New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed...New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed to expand investment and construction models by promoting the deployment of energy-storage facilities through the ways of self-construction,leasing,and purchasing,and to encourage the development of the shared energy-storage.However,the current scarcity in the model of the shared energy-storage invest-ment and construction substantially restricts its development,particularly due to unclear mechanisms for cost and benefit allocation,which also discourages potential investors.To address the issue,this paper proposes investment and construction models for shared energy-storage that aligns with the present stage of energy storage development.In specific,three main models are introduced:(1)Cen-tralized Self-built Shared Energy-Storage model(CSSES),(2)Third-party Investment Shared Energy-Storage model(TISES),and(3)Distributed Self-built Shared Energy Storage(DSSES)model.The cost–benefit analysis is conducted for each model.The results indicate that the CSSES model achieves the highest internal rate of return(11.5%)and the shortest payback period,while the DSSES model per-forms acceptable with an IRR of 9.4%.In contrast,the TISES model shows the lowest IRR(6.7%)and requires higher electricity price for being feasible.Furthermore,the study employs the entropy weight method and the analytic hierarchy process(AHP)for indicator eval-uation,and integrates the technique for order preference by the similarity to an ideal solution(TOPSIS)for scheme optimization.The results show that both the CSSES model and the DSSES model achieve the highest proximity scores.Under environmental regulations,these models demonstrate superior economic benefits by optimizing energy storage utilization,reducing user costs,and enhancing overall profitability.展开更多
为探究黑龙江流域碳储量的时空变化,并对该流域未来的碳储量情况进行分情景的模拟预测,笔者在黑龙江流域对比3个元胞自动机模型,选定并利用斑块生成土地覆盖模拟模型(patch generating land use simulation,PLUS)耦合生态系统服务和交...为探究黑龙江流域碳储量的时空变化,并对该流域未来的碳储量情况进行分情景的模拟预测,笔者在黑龙江流域对比3个元胞自动机模型,选定并利用斑块生成土地覆盖模拟模型(patch generating land use simulation,PLUS)耦合生态系统服务和交易的综合评估模型(integrated valuation of ecosystem services and trade-offs,InVEST)来模拟黑龙江流域未来的土地利用和土地覆盖(land use and land cover,LULC)以及碳储量演变,开展大尺度跨国LULC演变和碳储量变化研究。结果表明:(1)PLUS模型对于黑龙江流域的大尺度跨国LULC模拟有较好的精度(OA=0.897 2,Kappa=0.842 6)。(2)2000—2020年,黑龙江流域内的土地覆盖转变以林地、耕地和草地之间的转变为主,同时人造地表迅速扩张,挤占耕地面积。气温和降水是林地、草地和耕地扩张的重要驱动因素,耕地的扩展因素还和GDP有较大的关系。(3)PLUS模型耦合InVEST模型能够实现在黑龙江流域的碳储量变化分析和预测。从2000到2020年,黑龙江流域内的碳储量先减少后增加,总体减少了3.171×10^(7) t,其中中国部分的碳储量减少1.930×10^(7)t,俄罗斯部分减少0.090×10^(7)t,蒙古国部分减少0.017×10^(7)t。分情景预测2030年的LULC和碳储量,生态保护优先情景的碳储量最大,达到了619.350×10^(7)t,中国部分增加0.530×10^(7)t,达到325.110×10^(7)t,俄罗斯部分增加0.010×10^(7)t,达到249.250×10^(7)t,蒙古国部分减少0.180×10^(7)t,达到44.990×10^(7)t。研究表明人类活动与自然环境在实现碳中和中的重要性,并指出应采取生态保护措施以提升区域碳储量水平。展开更多
Cash flow is a core element for enterprises to maintain operations and development.Cash flow forecasting models,through systematic analysis of an enterprise’s historical cash flow data,trends in operating activities,...Cash flow is a core element for enterprises to maintain operations and development.Cash flow forecasting models,through systematic analysis of an enterprise’s historical cash flow data,trends in operating activities,and external environmental factors,scientifically predict the scale,direction,and fluctuation of cash flow within a certain period in the future.This article focuses on the application of cash flow forecasting models in enterprise investment and financing decisions,sorts out the types and core functions of the models,analyzes their specific roles in investment project screening,financing plan formulation,risk prevention and control,and fund allocation,points out the existing problems in current applications,and proposes optimization paths.Research shows that the scientific application of cash flow forecasting models can enhance the accuracy and rationality of enterprises’investment and financing decisions,and help enterprises achieve sustainable development.展开更多
Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical si...Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%.展开更多
基金supported by the Humanities and Social Sciences of Ministry of Education Planning Fund of China(Grant No.21YJA790009)the National Natural Science Foundation of China(Grant No.72140001).
