Monkeypox virus(MPXV),a member of the Orthopoxvirus genus,caused a large-scale global outbreak in 2022.Developing mouse models for MPXV infection is crucial for advancing research on vaccines and therapeutic intervent...Monkeypox virus(MPXV),a member of the Orthopoxvirus genus,caused a large-scale global outbreak in 2022.Developing mouse models for MPXV infection is crucial for advancing research on vaccines and therapeutic interventions.To address this,we conducted a comparative study on the susceptibility of six mouse strains—severe combined immune-deficiency(SCID),nude,genetically diabetic(db/db)and obese(ob/ob),C57BL/6J,and BALB/c—to MPXV infection.Mouse strains were infected with MPXV via intranasal inoculation,and body weight changes and mortality were monitored post-infection.Additionally,the tissue distribution of MPXV and the pathological changes in the lung tissues of the infected mice were evaluated.The results demonstrated that SCID and nude mice exhibited significant weight loss following MPXV infection,with 100%mortality observed in SCID mice,while no mortality occurred in nude mice.In contrast,the other mouse strains showed no significant weight loss or mortality.Notably,the viral load in the lung tissues of SCID and nude mice was the highest among the tested strains.Furthermore,we investigated the impact of different inoculation routes—intranasal(I.N.),intraperitoneal(I.P.),and intravenous(I.V.)—on the pathogenicity of MPXV in mice.The results revealed that the intravenous route induced more pronounced pathogenic effects compared to the intranasal and intraperitoneal routes.In summary,this study provides valuable insights into the development of MPXV-infected mouse models,offering a foundation for further research on MPXV pathogenesis and therapeutic drug development.展开更多
Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger gra...Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger grain size than unidirectional rolling aged(URA)sheet due to the occurrence of dynamic recovery during rolling which reduces the dislocation density and delays dynamic recrystallization(DRX).The URA sheet has basal texture and RD favored texture while CRA sheet has multiple-peak texture.Both sheets precipitate β'phase and CRA sheet exhibits a stronger aging response.The CRA sheet has higher yield strength and tensile strength than URA sheet,with reduced yield strength anisotropy but increased tensile strength anisotropy.Taking into account different strengthening mechanisms,although the finer grain size of URA sheet enhances grain boundary strengthening,CRA sheet is more responsive to aging,leading to superior aging-precipitated phase strengthening and consequently higher yield strength.展开更多
Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central...Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.展开更多
The rapid transformation of Arctic maritime routes,driven by diminishing sea ice and shifting geopolitical conditions,presents both opportunities and challenges for global shipping.This study develops an integrated op...The rapid transformation of Arctic maritime routes,driven by diminishing sea ice and shifting geopolitical conditions,presents both opportunities and challenges for global shipping.This study develops an integrated optimization framework for sustainable Arctic marine logistics,grounded in Agile Supply Chain Theory(ASCT),to address cost efficiency,environmental sustainability,and operational robustness under climate and policy uncertainty.A Mixed‐Integer Linear Programming(MILP)model was employed to optimize vessel routing across Arctic corridors,incorporating Energy Efficiency Operational Indicator(EEOI)and Carbon Intensity Indicator(CII)metrics directly into the objective function.Scenario analyses tested performance under varying climate conditions and policy constraints.The model was parameterized using vessel operational data from Arctic shipping logs,environmental datasets from ESA CryoSat‐2 and NSIDC,port accessibility records from Arctic port authorities,and economic data from Clarksons and the World Bank,ensuring realistic and replicable inputs for the analysis.Results demonstrate that ASCT‐based optimized routes achieved an average 14.8%reduction in operating costs,12.3%reduction in CO₂emissions,and an 11.6%improvement in EEOI,with the majority of voyages improving by at least one CII grade.Robustness analysis showed that optimized routes maintained up to 14.7 percentage points higher feasibility under severe ice scenarios and reduced cost volatility by 20–28%under carbon tax regimes.These findings confirm the value of embedding agility and resilience principles into Arctic shipping,aligning operational efficiency with International Maritime Organization(IMO)decarbonization objectives.The study extends ASCT into extreme maritime contexts,offering a replicable model for sustainable route planning in high‐risk logistics sectors.展开更多
Meta-heuristic evolutionary algorithms have become widely used for solving complex optimization problems.However,their effectiveness in real-world applications is often limited by the need for many evaluations,which c...Meta-heuristic evolutionary algorithms have become widely used for solving complex optimization problems.However,their effectiveness in real-world applications is often limited by the need for many evaluations,which can be both costly and time-consuming.This is especially true for large-scale transportation networks,where the size of the problem and the high computational cost can hinder the algorithm’s performance.To address these challenges,recent research has focused on using surrogate-assisted models.These models aim to reduce the number of expensive evaluations and improve the efficiency of solving time-consuming optimization problems.This paper presents a new two-layer Surrogate-Assisted Fish Migration Optimization(SA-FMO)algorithm designed to tackle high-dimensional and computationally heavy problems.The global surrogate model offers a good approximation of the entire problem space,while the local surrogate model focuses on refining the solution near the current best option,improving local optimization.To test the effectiveness of the SA-FMO algorithm,we first conduct experiments using six benchmark functions in a 50-dimensional space.We then apply the algorithm to optimize urban rail transit routes,focusing on the Train Routing Optimization problem.This aims to improve operational efficiency and vehicle turnover in situations with uneven passenger flow during transit disruptions.The results show that SA-FMO can effectively improve optimization outcomes in complex transportation scenarios.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
