This paper firstly investigated the land-use and land-cover change （LUCC） in the Hun-Taizi River water- shed, Northeast China from 1988 to 2004 based on remotely sensed images and geographic information systems （GI...This paper firstly investigated the land-use and land-cover change （LUCC） in the Hun-Taizi River water- shed, Northeast China from 1988 to 2004 based on remotely sensed images and geographic information systems （GIS） technology. Then, using the famous land-use change model of Conversion of Land Use and its Effects at Small re- gional extent （CLUE-S）, this paper simulated the land use changes under historical trend （HT）, urban planning （UP） and ecological protection （EP） scenarios considering urban planning and ecological protection over the next 20 years. The simulated results under UP scenario in 2020 were compared with the planning map to assess the feasibility of us- ing land-use change model to guide regional planning. Results show that forest land, dry farmland, paddy, and shrub land were the main land-use categories. Paddy and dry farmland being converted to urban area and rural settlement characterized the land-use change from 1988 to 2004. The main land-use categories changed over time. Landscape-pattem fragmentation will be worse under HT and UP scenarios, but better in EP scenario. The comparing results of simulated map with planning map in 2020 show that land-use change model is powerful tool to guide regional planning. Land-use scenarios can support regional planning and policy-making through analyzing future consequences scientifically.展开更多
In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, t...In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-160 scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.展开更多
Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy ban...Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy bands.Nose events have been studied extensively both with observations and simulations since first discovered in 1970s.In this study we use the UBK method to model the different L-shell penetration characteristics for a multi-band nose event observed by Cluster/CODIF on April 11,2002.The modeled open-closed orbit separatrices are generally smaller than the observed L-shell penetrations for outbound crossing;the difference varies from 2.02 to 0.62 R E for different energy channels of H + bands and from 1.88 to 1.10 R E for O + band.The average difference is 1.46 R E.The separatrices for the inbound crossing are generally larger than those of outbound crossing and are more consistent with the observed L-shell penetration depths.The modeled open-closed orbit separatrices are smaller than the observed L-shell penetrations for 6.5-17.1 keV energy channels of H + bands but larger for 4.0-5.1 keV(due to closed banana orbits region) and 21.7-35.2 keV(due to energy increasing) energy channels of H + bands.For O + band,the difference between the modeled open-closed orbit separatrix and observed L-shell penetrations of 4.6 keV energy channel is larger(due to closed banana orbits region),the difference of 7.4 keV energy channel is smaller.The overall average difference is 0.043 R E for nose structures of inbound crossing.The discrepancies between the model and observation may come from the magnetic field and electric potential models we used.The formation of multi nose event and relations to the observed plasma flow vortices are discussed,the local intense E Y may relate to the formation of the observed multi nose structures.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.40801069)Special Research Program for Public-welfare Forestry of China(No.200804001)
文摘This paper firstly investigated the land-use and land-cover change （LUCC） in the Hun-Taizi River water- shed, Northeast China from 1988 to 2004 based on remotely sensed images and geographic information systems （GIS） technology. Then, using the famous land-use change model of Conversion of Land Use and its Effects at Small re- gional extent （CLUE-S）, this paper simulated the land use changes under historical trend （HT）, urban planning （UP） and ecological protection （EP） scenarios considering urban planning and ecological protection over the next 20 years. The simulated results under UP scenario in 2020 were compared with the planning map to assess the feasibility of us- ing land-use change model to guide regional planning. Results show that forest land, dry farmland, paddy, and shrub land were the main land-use categories. Paddy and dry farmland being converted to urban area and rural settlement characterized the land-use change from 1988 to 2004. The main land-use categories changed over time. Landscape-pattem fragmentation will be worse under HT and UP scenarios, but better in EP scenario. The comparing results of simulated map with planning map in 2020 show that land-use change model is powerful tool to guide regional planning. Land-use scenarios can support regional planning and policy-making through analyzing future consequences scientifically.
基金The project supported by National Natural Science Foundation of China under Grant No. 10465001
文摘In the framework of KMT multiple scattering theory, an optical potential for the intermediate energy proton-160 elastic scattering is presented based on the α particle model of 160. The differential cross sections, the analyzing powers, and the total cross sections of the intermediate energy proton-160 scattering have been calculated by using the obtained optical potential. The main features of the measured angular distributions of the cross section and the analyzing power can be well described. The calculated total cross sections are in good agreement with the experimental data at energies below 0.7 GeV and underestimate the data about 8% at higher energies.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40831061,41074117)
文摘Nose event,which names after the nose-like shape of structures in ion spectrograms observed by satellite in the inner magnetosphere,refers to the deep inward penetration of ions from magnetotail at discrete energy bands.Nose events have been studied extensively both with observations and simulations since first discovered in 1970s.In this study we use the UBK method to model the different L-shell penetration characteristics for a multi-band nose event observed by Cluster/CODIF on April 11,2002.The modeled open-closed orbit separatrices are generally smaller than the observed L-shell penetrations for outbound crossing;the difference varies from 2.02 to 0.62 R E for different energy channels of H + bands and from 1.88 to 1.10 R E for O + band.The average difference is 1.46 R E.The separatrices for the inbound crossing are generally larger than those of outbound crossing and are more consistent with the observed L-shell penetration depths.The modeled open-closed orbit separatrices are smaller than the observed L-shell penetrations for 6.5-17.1 keV energy channels of H + bands but larger for 4.0-5.1 keV(due to closed banana orbits region) and 21.7-35.2 keV(due to energy increasing) energy channels of H + bands.For O + band,the difference between the modeled open-closed orbit separatrix and observed L-shell penetrations of 4.6 keV energy channel is larger(due to closed banana orbits region),the difference of 7.4 keV energy channel is smaller.The overall average difference is 0.043 R E for nose structures of inbound crossing.The discrepancies between the model and observation may come from the magnetic field and electric potential models we used.The formation of multi nose event and relations to the observed plasma flow vortices are discussed,the local intense E Y may relate to the formation of the observed multi nose structures.
