Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also inc...Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also increase nutrient availability to plants. To test this premise, four application rates （0.0 g·kg^-1, 0.33 g·kg^-1, 1.66 g·kg^-1, 3.33 g·kg^-1 and 6.66 g·kg^-1） ofa PAM were mixed with sandy and loamy soils to evaluate its effect on nutrient leaching and retention in these soils. Miscible displacements of chloride were conducted on columns of PAM-soil mixtures and results were evaluated by an equilibrium CDE （convection dispersion equation） model. Increasing the PAM rates up to 1.66 g·kg^-1 resulted in increased early appearance and dispersive transport of chloride in sand. In addition, increasing the PAM rates gradually caused increased tailing of the breakthrough curves of chloride in both soils. These suggested that PAM increased preferential transport of chloride while it increased retention of chloride in soils. Effect of PAM on preferential transport and retardation of CI was greater in sand than loam.展开更多
公路行业数字化转型发展十分迫切,数字化交付是实现工程数字化的重要手段,但目前缺少对交付过程管控方法的研究,导致目前交付成果质量与效率不高,并存在交付成果跨阶段应用率低的问题。基于CDE(Common Data Environments),研究并提出了...公路行业数字化转型发展十分迫切,数字化交付是实现工程数字化的重要手段,但目前缺少对交付过程管控方法的研究,导致目前交付成果质量与效率不高,并存在交付成果跨阶段应用率低的问题。基于CDE(Common Data Environments),研究并提出了公路工程全生命期数字化交付技术路径,明确了数据准备、信息生产及信息应用的方法与内涵,规范了数字化交付过程。进一步研究了数字化交付过程中数据准备流程、责任矩阵与实施方案编制方法、CDE平台功能架构、全生命期一模到底技术应用方法等关键技术,为公路工程全生命期数字化、智慧化发展奠定基础。展开更多
文摘Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also increase nutrient availability to plants. To test this premise, four application rates （0.0 g·kg^-1, 0.33 g·kg^-1, 1.66 g·kg^-1, 3.33 g·kg^-1 and 6.66 g·kg^-1） ofa PAM were mixed with sandy and loamy soils to evaluate its effect on nutrient leaching and retention in these soils. Miscible displacements of chloride were conducted on columns of PAM-soil mixtures and results were evaluated by an equilibrium CDE （convection dispersion equation） model. Increasing the PAM rates up to 1.66 g·kg^-1 resulted in increased early appearance and dispersive transport of chloride in sand. In addition, increasing the PAM rates gradually caused increased tailing of the breakthrough curves of chloride in both soils. These suggested that PAM increased preferential transport of chloride while it increased retention of chloride in soils. Effect of PAM on preferential transport and retardation of CI was greater in sand than loam.
文摘公路行业数字化转型发展十分迫切,数字化交付是实现工程数字化的重要手段,但目前缺少对交付过程管控方法的研究,导致目前交付成果质量与效率不高,并存在交付成果跨阶段应用率低的问题。基于CDE(Common Data Environments),研究并提出了公路工程全生命期数字化交付技术路径,明确了数据准备、信息生产及信息应用的方法与内涵,规范了数字化交付过程。进一步研究了数字化交付过程中数据准备流程、责任矩阵与实施方案编制方法、CDE平台功能架构、全生命期一模到底技术应用方法等关键技术,为公路工程全生命期数字化、智慧化发展奠定基础。
