| 2 | He-enhanced heterogeneity of radiation-induced segregation in FeNiCoCr high-entropy alloy显示文摘Radiation-induced segregation(RIS) is a typical non-equilibrium process that can dramatically alter the behavior of defect sinks and material properties under irradiation. However, RIS mechanisms have been rarely studied around small He bubbles owing to the technical challenges involved in direct measurements of local chemistry. Here, using state-of-the-art atom probe tomography, we report the RIS behavior near He bubbles in the Fe Ni Co Cr high-entropy alloy that indicates Co segregates most strongly, followed by weaker Ni segregation, whereas Fe and Cr are depleted almost to the same degree. Exceptionally, the magnitude of Co segregation around He bubbles is higher than previously measured values at voids and dislocation loops. Electron energy-loss spectroscopy was used to measure the He density and pressure inside individual bubbles. We demonstrate that He bubbles are over-pressurized at the irradiation temperature that could result in the vacancy bias and the subsequent vacancy-dominated RIS mechanism.First-principles calculations further reveal that there are repulsive interactions between He and Co atoms that may reduce the frequency of Co-vacancy exchange. As a result, He atoms likely retard Co diffusion via the vacancy mechanism and enhance the heterogeneity of RIS in Co-containing multicomponent alloys. These insights could provide the basis for understanding He effects in nuclear materials and open an avenue for tailoring the local chemical order of medium-and high-entropy alloys. | W.T.Lin G.M.Yeli G.Wang J.H.Lin S.J.Zhao D.Chen S.F.Liu F.L.Meng Y.R.Li F.He Y.Lu J.J.Kai | 2022 | Journal of Materials Science & Technology2022，，6： | 0 |
| 3 | DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR MANAGING PESTICIDE LOSSES IN AGRICULTURAL WATERSHEDS显示文摘In this study, a decision support system for managing pesticides losses in agricultural watersheds, based on a number of simulation, GIS and RS technologies was developed. The system allows acquisition of information through not only on-site survey but also RS technologies. Aerial photographs were used to generate DEM, and a set of terrain analysis methods were employed to calculate hydrological parameters that are needed for the pesticide loss model. The system also facilitates convenient management and presentation of vast amounts of modeling inputs and outputs through user interfaces. A case study in the Kintore Creek Watershed, Ontario, Canada was undertaken to provide bases for environmental management in the watershed and to demonstrate practical applicability of the developed DSS. The modeling outputs were verified through monitoring data, demonstrating reasonable prediction accuracy. The result indicated that the model provides an effective means for forecasting pesticide losses from agriculture lands. Especially, incorporation of GIS and remote sensing with the pesticides losses model provide a powerful tool for system simulation and environmental management. The major contribution of this study is the development of a new integrated modeling system for simulating fate of pesticides in agricultural lands, as well as its application to a real Canadian case study. In detail, a dynamic simulation model was developed, a solution algorithm was implemented, and the modeling results were verified. The developed simulator was also enhanced through incorporation of GIS and RS technologies within its framework to facilitate effective data acquisition and management, as well as input/output presentation. DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR MANAGING PESTICIDE LOSSES IN AGRICULTURAL WATERSHEDS Y.-F. LI1, Y. R. LI2, G. H. HUANG2, J. STRUGER3, J. D. FISCHER4, Xinzhu WANG5, B. CHEN2, J. B. LI2 and X. H. NIE2 ABSTRACT In this study, a decision support system for managing pesticides losses in agricultural watersheds, based on a number of simulation, GIS and RS technologies was developed. The system allows acquisition of information through not only on-site survey but also RS technologies. Aerial photographs were used to generate DEM, and a set of terrain analysis methods were employed to calculate hydrological parameters that are needed for the pesticide loss model. The system also facilitates convenient management and presentation of vast amounts of modeling inputs and outputs through user interfaces. A case study in the Kintore Creek Watershed, Ontario, Canada was undertaken to provide bases for environmental management in the watershed and to demonstrate practical applicability of the developed DSS. The modeling outputs were verified through monitoring data, demonstrating reasonable prediction accuracy. The result indicated that the model provides an effective means for forecasting pesticide losses from agriculture lands. Especially, incorporation of GIS and remote sensing with the pesticides losses model provide a powerful tool for system simulation and environmental management. The major contribution of this study is the development of a new integrated modeling system for simulating fate of pesticides in agricultural lands, as well as its application to a real Canadian case study. In detail, a dynamic simulation model was developed, a solution algorithm was implemented, and the modeling results were verified. The developed simulator was also enhanced through incorporation of GIS and RS technologies within its framework to facilitate effective data acquisition and management, as well as input/output presentation. Key Words: Agriculture, Decision, GIS, Nonpoint source, Pesticide, Rainfall, Remote sensing, Runoff, Simulation, | Y.-F.LI Y.R.LI G.H.HUANG J.STRUGER J.D.FISCHER B.CHEN J.B.LI X.H.NIE | 2003 | International Journal of Sediment Research2003，18，1： | 0 |
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