The main aim in this research is comparison the parameters of some storm events in the watershed using two loss models in Unit hydrograph method by HEC-HMS. SCS Curve Number and Green-Ampt methods by developing loss m...The main aim in this research is comparison the parameters of some storm events in the watershed using two loss models in Unit hydrograph method by HEC-HMS. SCS Curve Number and Green-Ampt methods by developing loss model as a major component in runoff and flood modeling. The study is conducted in the Kuala Lumpurwatershed with674 km2 area located in Klang basin inMalaysia. The catchment delineation is generated for the Klang watershed to get sub-watershed parameters by using HEC-GeoHMS extension in ARCGIS. Then all the necessary parameters are assigned to the models applied in this study to run the runoff and flood model. The results showed that there was no significant difference between the SCS-CN and Green-Ampt loss method applied in the Klang watershed. Estimated direct runoff and Peak discharge (r = 0.98) indicates a statistically positive correlations between the results of the study. And also it has been attempted to use objective functions in HEC-HMS (percent error peaks and percent error volume) to classify the methods. The selection of best method is on the base of considering least difference between the results of simulation to observed events in hydrographs so that it can address which model is suit for runoff-flood simulation in Klang watershed. Results showed that SCS CN and Green-Ampt methods, in three events by fitting with percent error in peak and percent error in volume had no significant difference.展开更多
Among the most basic challenges of hydrology are the prediction and quantification of catchment surface runoff. The runoff curve number （CN） is a key factor in determining runoff in the SCS （Soil Conservation Serv...Among the most basic challenges of hydrology are the prediction and quantification of catchment surface runoff. The runoff curve number （CN） is a key factor in determining runoff in the SCS （Soil Conservation Service） based hydrologic modeling method. The traditional SCS-CN method for calculating the composite curve number is very tedious and consumes a major portion of the hydrologic modeling time. Therefore, geographic information systems （G/S） are now being used in combination with the SCS-CN method. This paper assesses the modeling of flow in West Bank catchments using the GIS-based SCS-CN method. The West Bank, Palestine, is characterized as an arid to semi-arid region with annual rainfall depths ranging between 100 mm in the vicinity of the Jordan River to 700 mm in the mountains extending across the central parts of the region. The estimated composite curve number for the entire West Bank is about 50 assuming dry conditions. This paper clearly demonstrates that the integration of GIS with the SCS-CN method provides a powerful tool for estimating runoff volumes in West Bank catchments, representing arid to semi-arid catchments of Palestine.展开更多
The g-factor hence the magnetic moment,of the isomeric state <sup>43</sup>Sc（|9/2<sup>-</sup>,3.1232 MeV）has been measured by the time differential perturbed angular distributionmethod.The me...The g-factor hence the magnetic moment,of the isomeric state <sup>43</sup>Sc（|9/2<sup>-</sup>,3.1232 MeV）has been measured by the time differential perturbed angular distributionmethod.The measured values are g=0.3279（19）and μ=3.108（18）nm.展开更多
Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a pro...Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a promising alternative to achieve low power consumption and nonvolatile electric control of magnetic properties.In this paper,a two-dimensional multiferroic van der Waals heterostructure OsCl_(2)/Sc_(2)CO_(2),which is composed of ferromagnetic monolayer OsCl_(2)and ferroelectric monolayer Sc_(2)CO_(2),is studied by first-principles density functional theory.The results show that by reversing the direction of the electric polarization of Sc_(2)CO_(2),OsCl_(2)can be transformed from a semiconductor to a half-metal,demonstrating a nonvolatile electrical manipulation of the heterostructure through ferroelectric polarization.The underlying physical mechanism is explained by band alignments and charge density differences.Furthermore,based on the heterostructure,we construct a multiferroic tunnel junction with a tunnel electroresistance ratio of 3.38×10^(14)%and a tunnel magnetoresistance ratio of 5.04×10^(6)%,allowing control of conduction states via instantaneous electric or magnetic fields.The findings provide a feasible strategy for designing advanced nanodevices based on the giant tunnel electroresistance and tunnel magnetoresistance effects.展开更多
文摘The main aim in this research is comparison the parameters of some storm events in the watershed using two loss models in Unit hydrograph method by HEC-HMS. SCS Curve Number and Green-Ampt methods by developing loss model as a major component in runoff and flood modeling. The study is conducted in the Kuala Lumpurwatershed with674 km2 area located in Klang basin inMalaysia. The catchment delineation is generated for the Klang watershed to get sub-watershed parameters by using HEC-GeoHMS extension in ARCGIS. Then all the necessary parameters are assigned to the models applied in this study to run the runoff and flood model. The results showed that there was no significant difference between the SCS-CN and Green-Ampt loss method applied in the Klang watershed. Estimated direct runoff and Peak discharge (r = 0.98) indicates a statistically positive correlations between the results of the study. And also it has been attempted to use objective functions in HEC-HMS (percent error peaks and percent error volume) to classify the methods. The selection of best method is on the base of considering least difference between the results of simulation to observed events in hydrographs so that it can address which model is suit for runoff-flood simulation in Klang watershed. Results showed that SCS CN and Green-Ampt methods, in three events by fitting with percent error in peak and percent error in volume had no significant difference.
