Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which t...Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which th e length-radius dimension describes change of network density,and ramification-radius dimension describes complexity and accessibility of urban network.It i s propitious to analyze urban traffic network and to understand dynamic c hange process of traffic network using expanding f ractal-dimension quantification.Meanwhile the length-radius dimension and ramifica-tion-radius dimension could be rega rd as reference factor of quantitative describing urban traffic network.展开更多
Flipped learning is a reversal of the traditional teaching strategy, which has changed the timing of teacher＇s lectures and homework. In this revolutionary situation, the appropriateness of the before-class videos an...Flipped learning is a reversal of the traditional teaching strategy, which has changed the timing of teacher＇s lectures and homework. In this revolutionary situation, the appropriateness of the before-class videos and other materials and the arrangement of class in the classroom play an important role in the fulfillment of application of the materials. Classical TED speeches are the excellent options for English language learners＇ flipped learning. This paper tends to make a case study of the application of TED speeches into flipped learning, taking the speeches with the keyword ＂transportation＂ as an example.展开更多
The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiol...The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiological [Tr （rectal temperature）, HR （heart） and RR （respiratory rates）, and circulating levels of Cor （cortisol）, Glu （glucose） and minerals] parameters in Moroccan dromedary camels. The animals were subjected to road transportation stressor for 2 h by truck during the hot-dry season. Blood samples were collected before loading and transport, and at the end of transport. Transportation induced a significant increase （P 〈 0.05） of erythrocytes count, Ht, EOF, Tr, HR and RR by comparison to values observed before transportation. The same stress conditions induced a significant increase （P 〈 0.05） of plasma Cor （ng/mL） and blood Glu （mM） （220 ± 30 vs. 137 ± 20, 9.7 ± 1.2 vs. 6.4 ± 1. 1 respectively） and a significant decrease （P 〈 0.05） of plasma magnesium （mM） （0.5 ± 0.1 vs. 0.9 ± 0.1） comparatively to pre-transportation values. These results indicate that road transportation associated to heat may be considered as a potent stressor which is able to induce several cellular alterations in camels. Further studies of an eventual protective role of vitamin C against haemolysis induced by transportation stress in camel are needed.展开更多
As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relativel...As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relatively mature discipline. During the period 1930– 1980, the development of transportation geography consisted mainly of the publication of theoretical texts. During 1980–2000, it gradually became a systematic discipline. Since the start of the 21 st century, transportation geography has focused mainly on exploring the impacts of transportation on socio-economic development. Currently, studies on transportation geography have led to significant developments in a number of areas, including transportation theory, facility distribution and planning, transportation flows and network analysis, evaluation of transport modes, transportation planning, and simulation and assessment of urban transportation. Such studies have also enriched human geography research, provided a wider geographical overview and elucidated the development mechanism of transportation, as well as helped to understand the impacts of transport development on socio-economic systems. Some findings obtained by geographers have been widely used in transportation geography and related fields, including the four basic laws of transportation generation, the hub–spoke mode of transport organization, the subordinating and guiding functions of transportation on socio-economic development, regional transport dominance measures, accessibility measures, and spatial organization of port systems.展开更多
We first propose fundamental solutions of wave propagation in dispersive chain subject to a localized initial perturbation in the displacement. Analytical solutions are obtained for both second order nonlinear dispers...We first propose fundamental solutions of wave propagation in dispersive chain subject to a localized initial perturbation in the displacement. Analytical solutions are obtained for both second order nonlinear dispersive chain and homogenous harmonic chain using stationary phase approximation. Solution is also compared with numerical results from molecular dynamics （MD） simulations. Locally dominant phonon modes （k-space） are introduced based on these solutions. These locally defined spatially and temporally varying phonon modes k（x, t） are critical to the concept of the local thermodynamic equilibrium （LTE）. Wave propagation accompanying with the nonequilibrium dynamics leads to the excitation of these locally defined phonon modes. It is found that the system energy is gradually redistributed among these excited phonons modes （k-space）. This redistribution process is only possible with nonlinear dispersion and requires a finite amount of time to achieve a steady state distribution. This time scale is dependent on the spatial distribution （or frequency content） of the initial perturbation and the dispersion relation. Sharper and more concentrated perturbation leads to a faster energy redistribution and dissipation. This energy redistribution generates localized phonons with various frequencies that can be important for phonon-phonon interaction and energy dissipation in nonlinear systems. Depending on the initial perturbation and temperature, the time scale associated with this energy distribution can be critical for energy dissipation compared to the Umklapp scattering process. Ballistic type of heat transport along the harmonic chain reveals that at any given position, the lowest mode （k = O） is excited first and gradually expanding to the highest mode （km^（x,t））, where km^（x,t） can only asymptotically approach the maximum mode kB of the first Brillouin zone （kmax（x,t） --~ kB）. NO energy distributed into modes with k_max（x,t） 〈 k 〈 k^B demonstrates that the local thermodynamic equilibrium cannot be established in harmonic chain. Energy is shown to be uniformly distributed in all available phonon modes k ≤ _max（x, t） at any position with heat transfer along the harmonic chain. The energy flux along the chain is shown to be a constant with time and proportional to the sound speed （ballistic transport）. Comparison with the Fourier＇s law leads to a time-dependent thermal conductivity that diverges with time.展开更多
文摘Traffic network is an importance asp ect of researching controllable parameters of an urban spatial morpholo-gy.Based on GIS,traffic network str ucture complexity can be understood by using fractal geometry in which th e length-radius dimension describes change of network density,and ramification-radius dimension describes complexity and accessibility of urban network.It i s propitious to analyze urban traffic network and to understand dynamic c hange process of traffic network using expanding f ractal-dimension quantification.Meanwhile the length-radius dimension and ramifica-tion-radius dimension could be rega rd as reference factor of quantitative describing urban traffic network.
