China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-...China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-speed rail(HSR) network and the second-largest expressway network in the world. This paper explores the relationship between accessibility and economic growth in China from 1990 to 2010. In the study, the basic research units include 333 prefecture-level cities and four municipalities. We explore a bivariate analysis framework of accessibility and economic growth, and their increase rates, to examine this relationship using long-term panel data. The results indicate that, first, accessibility and economic growth show a significant positive relationship using both cross-section and panel data, while the increase rate in accessibility and GDP indicate no significant relationship using cross-section data and a poor significant relationship using panel data. Second, the distributions of local advantage are uneven. Cities with low local advantage with respect to accessibility and GDP are mainly located in China′s eastern coastal region or the provincial capitals, while those with low local advantage in terms of their increase rates are located in the western region. Third, as China′s economic growth and transport networks have evolved, the distribution of local advantage shows little change in terms of accessibility and GDP, but a greater change in terms of their increase rates, which is largely influenced by the distribution of expressway and HSR networks.展开更多
This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development conditi...This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development condition of a mining area, were brought forward, and the system evaluation was given.展开更多
Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop pl...Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop plate oscillating heat pipe with parallel channels(POHP-PC) were experimentally investigated by varying liquid filled ratios(50%, 70%, 85%), section scales(1 mm×1 mm and 1 mm×1.5 mm), inclination angles, working fluids and heating inputs. It was found that during operating there was mixed flow consisting of plug flow and annular flow in channels of oscillating heat pipe at steady-state. There was an equilibrium position for working fluid of condenser during oscillating, and periodic oscillations occurred up and down in the vicinity of equilibrium position. With heat input increasing, equilibrium position rose slowly as a result of vapor pressure of evaporation.Evaporation temperature oscillating amplitude possessed a trend of small-large-small and frequency trend was of small-large during steady-state. It may be generally concluded that temperature, whether evaporator or condenser, fluctuated sharply or rose continuously when oscillating heat pipe coming to dry burning state. Simultaneously, it was found that temperature difference of cooling water possibly dropped with heat input rising during dry burning state. Thermal resistance of No. 2 with acetone was lower than that of No. 1 during experiments, but No. 2 achieving heat transfer limit was earlier than No. 1. However, with ethanol, thermal resistance of No. 1 and No. 2 were similar with the heating input less than 110-120 W and filling ratios of 50% and 70%. And with filling ratio of 85%, heating transfer performance of No. 2 was better compared to No. 1 during all the experiments.展开更多
A simplified bi-variable human error probability calculation method is developed by incorporating two common performance condition( CPC) factors, which are modified from factors employed in cognitive reliability and e...A simplified bi-variable human error probability calculation method is developed by incorporating two common performance condition( CPC) factors, which are modified from factors employed in cognitive reliability and error analysis method(CREAM) to take into account the characteristics of shipping operations. After the influencing factors are identified, Markov method is used to calculate the values of human reliability. The proposed method does not rely on the involvement of experts in the field of human factor nor depend on historical accidents or human error statistics. It is applied to the case of the crew on board of an ocean going dry bulk carrier. The caculated results agree with the actual case, which verifies the validity of the model.展开更多
Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most...Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most commonly accepted as the three pillars of sustainability. In this paper, various sustainability indicators have been identified during the construction stage for elevated transportation corridors and thereafter classified under various categories. Using fuzzy VIKOR technique, sustainability evaluation of transportation corridors is made on two selected project sites of two different government organizations using various identified sustainability indicators, i.e., a 3.2-km long elevated road project under construction from Vikaspuri to Meerabagh in West Delhi by PWD (Public Works Department) and the metro rail elevated corridor (part) from Punjabi Bagh to Mayapuri as a part of Phase 3, Line 7 by DMRC (Delhi Metro Rail Corporation). The study is made at both sites in the midst of the construction period and it is identified that during the construction stage, the sustainability of these transportation corridors is just not limited to three pillars, but in actuality, it is much beyond that. From the study, it is inferred that the metro rail elevated corridor is a more sustainable corridor, in the context of the identified sustainability indicators.展开更多
Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a obje...Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a objective, the method of determining the surge bunker’s rational size is put forward. Also, the problems of rational position of surge bunker are analysesed.展开更多
