Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is...Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is the transport of a major mitotic signaling module,the chromosomal passenger complex(CPC),along the microtubule toward the equatorial cortex by a kinesin-6 motor during anaphase,where the CPC can interact with the microtubule.Here,an analytical theory is presented on the dynamics of the molecular motor transporting a track-interacted cargo.The theory is then applied to the transport of the track-interacted cargo by kinesin-6 and by kinesin-1 motors,with the theoretical results reproducing quantitatively the available experimental data.It is found that a diffusive cargo along the track,with the diffusion constant≥0.1μm2s-1,can largely enhance the processivity relative to the non-diffusive cargo and relative to the cargo having no interaction with the track.展开更多
This paper proposes a novel cargo loading algorithm applicable to automated conveyor-type loading systems.The algorithm offers improvements in computational efficiency and robustness by utilizing the concept of discre...This paper proposes a novel cargo loading algorithm applicable to automated conveyor-type loading systems.The algorithm offers improvements in computational efficiency and robustness by utilizing the concept of discrete derivatives and introducing logistics-related constraints.Optional consideration of the rotation of the cargoes was made to further enhance the optimality of the solutions,if possible to be physically implemented.Evaluation metrics were developed for accurate evaluation and enhancement of the algorithm’s ability to efficiently utilize the loading space and provide a high level of dynamic stability.Experimental results demonstrate the extensive robustness of the proposed algorithm to the diversity of cargoes present in Business-to-Consumer environments.This study contributes practical advancements in both cargo loading optimization and automation of the logistics industry,with potential applications in last-mile delivery services,warehousing,and supply chain management.展开更多
Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because ...Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because it is carried out during flight, it is necessary to investigate the influences of the drop process on flight characteristics to ensure successful execution of the task. This article mainly studies the modeling of flight systems in large flying transport planes with cargo moving in it. By buildi...展开更多
Established in 2019,the Shandong Port Group(SPG)comprises four port groups(Qingdao Port,Rizhao Port,Yantai Port,and Bohaiwan Port)and 12 business segments.SPG connects 3,345 kilometers of coastline within Shandong Pro...Established in 2019,the Shandong Port Group(SPG)comprises four port groups(Qingdao Port,Rizhao Port,Yantai Port,and Bohaiwan Port)and 12 business segments.SPG connects 3,345 kilometers of coastline within Shandong Province.Its cargo throughput has consistently ranked first globally for many years,and its container volume growth ranks second globally,forming a port cluster covering the entire industrial chain.展开更多
On December 18,2025, Hainan Free Trade Port (Hainan FTP) officially began islandwide special customs operations.Although only two months have passed since this landmark step, the shift is already visible everywhere—f...On December 18,2025, Hainan Free Trade Port (Hainan FTP) officially began islandwide special customs operations.Although only two months have passed since this landmark step, the shift is already visible everywhere—from the bustling flow of international passengers at Haikou Meilan International Airport to the steady stream of cargo vessels calling at Yangpu Port, and even in the sustained attention investors are paying to “Hainan-related” stocks.Together, these signals point to one clear conclusion:China’s largest special economic zone has entered a new phase of development.展开更多
Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unco...Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.展开更多
Purpose-This paper provides a comprehensive analysis of the Brazilian freight railway system,examining the efficacy of the current concession renewal model in light of persistent structural problems such as market con...Purpose-This paper provides a comprehensive analysis of the Brazilian freight railway system,examining the efficacy of the current concession renewal model in light of persistent structural problems such as market concentration,cargo dependence on export commodities and underutilization of the network.Situating Brazil within the broader international debate on railway reforms,the paper evaluates whether the ongoing early renewal of concessions can deliver a more diversified and competitive freight system.Design/methodology/approach-The study adopts a sequential mixed-methods research design that integrates longitudinal quantitative analysis with qualitative institutional and policy evaluation.The quantitative component examines time-series indicators published by ANTT,DNIT and INFRA S.A.from 1999 to 2023 to identify structural patterns in traffic growth,investment,safety and market concentration.The qualitative component employs a process-tracing logic to reconstruct the evolution of concession renewals and the implementation of Railway Law 14.273/2021,drawing on concepts from regulatory economics,institutional theory and industrial organization.These empirical streams are synthesized through an analytical framework that connects three dimensions-regulatory design,market structure and system performance-allowing for a systematic assessment of how Brazil’s institutional configuration shapes incentives,competitive dynamics and network