Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modal...Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modality that integrates knowledge,ability,practice,and innovation(KAPI)for Database System Course.The teaching modality contains three parts:top-level design,course learning process,and course assurance and evaluation.The top-level design sorts out the core knowledge of the course and determines a mixed online and offline teaching platform.The course learning process emphasizes the correspondence transformation relationship between core knowledge points and ability enhancement,and the course is practiced in the form of experimental projects to finally enhance students’innovation consciousness and ability.The assurance and evaluation of the course are based on the outcome-based education(OBE)orientation,which realizes the objective evaluation of students’learning process and final performance.The teaching results of the course in the past 2 years show that the KAPI-based teaching modality has achieved better results.Meanwhile,students are satisfied with the evaluation of the modality.The teaching modality in this paper helps to stimulate students’initiatives,and improve their knowledge vision and practical ability,and thus helps to cultivate innovative and high-quality engineering talents required by the emerging engineering education.展开更多
Since the Beijing 2022 Winter Olympics was the first Winter Olympics in history held in continental winter monsoon climate conditions across complex terrain areas,there is a deficiency of relevant research,operational...Since the Beijing 2022 Winter Olympics was the first Winter Olympics in history held in continental winter monsoon climate conditions across complex terrain areas,there is a deficiency of relevant research,operational techniques,and experience.This made providing meteorological services for this event particularly challenging.The China Meteorological Administration(CMA)Earth System Modeling and Prediction Centre,achieved breakthroughs in research on short-and medium-term deterministic and ensemble numerical predictions.Several key technologies crucial for precise winter weather services during the Winter Olympics were developed.A comprehensive framework,known as the Operational System for High-Precision Weather Forecasting for the Winter Olympics,was established.Some of these advancements represent the highest level of capabilities currently available in China.The meteorological service provided to the Beijing 2022 Games also exceeded previous Winter Olympic Games in both variety and quality.This included achievements such as the“100-meter level,minute level”downscaled spatiotemporal resolution and forecasts spanning 1 to 15 days.Around 30 new technologies and over 60 kinds of products that align with the requirements of the Winter Olympics Organizing Committee were developed,and many of these techniques have since been integrated into the CMA’s operational national forecasting systems.These accomplishments were facilitated by a dedicated weather forecasting and research initiative,in conjunction with the preexisting real-time operational forecasting systems of the CMA.This program represents one of the five subprograms of the WMO’s high-impact weather forecasting demonstration project(SMART2022),and continues to play an important role in their Regional Association(RA)II Research Development Project(Hangzhou RDP).Therefore,the research accomplishments and meteorological service experiences from this program will be carried forward into forthcoming highimpact weather forecasting activities.This article provides an overview and assessment of this program and the operational national forecasting systems.展开更多
To represent model uncertainties more comprehensively,a stochastically perturbed parameterization(SPP)scheme consisting of temporally and spatially varying perturbations of 18 parameters in the microphysics,convection...To represent model uncertainties more comprehensively,a stochastically perturbed parameterization(SPP)scheme consisting of temporally and spatially varying perturbations of 18 parameters in the microphysics,convection,boundary layer,and surface layer parameterization schemes,as well as the stochastically perturbed parameterization tendencies(SPPT)scheme,and the stochastic kinetic energy backscatter(SKEB)scheme,is applied in the Global and Regional Assimilation and Prediction Enhanced System-Regional Ensemble Prediction System(GRAPES-REPS)to evaluate and compare the general performance of various combinations of multiple stochastic physics schemes.Six experiments are performed for a summer month(1-30 June 2015)over China and multiple verification