文摘New energy-storage systems play a pivotal role in the development of the new power system for advancing the energy transition in China.In the“14th Five-Year Plan”for the New Energy-Storage Development,it is proposed to expand investment and construction models by promoting the deployment of energy-storage facilities through the ways of self-construction,leasing,and purchasing,and to encourage the development of the shared energy-storage.However,the current scarcity in the model of the shared energy-storage invest-ment and construction substantially restricts its development,particularly due to unclear mechanisms for cost and benefit allocation,which also discourages potential investors.To address the issue,this paper proposes investment and construction models for shared energy-storage that aligns with the present stage of energy storage development.In specific,three main models are introduced:(1)Cen-tralized Self-built Shared Energy-Storage model(CSSES),(2)Third-party Investment Shared Energy-Storage model(TISES),and(3)Distributed Self-built Shared Energy Storage(DSSES)model.The cost–benefit analysis is conducted for each model.The results indicate that the CSSES model achieves the highest internal rate of return(11.5%)and the shortest payback period,while the DSSES model per-forms acceptable with an IRR of 9.4%.In contrast,the TISES model shows the lowest IRR(6.7%)and requires higher electricity price for being feasible.Furthermore,the study employs the entropy weight method and the analytic hierarchy process(AHP)for indicator eval-uation,and integrates the technique for order preference by the similarity to an ideal solution(TOPSIS)for scheme optimization.The results show that both the CSSES model and the DSSES model achieve the highest proximity scores.Under environmental regulations,these models demonstrate superior economic benefits by optimizing energy storage utilization,reducing user costs,and enhancing overall profitability.
文摘为探究黑龙江流域碳储量的时空变化,并对该流域未来的碳储量情况进行分情景的模拟预测,笔者在黑龙江流域对比3个元胞自动机模型,选定并利用斑块生成土地覆盖模拟模型(patch generating land use simulation,PLUS)耦合生态系统服务和交易的综合评估模型(integrated valuation of ecosystem services and trade-offs,InVEST)来模拟黑龙江流域未来的土地利用和土地覆盖(land use and land cover,LULC)以及碳储量演变,开展大尺度跨国LULC演变和碳储量变化研究。结果表明:(1)PLUS模型对于黑龙江流域的大尺度跨国LULC模拟有较好的精度(OA=0.897 2,Kappa=0.842 6)。(2)2000—2020年,黑龙江流域内的土地覆盖转变以林地、耕地和草地之间的转变为主,同时人造地表迅速扩张,挤占耕地面积。气温和降水是林地、草地和耕地扩张的重要驱动因素,耕地的扩展因素还和GDP有较大的关系。(3)PLUS模型耦合InVEST模型能够实现在黑龙江流域的碳储量变化分析和预测。从2000到2020年,黑龙江流域内的碳储量先减少后增加,总体减少了3.171×10^(7) t,其中中国部分的碳储量减少1.930×10^(7)t,俄罗斯部分减少0.090×10^(7)t,蒙古国部分减少0.017×10^(7)t。分情景预测2030年的LULC和碳储量,生态保护优先情景的碳储量最大,达到了619.350×10^(7)t,中国部分增加0.530×10^(7)t,达到325.110×10^(7)t,俄罗斯部分增加0.010×10^(7)t,达到249.250×10^(7)t,蒙古国部分减少0.180×10^(7)t,达到44.990×10^(7)t。研究表明人类活动与自然环境在实现碳中和中的重要性,并指出应采取生态保护措施以提升区域碳储量水平。
文摘Cash flow is a core element for enterprises to maintain operations and development.Cash flow forecasting models,through systematic analysis of an enterprise’s historical cash flow data,trends in operating activities,and external environmental factors,scientifically predict the scale,direction,and fluctuation of cash flow within a certain period in the future.This article focuses on the application of cash flow forecasting models in enterprise investment and financing decisions,sorts out the types and core functions of the models,analyzes their specific roles in investment project screening,financing plan formulation,risk prevention and control,and fund allocation,points out the existing problems in current applications,and proposes optimization paths.Research shows that the scientific application of cash flow forecasting models can enhance the accuracy and rationality of enterprises’investment and financing decisions,and help enterprises achieve sustainable development.
基金financially supported by the National Key Research and Development Program of China (2022YFB3706802)。
文摘Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%.