The paper presents the methods proposed by the authors to be applied in operation of substations. The substations taken in consideration were rehabilitated by replacing the existing equipments by new equipments, the l...The paper presents the methods proposed by the authors to be applied in operation of substations. The substations taken in consideration were rehabilitated by replacing the existing equipments by new equipments, the last generation. The methods consist in study of equipment's failures, study of equipment's behaviour, study of substation architecture and study of systems operation. Paper presents new equipments on their architecture and performances. The parts of method exposed in this paper are based on the operational reliability. The mathematical methods and new analyses methods are given for resolving the issues on operation of substations. The results of this study will be used to obtain the best solution for operation of the substations. The results of the analysis were applied to some substation from the Transmission Power Grid.展开更多
The procedure of reliability-based fatigue analysis of liquefied natural gas(LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave headi...The procedure of reliability-based fatigue analysis of liquefied natural gas(LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method(FEM) . Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis,Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory,fatigue damage is characterized by an S-N relationship,and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.展开更多
The purpose of this research is to explore the principle of the man-object relationship to identify the issues shown when handling packaging and emphasizing the usability aspect. For that, the theoretical reference of...The purpose of this research is to explore the principle of the man-object relationship to identify the issues shown when handling packaging and emphasizing the usability aspect. For that, the theoretical reference of the research involves the analysis of the parameters according to the aspects that involve the use interactions of packaging in agreement with the definition and scientific concepts of ergonomics, allied to the development of product projects, discussing forms, handling, load transportation and the support of the product. Therefore, improperly handling of the packaging may cause damages to the products and even potential accidents. Coding and decoding are significant to facilitate the use recognition within the individual's repertoire. The packaging, within the macro-ergonomics universe, may be the object of ergonomics, whose contribution to solve problems is related to labor activities, by dealing with packaging, transportation and load resulting from the man-object interaction. The incorrect identification of information may lead to problems of interpretation and misuse, from the handling to the disposal of packaging. For this reason, this research suggests the adjustment of the man-object interface which may lead users to make mistakes regarding use and important choices, through adequate handling actions.展开更多
In this work, we selected a magnetic-semiconductor as an interlayer and investigated the electronic transport properties in the ferromagnetic/ferromagnetic-semiconductor/ferromagnetic (FM/FS/FM) trilayers. The results...In this work, we selected a magnetic-semiconductor as an interlayer and investigated the electronic transport properties in the ferromagnetic/ferromagnetic-semiconductor/ferromagnetic (FM/FS/FM) trilayers. The results indicate that the large TMR comparable to that in ferromagnetic/metal oxide/ferromagnetic sandwich can be obtained in the FM/FS/FM multilayers with considering the spin filter effect in the magnetic semiconductor layer. Moreover, the transmission coefficient and TMR can be tuned through thickness, Rashba spin-orbit coupling strength and molecular field of the magnetic semiconductor. Our calculations could provide a way to design the semiconductor spintronic devices with excellent and controllable properties.展开更多
Peristaltic flow by a sinusoidal traveling wave in the walls of two-dimensional channel with wall properties is investigated. The channel is filled with incompressible Eyring-Powell fluid. Mathematical modeling is dev...Peristaltic flow by a sinusoidal traveling wave in the walls of two-dimensional channel with wall properties is investigated. The channel is filled with incompressible Eyring-Powell fluid. Mathematical modeling is developed through aspects of Hall current, thermal deposition and convection. Long wavelength and low Reynolds number considerations are adopted. Perturbation solutions to the resulting problem for small material parameter of fluid are obtained. Expressions of velocity, temperature, concentration and stream function are derived. Variations of pertinent parameters on the physical quantities of interest are explored in detail. The present analysis is especially important to predict the rheological characteristics in engineering applications by peristalsis.展开更多
基金National Natural Science Foundation of China(No.41371143,41171107)
文摘China′s economy and transport infrastructure have both experienced rapid development since 1978, and especially since 1990. Today, China is the second-largest economic entity in terms of GDP and has the largest high-speed rail(HSR) network and the second-largest expressway network in the world. This paper explores the relationship between accessibility and economic growth in China from 1990 to 2010. In the study, the basic research units include 333 prefecture-level cities and four municipalities. We explore a bivariate analysis framework of accessibility and economic growth, and their increase rates, to examine this relationship using long-term panel data. The results indicate that, first, accessibility and economic growth show a significant positive relationship using both cross-section and panel data, while the increase rate in accessibility and GDP indicate no significant relationship using cross-section data and a poor significant relationship using panel data. Second, the distributions of local advantage are uneven. Cities with low local advantage with respect to accessibility and GDP are mainly located in China′s eastern coastal region or the provincial capitals, while those with low local advantage in terms of their increase rates are located in the western region. Third, as China′s economic growth and transport networks have evolved, the distribution of local advantage shows little change in terms of accessibility and GDP, but a greater change in terms of their increase rates, which is largely influenced by the distribution of expressway and HSR networks.