基金supported by the GLOWA-JR Project of the German Federal Ministry of Education and Research (BMBF)
文摘Among the most basic challenges of hydrology are the prediction and quantification of catchment surface runoff. The runoff curve number （CN） is a key factor in determining runoff in the SCS （Soil Conservation Service） based hydrologic modeling method. The traditional SCS-CN method for calculating the composite curve number is very tedious and consumes a major portion of the hydrologic modeling time. Therefore, geographic information systems （G/S） are now being used in combination with the SCS-CN method. This paper assesses the modeling of flow in West Bank catchments using the GIS-based SCS-CN method. The West Bank, Palestine, is characterized as an arid to semi-arid region with annual rainfall depths ranging between 100 mm in the vicinity of the Jordan River to 700 mm in the mountains extending across the central parts of the region. The estimated composite curve number for the entire West Bank is about 50 assuming dry conditions. This paper clearly demonstrates that the integration of GIS with the SCS-CN method provides a powerful tool for estimating runoff volumes in West Bank catchments, representing arid to semi-arid catchments of Palestine.
基金supported by National Natural Science Foundation of ChinaNuclear Industry Science Foundation of China
文摘The g-factor hence the magnetic moment,of the isomeric state <sup>43</sup>Sc（|9/2<sup>-</sup>,3.1232 MeV）has been measured by the time differential perturbed angular distributionmethod.The measured values are g=0.3279（19）and μ=3.108（18）nm.
基金supported by the National Natural Science Foundation of China(Grant Nos.12074213,11574108,and 12104253)the National Key R&D Program of China(Grant No.2022YFA1403103)+2 种基金the Major Basic Program of the Natural Science Foundation of Shandong Province(Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Provincial(Grant No.ZR2023MA082)the Project of Introduction and Cultivation for Young Innovative Talents in Colleges and Universities of Shandong Province。
文摘Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a promising alternative to achieve low power consumption and nonvolatile electric control of magnetic properties.In this paper,a two-dimensional multiferroic van der Waals heterostructure OsCl_(2)/Sc_(2)CO_(2),which is composed of ferromagnetic monolayer OsCl_(2)and ferroelectric monolayer Sc_(2)CO_(2),is studied by first-principles density functional theory.The results show that by reversing the direction of the electric polarization of Sc_(2)CO_(2),OsCl_(2)can be transformed from a semiconductor to a half-metal,demonstrating a nonvolatile electrical manipulation of the heterostructure through ferroelectric polarization.The underlying physical mechanism is explained by band alignments and charge density differences.Furthermore,based on the heterostructure,we construct a multiferroic tunnel junction with a tunnel electroresistance ratio of 3.38×10^(14)%and a tunnel magnetoresistance ratio of 5.04×10^(6)%,allowing control of conduction states via instantaneous electric or magnetic fields.The findings provide a feasible strategy for designing advanced nanodevices based on the giant tunnel electroresistance and tunnel magnetoresistance effects.