文摘Flipped learning is a reversal of the traditional teaching strategy, which has changed the timing of teacher＇s lectures and homework. In this revolutionary situation, the appropriateness of the before-class videos and other materials and the arrangement of class in the classroom play an important role in the fulfillment of application of the materials. Classical TED speeches are the excellent options for English language learners＇ flipped learning. This paper tends to make a case study of the application of TED speeches into flipped learning, taking the speeches with the keyword ＂transportation＂ as an example.
文摘The purpose of this study was to determine the effects of road transportation under heat conditions on some haematological [Ht （haematocrit）, blood cells count and EOF （erythrocytes osmotic fragility）] and physiological [Tr （rectal temperature）, HR （heart） and RR （respiratory rates）, and circulating levels of Cor （cortisol）, Glu （glucose） and minerals] parameters in Moroccan dromedary camels. The animals were subjected to road transportation stressor for 2 h by truck during the hot-dry season. Blood samples were collected before loading and transport, and at the end of transport. Transportation induced a significant increase （P 〈 0.05） of erythrocytes count, Ht, EOF, Tr, HR and RR by comparison to values observed before transportation. The same stress conditions induced a significant increase （P 〈 0.05） of plasma Cor （ng/mL） and blood Glu （mM） （220 ± 30 vs. 137 ± 20, 9.7 ± 1.2 vs. 6.4 ± 1. 1 respectively） and a significant decrease （P 〈 0.05） of plasma magnesium （mM） （0.5 ± 0.1 vs. 0.9 ± 0.1） comparatively to pre-transportation values. These results indicate that road transportation associated to heat may be considered as a potent stressor which is able to induce several cellular alterations in camels. Further studies of an eventual protective role of vitamin C against haemolysis induced by transportation stress in camel are needed.
基金National Natural Science Foundation of China,No.41171107No.41371143
文摘As an important branch of human geography, transportation geography has experienced three periods of evolution: foundation, systematization, and rapid development of the discipline. It has gradually become a relatively mature discipline. During the period 1930– 1980, the development of transportation geography consisted mainly of the publication of theoretical texts. During 1980–2000, it gradually became a systematic discipline. Since the start of the 21 st century, transportation geography has focused mainly on exploring the impacts of transportation on socio-economic development. Currently, studies on transportation geography have led to significant developments in a number of areas, including transportation theory, facility distribution and planning, transportation flows and network analysis, evaluation of transport modes, transportation planning, and simulation and assessment of urban transportation. Such studies have also enriched human geography research, provided a wider geographical overview and elucidated the development mechanism of transportation, as well as helped to understand the impacts of transport development on socio-economic systems. Some findings obtained by geographers have been widely used in transportation geography and related fields, including the four basic laws of transportation generation, the hub–spoke mode of transport organization, the subordinating and guiding functions of transportation on socio-economic development, regional transport dominance measures, accessibility measures, and spatial organization of port systems.
文摘We first propose fundamental solutions of wave propagation in dispersive chain subject to a localized initial perturbation in the displacement. Analytical solutions are obtained for both second order nonlinear dispersive chain and homogenous harmonic chain using stationary phase approximation. Solution is also compared with numerical results from molecular dynamics （MD） simulations. Locally dominant phonon modes （k-space） are introduced based on these solutions. These locally defined spatially and temporally varying phonon modes k（x, t） are critical to the concept of the local thermodynamic equilibrium （LTE）. Wave propagation accompanying with the nonequilibrium dynamics leads to the excitation of these locally defined phonon modes. It is found that the system energy is gradually redistributed among these excited phonons modes （k-space）. This redistribution process is only possible with nonlinear dispersion and requires a finite amount of time to achieve a steady state distribution. This time scale is dependent on the spatial distribution （or frequency content） of the initial perturbation and the dispersion relation. Sharper and more concentrated perturbation leads to a faster energy redistribution and dissipation. This energy redistribution generates localized phonons with various frequencies that can be important for phonon-phonon interaction and energy dissipation in nonlinear systems. Depending on the initial perturbation and temperature, the time scale associated with this energy distribution can be critical for energy dissipation compared to the Umklapp scattering process. Ballistic type of heat transport along the harmonic chain reveals that at any given position, the lowest mode （k = O） is excited first and gradually expanding to the highest mode （km^（x,t））, where km^（x,t） can only asymptotically approach the maximum mode kB of the first Brillouin zone （kmax（x,t） --~ kB）. NO energy distributed into modes with k_max（x,t） 〈 k 〈 k^B demonstrates that the local thermodynamic equilibrium cannot be established in harmonic chain. Energy is shown to be uniformly distributed in all available phonon modes k ≤ _max（x, t） at any position with heat transfer along the harmonic chain. The energy flux along the chain is shown to be a constant with time and proportional to the sound speed （ballistic transport）. Comparison with the Fourier＇s law leads to a time-dependent thermal conductivity that diverges with time.