文摘This paper discussed the necessity of establishing a computer network in a mining railway transport management system. The network structure and the system security design, associated with the real development condition of a mining area, were brought forward, and the system evaluation was given.
基金Project(51306198)supported by the National Natural Science Foundation of ChinaProject(NR2013K07)supported by Beijing Key Lab of Heating,Gas Supply,Ventilating and Air Conditioning Engineering,China+1 种基金Project(331614013)supported by Beijing University of Civil Engineering and Architecture,ChinaProject(00921915023)supported by Organization Department of Beijing,China
文摘Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop plate oscillating heat pipe with parallel channels(POHP-PC) were experimentally investigated by varying liquid filled ratios(50%, 70%, 85%), section scales(1 mm×1 mm and 1 mm×1.5 mm), inclination angles, working fluids and heating inputs. It was found that during operating there was mixed flow consisting of plug flow and annular flow in channels of oscillating heat pipe at steady-state. There was an equilibrium position for working fluid of condenser during oscillating, and periodic oscillations occurred up and down in the vicinity of equilibrium position. With heat input increasing, equilibrium position rose slowly as a result of vapor pressure of evaporation.Evaporation temperature oscillating amplitude possessed a trend of small-large-small and frequency trend was of small-large during steady-state. It may be generally concluded that temperature, whether evaporator or condenser, fluctuated sharply or rose continuously when oscillating heat pipe coming to dry burning state. Simultaneously, it was found that temperature difference of cooling water possibly dropped with heat input rising during dry burning state. Thermal resistance of No. 2 with acetone was lower than that of No. 1 during experiments, but No. 2 achieving heat transfer limit was earlier than No. 1. However, with ethanol, thermal resistance of No. 1 and No. 2 were similar with the heating input less than 110-120 W and filling ratios of 50% and 70%. And with filling ratio of 85%, heating transfer performance of No. 2 was better compared to No. 1 during all the experiments.
基金Supported by the National Basic Research Program of China("973"Program,No.2014CB046804)National Natural Science Foundation of China(No.51239008)+1 种基金Foundation of State Key Laboratory of Marine Engineering of Shanghai Jiaotong UniversityFoundation for Innovative Research Groups of National Natural Science Foundation of China(No.51021004)
文摘A simplified bi-variable human error probability calculation method is developed by incorporating two common performance condition( CPC) factors, which are modified from factors employed in cognitive reliability and error analysis method(CREAM) to take into account the characteristics of shipping operations. After the influencing factors are identified, Markov method is used to calculate the values of human reliability. The proposed method does not rely on the involvement of experts in the field of human factor nor depend on historical accidents or human error statistics. It is applied to the case of the crew on board of an ocean going dry bulk carrier. The caculated results agree with the actual case, which verifies the validity of the model.
文摘Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most commonly accepted as the three pillars of sustainability. In this paper, various sustainability indicators have been identified during the construction stage for elevated transportation corridors and thereafter classified under various categories. Using fuzzy VIKOR technique, sustainability evaluation of transportation corridors is made on two selected project sites of two different government organizations using various identified sustainability indicators, i.e., a 3.2-km long elevated road project under construction from Vikaspuri to Meerabagh in West Delhi by PWD (Public Works Department) and the metro rail elevated corridor (part) from Punjabi Bagh to Mayapuri as a part of Phase 3, Line 7 by DMRC (Delhi Metro Rail Corporation). The study is made at both sites in the midst of the construction period and it is identified that during the construction stage, the sustainability of these transportation corridors is just not limited to three pillars, but in actuality, it is much beyond that. From the study, it is inferred that the metro rail elevated corridor is a more sustainable corridor, in the context of the identified sustainability indicators.
