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Despite the long existence of port geography research, there has been no systematic investigation on its evolution and research trends. Hence, through investigating 155 port geography articles featured in geography journals between 1956 and 2011, this article studied the evolution and research trends of port geography. The article argues that port geography had gradually evolved from a secondary and encyclopedic subdiscipline within transport and human geographies to a primary and specialized one. Such a trend had blurred its “geographicalness,” however, with port geography moving toward the more applied and interdisciplinary transportation. The article also indicates that further research would be required to understand the communication between port geography and other disciplines, as well as philosophical and epistemological issues.  相似文献   
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North China Plain (Huabei Plain) is one of the most densely populated regions on earth. Due to excessive underground water extraction, the North China Plain has been experiencing severe ground deformation over the last three decades. Therefore, for the purpose of hazard mitigation, it is necessary to monitor the ground displacement occurred in this region. As an extension of the differential radar interferometry (DInSAR) technique, advanced DInSAR techniques involving multiple images have demonstrated the potential to effectively map ground displacement. Such techniques are able to measure the temporal evolution of ground deformation with millimetre-level accuracy by using a stack of differential interferograms. In this study, the ALOS PALSAR data acquired over the North China Plain, which cover an area of approximately 16,000 km $^2$ , were processed based on the concept of advanced DInSAR techniques. Because of the large size of the PALSAR images, a targeted processing strategy was designed. This strategy is able to reduce required disk storage space and I/O operations, leading to the improvement of the computational efficiency. The resulting mean deformation velocity map demonstrates that a large portion of the area covered by the data was affected by various degrees of ground deformation between January 2007 and April 2010. The ground deformation is mostly distributed in rural areas, while the downtown areas are generally stable.  相似文献   
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The urban environment has been dramatically changed by artificial constructions. How the modified urban geometry affects the urban climate and therefore human thermal comfort has become a primary concern for urban planners. The present study takes a simulation approach to analyze the influence of urban geometry on the urban climate and maps this climatic understanding from a quantitative perspective. A geographical building database is used to characterize two widely discussed aspects: urban heat island effect (UHI) and wind dynamics. The parameters of the sky view factor (SVF) and the frontal area density (FAD) are simulated using ArcGIS-embedded computer programs to link urban geometry with the UHI and wind dynamic conditions. The simulated results are synergized and classified to evaluate different urban climatic conditions based on thermal comfort consideration. A climatic map is then generated implementing the classification. The climatic map shows reasonable agreement with thermal comfort understanding, as indicated by the biometeorological index of the physiological equivalent temperature (PET) obtained in an earlier study. The proposed climate mapping approach can provide both quantitative and visual evaluation of the urban environment for urban planners with climatic concerns. The map could be used as a decision support tool in planning and policy-making processes. An urban area in Hong Kong is used as a case study.  相似文献   
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The paper investigates the roles and nature of postgraduate education on the professionalization of the shipping industry. The recent growth of postgraduate education is marked by the massive expansion of professional programmes on disciplines which traditionally emphasized non-academic, apprentice-style learning approach, including shipping business and management. The reasons behind such growth of demands, however, have remained scarce and empirically under-researched. Understanding this deficiency, in this study, we have undertaken a questionnaire survey completed by students/graduates who are pursuing/have recently pursued masters' programmes in shipping-related business and management offered by six Asian and European universities. Specifically, we analyze student motivations, considerations, and sources of information before enrolling such programmes, the extent that the shipping industry or other forces act as driving forces towards such enrollment, as well as students' evaluation of the postgraduate programmes that they are pursing/have pursued. Integrated in these discussions are comparative analyses of the data provided by different student groups based on their professional experiences and cultural backgrounds. We believe that this study has provided the lacking empirical inputs essential for achieving the sustainable development of postgraduate education in shipping business and management.  相似文献   
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The plastic tube cast-in-place concrete pile (TC pile) with a small diameter consists of pre-driven plastic tube filled with concrete. Based on the case of TC pile-reinforced embankment on soft ground, and according to the monitoring data of the TC pile-reinforced embankment system, the treatment effect and reinforcement characteristics for this system were analyzed. The field monitoring results indicates that the critical height of embankment is about 1.1 times the pile net spacing, and the small-spacing arranged TC piles can be applied to low embankment engineering; the load share rate can reflect the degree of soil arching more better and steadily and exceeds 70 % at the end of monitoring period; the settlements of pile cap and soil between piles mainly occurs in the embankment construction period; the different settlement between pile cap and soil approaches the maximum and then reduces gradually when the embankment height is about 2.2 times the pile net spacing. The variation of layered settlement and pore water pressure illustrates that the embankment settlement is mainly caused by the compression of soils within pile length, which is about 90 % of the total settlement; the influence depth of pore water pressure is about 1/3 pile length.  相似文献   
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A study is presented of the nonlinear self-modulation of low-frequency electrostatic dust acoustic waves (DAWs) propagating in a dusty plasma, within the theoretical framework of the nonextensive statistics proposed by Tsallis. Using the reductive perturbation method (RPM), the nonlinear Schrödinger equation (NLSE) which governs the modulational instability (MI) of the DAWs is obtained. The presence of the nonextensive electron/ion distribution is shown to influence the MI of the waves. Furthermore it is observed that nonextensive distributed ions has more effect on the MI of the DAW than electrons.  相似文献   
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