To improve the efficiency of ship traffic in frequently traded sea areas and respond to the national“dual-carbon”strategy,a multi-objective ship route induction model is proposed.Considering the energy-saving and en...To improve the efficiency of ship traffic in frequently traded sea areas and respond to the national“dual-carbon”strategy,a multi-objective ship route induction model is proposed.Considering the energy-saving and environmental issues of ships,this study aims to improve the transportation efficiency of ships by providing a ship route induction method.Ship data from a certain bay during a defined period are collected,and an improved backpropagation neural network algorithm is used to forecast ship traffic.On the basis of the forecasted data and ship route induction objectives,dynamic programming of ship routes is performed.Experimental results show that the routes planned using this induction method reduce the combined cost by 17.55%compared with statically induced routes.This method has promising engineering applications in improving ship navigation efficiency,promoting energy conservation,and reducing emissions.展开更多
In order to increase productivity and reduce energy consumption of steelmaking-continuous casting(SCC) production process, especially with complicated technological routes, the cross entropy(CE) method was adopted to ...In order to increase productivity and reduce energy consumption of steelmaking-continuous casting(SCC) production process, especially with complicated technological routes, the cross entropy(CE) method was adopted to optimize the SCC production scheduling(SCCPS) problem. Based on the CE method, a matrix encoding scheme was proposed and a backward decoding method was used to generate a reasonable schedule. To describe the distribution of the solution space, a probability distribution model was built and used to generate individuals. In addition, the probability updating mechanism of the probability distribution model was proposed which helps to find the optimal individual gradually. Because of the poor stability and premature convergence of the standard cross entropy(SCE) algorithm, the improved cross entropy(ICE) algorithm was proposed with the following improvements: individual generation mechanism combined with heuristic rules, retention mechanism of the optimal individual, local search mechanism and dynamic parameters of the algorithm. Simulation experiments validate that the CE method is effective in solving the SCCPS problem with complicated technological routes and the ICE algorithm proposed has superior performance to the SCE algorithm and the genetic algorithm(GA).展开更多
The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples ...The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples were used for genetic diversity analysis based on inter-simple sequence repeat(ISSR)and 108 samples were used for multi-gene sequence analysis based on five gene fragments.The results indicated that populations of C.zeina were differentiated with a relatively high genetic level and were classified into two major groups and seven subgroups.The intra-population genetic differentiation of C.zeina is the leading cause of population variation in China,and interpopulation genetic similarity is closely related to the colonization time and spread direction.The multi-gene sequence analysis of C.zeina isolates demonstrated that there were nine haplotypes.Genetic diversity and multi-gene sequence revealed that Yunnan population of C.zeina,the earliest colonizing in China,had the highest genetic and haplotype diversity and had experienced an expansion event.With the influence of the southwest monsoon in the Indian Ocean,C.zeina from Yunnan gradually moved to Sichuan,Guizhou,Shaanxi,Gansu,and Chongqing.Meanwhile,C.zeina was transferred directly from the Yunnan into the Hubei Province via seed and then came into Shaanxi,Henan,and Chongqing along with the wind from Hubei.展开更多
With rapid development of air transportation,the airspace structure of the future will need to be flexible and dynamic to accommodate the increase in traffic demand.The corridors-in-the-sky has become a new technology...With rapid development of air transportation,the airspace structure of the future will need to be flexible and dynamic to accommodate the increase in traffic demand.The corridors-in-the-sky has become a new technology to support the full exploitation and utilization of airspace resources.This paper proposes a method of designing corridor,identifying congestion state,and analyzing the influence of air routes’traffic flow.From this,we have reached a number of conclusions.(1)The congestion periods present the multi-peak"wavy"scattered distributions and the peaks back-end agglomeration characteristics in the whole day.(2)The congestion segments present the structural characteristics of unbalanced coverage and concentrated distribution to the crossing points.The corridors with high congestion level present as an italic"N-shaped"frame,which presents incomplete penetration of short segments.(3)For the temporal and spatial interaction,there are two types of congestion segments,and there are some common congestion periods in different congestion segments of multiple corridors.The high-density air route plays a relatively decisive role in corridor congestion,and the influence of two directions is unbalanced.This research can provide a basis for the dynamic evaluation of China’s airspace resources and corridors construction in the future.展开更多
Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, t...Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level （i.e. repeatability in migratory routes and timing） still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability （or conversely, the flexibility） in migration. To this end, we analysed a dataset of 48 trips （23 springs and 25 autumns） recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration （13 ± 2 days, range = 9-18 d） than in spring migration （19 ± 3 days, range = 13-26 d）, which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration （i.e. strong endogenous control of migration） and high flexibility in routes [Current Zoology 60 （5）： 642-652, 2014].展开更多
Single-layer superconductors are ideal materials for fabricating superconducting nano devices.However,up to date,very few single-layer elemental superconductors have been predicted and especially no one has been succe...Single-layer superconductors are ideal materials for fabricating superconducting nano devices.However,up to date,very few single-layer elemental superconductors have been predicted and especially no one has been successfully synthesized yet.Here,using crystal structure search techniques and ab initio calculations,we predict that a single-layer planar carbon sheet with 4-and 8-membered rings called T-graphene is a new intrinsic elemental superconductor with superconducting critical temperature(Tc)up to around 20.8 K.More importantly,we propose a synthesis route to obtain such a single-layer T-graphene,that is,a T-graphene potassium intercalation compound(C4 K with P4/mmm symmetry)is firstly synthesized at high pressure(>11.5 GPa)and then quenched to ambient condition;and finally,the single-layer T-graphene can be either exfoliated using the electrochemical method from the bulk C4 K,or peeled off from bulk T-graphite C4,where C4 can be obtained from C4 K by evaporating the K atoms.Interestingly,we find that the calculated Tc of C4 K is about 30.4 K at 0 GPa,which sets a new record for layered carbon-based superconductors.The present findings add a new class of carbon-based superconductors.In particular,once the single-layer T-graphene is synthesized,it can pave the way for fabricating superconducting devices together with other 2 D materials using the layer-by-layer growth techniques.展开更多
Background:The vulnerable Chinese Egret(Egretta eulophotes)is a long-distance migratory waterbird whose migration and wintering information is poorly understood.This study aims to identify the autumn migration routes ...Background:The vulnerable Chinese Egret(Egretta eulophotes)is a long-distance migratory waterbird whose migration and wintering information is poorly understood.This study aims to identify the autumn migration routes and wintering areas of juvenile Chinese Egrets and determine the migration movement traits of this species.Methods:Thirty-nine juvenile Chinese Egrets from the Fantuozi Island,an uninhabited offshore island with a large breeding colony of Chinese Egrets in Dalian,China,were tracked using GPS/GSM transmitters.Some feathers from each tracked juvenile were collected for molecular identification of sex in the laboratory.The GPS locations,recorded at 2-h intervals from August 2018 to May 2020,were used for the analyses.Results:Of the 39 tracked juveniles,30 individuals began their migration between September and November,and 13 successfully completed their autumn migration between October and November.The juveniles migrated southward via three migration routes,coastal,oceanic and inland,mainly during the night.The migration duration,migration distance,flight speed,and stopover duration of the 13 juvenile egrets that completed migration averaged 5.08±1.04 days,3928.18±414.27 km,57.27±5.73 km/h,and 23.08±19.28 h,respectively.These juveniles wintered in the coastal wetlands of Southeast Asia including those in the Philippines,Vietnam,and Malaysia,and only one successfully began its spring migration in June 2020.Conclusions:This study newly finds that the oceanic route taken by juvenile Chinese Egrets,suggesting that the juveniles are able to fly over the Pacific Ocean without a stopover.Moreover,our novel data indicate that coastal wetlands along the East Asian-Australasian Flyway are important areas for both autumn migration stopover and the wintering of these juveniles,suggesting that international cooperation is important to conserve the vulnerable Chinese Egret and the wetland habitats on which it depends.展开更多
This paper presents a new passive-biped model consisting of a simplest walking model beneath an upper body, with no kinematic constraint. The upper body is attached to the legs with a linear torsional spring. The mode...This paper presents a new passive-biped model consisting of a simplest walking model beneath an upper body, with no kinematic constraint. The upper body is attached to the legs with a linear torsional spring. The model is a passive dynamic walker, so it walks down a slope without energy input. The governing equations of motion are derived and simulated for the parameter analysis purposes. Simulation results reveal some different routes to chaos that have not been observed in previous models.展开更多
Containership stowage plans are a pivotal teaches in the system of container transportation.With the increasing containers shipping,planning containership stowage has become more and more complicated.So intelligent st...Containership stowage plans are a pivotal teaches in the system of container transportation.With the increasing containers shipping,planning containership stowage has become more and more complicated.So intelligent stowage planning for containerships is of great significance.An effective stowage plan may improve efficiency of transportation system.First,the progress of containership stowage plan at home and abroad is reviewed,including the latest developments,such as the application of various optimization methods and computer techniques to the problem.Then,the complexities of the problem are discussed and areas where investigations are still needed are pointed out.This will provide a reference for further research on the subject.展开更多
