Global warming has led to a gradual extension of the navigable window for the Arctic Route,providing a realistic possibility for the normalized commercial operation of the Northeast Passage(NEP).Based on the changes i...Global warming has led to a gradual extension of the navigable window for the Arctic Route,providing a realistic possibility for the normalized commercial operation of the Northeast Passage(NEP).Based on the changes in the navigable window of the NEP,Russia’s proposed nuclear-powered icebreaker construction scheme,and China’s potential development of a moderately sized ice-class fleet,this study establishes three scenarios for the commercial operation of the NEP.These scenarios include:(a)normalized summer operational scenario(from July to October each year),(b)normalized summer-autumn operational scenario(from June to January of the following year),and(c)normalized year-round operational scenario(12 months per year).The cargo transportation potential of the NEP under three normalized operational scenarios was predicted based on the grey prediction model.On this basis,construction scale plans for China’s ice-class fleet to meet cargo transportation demands under the three normalized operational scenarios were designed.The economic benefits of different plans were evaluated using a profit-maximization linear programming model.The research results show the following:(1)The cargo transportation potential of the NEP demonstrates a rapid growth trend in the future,with annual throughput under year-round normalized operations expected to exceed 100 million tonnes and reach 297 million tonnes.(2)Under different normalized operational scenarios,the fleet scale and vessel type composition vary.Under the normalized summer operational scenario,the optimal scale for China’s ice-class fleet is 20 vessels,consisting solely of ships classed as PC7 by the International Association of Classification Societies(IACS).Under the normalized summer-autumn operational scenario,the optimal fleet scale is 31 vessels,including 30 IACS PC7 ships and 1 IACS PC3 ship.Under the normalized year-round operational scenario,the optimal fleet scale is 45 vessels,composed of 30 IACS PC7 ships,8 IACS PC3 ships,and 7 IACS PC2 ships.(3)Among the three normalized operational scenarios,the normalized year-round operational scenario yields the best economic benefits for the fleet scale,while the normalized summer operational scenario yields the lowest economic benefits.展开更多
Phosphogypsum-based materials (PBM) were synthesized with varied phase compositions of phosphogypsum,portland cement and fly ash.Effects of fractal growth characteristics on physicochemical properties,pore structure,c...Phosphogypsum-based materials (PBM) were synthesized with varied phase compositions of phosphogypsum,portland cement and fly ash.Effects of fractal growth characteristics on physicochemical properties,pore structure,compressive strength,as well as the hydration behaviour and mineralogical conversion of mortars were examined by a multitechnological approach,including mercury intrusion porosimetry,rietved phase analysis,thremal analysis,calorimetry and Fourier transforminfrared spectroscopy analysis.Expermental results indicate that the specimens cured with mosite resulted in higher strength and lower porosity compared with those cured in the drying chamber.In addition,a more complicated course of the aluminate and silicate reactions during the hydration process has been published,with the hydration products mainly consisting of calcium silicate hydrate (C-S-H),portlandite,ettringite,hemicarbonate,monocarboaluminate,calcite,quartz,a mixed AFm passed with carbonate,and hydroxide.After all,the nucleation process is a reaction that can be defined as a solid,liquid and gaseous phases that goes through the four stages of materialization mixing and modification,i e,hydration of low calcium content,secondary hydration,high calcium condensation and geoplymensation,respectively.The rupture,recombination,polymerization reactions of Si-O,Ca-O,Al-O bonds contribute to the nucleation mechanism that serves as the formation of C-S-H in hydration products.展开更多
基金Funding by Social Science Research of Ministry of Education of the People’s Republic of China“Study on issues related on the development and utilization of the Arctic Passage”(Grant no.20JHQ016)is acknowledged.
文摘Global warming has led to a gradual extension of the navigable window for the Arctic Route,providing a realistic possibility for the normalized commercial operation of the Northeast Passage(NEP).Based on the changes in the navigable window of the NEP,Russia’s proposed nuclear-powered icebreaker construction scheme,and China’s potential development of a moderately sized ice-class fleet,this study establishes three scenarios for the commercial operation of the NEP.These scenarios include:(a)normalized summer operational scenario(from July to October each year),(b)normalized summer-autumn operational scenario(from June to January of the following year),and(c)normalized year-round operational scenario(12 months per year).The cargo transportation potential of the NEP under three normalized operational scenarios was predicted based on the grey prediction model.On this basis,construction scale plans for China’s ice-class fleet to meet cargo transportation demands under the three normalized operational scenarios were designed.The economic benefits of different plans were evaluated using a profit-maximization linear programming model.The research results show the following:(1)The cargo transportation potential of the NEP demonstrates a rapid growth trend in the future,with annual throughput under year-round normalized operations expected to exceed 100 million tonnes and reach 297 million tonnes.(2)Under different normalized operational scenarios,the fleet scale and vessel type composition vary.Under the normalized summer operational scenario,the optimal scale for China’s ice-class fleet is 20 vessels,consisting solely of ships classed as PC7 by the International Association of Classification Societies(IACS).Under the normalized summer-autumn operational scenario,the optimal fleet scale is 31 vessels,including 30 IACS PC7 ships and 1 IACS PC3 ship.Under the normalized year-round operational scenario,the optimal fleet scale is 45 vessels,composed of 30 IACS PC7 ships,8 IACS PC3 ships,and 7 IACS PC2 ships.(3)Among the three normalized operational scenarios,the normalized year-round operational scenario yields the best economic benefits for the fleet scale,while the normalized summer operational scenario yields the lowest economic benefits.
文摘Phosphogypsum-based materials (PBM) were synthesized with varied phase compositions of phosphogypsum,portland cement and fly ash.Effects of fractal growth characteristics on physicochemical properties,pore structure,compressive strength,as well as the hydration behaviour and mineralogical conversion of mortars were examined by a multitechnological approach,including mercury intrusion porosimetry,rietved phase analysis,thremal analysis,calorimetry and Fourier transforminfrared spectroscopy analysis.Expermental results indicate that the specimens cured with mosite resulted in higher strength and lower porosity compared with those cured in the drying chamber.In addition,a more complicated course of the aluminate and silicate reactions during the hydration process has been published,with the hydration products mainly consisting of calcium silicate hydrate (C-S-H),portlandite,ettringite,hemicarbonate,monocarboaluminate,calcite,quartz,a mixed AFm passed with carbonate,and hydroxide.After all,the nucleation process is a reaction that can be defined as a solid,liquid and gaseous phases that goes through the four stages of materialization mixing and modification,i e,hydration of low calcium content,secondary hydration,high calcium condensation and geoplymensation,respectively.The rupture,recombination,polymerization reactions of Si-O,Ca-O,Al-O bonds contribute to the nucleation mechanism that serves as the formation of C-S-H in hydration products.
