Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea o...Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea or river.Network properties including the degree distribution,degree correlations,clustering,shortest path length,centrality and betweenness are studied in different definition of network topology.It is found that geographical constraint plays an important role in the network topology of SCLNC.We also study the traffic flow of SCLNC based on the weighted network representation,and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology.Other features related to SCLNC are also investigated.展开更多
This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constru...This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constructs a Sino-US container shipping network through voyage weighting and analyzes the essential structural characteristics to explore the network’s complex structural fea-tures.The network’s evolution is examined from three perspectives,namely,time,space,and event influence,aiming to comprehens-ively explore the network’s evolution mechanism.The results revealed that:1)the weighted Sino-US container shipping network exhib-its small-world and scale-free properties.Key hub ports in the United States include NEW YORK NY,SAVANNAH GA,LOS ANGELES CA,and OAKLAND CA,whereas SHANGHAI serving as the hub port in China.The geographical distribution of these hub ports is uneven.2)Concerning the evolution of the weighted Sino-US container shipping network,from a temporal perspective,the evolution of the regional structure of the entire Sino-US region and the Inland United States is in a stage of radiative expansion and de-velopment,with a need for further enhancement in competitiveness and development speed.The evolution of the regional structure of southern China and Europe is transitioning from the stage of radiative expansion and development to an advanced equilibrium stage.The shipping development in Northern China,the Western and Eastern United States,and Asia is undergoing significant changes but faces challenges of fierce competition and imbalances.From a spatial perspective,the rationality and effectiveness of the improved weighted Barrat-Barthelemy-Vespignani(BBV)model are confirmed through theoretical derivation.The applicability of the improved evolution model is verified by simulating the evolution of the weighted Sino-US container shipping network.From an event impact per-spective,the Corona Virus Disease 2019(COVID-19)pandemic has not fundamentally affected the spatial pattern of the weighted Sino-US container shipping network but has significantly impacted the network’s connectivity.The network lacks sufficient resilience and stability in emergency situations.3)Based on the analysis of the structural characteristics and evolution of the weighted Sino-US con-tainer shipping network,recommendations for network development are proposed from three aspects:emphasizing the development of hub ports,focusing on the balanced development of the network,and optimizing the layout of Chinese ports.展开更多
The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(b...The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(bpda)2](2,1,4-ndc=1,4-naphthalenedicarboxylate;dmc=dimethylcarbamate)through mixed-ligand coordination under hydro(solvo)thermal conditions is reported.Both compounds 1 and 2 are made up of a two-dimensional layered network with a decorated 44-sql topology from the associated dinuclear two-blade paddlewheel building units.The bis-amide groups of the bpda ligands in the layered structures of 1 and 2 are sheltered and participate in multiple hydrogen-bonding interactions.Compounds 1 and 2 are both highly thermally stable at temperatures over 300°C and exhibit solid-state luminescence properties.In comparison with the CO_(2)adsorption behavior of the related compound{[Zn4(1,4-bdc)4(bpda)4]·5DMF·3H_(2)O}n(3,1,4-bdc=1,4-benzenedicarboxylate),both the desolvated sample of 1 and the thermally-activated sample of 2 show a lower CO_(2)uptake capacity and a decreased Qst trace with increasing CO_(2)uptake.These results show that no meaningful cooperative binding occurs between the amide groups and CO_(2)molecules in the condensed 2D structures of 1 and 2.By varying the dicarboxylate ligand from 1,3-bdc,1,4-ndc to 1,4-bdc,the amide-functionalized products 1-3 induce subtle changes in their structures.In particular,the intimate interrelationship between the structural characteristics of amide groups and the CO_(2)adsorption behavior of such compounds is clearly demonstrated.展开更多
基金supported by Youth Foundation for Research of the Waterborne Transportation Institute.
文摘Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea or river.Network properties including the degree distribution,degree correlations,clustering,shortest path length,centrality and betweenness are studied in different definition of network topology.It is found that geographical constraint plays an important role in the network topology of SCLNC.We also study the traffic flow of SCLNC based on the weighted network representation,and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology.Other features related to SCLNC are also investigated.