Antagonising effects of α-ketoglutarate (α-KG) could be attributed to complexing of the reactive nucleophile (CN-) to form cyanohydrin in cyanide intoxication. However, an enormous protection obtained could not be d...Antagonising effects of α-ketoglutarate (α-KG) could be attributed to complexing of the reactive nucleophile (CN-) to form cyanohydrin in cyanide intoxication. However, an enormous protection obtained could not be delineated on account of possible in situ binding of α-KG given intraperitoneally (i.p.) in mice to cyanide administered through the same route. The present study was designed to see the efficacy of a-KG alone or in combination with sodium nitrite (SN) and/or sodium thiosulfate (STS) in male mice exposed to cyanide administered through subcutaneous (s.c.) or inhalation route. A technique for generation of hydrogen cyanide (HCN) is also discussed. On the basis of protection index (PI), defined here as the LD50 of cyanide in protected mice/LD50 of cyanide in unprotected mice and survival time, STS + α-KG regimen was equipotent to the conventional SN + STS regimen. This is further substantiated by effect of α-KG in reducing plasma cyanide levels. The efficacy of α-KG remains undeterred irrespective of the route of cyanide intoxication, while the magnitude of protection varies.展开更多
In order to solve cruise missile route planning problem for low-altitude penetration , a hy- brid particle swarm optimization （ HPSO ） algorithm is proposed. Firstly, K-means clustering algo- rithm is applied to div...In order to solve cruise missile route planning problem for low-altitude penetration , a hy- brid particle swarm optimization （ HPSO ） algorithm is proposed. Firstly, K-means clustering algo- rithm is applied to divide the particle swarm into multiple isolated sub-populations, then niche algo- rithm is adopted to make all particles independently search for optimal values in their own sub-popu- lations. Finally simulated annealing （SA） algorithm is introduced to avoid the weakness of PSO algo- rithm, which can easily be trapped into the local optimum in the search process. The optimal value obtained by every sub-population search corresponds to an optimal route, multiple different optimal routes are provided for cruise missile. Simulation results show that the HPSO algorithm has a fast convergence rate, and the planned routes have flat ballisticpaths and short ranges which meet the low-altitude penetration requirements.展开更多
The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (trans...The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (transmission electronic microscope) and SEM (scanning electron microscope). It was found that MA-POE, as an impact modifier, had a profound effect upon the toughness of the PA-6/nano-CaCO3 composite. In particular, by adopting two-stage blending route, the microstructure of the ternary composites turned to core-shell structure, and the impact toughness was improved greatly. At the same time, tensile strength and dynamic storage modulus (E1) were higher than those with one-stage blending route processed ternary composite. The results suggest that blending routes may improve the properties of PA-6/nano-CaCO3/MA-POE ternary composites.展开更多
This paper presents a novel energy-aware algorithm for service composition based on sharing routes in Wireless Sensor Networks (WSNs). The method integrates the resource of the overlapping WSNs to a virtual resource p...This paper presents a novel energy-aware algorithm for service composition based on sharing routes in Wireless Sensor Networks (WSNs). The method integrates the resource of the overlapping WSNs to a virtual resource pool in the execution cycles of the workflow. This approach chooses the suitable service instances according to the current execution environment and user requirements with minimum energy consumption. Finally, the performance of sharing routes service composition selection in WSNs has been evaluated.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2023YFD1800403 and 2023YFD1800404)。
文摘Monkeypox virus(MPXV),a member of the Orthopoxvirus genus,caused a large-scale global outbreak in 2022.Developing mouse models for MPXV infection is crucial for advancing research on vaccines and therapeutic interventions.To address this,we conducted a comparative study on the susceptibility of six mouse strains—severe combined immune-deficiency(SCID),nude,genetically diabetic(db/db)and obese(ob/ob),C57BL/6J,and BALB/c—to MPXV infection.Mouse strains were infected with MPXV via intranasal inoculation,and body weight changes and mortality were monitored post-infection.Additionally,the tissue distribution of MPXV and the pathological changes in the lung tissues of the infected mice were evaluated.The results demonstrated that SCID and nude mice exhibited significant weight loss following MPXV infection,with 100%mortality observed in SCID mice,while no mortality occurred in nude mice.In contrast,the other mouse strains showed no significant weight loss or mortality.Notably,the viral load in the lung tissues of SCID and nude mice was the highest among the tested strains.Furthermore,we investigated the impact of different inoculation routes—intranasal(I.N.),intraperitoneal(I.P.),and intravenous(I.V.)—on the pathogenicity of MPXV in mice.The results revealed that the intravenous route induced more pronounced pathogenic effects compared to the intranasal and intraperitoneal routes.In summary,this study provides valuable insights into the development of MPXV-infected mouse models,offering a foundation for further research on MPXV pathogenesis and therapeutic drug development.