文摘Based on the function analysis of surge bunker in mine haulage system, the authors raise the calculation methods of the total output of a mine haulage system. Taking the maximum of system’s total throughput as a objective, the method of determining the surge bunker’s rational size is put forward. Also, the problems of rational position of surge bunker are analysesed.
文摘The paper presents the methods proposed by the authors to be applied in operation of substations. The substations taken in consideration were rehabilitated by replacing the existing equipments by new equipments, the last generation. The methods consist in study of equipment's failures, study of equipment's behaviour, study of substation architecture and study of systems operation. Paper presents new equipments on their architecture and performances. The parts of method exposed in this paper are based on the operational reliability. The mathematical methods and new analyses methods are given for resolving the issues on operation of substations. The results of this study will be used to obtain the best solution for operation of the substations. The results of the analysis were applied to some substation from the Transmission Power Grid.
文摘The procedure of reliability-based fatigue analysis of liquefied natural gas(LNG) carrier of membrane type under wave loads is presented. The stress responses of the hotspots in regular waves with different wave heading angles and wave lengths are evaluated by global ship finite element method(FEM) . Based on the probabilistic distribution function of hotspots' short-term stress-range using spectral-based analysis,Weibull distribution is adopted and discussed for fitting the long-term probabilistic distribution of stress-range. Based on linear cumulative damage theory,fatigue damage is characterized by an S-N relationship,and limit state function is established. Structural fatigue damage behavior of several typical hotspots of LNG middle ship section is clarified and reliability analysis is performed. It is believed that the presented results and conclusions can be of use in calibration for practical design and initial fatigue safety evaluation for membrane type LNG carrier.
文摘The purpose of this research is to explore the principle of the man-object relationship to identify the issues shown when handling packaging and emphasizing the usability aspect. For that, the theoretical reference of the research involves the analysis of the parameters according to the aspects that involve the use interactions of packaging in agreement with the definition and scientific concepts of ergonomics, allied to the development of product projects, discussing forms, handling, load transportation and the support of the product. Therefore, improperly handling of the packaging may cause damages to the products and even potential accidents. Coding and decoding are significant to facilitate the use recognition within the individual's repertoire. The packaging, within the macro-ergonomics universe, may be the object of ergonomics, whose contribution to solve problems is related to labor activities, by dealing with packaging, transportation and load resulting from the man-object interaction. The incorrect identification of information may lead to problems of interpretation and misuse, from the handling to the disposal of packaging. For this reason, this research suggests the adjustment of the man-object interface which may lead users to make mistakes regarding use and important choices, through adequate handling actions.
基金Sichuan Province Academic and Technical Leader Training Foundation (Grant No. 25727501)the Subject Construction Foundations of Southwest University for Nationalities (Grant No.2012XWD-S0805)
文摘In this work, we selected a magnetic-semiconductor as an interlayer and investigated the electronic transport properties in the ferromagnetic/ferromagnetic-semiconductor/ferromagnetic (FM/FS/FM) trilayers. The results indicate that the large TMR comparable to that in ferromagnetic/metal oxide/ferromagnetic sandwich can be obtained in the FM/FS/FM multilayers with considering the spin filter effect in the magnetic semiconductor layer. Moreover, the transmission coefficient and TMR can be tuned through thickness, Rashba spin-orbit coupling strength and molecular field of the magnetic semiconductor. Our calculations could provide a way to design the semiconductor spintronic devices with excellent and controllable properties.
文摘Peristaltic flow by a sinusoidal traveling wave in the walls of two-dimensional channel with wall properties is investigated. The channel is filled with incompressible Eyring-Powell fluid. Mathematical modeling is developed through aspects of Hall current, thermal deposition and convection. Long wavelength and low Reynolds number considerations are adopted. Perturbation solutions to the resulting problem for small material parameter of fluid are obtained. Expressions of velocity, temperature, concentration and stream function are derived. Variations of pertinent parameters on the physical quantities of interest are explored in detail. The present analysis is especially important to predict the rheological characteristics in engineering applications by peristalsis.