基金Under the auspices of National Natural Science Foundation of China(No.41201473,41371975)。
文摘This study selected the Sino-US route data from the top 30 global container liner companies between December 1,2019,and December 29,2019,as the data source utilizing the complex network research methodology.It constructs a Sino-US container shipping network through voyage weighting and analyzes the essential structural characteristics to explore the network’s complex structural fea-tures.The network’s evolution is examined from three perspectives,namely,time,space,and event influence,aiming to comprehens-ively explore the network’s evolution mechanism.The results revealed that:1)the weighted Sino-US container shipping network exhib-its small-world and scale-free properties.Key hub ports in the United States include NEW YORK NY,SAVANNAH GA,LOS ANGELES CA,and OAKLAND CA,whereas SHANGHAI serving as the hub port in China.The geographical distribution of these hub ports is uneven.2)Concerning the evolution of the weighted Sino-US container shipping network,from a temporal perspective,the evolution of the regional structure of the entire Sino-US region and the Inland United States is in a stage of radiative expansion and de-velopment,with a need for further enhancement in competitiveness and development speed.The evolution of the regional structure of southern China and Europe is transitioning from the stage of radiative expansion and development to an advanced equilibrium stage.The shipping development in Northern China,the Western and Eastern United States,and Asia is undergoing significant changes but faces challenges of fierce competition and imbalances.From a spatial perspective,the rationality and effectiveness of the improved weighted Barrat-Barthelemy-Vespignani(BBV)model are confirmed through theoretical derivation.The applicability of the improved evolution model is verified by simulating the evolution of the weighted Sino-US container shipping network.From an event impact per-spective,the Corona Virus Disease 2019(COVID-19)pandemic has not fundamentally affected the spatial pattern of the weighted Sino-US container shipping network but has significantly impacted the network’s connectivity.The network lacks sufficient resilience and stability in emergency situations.3)Based on the analysis of the structural characteristics and evolution of the weighted Sino-US con-tainer shipping network,recommendations for network development are proposed from three aspects:emphasizing the development of hub ports,focusing on the balanced development of the network,and optimizing the layout of Chinese ports.
文摘The self-assembly of zinc-organic coordination polymers[Zn2(1,3-bdc)2(bpda)2]·3DMF·0.5H_(2)O(1,1,3-bdc=1,3-benzenedicarboxylate;bpda=N,N’-bis(pyridine-4-yl)-1,4-benzenedicarboxamide)and[Zn2(1,4-ndc)(dmc)2(bpda)2](2,1,4-ndc=1,4-naphthalenedicarboxylate;dmc=dimethylcarbamate)through mixed-ligand coordination under hydro(solvo)thermal conditions is reported.Both compounds 1 and 2 are made up of a two-dimensional layered network with a decorated 44-sql topology from the associated dinuclear two-blade paddlewheel building units.The bis-amide groups of the bpda ligands in the layered structures of 1 and 2 are sheltered and participate in multiple hydrogen-bonding interactions.Compounds 1 and 2 are both highly thermally stable at temperatures over 300°C and exhibit solid-state luminescence properties.In comparison with the CO_(2)adsorption behavior of the related compound{[Zn4(1,4-bdc)4(bpda)4]·5DMF·3H_(2)O}n(3,1,4-bdc=1,4-benzenedicarboxylate),both the desolvated sample of 1 and the thermally-activated sample of 2 show a lower CO_(2)uptake capacity and a decreased Qst trace with increasing CO_(2)uptake.These results show that no meaningful cooperative binding occurs between the amide groups and CO_(2)molecules in the condensed 2D structures of 1 and 2.By varying the dicarboxylate ligand from 1,3-bdc,1,4-ndc to 1,4-bdc,the amide-functionalized products 1-3 induce subtle changes in their structures.In particular,the intimate interrelationship between the structural characteristics of amide groups and the CO_(2)adsorption behavior of such compounds is clearly demonstrated.
