Rail transport in most developing countries, is usually the least developed mode. For instance, in Nigeria the vibrant fortune of rail transport operations and development has been on decline since mid 1970s.The devel...Rail transport in most developing countries, is usually the least developed mode. For instance, in Nigeria the vibrant fortune of rail transport operations and development has been on decline since mid 1970s.The developmental gap in rail transport in Nigeria is responsible for a significant level of access denial to a safer, affordable and environmentally-friendly mode of transport, to the younger generation of Nigerians. Through a critique of past railways developmental projects and policies, this paper was able to identify the principal factors responsible for its intangible contributions to the socio-economic development of Nigeria. It further highlighted the role（s） politics of policies inconsistency and somersault plays, to the detriment of realization of a vibrant railway system in Nigeria. The findings revealed that discontinuity and incoherence in policy implementation by successful governments, policy reversal as well as uncoordinated national transport policy goal and objectives as clogs in the wheel of progress of railways development in Nigeria. In conclusion, the paper hinged the rapid development of the rail industry in Nigeria on institutional paradigm shift, whereby the rail authority will enjoy a reasonable level of autonomy in decision making, finance and investment in rail operations, infrastructure supply and technological advancement in Nigeria.展开更多
A singularly perturbed second-order semilinear differential equation with integral boundary conditions is considered. By the method of boundary functions, the conditions under which there exists an internal transition...A singularly perturbed second-order semilinear differential equation with integral boundary conditions is considered. By the method of boundary functions, the conditions under which there exists an internal transition layer for the original problem are established. The existence of spike-type solution is obtained by smoothly connecting the solutions of left and right associated problems, and the asymptotic expansion of the spike-type solution is also presented.展开更多
Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geo...Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.展开更多
The development and application of the ''digital mine'' concept in China depends heavily upon the use of remote sensing data as well as domestic expertise and awareness. Illegal mining of mineral resou...The development and application of the ''digital mine'' concept in China depends heavily upon the use of remote sensing data as well as domestic expertise and awareness. Illegal mining of mineral resources has been a serious long term problem frustrating the Xishimen Iron Ore Mine management. This mine is located in Wu'an county in Hebei province, China. Illegal activities have led to enormous economic losses by interfering with the normal operation of the Xishimen mine and have ruined the surrounding environ- ment and the stability of the Mahe riverbed the crosses the mined area. This paper is based on field recon- naissance taken over many years around the mine area. The ground survey data are integrated with Differential Synthetic Aperture Radar Interferometry (D-InSAR) results from ALOS/PALSAR data to pin- point mining locations. By investigating the relationship between the resulting interferometric deforma- tion pattern and the mining schedule, which is known a priori, areas affected by illegal mining activities are identified. To some extent these areas indicate the location of the illegal site. The results clearly dem- onstrate D-InSAR's ability to cost-effectively monitor illegal mining activities.展开更多
The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four ...The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.展开更多
文摘Rail transport in most developing countries, is usually the least developed mode. For instance, in Nigeria the vibrant fortune of rail transport operations and development has been on decline since mid 1970s.The developmental gap in rail transport in Nigeria is responsible for a significant level of access denial to a safer, affordable and environmentally-friendly mode of transport, to the younger generation of Nigerians. Through a critique of past railways developmental projects and policies, this paper was able to identify the principal factors responsible for its intangible contributions to the socio-economic development of Nigeria. It further highlighted the role（s） politics of policies inconsistency and somersault plays, to the detriment of realization of a vibrant railway system in Nigeria. The findings revealed that discontinuity and incoherence in policy implementation by successful governments, policy reversal as well as uncoordinated national transport policy goal and objectives as clogs in the wheel of progress of railways development in Nigeria. In conclusion, the paper hinged the rapid development of the rail industry in Nigeria on institutional paradigm shift, whereby the rail authority will enjoy a reasonable level of autonomy in decision making, finance and investment in rail operations, infrastructure supply and technological advancement in Nigeria.
基金National Natural Science Foundation of China(No.10701023)the Fundamental Research Funds for the Central Universities,China+1 种基金E-Institutes of Shanghai Municipal Education Commission,China(No.E03004)Natural Science Foundation of Shanghai,China(No.10ZR1400100)
文摘A singularly perturbed second-order semilinear differential equation with integral boundary conditions is considered. By the method of boundary functions, the conditions under which there exists an internal transition layer for the original problem are established. The existence of spike-type solution is obtained by smoothly connecting the solutions of left and right associated problems, and the asymptotic expansion of the spike-type solution is also presented.
文摘Locating the mineral processing plant near a mine is the most important parameter that affects the whole process.Many factors,and their preferences,should be considered in this stage.The factors include economical,geological,technical,environmental and tectonic parameters.A multi-criteria decision making method is necessary to rank the alternatives.In this paper we describe how plant location is selected by using the Analytic Hierarchy Process(AHP).This method,with eight criteria,was used to select a location for the mineral processing plant at the Sangan iron ore mine(phase 1).Three alternatives for the processing plant were evaluated.The main criteria were distance from the mine,access to heavy machinery transport,the amount of excavation required for grading,bed mixture capacity,belt conveyor length,distance from the tailing dam,distance from the waste dumps and surface water diversion requirements.Finally,the alternatives were ranked and the best location was proposed.
基金supported by the National Hi-Tech Research and Development Program of China (No. 2009AA11Z105)the sponsors of Hanxing Iron Ore Mine Administration Bureau for providing the research funds,insitu test assistance and monitor work
文摘The development and application of the ''digital mine'' concept in China depends heavily upon the use of remote sensing data as well as domestic expertise and awareness. Illegal mining of mineral resources has been a serious long term problem frustrating the Xishimen Iron Ore Mine management. This mine is located in Wu'an county in Hebei province, China. Illegal activities have led to enormous economic losses by interfering with the normal operation of the Xishimen mine and have ruined the surrounding environ- ment and the stability of the Mahe riverbed the crosses the mined area. This paper is based on field recon- naissance taken over many years around the mine area. The ground survey data are integrated with Differential Synthetic Aperture Radar Interferometry (D-InSAR) results from ALOS/PALSAR data to pin- point mining locations. By investigating the relationship between the resulting interferometric deforma- tion pattern and the mining schedule, which is known a priori, areas affected by illegal mining activities are identified. To some extent these areas indicate the location of the illegal site. The results clearly dem- onstrate D-InSAR's ability to cost-effectively monitor illegal mining activities.
基金Supported by Program for New Century Excellent Talents in University (No. NCET-06-0228)
文摘The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.