utilization.Findings-The analysis confirms that the early renewal of concessions has successfully secured substantial private investment for capacity expansion on existing trunk lines.However,it has perpetuated the vertically integrated model,reinforcing the market power of incumbent operators and failing to significantly promote intramodal competition or cargo diversification.The system remains dominated by iron ore and agricultural commodities,with general cargo representing a minuscule share.The new authorization regime and short-line railway policies present a viable pathway for market opening but face significant operational and institutional barriers to implementation.Originality/value-This research offers a timely and critical assessment of a pivotal moment in Brazilian railway policy.It moves beyond a simplistic evaluation of volume growth to a structural analysis of market failures and the interplay between concession renewal and regulatory innovation.The findings provide actionable insights for policymakers in Brazil and other emerging economies seeking to balance private investment with public interest goals in railway infrastructure,highlighting the necessity of complementary,pro-competitive measures alongside financial investment.展开更多
A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically l...A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically loading containers on and off large cargo vessels.Cargo volumes here have surged as a result of a slew of special customs policies that went into force in December 2025.展开更多
To study the characteristics of cargo extraction, the initial phase of airdrop process, a high fidelity and extendibility simulation model with uniform motion equations for all states during extraction is developed on...To study the characteristics of cargo extraction, the initial phase of airdrop process, a high fidelity and extendibility simulation model with uniform motion equations for all states during extraction is developed on the basis of dynamics methods and contact models between cargo and aircraft. Simulation results agree well with tests data. Cargo exit parameters, which contribute to cargo pitch after extraction, are studied. Simplified computation model of dimensionless exit time is developed and used to evaluate the relation between extraction phase and landing accuracy. Safe interval model is introduced to evaluate the safety of extraction process. Also, relations between initial parameters, including pull coefficient, aircraft pitch and CG coefficient, etc, and result parameters, including exit time, cargo safety, pitch, etc, are developed to help design of airdrop system, especially the selection of extraction parachute and cargo deployment.展开更多
Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to susta...Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals： maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.展开更多
As international maritime organization （IMO） draft 289 was adopted to develop a low-alloy anti-corrosion steel for the deck of cargo oil tank and to understand corrosion mechanism, corrosion behavior of a low-alloy ...As international maritime organization （IMO） draft 289 was adopted to develop a low-alloy anti-corrosion steel for the deck of cargo oil tank and to understand corrosion mechanism, corrosion behavior of a low-alloy steel with chromium contents was studied in O2-CO2-SO2-H2 S wet gas environment. Corrosion rate was measured, and the microstructure and morphology of corrosion product film were characterized by scanning electron microscopy （SEM）. The phase and chemical composition of the corrosion product film were investigated by X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS）, respectively. The effect of misorientation distribution on corro- sion resistance of steel was evaluated by electron backscattered diffraction （EBSD）. The results showed that corro- sion rate decreased with increasing chromium content in the low-alloy steel, and the corrosion type was general corrosion. The phenomenon of chromium enrichment was found in corrosion product film consisting of a-FeOOH, γ- FeOOH, sulphur, FeS2 and Fel-xS. The increase of chromium content decreases the amount of high-angle grain boundaries, thus resulting in the improvement of corrosion resistance.展开更多
The robustness of cargo ship transportation networks is essential to the stability of the world trade system. The current research mainly focuses on the coarse-grained, holistic cargo ship transportation network while...The robustness of cargo ship transportation networks is essential to the stability of the world trade system. The current research mainly focuses on the coarse-grained, holistic cargo ship transportation network while ignoring the structural diversity of different sub-networks. In this paper, we evaluate the robustness of the global cargo ship transportation network based on the most recent Automatic Identification System（AIS） data available. First, we subdivide three typical cargo ship transportation networks（i.e., oil tanker, container ship and bulk carrier） from the original cargo ship transportation network. Then, we design statistical indices based on complex network theory and employ four attack strategies, including random attack and three intentional attacks（i.e., degree-based attack, betweenness-based attack and flux-based attack） to evaluate the robustness of the three typical cargo ship transportation networks. Finally, we compare the integrity of the remaining ports of the network when a small proportion of ports lose their function. The results show that 1） compared with the holistic cargo ship transportation network, the fine-grain-based cargo ship transportation networks can fully reflect the pattern