metrics are used.The results show that:(1)All stochastic experiments outperform the control(CTL)experiment,and all combinations of stochastic parameterization schemes perform better than the single SPP scheme,indicating that stochastic methods can effectively improve the forecast skill,and combinations of multiple stochastic parameterization schemes can better represent model uncertainties;(2)The combination of all three stochastic physics schemes(SPP,SPPT,and SKEB)outperforms any other combination of two schemes in precipitation forecasting and surface and upper-air verification to better represent the model uncertainties and improve the forecast skill;(3)Combining SKEB with SPP and/or SPPT results in a notable increase in the spread and reduction in outliers for the upper-air wind speed.SKEB directly perturbs the wind field and therefore its addition will greatly impact the upper-air wind-speed fields,and it contributes most to the improvement in spread and outliers for wind;(4)The introduction of SPP has a positive added value,and does not lead to large changes in the evolution of the kinetic energy(KE)spectrum at any wavelength;(5)The introduction of SPPT and SKEB would cause a 5%-10%and 30%-80%change in the KE of mesoscale systems,and all three stochastic schemes(SPP,SPPT,and SKEB)mainly affect the KE of mesoscale systems.This study indicates the potential of combining multiple stochastic physics schemes and lays a foundation for the future development and design of regional and global ensembles.展开更多
A spiropyran-based probe was developed.It serves as a fluorescence turn-on probe for selective detection of Ce^3+in both ethanol and aqueous(water/ethanol,1:9 or 9:1,v/v)media.Ce3+can induce photochromism of the probe...A spiropyran-based probe was developed.It serves as a fluorescence turn-on probe for selective detection of Ce^3+in both ethanol and aqueous(water/ethanol,1:9 or 9:1,v/v)media.Ce3+can induce photochromism of the probe though the probe exhibits negligible photochromic property by itself.The probe is sensitive to Ce3+and the detection limit reaches 1.7μmol/L.It exhibits a high selectivity for Ce^3+ion over other common metal cations including Li^+,Na^+,Ag^+,Sr^2+,Ni^2+,Co^2+,Hg^2+,Zn^2+,Cr^3+,Al^3+,Fe^3+and Bi^3+and lanthanide ions Nd^3+,Yb^3+and La^3+.The probe may be used for quantitative determination of the concentration of Ce3+ion in a range of 1-10μmol/L and for application to environmental water samples.Sensing mechanism of the probe towards Ce3+ion is proposed.展开更多
Background:The Tibetan antelope(Pantholops hodgsonii)is a migratory ungulate species that inhabits the Qinghai-Tibet Plateau.In recent years,the population of Tibetan antelope has steadily increased owing to rigorous ...Background:The Tibetan antelope(Pantholops hodgsonii)is a migratory ungulate species that inhabits the Qinghai-Tibet Plateau.In recent years,the population of Tibetan antelope has steadily increased owing to rigorous protection measures to safeguard the species from commercial poaching.Currently,infrastructure development,competition with domestic livestock,and predation are the principal factors threatening the survival of Tibetan antelope.Result:Our study found that migratory Tibetan antelope can adapt to the development of infrastructure over time,decreasing the potential negative impacts of such developments.Conclusion:We,therefore,urge infrastructure development companies to incorporate wildlife corridors that enable free movement of wildlife populations,particularly for migratory species.展开更多
Two-echelon routing problems,including variants such as the two-echelon vehicle routing problem(2E-VRP)and the two-echelon location routing problem(2E-LRP),involve assignment and location decisions.However,the two-ech...Two-echelon routing problems,including variants such as the two-echelon vehicle routing problem(2E-VRP)and the two-echelon location routing problem(2E-LRP),involve assignment and location decisions.However,the two-echelon time-constrained vehicle routing problem(2E-TVRP)that caters to from-linehaul-to-delivery practices does not involve assignment decisions.This routing problem variant for networks with two eche-lons has not yet attracted enough research interest.Localized or long-distance services suffer from the lack of the assignment decisions between satellites and customers.Therefore,the 2E-TVRP,rather than using assignment decisions,adopts time constraints to decide the routes on each of the two interacting echelons:large-capacity vehicles trans-port cargoes among satellites on the first echelon,and small-capacity vehicles deliver cargoes from satellites to customers on the second echelon.This study introduces a mixed integer linear programming model for the 2E-TVRP and proposes a heuristic algorithm that incorporates the savings algorithm followed by a variable neighborhood search phase.Illustrative examples are used to test the mathematical formulation and the heuristic and a case study is used to demonstrate that the heuristic can effectively solve realistic-size instances of the 2E-TVRP.展开更多
