Complex adaptive sys tem theory is a new and important embranchment of system science, which prov ides a new thought to research water resources allocation system. Based on the a nalysis of complexity and complex adap...Complex adaptive sys tem theory is a new and important embranchment of system science, which prov ides a new thought to research water resources allocation system. Based on the a nalysis of complexity and complex adaptive mechanism of water resources allocat ion system, a fire-new analysis model is presented in this paper. With t he description of dynamical mechanism of system, behavior characters of agents and the evaluation method of system status, an integrity research system is built to analyse the evolvement rule of water resources allocation system. A nd a brief research for the impact of water resources allocation in benefi cial regions of the Water Transfer from South to North China Project is conducted.展开更多
Within the context of global climate change, achieving sustainable development in Northeast Asia will require in-depth research into the key scientific issues from both theoretical and empirical perspectives. This pap...Within the context of global climate change, achieving sustainable development in Northeast Asia will require in-depth research into the key scientific issues from both theoretical and empirical perspectives. This paper assesses that the main issues to be addressed are：（i） researches on the structure, function and differentiation disciplines of the vast and complex regional resources-environment-socio-economic system that is Northeast Asia and on how the region can respond and evolve. （ii） Failing to find a mode for sustainable development is one of the most serious restrictive factors to development in Northeast Asia. （iii） Development of cross-border regional socio-economic models for sustainable development is essential. And （iv） the strategies above require cross-border technical support platforms to guarantee a consistent approach to regional sustainability in Northeast Asia.展开更多
Background:Subependymal giant cell astrocytoma (SEGA) is a clinically benign brain tumor associated with tuberous sclerosis complex (TSC).There are still controversies on early diagnosis of the tumor.Methods:CT and MR...Background:Subependymal giant cell astrocytoma (SEGA) is a clinically benign brain tumor associated with tuberous sclerosis complex (TSC).There are still controversies on early diagnosis of the tumor.Methods:CT and MR imaging of 20 patients with pathologically confirmed SEGA were retrospectively reviewed.Two radiologists evaluated the location,shape,size,number,edge,cerebral edema,homogeneous or heterogeneous appearance,attenuation and signal intensity,degree of enhancement and calcification of lesions.Their prognoses were based on clinical observations.Results;SEGA showed similar features in imaging:an extra-axial,well-circumscribed,periventricular mass,isodense or slightly hyperdense on CT,hypointensity on T1-weighted imaging and isointensity to hyperintensity on T2-weighted imaging.The mass enhanced markedly and heterogeneously after the administration of contrast agent.Subependymal nodules were demonstrated in 5 cases.Remarkably,17 patients (85％) showed ventricular dilatation and 14 patients (70％) showed calcification in CT and MR imaging.Moreover,perifocal edema was not significantly near the masses.Four cases are associated with tuberous sclerosis complex (TSC).Conclusions:Although there are no pathognomonic imaging findings for SEGA,the following clinical and imaging features might be helpful for the diagnosis,such as the initial age of first or second decade,typical location in the periventricular regions adjacent to the foramen of Monro,hydrocephalus accompanied with raised intracranial pressure,TSC and marked heterogeneous enhancement.展开更多
文摘Complex adaptive sys tem theory is a new and important embranchment of system science, which prov ides a new thought to research water resources allocation system. Based on the a nalysis of complexity and complex adaptive mechanism of water resources allocat ion system, a fire-new analysis model is presented in this paper. With t he description of dynamical mechanism of system, behavior characters of agents and the evaluation method of system status, an integrity research system is built to analyse the evolvement rule of water resources allocation system. A nd a brief research for the impact of water resources allocation in benefi cial regions of the Water Transfer from South to North China Project is conducted.
基金the Principal of State Basic Science Key Project"Comprehensive Scientific Survey in Northern China and Its AdjacentAreas"(Award No.2007FY110300)the National Natural Science Foundation Item"Carbon Emissions Effects and Its ImpactMechanism for the Development of Resource-based City"(Award No.41101117)
文摘Within the context of global climate change, achieving sustainable development in Northeast Asia will require in-depth research into the key scientific issues from both theoretical and empirical perspectives. This paper assesses that the main issues to be addressed are：（i） researches on the structure, function and differentiation disciplines of the vast and complex regional resources-environment-socio-economic system that is Northeast Asia and on how the region can respond and evolve. （ii） Failing to find a mode for sustainable development is one of the most serious restrictive factors to development in Northeast Asia. （iii） Development of cross-border regional socio-economic models for sustainable development is essential. And （iv） the strategies above require cross-border technical support platforms to guarantee a consistent approach to regional sustainability in Northeast Asia.
文摘Background:Subependymal giant cell astrocytoma (SEGA) is a clinically benign brain tumor associated with tuberous sclerosis complex (TSC).There are still controversies on early diagnosis of the tumor.Methods:CT and MR imaging of 20 patients with pathologically confirmed SEGA were retrospectively reviewed.Two radiologists evaluated the location,shape,size,number,edge,cerebral edema,homogeneous or heterogeneous appearance,attenuation and signal intensity,degree of enhancement and calcification of lesions.Their prognoses were based on clinical observations.Results;SEGA showed similar features in imaging:an extra-axial,well-circumscribed,periventricular mass,isodense or slightly hyperdense on CT,hypointensity on T1-weighted imaging and isointensity to hyperintensity on T2-weighted imaging.The mass enhanced markedly and heterogeneously after the administration of contrast agent.Subependymal nodules were demonstrated in 5 cases.Remarkably,17 patients (85％) showed ventricular dilatation and 14 patients (70％) showed calcification in CT and MR imaging.Moreover,perifocal edema was not significantly near the masses.Four cases are associated with tuberous sclerosis complex (TSC).Conclusions:Although there are no pathognomonic imaging findings for SEGA,the following clinical and imaging features might be helpful for the diagnosis,such as the initial age of first or second decade,typical location in the periventricular regions adjacent to the foramen of Monro,hydrocephalus accompanied with raised intracranial pressure,TSC and marked heterogeneous enhancement.