and process of global cargo transportation; 2） different cargo ship networks behave heterogeneously in terms of their robustness, with the container network being the weakest and the bulk carrier network being the strongest; and 3） small-scale intentional attacks may have significant influence on the integrity of the container network but a minor impact on the bulk carrier and oil tanker transportation networks. These conclusions can help improve the decision support capabilities in maritime transportation planning and emergency response and facilitate the establishment of a more reliable maritime transportation system.Abstract： The robustness of cargo ship transportation networks is essential to the stability of the world trade system. The current research mainly focuses on the coarse-grained, holistic cargo ship transportation network while ignoring the structural diversity of different sub-networks. In this paper, we evaluate the robustness of the global cargo ship transporta- tion network based on the most recent Automatic Identification System （AIS） data available. First, we subdivide three typical cargo ship transportation networks （i.e., oil tanker, container ship and bulk carrier） from the original cargo ship transportation network. Then, we design statistical indices based on complex network theory and employ four attack strategies, in- cluding random attack and three intentional attacks （i.e., degree-based attack, between- ness-based attack and flux-based attack） to evaluate the robustness of the three typical cargo ship transportation networks. Finally, we compare the integrity of the remaining ports of the network when a small proportion of ports lose their function. The results show that 1） com- pared with the holistic cargo ship transportation network, the fine-grain-based cargo ship transportation networks can fully reflect the pattern and process of global cargo transportation 2） different cargo ship networks behave heterogeneously in terms of their robustness, with the container network being the weakest and the bulk carrier network being the strongest; and 3） small-scale intentional attacks may have significant influence on the integrity of the con- tainer network but a minor impact on the bulk carrier and oil tanker transportation networks.These conclusions can help improve the decision support capabilities in maritime transportation planning and emergency response and facilitate the establishment of a more reliable maritime transportation system.展开更多
Corrosion behavior of low-alloy steel was investigated in simulated cargo oil tank （COT） bottom plate service environment （10% NaCl solution, pH = 0.85）. The corrosion behavior of inclusion was studied by in-situ ...Corrosion behavior of low-alloy steel was investigated in simulated cargo oil tank （COT） bottom plate service environment （10% NaCl solution, pH = 0.85）. The corrosion behavior of inclusion was studied by in-situ scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. It was found that pitting corrosion was inclined to occur around the place where inclusions exist. After initial corrosion, an area of 10-20μm in diameter was formed as a cireinate cathode around the edge of inclusion. MnS inclusion dissolved in the simulated COT corrosion solution before low-alloy steel matrix, and pitting was formed at the place where MnS dissolved. TiO2 inclusion dissolved in the simulated COT corrosion solution after low alloy steel matrix, and pitting was formed at the place where steel matrix dissolved. The corrosion tended to occur at the area where the curvature radius of inclusion is smaller. The size of round TiO2 inclusions had little influence on corrosion behavior in this certain environment.展开更多
Fuel consumption has always been a matter of concern for ships propulsion. In this research we aim to develop computer models of several containership cargo stacking configurations and discuss an optimal configuration...Fuel consumption has always been a matter of concern for ships propulsion. In this research we aim to develop computer models of several containership cargo stacking configurations and discuss an optimal configuration at a constant front wind speed. The paper presents the simulation results by using ANSYS CFX for a 1:4 scale PostPanamax 9000 TEU containership. The ship is modelled in a cubic domain that contains unstructured mesh with details, in such a way that can demonstrate the influence of the container configuration on wind force. Also the numerical results are verified versus wind tunnel test data. An optimal stack configuration led to about 25%reduction in air resistance. It is proposed that in order to reduce the wind drag force and consequently reduce the fuel consumption and pollutant emissions, empty spaces between the cargo containers and unbalanced cargo distribution over the deck should be inhibited. Also, it is advised to make the cargo distribution on the most forward and aftward deck areas more streamlined.展开更多
High-fidelity cargo airdrop simulation requires the contact dynamics between an aircraft and a cargo to be modeled accurately. This paper presents a general and efficient contact-friction model for simulation of aircr...High-fidelity cargo airdrop simulation requires the contact dynamics between an aircraft and a cargo to be modeled accurately. This paper presents a general and efficient contact-friction model for simulation of aircraft-cargo coupling dynamics during airdrops. The proposed approach has the same essence as that of the finite element node-to-segment contact formulation, which leads to a flexible, straight forward, and efficient code implementation. The formulation is developed under an arbitrary moving frame with both the aircraft and the cargo being treated as general six-degree-of-freedom rigid bodies, and thus it eliminates the restrictions of lateral symmetric assumptions in most existing methods. Moreover, the aircraft-cargo coupling algorithm is discussed in detail, and some practical implementation details are presented. The accuracy and capability of the present method are demonstrated through three numerical examples with increasing complexity and fidelity.展开更多
