A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to fo...A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to focus the effect of percolation pattern on accumulation of cupper （Cu） and cadmium （Cd） in rice plants in contaminated paddy filed with soil dressing models. Percolation pattern has significant effect on soil environment, especially redox potential that may influence mobilization of Cd, Cu and other elements. In open system percolation models, the plowsole and subsoil were in oxidative condition （600 mV）, whereas reduction condition （-200 mV） was measured in closed system percolation models. Accumulations of Cu and Cd in all parts of rice plants （roots, grains, stems and leaves） were found higher in an open system percolation with the paddy field model comparatively than in a closed system percolation. The soil redox （Eh） condition influenced by the percolation pattern might be one of the main factors for uptake and accumulation of Cu and Cd in rice plants. The plant height and stem number were found lower in open system percolation comparatively to closed system percolation. In the yields section, the average panicle length, number of panicle and rice grain/hill and weight of grain/hill were lower in open system percolation than the closed system percolation.展开更多
Facilities connectivity is a priority area for implementing the Belt and Road Initiative(BRI). The "China-Europe Railway Express"(CER Express) mode of transport organization links China with Europe by fast-t...Facilities connectivity is a priority area for implementing the Belt and Road Initiative(BRI). The "China-Europe Railway Express"(CER Express) mode of transport organization links China with Europe by fast-track cargo rail. A major instance of facilities connectivity related to this project is an important practical and symbolic instance of BRI transport cooperation. The strategic significance of the CER Express and a number of operational issues are outlined, as are the implications of limited market potential for costs and competitiveness. A "hub-and-spoke" organizational model that can generate scale economies and reduce costs is proposed. To examine the establishment of an organizational model of this kind, the economic hinterlands of Alashankou, Erenhot, and Manzhouli are identified under high-, mediumand low-cost scenarios using an analytical methodology that determines distance and economic costs, and a number of transport hubs(that include Harbin, Zhengzhou, and Lanzhou) are identified. The results found that the cost of the routes from 314 Chinese cities to Moscow is the lowest via Manzhouli in the high-and medium-cost scenarios, but the routes change via Erenhot in the low-cost scenario. A number of policy recommendations should follow up.展开更多
文摘A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to focus the effect of percolation pattern on accumulation of cupper （Cu） and cadmium （Cd） in rice plants in contaminated paddy filed with soil dressing models. Percolation pattern has significant effect on soil environment, especially redox potential that may influence mobilization of Cd, Cu and other elements. In open system percolation models, the plowsole and subsoil were in oxidative condition （600 mV）, whereas reduction condition （-200 mV） was measured in closed system percolation models. Accumulations of Cu and Cd in all parts of rice plants （roots, grains, stems and leaves） were found higher in an open system percolation with the paddy field model comparatively than in a closed system percolation. The soil redox （Eh） condition influenced by the percolation pattern might be one of the main factors for uptake and accumulation of Cu and Cd in rice plants. The plant height and stem number were found lower in open system percolation comparatively to closed system percolation. In the yields section, the average panicle length, number of panicle and rice grain/hill and weight of grain/hill were lower in open system percolation than the closed system percolation.
基金A Category of Strategic Priority Research National Program of the Chinese Academy of Sciences,No.XDA20010101National Natural Science Foundation of China,No.41722103Ministry of Education of Humanities and Social Science Youth Fund Project,No.17YJC790064
文摘Facilities connectivity is a priority area for implementing the Belt and Road Initiative(BRI). The "China-Europe Railway Express"(CER Express) mode of transport organization links China with Europe by fast-track cargo rail. A major instance of facilities connectivity related to this project is an important practical and symbolic instance of BRI transport cooperation. The strategic significance of the CER Express and a number of operational issues are outlined, as are the implications of limited market potential for costs and competitiveness. A "hub-and-spoke" organizational model that can generate scale economies and reduce costs is proposed. To examine the establishment of an organizational model of this kind, the economic hinterlands of Alashankou, Erenhot, and Manzhouli are identified under high-, mediumand low-cost scenarios using an analytical methodology that determines distance and economic costs, and a number of transport hubs(that include Harbin, Zhengzhou, and Lanzhou) are identified. The results found that the cost of the routes from 314 Chinese cities to Moscow is the lowest via Manzhouli in the high-and medium-cost scenarios, but the routes change via Erenhot in the low-cost scenario. A number of policy recommendations should follow up.
