TOptimization of regional landscape pattern is significant for improving function and value of ecosystem,and restraining the expansion of urban layout.Taking Chengdu City for example,this paper applied RS and GIS tech...TOptimization of regional landscape pattern is significant for improving function and value of ecosystem,and restraining the expansion of urban layout.Taking Chengdu City for example,this paper applied RS and GIS techniques,landscape indexes and ecological service function evaluation to further analyze the temporal and spatial characteristics of landscape pattern and spatial differences of regional ecological functions,and on this basis,identified the spatial distribution of ecological source lands.Based on the long-term objective of building Chengdu into a modem garden city,this paper applied the accumulative cost distance model and introduced garden city theory to construct regional ecological corridors and ecological nodes,and explored the approaches of optimizing landscape pattern of modem garden city.The results showed that a great deal of arable land has been transferred to construction land in the urbanization;intensity of regional ecological functions showed obvious spatial differences;ecological source lands were mainly distributed in the Longmen Mountain,the Qionglai Mountain,the Changqiu Mountain and the Longquan Mountain;according to actual conditions of the study area,the road ecological corridors,river corridors and agricultural corridors in the layout of "four rings and six radial corridors" were constructed;ecological nodes dominated by intersection,wetland and forest park were formed.This research method and results are significant references for building Chengdu into a modem garden展开更多
In view of the seriously-polluted water and broken eco-waterscapes in the Qiusuo Brook on campus of China Three Gorges University,this paper proposed the ecological restoration concept and mode of campus river accordi...In view of the seriously-polluted water and broken eco-waterscapes in the Qiusuo Brook on campus of China Three Gorges University,this paper proposed the ecological restoration concept and mode of campus river according to field investigation and monitoring results,i.e. "reduce exogenous pollution—restore sediment microorganism—build intensified plant filter strip—build river water ecosystem and optimize landscapes—maintain ecological river course".In addition to introducing the design concept and principle of this mode,this paper specified the concrete projects such as sewage interception and water supplement,restoration of sediment microorganism,restoration of water plants,ecological restoration of embankment etc.,and also gave planar layouts and sketches of some projects,in order to provide references for the researches and practices of campus river ecological restoration in China Three Gorges University and other similar projects.展开更多
Optimization is ubiquitous in the control of quantum dynamics in atomic,molecular,and optical systems.The ease or difficulty of finding control solutions,which is practically crucial for developing quantum technologie...Optimization is ubiquitous in the control of quantum dynamics in atomic,molecular,and optical systems.The ease or difficulty of finding control solutions,which is practically crucial for developing quantum technologies,is highly dependent on the geometry of the underlying optimization landscapes.In this review,we give an introduction to the basic concepts in the theory of quantum optimal control landscapes,and their trap-free critical topology under two fundamental assumptions.Furthermore,the effects of various factors on the search effort are discussed,including control constraints,singularities,saddles,noises,and non-topological features of the landscapes.Additionally,we review recent experimental advances in the control of molecular and spin systems.These results provide an overall understanding of the optimization complexity of quantum control dynamics,which may help to develop more efficient optimization algorithms for quantum control systems,and as a promising extension,the training processes in quantum machine learning.展开更多
基金Sponsored by National"Twelfth Five-year Plan"Science and Technology Support Program(2012BAJ21B08)Program of the Ministry of Environmental Protection
文摘TOptimization of regional landscape pattern is significant for improving function and value of ecosystem,and restraining the expansion of urban layout.Taking Chengdu City for example,this paper applied RS and GIS techniques,landscape indexes and ecological service function evaluation to further analyze the temporal and spatial characteristics of landscape pattern and spatial differences of regional ecological functions,and on this basis,identified the spatial distribution of ecological source lands.Based on the long-term objective of building Chengdu into a modem garden city,this paper applied the accumulative cost distance model and introduced garden city theory to construct regional ecological corridors and ecological nodes,and explored the approaches of optimizing landscape pattern of modem garden city.The results showed that a great deal of arable land has been transferred to construction land in the urbanization;intensity of regional ecological functions showed obvious spatial differences;ecological source lands were mainly distributed in the Longmen Mountain,the Qionglai Mountain,the Changqiu Mountain and the Longquan Mountain;according to actual conditions of the study area,the road ecological corridors,river corridors and agricultural corridors in the layout of "four rings and six radial corridors" were constructed;ecological nodes dominated by intersection,wetland and forest park were formed.This research method and results are significant references for building Chengdu into a modem garden
基金Sponsored by Science Fund of China Three Gorges University(KJ2011B028)National Science Foundation for Young Scientists of China(41401586)
文摘In view of the seriously-polluted water and broken eco-waterscapes in the Qiusuo Brook on campus of China Three Gorges University,this paper proposed the ecological restoration concept and mode of campus river according to field investigation and monitoring results,i.e. "reduce exogenous pollution—restore sediment microorganism—build intensified plant filter strip—build river water ecosystem and optimize landscapes—maintain ecological river course".In addition to introducing the design concept and principle of this mode,this paper specified the concrete projects such as sewage interception and water supplement,restoration of sediment microorganism,restoration of water plants,ecological restoration of embankment etc.,and also gave planar layouts and sketches of some projects,in order to provide references for the researches and practices of campus river ecological restoration in China Three Gorges University and other similar projects.
基金support by the National Key R&D Program of China(No.2018YFA0306703)National Natural Science Foundation of China(NSFC)(Nos.61833010 and 61773232)a grant from the Institute for Guo Qiang,Tsinghua University.H.Rabitz acknowledges the support of US Department of Energy(No.DE-FGO2-O2ER15344).
文摘Optimization is ubiquitous in the control of quantum dynamics in atomic,molecular,and optical systems.The ease or difficulty of finding control solutions,which is practically crucial for developing quantum technologies,is highly dependent on the geometry of the underlying optimization landscapes.In this review,we give an introduction to the basic concepts in the theory of quantum optimal control landscapes,and their trap-free critical topology under two fundamental assumptions.Furthermore,the effects of various factors on the search effort are discussed,including control constraints,singularities,saddles,noises,and non-topological features of the landscapes.Additionally,we review recent experimental advances in the control of molecular and spin systems.These results provide an overall understanding of the optimization complexity of quantum control dynamics,which may help to develop more efficient optimization algorithms for quantum control systems,and as a promising extension,the training processes in quantum machine learning.