基金the support from the General Program of the Educational Teaching Reform Research Project of Northwestern Polytechnical University(Grant No.2023JGY35)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515110252)+1 种基金the Double First-class Construction Foundation(Grant No.22GH010616)the Northwestern Polytechnical University of Graduate Student Quality Improvement Program(Grant No.22GZ210101)。
文摘Nowadays,it is extremely urgent for the software engineering education to cultivate the knowledge and ability of database talents in the era of big data.To this end,this paper proposes a talent training teaching modality that integrates knowledge,ability,practice,and innovation(KAPI)for Database System Course.The teaching modality contains three parts:top-level design,course learning process,and course assurance and evaluation.The top-level design sorts out the core knowledge of the course and determines a mixed online and offline teaching platform.The course learning process emphasizes the correspondence transformation relationship between core knowledge points and ability enhancement,and the course is practiced in the form of experimental projects to finally enhance students’innovation consciousness and ability.The assurance and evaluation of the course are based on the outcome-based education(OBE)orientation,which realizes the objective evaluation of students’learning process and final performance.The teaching results of the course in the past 2 years show that the KAPI-based teaching modality has achieved better results.Meanwhile,students are satisfied with the evaluation of the modality.The teaching modality in this paper helps to stimulate students’initiatives,and improve their knowledge vision and practical ability,and thus helps to cultivate innovative and high-quality engineering talents required by the emerging engineering education.
基金This work was jointly supported by the National Natural Science Foundation of China(Grant Nos.41975137,42175012,and 41475097)the National Key Research and Development Program(Grant No.2018YFF0300103).
文摘Since the Beijing 2022 Winter Olympics was the first Winter Olympics in history held in continental winter monsoon climate conditions across complex terrain areas,there is a deficiency of relevant research,operational techniques,and experience.This made providing meteorological services for this event particularly challenging.The China Meteorological Administration(CMA)Earth System Modeling and Prediction Centre,achieved breakthroughs in research on short-and medium-term deterministic and ensemble numerical predictions.Several key technologies crucial for precise winter weather services during the Winter Olympics were developed.A comprehensive framework,known as the Operational System for High-Precision Weather Forecasting for the Winter Olympics,was established.Some of these advancements represent the highest level of capabilities currently available in China.The meteorological service provided to the Beijing 2022 Games also exceeded previous Winter Olympic Games in both variety and quality.This included achievements such as the“100-meter level,minute level”downscaled spatiotemporal resolution and forecasts spanning 1 to 15 days.Around 30 new technologies and over 60 kinds of products that align with the requirements of the Winter Olympics Organizing Committee were developed,and many of these techniques have since been integrated into the CMA’s operational national forecasting systems.These accomplishments were facilitated by a dedicated weather forecasting and research initiative,in conjunction with the preexisting real-time operational forecasting systems of the CMA.This program represents one of the five subprograms of the WMO’s high-impact weather forecasting demonstration project(SMART2022),and continues to play an important role in their Regional Association(RA)II Research Development Project(Hangzhou RDP).Therefore,the research accomplishments and meteorological service experiences from this program will be carried forward into forthcoming highimpact weather forecasting activities.This article provides an overview and assessment of this program and the operational national forecasting systems.
基金National Key Research and Development(R&D)Program of China,(Grant No.2018YFC1507405).
