A geometrically similar scaling was made from small-scale specimen to full-scale stiffened panels and then their collapse behaviour is investigated. It is considered that the stiffened panel compressive ultimate stren...A geometrically similar scaling was made from small-scale specimen to full-scale stiffened panels and then their collapse behaviour is investigated. It is considered that the stiffened panel compressive ultimate strength test was designed according to geometrical scaling laws so that the output of the test could be used as representative of the stiffened panels of the compressive zone of a tanker hull subjected to vertical bending moment. The ultimate strength of a tanker hull is analysed by a FE analysis using the experimentally developed master stress-strain curves which are obtained by the beam tension test and the compressive test of the stiffened panel, and are then compared with the result achieved by the progressive collapse method.展开更多
MGAC (Motion Geometric Active Contours), a new variational framework of geometric active contours to track multiple nonrigid moving objects in the clutter background in image sequences is presented. This framework, in...MGAC (Motion Geometric Active Contours), a new variational framework of geometric active contours to track multiple nonrigid moving objects in the clutter background in image sequences is presented. This framework, incorporating with the motion edge information, consists of motion detection and tracking stages. At the motion detection stage, the motion edge map provides an approximate edge map of the moving objects. Then, a tracking stage, merely using the static edge information, is considered to improve the motion detection result. Force field regularization method is used to extend the capture range of the edge attraction force field in both stages. Experiments demonstrate that the proposed framework is valid for tracking multiple nonrigid objects in the clutter background.展开更多
With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the...With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the ongoing provision of benefits of stakeholders are characteristics of cultural routes. Therefore, the importance of cooperative relations and systematic development among stakeholders in tourism activities along cultural routes has become a subject of interest. This paper selects local government, tourism enterprises and local community residents, all of which play a key role in the Ancient Tea Horse Road cultural route in the south of Yunnan, as the main stakeholders. We use game theory to construct a model to trace interactions between local government and tourism enterprises, between tourism enterprises and community residents, and between local government and community residents. The paper then analyzes the different interests of the three parties and key factors that influence them in the game process. This provided a certain scientific basis for the win-win decisions regarding tourism development made by the three parties. Our results show that the final decision choices of the three parties depend on the initial payoff matrix of the game, and the influence of key parameters. When making decisions about tourism, the government should respect the wishes of local residents, strengthen protections of local traditions, manage the unreasonable behavior of tourism enterprises as they develop tourism, and develop appropriate penalties for violations of regulations. When tourism enterprises carry out tourism development, they should let community residents take the initiative and fully participate in tourism activities, and be sure that income from tourism is fed back to local residents, to ensure that tourism is mutually beneficial. The study shows that conflicts among the three parties originated mainly from differences in interests, but that the three parties also shared common interests. With a goal of coordinating interests, we can establish relevant mechanisms, follow the principle of interest realization, attach importance to supervision and management, strengthen community participation and decision-making, and realize win-win results for the three parties.展开更多
To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then ...To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then withdrawn for several days by aortic debanding,followed by subsequent myocardial exposure to ischemia/reperfusion(I/R).Following I/R injury,the myocardial infarct size and apoptosis were markedly reduced,and contractile function was significantly improved in the TAC preconditioning group compared with the control group.Mechanistically,hypertrophic preconditioning remarkably alleviated I/R-induced oxidative stress,as evidenced by the increased reduced nicotinamide adenine dinucleotide phosphate(NADPH)/nicotinamide adenine dinucleotide phosphate(NADP)ratio,increase in the reduced glutathione(GSH)/oxidized glutathione(GSSH)ratio,and reduced mitochondrial reactive oxygen species(ROS)production.Moreover,TAC preconditioning inhibited caspase-3 activation and mitigated the mitochondrial impairment by deacetylating isocitrate dehydrogenase 2(IDH2)via a sirtuin 3(SIRT3)-dependent mechanism.In addition,the expression of a genetic deacetylation mimetic IDH2 mutant(IDH2 K413R)in cardiomyocytes,which increased IDH2 enzymatic activity and decreased mitochondrial ROS production,and ameliorated I/R injury,whereas the expression of a genetic acetylation mimetic(IDH2 K413Q)in cardiomyocytes abolished these protective effects of hypertrophic preconditioning.Furthermore,both the activity and expression of the SIRT3 protein were markedly increased in preconditioned mice exposed to I/R.Treatment with an adenovirus encoding SIRT3 partially emulated the actions of hypertrophic preconditioning,whereas genetic ablation of SIRT3 in mice blocked the cardioprotective effects of hypertrophic preconditioning.The present study identifies hypertrophic preconditioning as a novel endogenous self-defensive and cardioprotective strategy for cardiac I/R injury that induces IDH2 deacetylation through a SIRT3-dependent mechanism.A therapeutic strategy targeting IDH2 may be a promising treatment for cardiac ischemic injury.展开更多
The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we...The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we formulate the principal radii for two kinds of catenary shells of revolution and their displacement type governing equations.Numerical simulations are carried out based on both Reissner-Meissner(R-M)mixed formulations and displacement formulations.Our investigations show that both deformation and stress response of elastic catenary shells of revolution are sensitive to its geometric parameter c,and reveal that the mechanics of the catenary shells of revolution has some advantages over the spherical shell for some loadings.Two complete codes in Maple are provided.展开更多
基金financed by the Portuguese Foundation for Science and Technology (Fundao para a Ciência e Tecnologia), under contract SFRH/BD/65120/2009
文摘A geometrically similar scaling was made from small-scale specimen to full-scale stiffened panels and then their collapse behaviour is investigated. It is considered that the stiffened panel compressive ultimate strength test was designed according to geometrical scaling laws so that the output of the test could be used as representative of the stiffened panels of the compressive zone of a tanker hull subjected to vertical bending moment. The ultimate strength of a tanker hull is analysed by a FE analysis using the experimentally developed master stress-strain curves which are obtained by the beam tension test and the compressive test of the stiffened panel, and are then compared with the result achieved by the progressive collapse method.