基金Project(2023GK2020)supported by the Key Research and Development Program of Hunan Province,China。
文摘Microstructure and mechanical properties of aged Mg-10Gd-2Y-0.4Zr-0.4Ag alloy sheets prepared by different rolling routes were investigated.The results showed that the cross rolling aged(CRA)sheet possesses larger grain size than unidirectional rolling aged(URA)sheet due to the occurrence of dynamic recovery during rolling which reduces the dislocation density and delays dynamic recrystallization(DRX).The URA sheet has basal texture and RD favored texture while CRA sheet has multiple-peak texture.Both sheets precipitate β'phase and CRA sheet exhibits a stronger aging response.The CRA sheet has higher yield strength and tensile strength than URA sheet,with reduced yield strength anisotropy but increased tensile strength anisotropy.Taking into account different strengthening mechanisms,although the finer grain size of URA sheet enhances grain boundary strengthening,CRA sheet is more responsive to aging,leading to superior aging-precipitated phase strengthening and consequently higher yield strength.
基金supported by the National Natural Science Foundation of China(Grant No.31672296).
文摘Ecological barriers present significant challenges to bird migration by limiting the availability of stopover sites and shelters. The Qinghai-Tibet Plateau, a major migratory barrier located in higher latitude Central Asia, exerts a substantial influence on avian migration patterns. Species traversing such ecological barriers may adopt multiple optimal routes, which can contribute to the formation of migratory divides. From 2018 to 2021, the migration routes of 13 adult Common Cuckoos (Cuculus canorus) breeding in the north of the Qinghai-Tibet Plateau were tracked using satellite transmitters. We found Common Cuckoos have two primary migration routes: western and eastern, respectively following western and eastern edges of the Qinghai-Tibet plateau. The eastern and western routes are likely the optimal routes for the Central Asian Common Cuckoos population to navigate the Qinghai-Tibet Plateau. Furthermore, two individuals exhibited intermediate migration routes, suggesting attempted traverses of the Qinghai-Tibet Plateau, although neither completed the migration. These intermediate routes may indicate migratory behavior influenced by hybridization between eastern and western populations or migratory flexibility. Common Cuckoos exhibit significantly faster migration speed, flight speed, and shorter stopover durations during spring compared to autumn. The observed seasonal differences in migration behavior support birds following time-minimization strategies during spring migration. These results revealed the diverse migration routes of Common Cuckoos shaped by the Qinghai-Tibet Plateau and seasonal variation in migration patterns.
文摘The rapid transformation of Arctic maritime routes,driven by diminishing sea ice and shifting geopolitical conditions,presents both opportunities and challenges for global shipping.This study develops an integrated optimization framework for sustainable Arctic marine logistics,grounded in Agile Supply Chain Theory(ASCT),to address cost efficiency,environmental sustainability,and operational robustness under climate and policy uncertainty.A Mixed‐Integer Linear Programming(MILP)model was employed to optimize vessel routing across Arctic corridors,incorporating Energy Efficiency Operational Indicator(EEOI)and Carbon Intensity Indicator(CII)metrics directly into the objective function.Scenario analyses tested performance under varying climate conditions and policy constraints.The model was parameterized using vessel operational data from Arctic shipping logs,environmental datasets from ESA CryoSat‐2 and NSIDC,port accessibility records from Arctic port authorities,and economic data from Clarksons and the World Bank,ensuring realistic and replicable inputs for the analysis.Results demonstrate that ASCT‐based optimized routes achieved an average 14.8%reduction in operating costs,12.3%reduction in CO₂emissions,and an 11.6%improvement in EEOI,with the majority of voyages improving by at least one CII grade.Robustness analysis showed that optimized routes maintained up to 14.7 percentage points higher feasibility under severe ice scenarios and reduced cost volatility by 20–28%under carbon tax regimes.These findings confirm the value of embedding agility and resilience principles into Arctic shipping,aligning operational efficiency with International Maritime Organization(IMO)decarbonization objectives.The study extends ASCT into extreme maritime contexts,offering a replicable model for sustainable route planning in high‐risk logistics sectors.
