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
Global warming has made the regular operation of Arctic routes possible.This study selects hub ports based on infrastructure conditions and sea ice status,and then designs two pendulum route solutions for the Northeas...Global warming has made the regular operation of Arctic routes possible.This study selects hub ports based on infrastructure conditions and sea ice status,and then designs two pendulum route solutions for the Northeast Passage according to the distance between hub ports and ice-covered areas.We employ an evaluation framework combining annual profit metrics with discounted net present value(NPV)analysis,conducting probabilistic economic assessments through Monte Carlo simulations(20,000 iterations).Key findings indicate that(1)both solutions demonstrate>90%probability of economic viability and(2)Solution I′,with hub ports closer to ice-covered areas than those in Solution II,yields 5.02%higher mean annual profit and 4.69%greater NPV.The results indicate that pendulum routes in the Northeast Passage can achieve economic benefits by enabling year-round regular operations.Moreover,shorter shipping distances between hub ports and ice-covered areas enhance economic viability.展开更多
Objective Schizophrenia is a complex neuropsychiatric disorder characterized by cognitive,affective,and behavioral abnormalities.Existing treatments have yielded limited effects on improving cognitive function.Recent ...Objective Schizophrenia is a complex neuropsychiatric disorder characterized by cognitive,affective,and behavioral abnormalities.Existing treatments have yielded limited effects on improving cognitive function.Recent studies have identified the abnormal differentiation of hippocampal neural stem cells(NSCs),neuronal loss,and dysregulated proliferation of astrocytes as significant pathological mechanisms contributing to the symptoms of schizophrenia.Impaired hippocampal neurogenesis may lead to emotional and cognitive deficits and biases in learning and memory,indicating that NSC differentiation is critical.NEP1-40,a Nogo-A receptor inhibitor,has shown promise for nerve protection and repair promotion.However,the effects of NEP1-40 on stem cell differentiation,the reduction in neuronal apoptosis,and the amelioration of schizophrenia-like behaviors have not been adequately investigated.This study examined the influence of NEP1-40 on NSC differentiation,hippocampal neuronal apoptosis,and proliferation in adolescent mice,along with its potential to enhance cognitive and behavioral outcomes in MK-801-induced schizophrenia mouse models.Methods In in vivo experiments,a schizophrenia mouse model was successfully established.Subsequently,behavioral tests were conducted,followed by Western blotting(WB)and immunofluorescence(IF)analyses.In in vitro settings,NSCs were cultured and transfected.Flow cytometry,along with WB and IF assays,was employed to evaluate the effects of NEP1-40.Results Schizophrenia-like behaviors in mice were significantly improved with the overexpression of NEP1-40.Compared with the model group,the NEP1-40 treatment group presented increased expression of a neuronal marker(Tuj1),reduced expression of an astroglial marker(GFAP),and decreased hippocampal neuronal apoptosis.NSC differentiation was assessed by quantifying the number of BrdU-positive cells coexpressing Tuj1 and GFAP in the hippocampal dentate gyrus.NEP1-40 treatment led to an increase in BrdU/Tuj1-positive cells and a reduction in BrdU/GFAP-positive cells.In cellular studies,NEP1-40 overexpression similarly increased the number of Tuj1-positive cells,reduced the number of GFAP-positive cells,decreased the degree of neuronal apoptosis,and promoted neuronal proliferation.Conclusion These findings demonstrated the neurogenic effects of NEP1-40 on NSCs and their potential to mitigate schizophrenia-like behaviors in vivo.展开更多
We present a comprehensive extension of the integral of first passage times(IFS)method to investigate the adsorption kinetics of polymers with multiple binding sites on planar surfaces.While effective for single-point...We present a comprehensive extension of the integral of first passage times(IFS)method to investigate the adsorption kinetics of polymers with multiple binding sites on planar surfaces.While effective for single-point adsorption,the original IFS method was limited in capturing the complex kinetics of multi-point adsorption due to inadequate reaction coordinates and theoretical frameworks.Our approach introduces a center-of-mass-based reaction coordinate and a generalized kinetic model that accounts for multi-barrier free energy landscapes characteristic of collective polymer diffusion and binding.This theoretical advancement,implemented using the adaptive bias force method for efficient sampling,enables prediction of adsorption kinetics across timescales from nanoseconds to seconds.Our results demonstrate that adsorption behavior is governed by two key factors:the number of binding monomers primarily controls desorption barriers and long-term stability,while the configuration of pre-adsorbed layers significantly modulates both adsorption and desorption rates.Polymers with three or more binding sites exhibit effectively irreversible adsorption due to exponentially increasing desorption barriers,whereas different adsorbed layer configurations lead to distinct equilibrium coverages and kinetic profiles.This extended IFS framework provides critical insights for designing functional surfaces in nanoscale sensing,macromolecular recognition,and tailored polymeric coatings where precise control over adsorption kinetics is essential.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Global warming has made the regular operation of Arctic routes possible.This study selects hub ports based on infrastructure conditions and sea ice status,and then designs two pendulum route solutions for the Northeast Passage according to the distance between hub ports and ice-covered areas.We employ an evaluation framework combining annual profit metrics with discounted net present value(NPV)analysis,conducting probabilistic economic assessments through Monte Carlo simulations(20,000 iterations).Key findings indicate that(1)both solutions demonstrate>90%probability of economic viability and(2)Solution I′,with hub ports closer to ice-covered areas than those in Solution II,yields 5.02%higher mean annual profit and 4.69%greater NPV.The results indicate that pendulum routes in the Northeast Passage can achieve economic benefits by enabling year-round regular operations.Moreover,shorter shipping distances between hub ports and ice-covered areas enhance economic viability.