文摘MGAC (Motion Geometric Active Contours), a new variational framework of geometric active contours to track multiple nonrigid moving objects in the clutter background in image sequences is presented. This framework, incorporating with the motion edge information, consists of motion detection and tracking stages. At the motion detection stage, the motion edge map provides an approximate edge map of the moving objects. Then, a tracking stage, merely using the static edge information, is considered to improve the motion detection result. Force field regularization method is used to extend the capture range of the edge attraction force field in both stages. Experiments demonstrate that the proposed framework is valid for tracking multiple nonrigid objects in the clutter background.
基金The Key Projects of Philosophy and Social Science Research Base in Yunnan Province (JD2019ZD03)The Ministry of Culture and Tourism of People’s Republic of China (WMYC20181-083)。
文摘With the emergence of the concept of cultural routes, researchers have increasingly turned their attention to the sustainable development of tourism along cultural routes. The needs for community participation and the ongoing provision of benefits of stakeholders are characteristics of cultural routes. Therefore, the importance of cooperative relations and systematic development among stakeholders in tourism activities along cultural routes has become a subject of interest. This paper selects local government, tourism enterprises and local community residents, all of which play a key role in the Ancient Tea Horse Road cultural route in the south of Yunnan, as the main stakeholders. We use game theory to construct a model to trace interactions between local government and tourism enterprises, between tourism enterprises and community residents, and between local government and community residents. The paper then analyzes the different interests of the three parties and key factors that influence them in the game process. This provided a certain scientific basis for the win-win decisions regarding tourism development made by the three parties. Our results show that the final decision choices of the three parties depend on the initial payoff matrix of the game, and the influence of key parameters. When making decisions about tourism, the government should respect the wishes of local residents, strengthen protections of local traditions, manage the unreasonable behavior of tourism enterprises as they develop tourism, and develop appropriate penalties for violations of regulations. When tourism enterprises carry out tourism development, they should let community residents take the initiative and fully participate in tourism activities, and be sure that income from tourism is fed back to local residents, to ensure that tourism is mutually beneficial. The study shows that conflicts among the three parties originated mainly from differences in interests, but that the three parties also shared common interests. With a goal of coordinating interests, we can establish relevant mechanisms, follow the principle of interest realization, attach importance to supervision and management, strengthen community participation and decision-making, and realize win-win results for the three parties.
基金supported by the National Natural Science Foundation of China(81870290,81521001,81800235,and 81800238)。
文摘To test the hypothesis that transient nonischemic stimulation of hypertrophy would render the heart resistant to subsequent ischemic stress,short-term transverse aortic constriction(TAC)was performed in mice and then withdrawn for several days by aortic debanding,followed by subsequent myocardial exposure to ischemia/reperfusion(I/R).Following I/R injury,the myocardial infarct size and apoptosis were markedly reduced,and contractile function was significantly improved in the TAC preconditioning group compared with the control group.Mechanistically,hypertrophic preconditioning remarkably alleviated I/R-induced oxidative stress,as evidenced by the increased reduced nicotinamide adenine dinucleotide phosphate(NADPH)/nicotinamide adenine dinucleotide phosphate(NADP)ratio,increase in the reduced glutathione(GSH)/oxidized glutathione(GSSH)ratio,and reduced mitochondrial reactive oxygen species(ROS)production.Moreover,TAC preconditioning inhibited caspase-3 activation and mitigated the mitochondrial impairment by deacetylating isocitrate dehydrogenase 2(IDH2)via a sirtuin 3(SIRT3)-dependent mechanism.In addition,the expression of a genetic deacetylation mimetic IDH2 mutant(IDH2 K413R)in cardiomyocytes,which increased IDH2 enzymatic activity and decreased mitochondrial ROS production,and ameliorated I/R injury,whereas the expression of a genetic acetylation mimetic(IDH2 K413Q)in cardiomyocytes abolished these protective effects of hypertrophic preconditioning.Furthermore,both the activity and expression of the SIRT3 protein were markedly increased in preconditioned mice exposed to I/R.Treatment with an adenovirus encoding SIRT3 partially emulated the actions of hypertrophic preconditioning,whereas genetic ablation of SIRT3 in mice blocked the cardioprotective effects of hypertrophic preconditioning.The present study identifies hypertrophic preconditioning as a novel endogenous self-defensive and cardioprotective strategy for cardiac I/R injury that induces IDH2 deacetylation through a SIRT3-dependent mechanism.A therapeutic strategy targeting IDH2 may be a promising treatment for cardiac ischemic injury.
基金supported by Xi'an University of Architecture and Technology(Grant No.002/2040221134).
文摘The catenary shells of revolution are widely used in church constructions due to their unique mechanics'features.To have a better understanding of the deformation and stress of the catenary shells of revolution,we formulate the principal radii for two kinds of catenary shells of revolution and their displacement type governing equations.Numerical simulations are carried out based on both Reissner-Meissner(R-M)mixed formulations and displacement formulations.Our investigations show that both deformation and stress response of elastic catenary shells of revolution are sensitive to its geometric parameter c,and reveal that the mechanics of the catenary shells of revolution has some advantages over the spherical shell for some loadings.Two complete codes in Maple are provided.