E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The ...E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The joint coupon corrosion test and potentiodynamic polarization test were carried out under the simulated corrosion environ- ment of the inner bottom plates of cargo oil tanks. The pitting initiation and propagation mechanism of the weld metal were studied by scanning electron microscopy and infinite focus. The results indicated that the microstructures of three kinds of weld metals are all composed of acicular ferrite, ferrite side-plate and proeutectoid ferrite. The micro- structure of heat affected zone is composed predominantly of bainite. Joint welded with low S filler wire has good me- chanical properties. S can decrease free corrosion potential and increase the corrosion tendency. The pitting initiation is oxide inclusion or sulfide oxide inclusion complex. S can induce the formation of occluded area and promote the corrosion propagation. The chemical compositions of weld metal is similar to base metal, which can limit the galvanic corrosion between weld metal and base metal, and avoid formation of corrosion step.展开更多
In response to the development of deep-sea oil and gas resources,which require a high degree of cooperation by crude oil transportation equipment,a new type of ship known as the cargo transfer vessel(CTV)has been deve...In response to the development of deep-sea oil and gas resources,which require a high degree of cooperation by crude oil transportation equipment,a new type of ship known as the cargo transfer vessel(CTV)has been developed.To provide a theoretical reference for the design and equipment of the CTV’s dynamic positioning system,in this paper,we take the new deepwater CTVas the study object and theoretically and numerically analyze its operation,wind load,current load,wave load,and navigational resistance in a range of Brazilian sea conditions with respect to its positioning and towing modes.We confirm that our proposed method can successfully calculate the total environmental load of the CTVand that the CTV is able to operate normally under the designed sea conditions.展开更多
A simulated corrosion test apparatus was used to investigate the corrosion behavior of a low alloy steel under simulated upper deck conditions in a cargo oil tank. The estimated corrosion loss of conventional E36 clas...A simulated corrosion test apparatus was used to investigate the corrosion behavior of a low alloy steel under simulated upper deck conditions in a cargo oil tank. The estimated corrosion loss of conventional E36 class ship plate steel is 4.27 mm, which is clearly inadequate compared with the standard adopted by International Maritime Organization. Outer rust layer of specimens starts to peel off after 77 days and becomes fragmented after 98 days. X-ray diffraction, scanning electron micros- copy, and Raman spectroscopy revealed that the resulting rust is composed of σ-FeOOH （the main protective phase）, Fe2O3, FeS, elemental S, and FeSO4. FeSO4 in the interface of the base and rust layer leads to localized corrosion. Elemental sulfur forms on the surface of σ-FeOOH, and the quantity and size thereof increase with increasing corrosion time. Furthermore, layered elemental sulfur promotes fracture and peels off the rust layer.展开更多
Coat protein complex Ⅱ(COPⅡ)-coated vesicles are responsible for transporting the cargoes from the endoplasmic reticulum(ER) to different destinations. c TAGE5/MEA6 is essential for the development and function of d...Coat protein complex Ⅱ(COPⅡ)-coated vesicles are responsible for transporting the cargoes from the endoplasmic reticulum(ER) to different destinations. c TAGE5/MEA6 is essential for the development and function of different organs. It regulates the assembly of COPⅡ carrier and cargo trafficking through direct or indirect interaction with COPII components. c TAGE5/MEA6 mainly coordinates with another scaffold protein, TANGO1, to play essential roles in the trafficking and secretion of both large and small cargoes in multiple organs. In this viewpoint, we would like to discuss the molecular mechanisms underlying c TAGE5/MEA6-mediated cargo transport and biological functions.展开更多
基金supported by the Youth Project of Science and Technology Research Program of Chongqing Education Commission of China(No.KJQN202404522)。
文摘Intracellular transports of cargoes are performed by biological molecular motors that move processively along their linear tracks.In some cases,the cargo can interact with the track.A typical example of these cases is the transport of a major mitotic signaling module,the chromosomal passenger complex(CPC),along the microtubule toward the equatorial cortex by a kinesin-6 motor during anaphase,where the CPC can interact with the microtubule.Here,an analytical theory is presented on the dynamics of the molecular motor transporting a track-interacted cargo.The theory is then applied to the transport of the track-interacted cargo by kinesin-6 and by kinesin-1 motors,with the theoretical results reproducing quantitatively the available experimental data.It is found that a diffusive cargo along the track,with the diffusion constant≥0.1μm2s-1,can largely enhance the processivity relative to the non-diffusive cargo and relative to the cargo having no interaction with the track.
