The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous proble...The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous problems of low flux,poor stability,and pollution resistance.Nanocelluloses(cellulose nanocrystals(CNC))with the advantages of hydrophilicity,ecofriendliness,and regeneration are ideal materials for the construction of separation membranes.In this paper,a flexible,antifouling,and durable nanocellulose-based membrane functionalized by block copolymer(poly(N-isopropylacrylamide)-b-poly(N,Ndimethylaminoethyl methacrylate))is prepared via chemical modification and self-assembly,showing high separation efficiency(above 99.6%)for stabilized oil-in-water emulsions,excellent anti-fouling and cycling stability,high-temperature resistance,and acid and alkali resistance.More importantly,the composite membrane has ultra-high flux in separating oil-in-water emulsions(29,003 L·m^(−2)·h^(−1)·bar^(−1))and oil/water mixture(51,444 L·m^(−2)·h^(−1)·bar^(−1)),which ensures high separation efficiency.With its durability,easy scale-up,and green regeneration,we envision this biomass-derived membrane will be an alternative to the existing commercial filter membrane in environmental remediation.展开更多
After-sale service plays an essential role in the electronics retail industry,where providers must supply the required repair parts to consumers during the product warranty period.The rapid evolution of electronic pro...After-sale service plays an essential role in the electronics retail industry,where providers must supply the required repair parts to consumers during the product warranty period.The rapid evolution of electronic products prevents part suppliers from maintaining continuous production,making it impossible to supply spare parts consistently during the warranty periods and requiring the providers to purchase all necessary spare parts on Last Time Buy(LTB).The uncertainty of customer demand in spare parts brings out difficulties to maintain optimal spare parts inventory.In this paper,we address the challenge of forecasting spare parts demand and optimizing the purchase volumes of spare parts during the regular monthly replenishment period and LTB.First,the problem is well defined and formulated based on the dynamic economic lotsize model.Second,a transfer function model is constructed between historical demand values and product sales,aiming to identify the length of warranty period and forecast the spare part demands.In addition,the linear Model Predictive Control(MPC)scheme is adopted to optimize the purchase volumes of spare part considering the inaccuracy in the demand forecasts.A real-world case considering different categories of spare parts consumption is studied.The results demonstrate that our proposed algorithm outperforms other algorithms in terms of forecasting accuracy and the inventory cost.展开更多
基金the financial support provided by the National Natural Science Foundation of China(Nos.22108125,21971113,and 22175094)Independent Innovation of Agricultural Science and Technology in Jiangsu Province(Nos.CX(21)3166,and CX(21)3163)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210627)Doctor Project of Mass Entrepreneurship and Innovation in Jiangsu Province(No.JSSCBS20210549)Nanjing Science&Technology Innovation Project for Personnel Studying Abroad and Research Start-up Funding of Nanjing Forestry University(No.163020259)Q.C.Z.appreciates the funding support from City University of Hong Kong and Hong Kong Institute for Advanced Study,City University of Hong Kong.
文摘The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous problems of low flux,poor stability,and pollution resistance.Nanocelluloses(cellulose nanocrystals(CNC))with the advantages of hydrophilicity,ecofriendliness,and regeneration are ideal materials for the construction of separation membranes.In this paper,a flexible,antifouling,and durable nanocellulose-based membrane functionalized by block copolymer(poly(N-isopropylacrylamide)-b-poly(N,Ndimethylaminoethyl methacrylate))is prepared via chemical modification and self-assembly,showing high separation efficiency(above 99.6%)for stabilized oil-in-water emulsions,excellent anti-fouling and cycling stability,high-temperature resistance,and acid and alkali resistance.More importantly,the composite membrane has ultra-high flux in separating oil-in-water emulsions(29,003 L·m^(−2)·h^(−1)·bar^(−1))and oil/water mixture(51,444 L·m^(−2)·h^(−1)·bar^(−1)),which ensures high separation efficiency.With its durability,easy scale-up,and green regeneration,we envision this biomass-derived membrane will be an alternative to the existing commercial filter membrane in environmental remediation.
基金supported by the National Key R&D Program of China(No.2021YFB3300400)National Natural Science Foundation of China(No.62203049).
文摘After-sale service plays an essential role in the electronics retail industry,where providers must supply the required repair parts to consumers during the product warranty period.The rapid evolution of electronic products prevents part suppliers from maintaining continuous production,making it impossible to supply spare parts consistently during the warranty periods and requiring the providers to purchase all necessary spare parts on Last Time Buy(LTB).The uncertainty of customer demand in spare parts brings out difficulties to maintain optimal spare parts inventory.In this paper,we address the challenge of forecasting spare parts demand and optimizing the purchase volumes of spare parts during the regular monthly replenishment period and LTB.First,the problem is well defined and formulated based on the dynamic economic lotsize model.Second,a transfer function model is constructed between historical demand values and product sales,aiming to identify the length of warranty period and forecast the spare part demands.In addition,the linear Model Predictive Control(MPC)scheme is adopted to optimize the purchase volumes of spare part considering the inaccuracy in the demand forecasts.A real-world case considering different categories of spare parts consumption is studied.The results demonstrate that our proposed algorithm outperforms other algorithms in terms of forecasting accuracy and the inventory cost.