基金supported by the National Natural Science Foundation of China(Project No.52172321,52102391)Sichuan Province Science and Technology Innovation Talent Project(2024JDRC0020)+1 种基金China Shenhua Energy Company Limited Technology Project(GJNY-22-7/2300-K1220053)Key science and technology projects in the transportation industry of the Ministry of Transport(2022-ZD7-132).
文摘Meta-heuristic evolutionary algorithms have become widely used for solving complex optimization problems.However,their effectiveness in real-world applications is often limited by the need for many evaluations,which can be both costly and time-consuming.This is especially true for large-scale transportation networks,where the size of the problem and the high computational cost can hinder the algorithm’s performance.To address these challenges,recent research has focused on using surrogate-assisted models.These models aim to reduce the number of expensive evaluations and improve the efficiency of solving time-consuming optimization problems.This paper presents a new two-layer Surrogate-Assisted Fish Migration Optimization(SA-FMO)algorithm designed to tackle high-dimensional and computationally heavy problems.The global surrogate model offers a good approximation of the entire problem space,while the local surrogate model focuses on refining the solution near the current best option,improving local optimization.To test the effectiveness of the SA-FMO algorithm,we first conduct experiments using six benchmark functions in a 50-dimensional space.We then apply the algorithm to optimize urban rail transit routes,focusing on the Train Routing Optimization problem.This aims to improve operational efficiency and vehicle turnover in situations with uneven passenger flow during transit disruptions.The results show that SA-FMO can effectively improve optimization outcomes in complex transportation scenarios.
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.
基金Supported by the National Key R&D Program of China project (2017YFC0805309)the National Natural Science Foundation of China (60602020)。
文摘To improve the efficiency of ship traffic in frequently traded sea areas and respond to the national“dual-carbon”strategy,a multi-objective ship route induction model is proposed.Considering the energy-saving and environmental issues of ships,this study aims to improve the transportation efficiency of ships by providing a ship route induction method.Ship data from a certain bay during a defined period are collected,and an improved backpropagation neural network algorithm is used to forecast ship traffic.On the basis of the forecasted data and ship route induction objectives,dynamic programming of ship routes is performed.Experimental results show that the routes planned using this induction method reduce the combined cost by 17.55%compared with statically induced routes.This method has promising engineering applications in improving ship navigation efficiency,promoting energy conservation,and reducing emissions.
基金Project(ZR2014FM036)supported by Shandong Provincial Natural Science Foundation of ChinaProject(ZR2010FZ001)supported by the Key Program of Shandong Provincial Natural Science Foundation of China
文摘In order to increase productivity and reduce energy consumption of steelmaking-continuous casting(SCC) production process, especially with complicated technological routes, the cross entropy(CE) method was adopted to optimize the SCC production scheduling(SCCPS) problem. Based on the CE method, a matrix encoding scheme was proposed and a backward decoding method was used to generate a reasonable schedule. To describe the distribution of the solution space, a probability distribution model was built and used to generate individuals. In addition, the probability updating mechanism of the probability distribution model was proposed which helps to find the optimal individual gradually. Because of the poor stability and premature convergence of the standard cross entropy(SCE) algorithm, the improved cross entropy(ICE) algorithm was proposed with the following improvements: individual generation mechanism combined with heuristic rules, retention mechanism of the optimal individual, local search mechanism and dynamic parameters of the algorithm. Simulation experiments validate that the CE method is effective in solving the SCCPS problem with complicated technological routes and the ICE algorithm proposed has superior performance to the SCE algorithm and the genetic algorithm(GA).
基金supported by the China Agriculture Research System from MOAR and MOF(CARS-02)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘The gray leaf spot caused by Cercospora zeina has become a serious disease in maize in China.The isolates of C.zeina from Yunnan,Sichuan,Guizhou,Hubei,Chongqing,Gansu,and Shaanxi were collected.From those,127 samples were used for genetic diversity analysis based on inter-simple sequence repeat(ISSR)and 108 samples were used for multi-gene sequence analysis based on five gene fragments.The results indicated that populations of C.zeina were differentiated with a relatively high genetic level and were classified into two major groups and seven subgroups.The intra-population genetic differentiation of C.zeina is the leading cause of population variation in China,and interpopulation genetic similarity is closely related to the colonization time and spread direction.The multi-gene sequence analysis of C.zeina isolates demonstrated that there were nine haplotypes.Genetic diversity and multi-gene sequence revealed that Yunnan population of C.zeina,the earliest colonizing in China,had the highest genetic and haplotype diversity and had experienced an expansion event.With the influence of the southwest monsoon in the Indian Ocean,C.zeina from Yunnan gradually moved to Sichuan,Guizhou,Shaanxi,Gansu,and Chongqing.Meanwhile,C.zeina was transferred directly from the Yunnan into the Hubei Province via seed and then came into Shaanxi,Henan,and Chongqing along with the wind from Hubei.