基金supported by the BK21 FOUR funded by the Ministry of Education of Korea and National Research Foundation of Korea,a Korea Agency for Infrastructure Technology Advancement(KAIA)grant funded by the Ministry of Land,Infrastructure,and Transport(Grant 1615013176)IITP(Institute of Information&Coummunications Technology Planning&Evaluation)-ICAN(ICT Challenge and Advanced Network of HRD)grant funded by the Korea government(Ministry of Science and ICT)(RS-2024-00438411).
文摘This paper proposes a novel cargo loading algorithm applicable to automated conveyor-type loading systems.The algorithm offers improvements in computational efficiency and robustness by utilizing the concept of discrete derivatives and introducing logistics-related constraints.Optional consideration of the rotation of the cargoes was made to further enhance the optimality of the solutions,if possible to be physically implemented.Evaluation metrics were developed for accurate evaluation and enhancement of the algorithm’s ability to efficiently utilize the loading space and provide a high level of dynamic stability.Experimental results demonstrate the extensive robustness of the proposed algorithm to the diversity of cargoes present in Business-to-Consumer environments.This study contributes practical advancements in both cargo loading optimization and automation of the logistics industry,with potential applications in last-mile delivery services,warehousing,and supply chain management.
基金National Natural Science Foundation of China (60134010)Aeronautical Science Foundation of China (2007ZD53053)
文摘Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because it is carried out during flight, it is necessary to investigate the influences of the drop process on flight characteristics to ensure successful execution of the task. This article mainly studies the modeling of flight systems in large flying transport planes with cargo moving in it. By buildi...
文摘Established in 2019,the Shandong Port Group(SPG)comprises four port groups(Qingdao Port,Rizhao Port,Yantai Port,and Bohaiwan Port)and 12 business segments.SPG connects 3,345 kilometers of coastline within Shandong Province.Its cargo throughput has consistently ranked first globally for many years,and its container volume growth ranks second globally,forming a port cluster covering the entire industrial chain.
文摘On December 18,2025, Hainan Free Trade Port (Hainan FTP) officially began islandwide special customs operations.Although only two months have passed since this landmark step, the shift is already visible everywhere—from the bustling flow of international passengers at Haikou Meilan International Airport to the steady stream of cargo vessels calling at Yangpu Port, and even in the sustained attention investors are paying to “Hainan-related” stocks.Together, these signals point to one clear conclusion:China’s largest special economic zone has entered a new phase of development.
基金supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)grant LU 2347/3-1(to PL).
文摘Autophagy is well-known for delivering cargo materials to lysosomes for proteolytic digestion.Recently,autophagy has emerged as a key mechanism in unconventional protein secretion(UPS).This perspective introduces unconventional secretion pathways,focusing on secretory autophagy and its role in secreting protein aggregates associated with neurodegenerative disorders.We also explore additional neuronal functions of secretory autophagy beyond the release of protein aggregates.We propose autophagosomes as transport organelles that deliver cargo material directly from the endoplasmatic reticulum(ER)to the plasma membrane rather than solely to lysosomes.
