The implementation of core competencies clarifies social talent needs and guides math classroom evaluation.Lower-grade primary students,highly malleable,need targeted teacher guidance.Teaching evaluation should meet t...The implementation of core competencies clarifies social talent needs and guides math classroom evaluation.Lower-grade primary students,highly malleable,need targeted teacher guidance.Teaching evaluation should meet the talent demands of the times,focusing on core literacy and essential character development.From this perspective,primary math teachers should optimize evaluation,build a diversified system,help students grow in math,find their learning position,and advance confidently.展开更多
Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like r...Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like rocks or soft bases such as mud and sand.In addition,there are benthic species that attach to the plant surfaces or other benthic animals,and inhabit the intertidal zone.In terms of feeding methods,most benthic animals feed on suspended matter and sediment.Most of them are invertebrates and are a complex ecological group.According to the size,they can be divided into macrobenthos and meio-benthos[1].Benthos are an important part of the water ecosystem.Using a typical river(Gaya River)in eastern Jilin Province,this paper analyzed the water quality,the components of benthic organisms and their biological density through sampling surveys of three typical locations in the upper,middle and lower reaches of the Gaya River.In addition,it made a biological evaluation of the water quality of the Gaya River.展开更多
Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four eval...Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four evaluation methods(namely, the classic statistical method, geostatistical method, information theory method, and fractal method), this study proposed a new scheme for evaluating the spatial heterogeneity of LSHCs. This scheme incorporates diverse remotely sensed surface parameters, e.g., leaf area index-LAI, the normalized difference vegetation index-NDVI, net radiation-Rn, and land surface temperature-LST. The LSHCs can be classified into three categories, namely homogeneous, moderately heterogeneous and highly heterogeneous based on the remotely sensed LAI data with a 30 m spatial resolution and the combination of normalized information entropy(S’) and coefficient of variation(CV). Based on the evaluation scheme, the spatial heterogeneity of land surface hydrothermal conditions at six typical flux observation stations in the Heihe River Basin during the vegetation growing season were evaluated. The evaluation results were consistent with the land surface type characteristics exhibited by Google Earth imagery and spatial heterogeneity assessed by high resolution remote sensing evapotranspiration data. Impact factors such as precipitation and irrigation events, spatial resolutions of remote sensing data, heterogeneity in the vertical direction, topography and sparse vegetation could also affect the evaluation results. For instance, short-term changes(precipitation and irrigation events) in the spatial heterogeneity of LSHCs can be diagnosed by energy factors, while long-term changes can be indicated by vegetation factors. The spatial heterogeneity of LSHCs decreases when decreasing the spatial resolution of remote sensing data. The proposed evaluation scheme would be useful for the quantification of spatial heterogeneity of LSHCs over flux observation stations toward the global scale, and also contribute to the improvement of the accuracy of estimation and validation for remotely sensed(or model simulated) evapotranspiration.展开更多
Comparative evaluation of cloud microphysics schemes has always been a focal point of meteorological research.Existing cloud microphysics schemes still face uncertainties.This study focuses on a cold vortex-induced he...Comparative evaluation of cloud microphysics schemes has always been a focal point of meteorological research.Existing cloud microphysics schemes still face uncertainties.This study focuses on a cold vortex-induced heavy rainfall event in Northeast China in July 2023,using the operational China Meteorological Administration Mesoscale Model(CMA-MESO)to conduct comparative retrospective experiments with the single-moment microphysics scheme WSM6(namely the Weather Research and Forecasting model Single Moment 6-class scheme)and the double-moment scheme called LIUMA.The goal is to evaluate the forecasting capabilities of the schemes for cold vortex-induced heavy rainfall.The results show that both schemes could generally reproduce this heavy rainfall event;however,the LIUMA scheme's precipitation time series exhibited a correlation coefficient of 0.75 and a root mean square error(RMSE)of 0.67 mm h-1,which are closer to observations compared to WSM6's values of 0.70 and 1.15 mm h-1,respectively.It is found that WSM6 overestimated precipitation intensity more significantly.Additionally,the raindrop size distributions(RSDs)from LIUMA are more consistent with the observations.The net latent heat peak in WSM6 is 2.2×10^(-4) K s^(-1),higher than that of LIUMA of 2.0×10^(-4) K s^(-1).The stronger latent heating in WSM6 enhanced dynamic effects,leading to more vigorous convection and overestimated precipitation intensity.The mixing ratios of ice-phase and liquid-phase hydrometeors simulated by LIUMA are higher than those by WSM6,with overestimation of ice-phase particles being particularly pronounced.This may be one of the reasons why the LIUMA simulated radar reflectivity is significantly stronger than the observations.The main differences between the two schemes lie in the representation of ice-phase processes and the interactions between ice-phase and liquid-phase particles,and a more detailed evaluation of these processes will require advanced cloud observation techniques.The results obtained from this study help better understand and further improve the CMA-MESO operational model performance in forecasting heavy rainfall.展开更多
文摘The implementation of core competencies clarifies social talent needs and guides math classroom evaluation.Lower-grade primary students,highly malleable,need targeted teacher guidance.Teaching evaluation should meet the talent demands of the times,focusing on core literacy and essential character development.From this perspective,primary math teachers should optimize evaluation,build a diversified system,help students grow in math,find their learning position,and advance confidently.