基金National Natural Science Foundation of China,No.41671121
文摘With rapid development of air transportation,the airspace structure of the future will need to be flexible and dynamic to accommodate the increase in traffic demand.The corridors-in-the-sky has become a new technology to support the full exploitation and utilization of airspace resources.This paper proposes a method of designing corridor,identifying congestion state,and analyzing the influence of air routes’traffic flow.From this,we have reached a number of conclusions.(1)The congestion periods present the multi-peak"wavy"scattered distributions and the peaks back-end agglomeration characteristics in the whole day.(2)The congestion segments present the structural characteristics of unbalanced coverage and concentrated distribution to the crossing points.The corridors with high congestion level present as an italic"N-shaped"frame,which presents incomplete penetration of short segments.(3)For the temporal and spatial interaction,there are two types of congestion segments,and there are some common congestion periods in different congestion segments of multiple corridors.The high-density air route plays a relatively decisive role in corridor congestion,and the influence of two directions is unbalanced.This research can provide a basis for the dynamic evaluation of China’s airspace resources and corridors construction in the future.
文摘Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level （i.e. repeatability in migratory routes and timing） still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability （or conversely, the flexibility） in migration. To this end, we analysed a dataset of 48 trips （23 springs and 25 autumns） recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration （13 ± 2 days, range = 9-18 d） than in spring migration （19 ± 3 days, range = 13-26 d）, which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration （i.e. strong endogenous control of migration） and high flexibility in routes [Current Zoology 60 （5）： 642-652, 2014].
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0300404the National Basic Research Program of China under Grant No 2015CB921202+2 种基金the National Nature Science Foundation of China under Grant Nos 11574133 and 11834006the Nature Science Foundation of Jiangsu Province under Grant No BK20150012the Fundamental Research Funds for the Central Universities,the Science Challenge Project(No TZ2016001)
文摘Single-layer superconductors are ideal materials for fabricating superconducting nano devices.However,up to date,very few single-layer elemental superconductors have been predicted and especially no one has been successfully synthesized yet.Here,using crystal structure search techniques and ab initio calculations,we predict that a single-layer planar carbon sheet with 4-and 8-membered rings called T-graphene is a new intrinsic elemental superconductor with superconducting critical temperature(Tc)up to around 20.8 K.More importantly,we propose a synthesis route to obtain such a single-layer T-graphene,that is,a T-graphene potassium intercalation compound(C4 K with P4/mmm symmetry)is firstly synthesized at high pressure(>11.5 GPa)and then quenched to ambient condition;and finally,the single-layer T-graphene can be either exfoliated using the electrochemical method from the bulk C4 K,or peeled off from bulk T-graphite C4,where C4 can be obtained from C4 K by evaporating the K atoms.Interestingly,we find that the calculated Tc of C4 K is about 30.4 K at 0 GPa,which sets a new record for layered carbon-based superconductors.The present findings add a new class of carbon-based superconductors.In particular,once the single-layer T-graphene is synthesized,it can pave the way for fabricating superconducting devices together with other 2 D materials using the layer-by-layer growth techniques.
基金supported by the National Natural Science Foundation of China(Grant Nos.42076107,41676123,and 41476113)。
文摘Background:The vulnerable Chinese Egret(Egretta eulophotes)is a long-distance migratory waterbird whose migration and wintering information is poorly understood.This study aims to identify the autumn migration routes and wintering areas of juvenile Chinese Egrets and determine the migration movement traits of this species.Methods:Thirty-nine juvenile Chinese Egrets from the Fantuozi Island,an uninhabited offshore island with a large breeding colony of Chinese Egrets in Dalian,China,were tracked using GPS/GSM transmitters.Some feathers from each tracked juvenile were collected for molecular identification of sex in the laboratory.The GPS locations,recorded at 2-h intervals from August 2018 to May 2020,were used for the analyses.Results:Of the 39 tracked juveniles,30 individuals began their migration between September and November,and 13 successfully completed their autumn migration between October and November.The juveniles migrated southward via three migration routes,coastal,oceanic and inland,mainly during the night.The migration duration,migration distance,flight speed,and stopover duration of the 13 juvenile egrets that completed migration averaged 5.08±1.04 days,3928.18±414.27 km,57.27±5.73 km/h,and 23.08±19.28 h,respectively.These juveniles wintered in the coastal wetlands of Southeast Asia including those in the Philippines,Vietnam,and Malaysia,and only one successfully began its spring migration in June 2020.Conclusions:This study newly finds that the oceanic route taken by juvenile Chinese Egrets,suggesting that the juveniles are able to fly over the Pacific Ocean without a stopover.Moreover,our novel data indicate that coastal wetlands along the East Asian-Australasian Flyway are important areas for both autumn migration stopover and the wintering of these juveniles,suggesting that international cooperation is important to conserve the vulnerable Chinese Egret and the wetland habitats on which it depends.