文摘Purpose-This paper provides a comprehensive analysis of the Brazilian freight railway system,examining the efficacy of the current concession renewal model in light of persistent structural problems such as market concentration,cargo dependence on export commodities and underutilization of the network.Situating Brazil within the broader international debate on railway reforms,the paper evaluates whether the ongoing early renewal of concessions can deliver a more diversified and competitive freight system.Design/methodology/approach-The study adopts a sequential mixed-methods research design that integrates longitudinal quantitative analysis with qualitative institutional and policy evaluation.The quantitative component examines time-series indicators published by ANTT,DNIT and INFRA S.A.from 1999 to 2023 to identify structural patterns in traffic growth,investment,safety and market concentration.The qualitative component employs a process-tracing logic to reconstruct the evolution of concession renewals and the implementation of Railway Law 14.273/2021,drawing on concepts from regulatory economics,institutional theory and industrial organization.These empirical streams are synthesized through an analytical framework that connects three dimensions-regulatory design,market structure and system performance-allowing for a systematic assessment of how Brazil’s institutional configuration shapes incentives,competitive dynamics and network utilization.Findings-The analysis confirms that the early renewal of concessions has successfully secured substantial private investment for capacity expansion on existing trunk lines.However,it has perpetuated the vertically integrated model,reinforcing the market power of incumbent operators and failing to significantly promote intramodal competition or cargo diversification.The system remains dominated by iron ore and agricultural commodities,with general cargo representing a minuscule share.The new authorization regime and short-line railway policies present a viable pathway for market opening but face significant operational and institutional barriers to implementation.Originality/value-This research offers a timely and critical assessment of a pivotal moment in Brazilian railway policy.It moves beyond a simplistic evaluation of volume growth to a structural analysis of market failures and the interplay between concession renewal and regulatory innovation.The findings provide actionable insights for policymakers in Brazil and other emerging economies seeking to balance private investment with public interest goals in railway infrastructure,highlighting the necessity of complementary,pro-competitive measures alongside financial investment.
文摘A deep-water harbour in Hainan has emerged as a pivotal gateway to regions around the world Located on the northwest tip of Hainan Island,Yangpu Port is bustling with activity,with towering gantry cranes frantically loading containers on and off large cargo vessels.Cargo volumes here have surged as a result of a slew of special customs policies that went into force in December 2025.
基金Aeronautical Science Foundation of China (04E51046)
文摘To study the characteristics of cargo extraction, the initial phase of airdrop process, a high fidelity and extendibility simulation model with uniform motion equations for all states during extraction is developed on the basis of dynamics methods and contact models between cargo and aircraft. Simulation results agree well with tests data. Cargo exit parameters, which contribute to cargo pitch after extraction, are studied. Simplified computation model of dimensionless exit time is developed and used to evaluate the relation between extraction phase and landing accuracy. Safe interval model is introduced to evaluate the safety of extraction process. Also, relations between initial parameters, including pull coefficient, aircraft pitch and CG coefficient, etc, and result parameters, including exit time, cargo safety, pitch, etc, are developed to help design of airdrop system, especially the selection of extraction parachute and cargo deployment.
文摘Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals： maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.
基金Item Sponsored by National Science and Technology Major Project of the Ministry of Science and Technology of China(2011ZX05016-004)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2011BAE25B00)
文摘As international maritime organization （IMO） draft 289 was adopted to develop a low-alloy anti-corrosion steel for the deck of cargo oil tank and to understand corrosion mechanism, corrosion behavior of a low-alloy steel with chromium contents was studied in O2-CO2-SO2-H2 S wet gas environment. Corrosion rate was measured, and the microstructure and morphology of corrosion product film were characterized by scanning electron microscopy （SEM）. The phase and chemical composition of the corrosion product film were investigated by X-ray diffraction （XRD） and energy dispersive spectroscopy （EDS）, respectively. The effect of misorientation distribution on corro- sion resistance of steel was evaluated by electron backscattered diffraction （EBSD）. The results showed that corro- sion rate decreased with increasing chromium content in the low-alloy steel, and the corrosion type was general corrosion. The phenomenon of chromium enrichment was found in corrosion product film consisting of a-FeOOH, γ- FeOOH, sulphur, FeS2 and Fel-xS. The increase of chromium content decreases the amount of high-angle grain boundaries, thus resulting in the improvement of corrosion resistance.
