been clarified.A three-dimensional light distribution model considering the geometry of incident radiation was employed in this study.This model was used to simulate the light distribution and potential photosynthetic production of rice canopy.The results indicate that the potential photosynthetic production of rice significantly increases in response to an increase in the diffuse fraction as long as global radiation does not decline greatly.The "fertilization effect" of diffuse radiation results from the reduction of leaf area with photosynthetic photon flux density(PPFD) below the light compensation point in response to an increasing diffuse fraction,and an increase in the leaf area with PPFD on the linear part of the light response curve.The increase in the diffuse fraction results in a significant increase in the photosynthetic rate of the upper canopy.High-performance computation is an easy-to-use and economic approach to overcome the computational constraints of the model.