文摘To represent model uncertainties more comprehensively,a stochastically perturbed parameterization(SPP)scheme consisting of temporally and spatially varying perturbations of 18 parameters in the microphysics,convection,boundary layer,and surface layer parameterization schemes,as well as the stochastically perturbed parameterization tendencies(SPPT)scheme,and the stochastic kinetic energy backscatter(SKEB)scheme,is applied in the Global and Regional Assimilation and Prediction Enhanced System-Regional Ensemble Prediction System(GRAPES-REPS)to evaluate and compare the general performance of various combinations of multiple stochastic physics schemes.Six experiments are performed for a summer month(1-30 June 2015)over China and multiple verification metrics are used.The results show that:(1)All stochastic experiments outperform the control(CTL)experiment,and all combinations of stochastic parameterization schemes perform better than the single SPP scheme,indicating that stochastic methods can effectively improve the forecast skill,and combinations of multiple stochastic parameterization schemes can better represent model uncertainties;(2)The combination of all three stochastic physics schemes(SPP,SPPT,and SKEB)outperforms any other combination of two schemes in precipitation forecasting and surface and upper-air verification to better represent the model uncertainties and improve the forecast skill;(3)Combining SKEB with SPP and/or SPPT results in a notable increase in the spread and reduction in outliers for the upper-air wind speed.SKEB directly perturbs the wind field and therefore its addition will greatly impact the upper-air wind-speed fields,and it contributes most to the improvement in spread and outliers for wind;(4)The introduction of SPP has a positive added value,and does not lead to large changes in the evolution of the kinetic energy(KE)spectrum at any wavelength;(5)The introduction of SPPT and SKEB would cause a 5%-10%and 30%-80%change in the KE of mesoscale systems,and all three stochastic schemes(SPP,SPPT,and SKEB)mainly affect the KE of mesoscale systems.This study indicates the potential of combining multiple stochastic physics schemes and lays a foundation for the future development and design of regional and global ensembles.
文摘A spiropyran-based probe was developed.It serves as a fluorescence turn-on probe for selective detection of Ce^3+in both ethanol and aqueous(water/ethanol,1:9 or 9:1,v/v)media.Ce3+can induce photochromism of the probe though the probe exhibits negligible photochromic property by itself.The probe is sensitive to Ce3+and the detection limit reaches 1.7μmol/L.It exhibits a high selectivity for Ce^3+ion over other common metal cations including Li^+,Na^+,Ag^+,Sr^2+,Ni^2+,Co^2+,Hg^2+,Zn^2+,Cr^3+,Al^3+,Fe^3+and Bi^3+and lanthanide ions Nd^3+,Yb^3+and La^3+.The probe may be used for quantitative determination of the concentration of Ce3+ion in a range of 1-10μmol/L and for application to environmental water samples.Sensing mechanism of the probe towards Ce3+ion is proposed.
基金This work was supported by the Science and Technology Department of Qinghai Province[2017-ZJ-724]the Ministry of Science and Technology of the People’s Republic of China[2019QZKK040104].
文摘Background:The Tibetan antelope(Pantholops hodgsonii)is a migratory ungulate species that inhabits the Qinghai-Tibet Plateau.In recent years,the population of Tibetan antelope has steadily increased owing to rigorous protection measures to safeguard the species from commercial poaching.Currently,infrastructure development,competition with domestic livestock,and predation are the principal factors threatening the survival of Tibetan antelope.Result:Our study found that migratory Tibetan antelope can adapt to the development of infrastructure over time,decreasing the potential negative impacts of such developments.Conclusion:We,therefore,urge infrastructure development companies to incorporate wildlife corridors that enable free movement of wildlife populations,particularly for migratory species.
基金This research work was supported by the Research Grant from the National Natural Science Foundation of China(grant number 71672005).
文摘Two-echelon routing problems,including variants such as the two-echelon vehicle routing problem(2E-VRP)and the two-echelon location routing problem(2E-LRP),involve assignment and location decisions.However,the two-echelon time-constrained vehicle routing problem(2E-TVRP)that caters to from-linehaul-to-delivery practices does not involve assignment decisions.This routing problem variant for networks with two eche-lons has not yet attracted enough research interest.Localized or long-distance services suffer from the lack of the assignment decisions between satellites and customers.Therefore,the 2E-TVRP,rather than using assignment decisions,adopts time constraints to decide the routes on each of the two interacting echelons:large-capacity vehicles trans-port cargoes among satellites on the first echelon,and small-capacity vehicles deliver cargoes from satellites to customers on the second echelon.This study introduces a mixed integer linear programming model for the 2E-TVRP and proposes a heuristic algorithm that incorporates the savings algorithm followed by a variable neighborhood search phase.Illustrative examples are used to test the mathematical formulation and the heuristic and a case study is used to demonstrate that the heuristic can effectively solve realistic-size instances of the 2E-TVRP.