基金Key Project of the Chinese Academy of Sciences,No.ZDRW-ZS-2016-6-3National Natural Science Foundation of China,No.41501490
文摘The robustness of cargo ship transportation networks is essential to the stability of the world trade system. The current research mainly focuses on the coarse-grained, holistic cargo ship transportation network while ignoring the structural diversity of different sub-networks. In this paper, we evaluate the robustness of the global cargo ship transportation network based on the most recent Automatic Identification System（AIS） data available. First, we subdivide three typical cargo ship transportation networks（i.e., oil tanker, container ship and bulk carrier） from the original cargo ship transportation network. Then, we design statistical indices based on complex network theory and employ four attack strategies, including random attack and three intentional attacks（i.e., degree-based attack, betweenness-based attack and flux-based attack） to evaluate the robustness of the three typical cargo ship transportation networks. Finally, we compare the integrity of the remaining ports of the network when a small proportion of ports lose their function. The results show that 1） compared with the holistic cargo ship transportation network, the fine-grain-based cargo ship transportation networks can fully reflect the pattern and process of global cargo transportation; 2） different cargo ship networks behave heterogeneously in terms of their robustness, with the container network being the weakest and the bulk carrier network being the strongest; and 3） small-scale intentional attacks may have significant influence on the integrity of the container network but a minor impact on the bulk carrier and oil tanker transportation networks. These conclusions can help improve the decision support capabilities in maritime transportation planning and emergency response and facilitate the establishment of a more reliable maritime transportation system.Abstract： The robustness of cargo ship transportation networks is essential to the stability of the world trade system. The current research mainly focuses on the coarse-grained, holistic cargo ship transportation network while ignoring the structural diversity of different sub-networks. In this paper, we evaluate the robustness of the global cargo ship transporta- tion network based on the most recent Automatic Identification System （AIS） data available. First, we subdivide three typical cargo ship transportation networks （i.e., oil tanker, container ship and bulk carrier） from the original cargo ship transportation network. Then, we design statistical indices based on complex network theory and employ four attack strategies, in- cluding random attack and three intentional attacks （i.e., degree-based attack, between- ness-based attack and flux-based attack） to evaluate the robustness of the three typical cargo ship transportation networks. Finally, we compare the integrity of the remaining ports of the network when a small proportion of ports lose their function. The results show that 1） com- pared with the holistic cargo ship transportation network, the fine-grain-based cargo ship transportation networks can fully reflect the pattern and process of global cargo transportation 2） different cargo ship networks behave heterogeneously in terms of their robustness, with the container network being the weakest and the bulk carrier network being the strongest; and 3） small-scale intentional attacks may have significant influence on the integrity of the con- tainer network but a minor impact on the bulk carrier and oil tanker transportation networks.These conclusions can help improve the decision support capabilities in maritime transportation planning and emergency response and facilitate the establishment of a more reliable maritime transportation system.
基金Item Sponsored by National Science and Technology Major Project of the Ministry of Science and Technology of China(2011ZX05016-004)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2011BAE25B00)
文摘Corrosion behavior of low-alloy steel was investigated in simulated cargo oil tank （COT） bottom plate service environment （10% NaCl solution, pH = 0.85）. The corrosion behavior of inclusion was studied by in-situ scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. It was found that pitting corrosion was inclined to occur around the place where inclusions exist. After initial corrosion, an area of 10-20μm in diameter was formed as a cireinate cathode around the edge of inclusion. MnS inclusion dissolved in the simulated COT corrosion solution before low-alloy steel matrix, and pitting was formed at the place where MnS dissolved. TiO2 inclusion dissolved in the simulated COT corrosion solution after low alloy steel matrix, and pitting was formed at the place where steel matrix dissolved. The corrosion tended to occur at the area where the curvature radius of inclusion is smaller. The size of round TiO2 inclusions had little influence on corrosion behavior in this certain environment.
文摘Fuel consumption has always been a matter of concern for ships propulsion. In this research we aim to develop computer models of several containership cargo stacking configurations and discuss an optimal configuration at a constant front wind speed. The paper presents the simulation results by using ANSYS CFX for a 1:4 scale PostPanamax 9000 TEU containership. The ship is modelled in a cubic domain that contains unstructured mesh with details, in such a way that can demonstrate the influence of the container configuration on wind force. Also the numerical results are verified versus wind tunnel test data. An optimal stack configuration led to about 25%reduction in air resistance. It is proposed that in order to reduce the wind drag force and consequently reduce the fuel consumption and pollutant emissions, empty spaces between the cargo containers and unbalanced cargo distribution over the deck should be inhibited. Also, it is advised to make the cargo distribution on the most forward and aftward deck areas more streamlined.