文摘This paper presents a new passive-biped model consisting of a simplest walking model beneath an upper body, with no kinematic constraint. The upper body is attached to the legs with a linear torsional spring. The model is a passive dynamic walker, so it walks down a slope without energy input. The governing equations of motion are derived and simulated for the parameter analysis purposes. Simulation results reveal some different routes to chaos that have not been observed in previous models.
基金Supported by High-tech Research of Educational Department of Liaoning Province (No.05L091)a Special Fund Support Item of Doctor Subject of Colleges and Universities(No.2000014125)
文摘Containership stowage plans are a pivotal teaches in the system of container transportation.With the increasing containers shipping,planning containership stowage has become more and more complicated.So intelligent stowage planning for containerships is of great significance.An effective stowage plan may improve efficiency of transportation system.First,the progress of containership stowage plan at home and abroad is reviewed,including the latest developments,such as the application of various optimization methods and computer techniques to the problem.Then,the complexities of the problem are discussed and areas where investigations are still needed are pointed out.This will provide a reference for further research on the subject.
文摘Antagonising effects of α-ketoglutarate (α-KG) could be attributed to complexing of the reactive nucleophile (CN-) to form cyanohydrin in cyanide intoxication. However, an enormous protection obtained could not be delineated on account of possible in situ binding of α-KG given intraperitoneally (i.p.) in mice to cyanide administered through the same route. The present study was designed to see the efficacy of a-KG alone or in combination with sodium nitrite (SN) and/or sodium thiosulfate (STS) in male mice exposed to cyanide administered through subcutaneous (s.c.) or inhalation route. A technique for generation of hydrogen cyanide (HCN) is also discussed. On the basis of protection index (PI), defined here as the LD50 of cyanide in protected mice/LD50 of cyanide in unprotected mice and survival time, STS + α-KG regimen was equipotent to the conventional SN + STS regimen. This is further substantiated by effect of α-KG in reducing plasma cyanide levels. The efficacy of α-KG remains undeterred irrespective of the route of cyanide intoxication, while the magnitude of protection varies.
基金Supported by the National Natural Science Foundation of China(91016004)
文摘In order to solve cruise missile route planning problem for low-altitude penetration , a hy- brid particle swarm optimization （ HPSO ） algorithm is proposed. Firstly, K-means clustering algo- rithm is applied to divide the particle swarm into multiple isolated sub-populations, then niche algo- rithm is adopted to make all particles independently search for optimal values in their own sub-popu- lations. Finally simulated annealing （SA） algorithm is introduced to avoid the weakness of PSO algo- rithm, which can easily be trapped into the local optimum in the search process. The optimal value obtained by every sub-population search corresponds to an optimal route, multiple different optimal routes are provided for cruise missile. Simulation results show that the HPSO algorithm has a fast convergence rate, and the planned routes have flat ballisticpaths and short ranges which meet the low-altitude penetration requirements.
基金This work was financially supported by the National Natural Science Foundation of China under grant No.29934070.
文摘The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (transmission electronic microscope) and SEM (scanning electron microscope). It was found that MA-POE, as an impact modifier, had a profound effect upon the toughness of the PA-6/nano-CaCO3 composite. In particular, by adopting two-stage blending route, the microstructure of the ternary composites turned to core-shell structure, and the impact toughness was improved greatly. At the same time, tensile strength and dynamic storage modulus (E1) were higher than those with one-stage blending route processed ternary composite. The results suggest that blending routes may improve the properties of PA-6/nano-CaCO3/MA-POE ternary composites.
基金supported by National Natural Science Foundation of China under Grant No. 60833002Natural Science Foundation of Beijing under Grant No.4091003Foundation Sciences of Beijing Jiaotong University under Grant No.2011YJS014
文摘This paper presents a novel energy-aware algorithm for service composition based on sharing routes in Wireless Sensor Networks (WSNs). The method integrates the resource of the overlapping WSNs to a virtual resource pool in the execution cycles of the workflow. This approach chooses the suitable service instances according to the current execution environment and user requirements with minimum energy consumption. Finally, the performance of sharing routes service composition selection in WSNs has been evaluated.