文摘旨在探索山东省及其子区域植被净生态系统生产力(Net Ecosystem Productivity,NEP)的时空变化特征及其驱动因素,评估气温(TEM)、降水(PRE)和饱和蒸汽压差(VPD)等因素对植被NEP的影响。基于2000-2020年间的植被净初级生产力(Net Primary Productivity,NPP),采用土壤呼吸地统计(Geostatistical Model of Soil Respiration,GSMSR)模型、植被NEP估算模型和地理探测器工具,通过趋势分析、相关分析和差异分析等研究方法,开展深入研究。结果表明,1)山东省植被NEP在2000-2020年间整体呈上升趋势,空间分布特征表现为从东北向西南递减,沿海地区高于内陆地区。全省植被NEP的年平均值为87.0 g·m^(-2)·a^(-1)(以C计),且超过1/3的地区由碳源区域转变为碳汇区域。2)山东省大部分地区植被NEP与气温、降水呈正相关,与饱和蒸汽压差呈负相关,不同因子间的交互作用普遍对植被NEP的影响大于单一因子的影响。3)山东省4个子区域(鲁西、鲁东、鲁北、鲁中南)植被NEP的变化趋势存在明显的空间分异,鲁中南地区植被NEP增加最为显著,其次是鲁西和鲁东地区,而鲁北地区的增幅相对较小。该研究为深入理解区域生态系统的碳循环动态以及制定相应的生态保护策略提供了科学依据。
基金funded by Ningxia Natural Science Foundation(No.2022AAC03154).
文摘Objective Schizophrenia is a complex neuropsychiatric disorder characterized by cognitive,affective,and behavioral abnormalities.Existing treatments have yielded limited effects on improving cognitive function.Recent studies have identified the abnormal differentiation of hippocampal neural stem cells(NSCs),neuronal loss,and dysregulated proliferation of astrocytes as significant pathological mechanisms contributing to the symptoms of schizophrenia.Impaired hippocampal neurogenesis may lead to emotional and cognitive deficits and biases in learning and memory,indicating that NSC differentiation is critical.NEP1-40,a Nogo-A receptor inhibitor,has shown promise for nerve protection and repair promotion.However,the effects of NEP1-40 on stem cell differentiation,the reduction in neuronal apoptosis,and the amelioration of schizophrenia-like behaviors have not been adequately investigated.This study examined the influence of NEP1-40 on NSC differentiation,hippocampal neuronal apoptosis,and proliferation in adolescent mice,along with its potential to enhance cognitive and behavioral outcomes in MK-801-induced schizophrenia mouse models.Methods In in vivo experiments,a schizophrenia mouse model was successfully established.Subsequently,behavioral tests were conducted,followed by Western blotting(WB)and immunofluorescence(IF)analyses.In in vitro settings,NSCs were cultured and transfected.Flow cytometry,along with WB and IF assays,was employed to evaluate the effects of NEP1-40.Results Schizophrenia-like behaviors in mice were significantly improved with the overexpression of NEP1-40.Compared with the model group,the NEP1-40 treatment group presented increased expression of a neuronal marker(Tuj1),reduced expression of an astroglial marker(GFAP),and decreased hippocampal neuronal apoptosis.NSC differentiation was assessed by quantifying the number of BrdU-positive cells coexpressing Tuj1 and GFAP in the hippocampal dentate gyrus.NEP1-40 treatment led to an increase in BrdU/Tuj1-positive cells and a reduction in BrdU/GFAP-positive cells.In cellular studies,NEP1-40 overexpression similarly increased the number of Tuj1-positive cells,reduced the number of GFAP-positive cells,decreased the degree of neuronal apoptosis,and promoted neuronal proliferation.Conclusion These findings demonstrated the neurogenic effects of NEP1-40 on NSCs and their potential to mitigate schizophrenia-like behaviors in vivo.
基金financially supported by the National Natural Science Foundation of China(No.12374207)the Natural Science Foundation of Jiangsu Province(No.BK20233001)supported by the Big Data Computing Center of Southeast University。
文摘We present a comprehensive extension of the integral of first passage times(IFS)method to investigate the adsorption kinetics of polymers with multiple binding sites on planar surfaces.While effective for single-point adsorption,the original IFS method was limited in capturing the complex kinetics of multi-point adsorption due to inadequate reaction coordinates and theoretical frameworks.Our approach introduces a center-of-mass-based reaction coordinate and a generalized kinetic model that accounts for multi-barrier free energy landscapes characteristic of collective polymer diffusion and binding.This theoretical advancement,implemented using the adaptive bias force method for efficient sampling,enables prediction of adsorption kinetics across timescales from nanoseconds to seconds.Our results demonstrate that adsorption behavior is governed by two key factors:the number of binding monomers primarily controls desorption barriers and long-term stability,while the configuration of pre-adsorbed layers significantly modulates both adsorption and desorption rates.Polymers with three or more binding sites exhibit effectively irreversible adsorption due to exponentially increasing desorption barriers,whereas different adsorbed layer configurations lead to distinct equilibrium coverages and kinetic profiles.This extended IFS framework provides critical insights for designing functional surfaces in nanoscale sensing,macromolecular recognition,and tailored polymeric coatings where precise control over adsorption kinetics is essential.