文摘High-fidelity cargo airdrop simulation requires the contact dynamics between an aircraft and a cargo to be modeled accurately. This paper presents a general and efficient contact-friction model for simulation of aircraft-cargo coupling dynamics during airdrops. The proposed approach has the same essence as that of the finite element node-to-segment contact formulation, which leads to a flexible, straight forward, and efficient code implementation. The formulation is developed under an arbitrary moving frame with both the aircraft and the cargo being treated as general six-degree-of-freedom rigid bodies, and thus it eliminates the restrictions of lateral symmetric assumptions in most existing methods. Moreover, the aircraft-cargo coupling algorithm is discussed in detail, and some practical implementation details are presented. The accuracy and capability of the present method are demonstrated through three numerical examples with increasing complexity and fidelity.
基金Sponsored by National Key Technology Research and Development Program of China(2011BAE25B01)
文摘E32 grade corrosion resistant steel was welded with welding wires with three different S contents. The mi crostructure, mechanical properties, inclusions, and corrosion behavior of welded joint were investigated. The joint coupon corrosion test and potentiodynamic polarization test were carried out under the simulated corrosion environ- ment of the inner bottom plates of cargo oil tanks. The pitting initiation and propagation mechanism of the weld metal were studied by scanning electron microscopy and infinite focus. The results indicated that the microstructures of three kinds of weld metals are all composed of acicular ferrite, ferrite side-plate and proeutectoid ferrite. The micro- structure of heat affected zone is composed predominantly of bainite. Joint welded with low S filler wire has good me- chanical properties. S can decrease free corrosion potential and increase the corrosion tendency. The pitting initiation is oxide inclusion or sulfide oxide inclusion complex. S can induce the formation of occluded area and promote the corrosion propagation. The chemical compositions of weld metal is similar to base metal, which can limit the galvanic corrosion between weld metal and base metal, and avoid formation of corrosion step.
基金supported by the National Natural Science Foundation of China(Grant No.51509046)Foundation of Ministry of Industry and Information Technology High-tech Ship Scientific Research(Grant No.2016-26)
文摘In response to the development of deep-sea oil and gas resources,which require a high degree of cooperation by crude oil transportation equipment,a new type of ship known as the cargo transfer vessel(CTV)has been developed.To provide a theoretical reference for the design and equipment of the CTV’s dynamic positioning system,in this paper,we take the new deepwater CTVas the study object and theoretically and numerically analyze its operation,wind load,current load,wave load,and navigational resistance in a range of Brazilian sea conditions with respect to its positioning and towing modes.We confirm that our proposed method can successfully calculate the total environmental load of the CTVand that the CTV is able to operate normally under the designed sea conditions.
文摘A simulated corrosion test apparatus was used to investigate the corrosion behavior of a low alloy steel under simulated upper deck conditions in a cargo oil tank. The estimated corrosion loss of conventional E36 class ship plate steel is 4.27 mm, which is clearly inadequate compared with the standard adopted by International Maritime Organization. Outer rust layer of specimens starts to peel off after 77 days and becomes fragmented after 98 days. X-ray diffraction, scanning electron micros- copy, and Raman spectroscopy revealed that the resulting rust is composed of σ-FeOOH （the main protective phase）, Fe2O3, FeS, elemental S, and FeSO4. FeSO4 in the interface of the base and rust layer leads to localized corrosion. Elemental sulfur forms on the surface of σ-FeOOH, and the quantity and size thereof increase with increasing corrosion time. Furthermore, layered elemental sulfur promotes fracture and peels off the rust layer.
基金supported by grants from the National Natural Science Foundation of China(91854118,31921002,31730108,32061143026)the major projects of the Ministry of Science and Technology(2021ZD0202300)Chinese Academy of Sciences(XDB32020100,YJKYYQ20200052)。
文摘Coat protein complex Ⅱ(COPⅡ)-coated vesicles are responsible for transporting the cargoes from the endoplasmic reticulum(ER) to different destinations. c TAGE5/MEA6 is essential for the development and function of different organs. It regulates the assembly of COPⅡ carrier and cargo trafficking through direct or indirect interaction with COPII components. c TAGE5/MEA6 mainly coordinates with another scaffold protein, TANGO1, to play essential roles in the trafficking and secretion of both large and small cargoes in multiple organs. In this viewpoint, we would like to discuss the molecular mechanisms underlying c TAGE5/MEA6-mediated cargo transport and biological functions.