文摘Benthos are aquatic organisms living at the bottom of water bodies for all or most of their life history.Apart from the settled and moving living,their forms of habitat are mostly attached to the hard substrate like rocks or soft bases such as mud and sand.In addition,there are benthic species that attach to the plant surfaces or other benthic animals,and inhabit the intertidal zone.In terms of feeding methods,most benthic animals feed on suspended matter and sediment.Most of them are invertebrates and are a complex ecological group.According to the size,they can be divided into macrobenthos and meio-benthos[1].Benthos are an important part of the water ecosystem.Using a typical river(Gaya River)in eastern Jilin Province,this paper analyzed the water quality,the components of benthic organisms and their biological density through sampling surveys of three typical locations in the upper,middle and lower reaches of the Gaya River.In addition,it made a biological evaluation of the water quality of the Gaya River.
基金the auspices of National Natural Science Foundation of China(No.41531174)National Basic Research Program of China(No.2015CB953702)。
文摘Land surface hydrothermal conditions(LSHCs) reflect land surface moisture and heat conditions, and play an important role in energy and water cycles in soil-plant-atmosphere continuum. Based on comparison of four evaluation methods(namely, the classic statistical method, geostatistical method, information theory method, and fractal method), this study proposed a new scheme for evaluating the spatial heterogeneity of LSHCs. This scheme incorporates diverse remotely sensed surface parameters, e.g., leaf area index-LAI, the normalized difference vegetation index-NDVI, net radiation-Rn, and land surface temperature-LST. The LSHCs can be classified into three categories, namely homogeneous, moderately heterogeneous and highly heterogeneous based on the remotely sensed LAI data with a 30 m spatial resolution and the combination of normalized information entropy(S’) and coefficient of variation(CV). Based on the evaluation scheme, the spatial heterogeneity of land surface hydrothermal conditions at six typical flux observation stations in the Heihe River Basin during the vegetation growing season were evaluated. The evaluation results were consistent with the land surface type characteristics exhibited by Google Earth imagery and spatial heterogeneity assessed by high resolution remote sensing evapotranspiration data. Impact factors such as precipitation and irrigation events, spatial resolutions of remote sensing data, heterogeneity in the vertical direction, topography and sparse vegetation could also affect the evaluation results. For instance, short-term changes(precipitation and irrigation events) in the spatial heterogeneity of LSHCs can be diagnosed by energy factors, while long-term changes can be indicated by vegetation factors. The spatial heterogeneity of LSHCs decreases when decreasing the spatial resolution of remote sensing data. The proposed evaluation scheme would be useful for the quantification of spatial heterogeneity of LSHCs over flux observation stations toward the global scale, and also contribute to the improvement of the accuracy of estimation and validation for remotely sensed(or model simulated) evapotranspiration.
基金Supported by the Open Project Fund of China Meteorological Administration Basin Heavy Rainfall Key Laboratory(2023BHR-Y12)National Key Research and Development Program of China(2023YFC3007700 and 2023YFC3007702)+4 种基金Key Scientific and Technology Research and Development Program of Jilin Province(20220203199SF and 20240304119SF)National Natural Science Foundation of China(42405014 and U2342212)Liaoning Provincial Natural Science Foundation of China(2024-BS-305)Joint Research Project for Meteorological Capacity Improvement(24NLTSQ007)National and Provincial Coordinated Research and Development Project of Numerical Weather Prediction of CMA(TCYF2024GS006)。
文摘Comparative evaluation of cloud microphysics schemes has always been a focal point of meteorological research.Existing cloud microphysics schemes still face uncertainties.This study focuses on a cold vortex-induced heavy rainfall event in Northeast China in July 2023,using the operational China Meteorological Administration Mesoscale Model(CMA-MESO)to conduct comparative retrospective experiments with the single-moment microphysics scheme WSM6(namely the Weather Research and Forecasting model Single Moment 6-class scheme)and the double-moment scheme called LIUMA.The goal is to evaluate the forecasting capabilities of the schemes for cold vortex-induced heavy rainfall.The results show that both schemes could generally reproduce this heavy rainfall event;however,the LIUMA scheme's precipitation time series exhibited a correlation coefficient of 0.75 and a root mean square error(RMSE)of 0.67 mm h-1,which are closer to observations compared to WSM6's values of 0.70 and 1.15 mm h-1,respectively.It is found that WSM6 overestimated precipitation intensity more significantly.Additionally,the raindrop size distributions(RSDs)from LIUMA are more consistent with the observations.The net latent heat peak in WSM6 is 2.2×10^(-4) K s^(-1),higher than that of LIUMA of 2.0×10^(-4) K s^(-1).The stronger latent heating in WSM6 enhanced dynamic effects,leading to more vigorous convection and overestimated precipitation intensity.The mixing ratios of ice-phase and liquid-phase hydrometeors simulated by LIUMA are higher than those by WSM6,with overestimation of ice-phase particles being particularly pronounced.This may be one of the reasons why the LIUMA simulated radar reflectivity is significantly stronger than the observations.The main differences between the two schemes lie in the representation of ice-phase processes and the interactions between ice-phase and liquid-phase particles,and a more detailed evaluation of these processes will require advanced cloud observation techniques.The results obtained from this study help better understand and further improve the CMA-MESO operational model performance in forecasting heavy rainfall.
