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51.
文章结合厦门港海沧航道扩建工程实践,介绍了利用全站仪与GPS-RTK(1+2)技术进行炸礁作业施工放样的基本原理,阐述了全站仪与GPS-RTK放样作业的具体步骤及效果,并通过对比分析,验证了GPS-RTK(1+2)技术的优越性。  相似文献   
52.
规划城际铁路台温连接线全长54.95km,连接温州S2线、台州S1线。三线运营组织方式相互关联,对轨道交通整体布局和效能的发挥具有重要影响。采用行车专业设计分析方法,研究了全贯通、部分贯通、独立运营三种行车组织方案。研究结果表明:部分贯通方案兼顾本线、跨线客流,开行跨线大交路和本线小交路列车,但本线两端终点站须进行方案改造。部分贯通方案在工程设计和多元化投资上均留有余地,是较为合理可行的方案。  相似文献   
53.
介绍了沧州地区沿海环境基本状况,从结构设计、防腐混凝土、防腐涂层等方面对桥梁防腐采取对策,对防腐混凝土、防腐涂层提出施工要求,通过综合措施达到桥梁混凝土耐久性要求。  相似文献   
54.
Coastal erosion is one of the major coastal problems currently facing Tanzania. Several factors, including sea level rise, geology, and rapid coastal population growth accompanied by rapid increase of human activities that interfere with natural processes, have been linked to the problem. One of the human activities that have been well linked to the problem of coastal erosion is illegal sand mining along beaches, coastal streams/rivers, and other restricted areas. This causes localized accelerated/ severe coastal erosion and enormous environmental degradation and threat to coastal properties. Illegal sand mining is presently a big industry in Tanzania, employing many youths, and has become a social, economical, and environmental problem. Thus, it is a sensitive issue. The problem of illegal sand mining in Tanzania is revisited, and possible measures to control it are proposed. Measures that can help to reduce/eliminate illegal sand mining are: governments to address effectively the problem of unemployment and poverty in the society by formulation of effective policies, including the total liberalization of the labor market and reduction of the tax burden and regulations on potential employers; identifying alternative sources of sand that are environmentally safe to mine, of good quality, and easily accessible; launching well-focused mass education on the problem of coastal erosion; encouraging formation of legally registered associations of sand-miners that will work closely with relevant authorities to curb illegal sand mining; and strengthening of governance and improving research funding in the country.  相似文献   
55.
Both the loggerhead sea turtle (Caretta caretta) and the green turtle (Chelonia mydas) live, feed, and nest in the Mediterranean, mostly on the beaches of Turkey and Greece. The greatest threat to the survival of Caretta caretta has been found to be on the sandy beaches where their lives begin. In this study, the digital terrain model (DTM) of the Iztuzu Beach in Turkey where the Caretta caretta sea turtles lay their eggs was prepared using a global positioning system (GPS) and a geographic information system (GIS). A flexible coastal geographic information system was prepared integrating the DTM with digitally processed satellite images and ground truth of the nesting area and its surroundings. Researchers, decision makers, other end users, or sea turtle experts can find and query any environmental information having a possible impact on the nesting area using a computer-based GIS database. A multidate monitoring of the nesting area allows users to extract and compare much information about the location and condition of the nests and will help researchers develop better strategies for protecting sea turtles.  相似文献   
56.
An assumption underlying the growing support for marine protected areas (MPAs) is that they meet conservation goals and provide economic benefits to fisheries and ecotourism. However, support for MPAs will be at risk if managers cannot assess whether various MPA objectives are being fulfilled. Current approaches to MPA management emphasize the need to evaluate performance criteria; however, there is little consensus on criteria and their evaluation. We propose a marine protected area evaluation model (MPAEM), based on and modified from a multidisciplinary approach used to assess the sustainability of fisheries, called rapid appraisal of fisheries (Rapfish). The application of the MPAEM was explored in a pilot study of 20 MPAs located in different regions of the world. Results indicate that the MPAEM can be used to evaluate MPA management effectiveness. However, the manner in which the evaluation attributes are scored and ways of engaging user groups should be explored before MPAEM can become part of the day-to-day management of MPAs.  相似文献   
57.
Beach management and coastal management are interwoven and scale-dependent activities in Australia. Present coastal policies are broad and designed for large, national, and statewide scales. They specify ecologically sustainable development as the overarching goal for coastal management and provide the context for beach management. On smaller scales, an approach focusing on the reduction of geomorphic hazards as the basis of beach management was established by the Coastline Hazard Policy, with nonhazard aspects of beach management such as ecological, economic, and social concerns assuming secondary importance. Although beach management can occur effectively under these coastal management arrangements, better guidance is required to make this process as effective and efficient as possible. This guidance - the policy framework - could be better developed for beach management and better integrated with existing coastal management arrangements. While this policy development is not strictly necessary to achieve positive outcomes from beach management, it is necessary to effectively guide implementation of the existing broad coastal policies. Effective goals for beach management are yet to be thought out and clearly articulated in Australia. A good start would be to couple the present goals of ecologically sustainable development and hazards reduction into a coherent goal for beach management. A specific policy for beaches should be developed given the importance of beaches in Australia.  相似文献   
58.

Development of awareness and capacity is a central component to the delivery of ICM and spans from local communities to national-level politicians. Education and training activities associated with ICM must be extremely varied to match both the existing capacity and role that the stakeholders play within the process of ICM. Consequently, there cannot be considered any effective “generic” ICM training; training must be tailored to match the requirements of target groups. The transfer and uptake of good-practice thus becomes an important aspect of quality enhancement in ICM capacity development. Six case studies from the Asia-Pacific region are presented that show diverse and innovative examples of good practice. A comparative analysis of these case studies is carried out in terms of institutional level of impact. In addition a generic systems-based evaluation framework is used to determine the extent to which the training impacts upon ICM implementation indicators. It is concluded that the exchange, transfer, and translation to local conditions of appropriate good practice in ICM capacity development can be an important element in enhancing the impact of ICM programs on the coastal environments and societies. Furthermore, there appears to be a positive link between the involvement of national/state/regional stakeholders in capacity-building initiatives and impacting a wider variety of indicators of ICM delivery.  相似文献   
59.
Satellite remote sensing technique has been used to observe the coastal area. This article reviews applications of remote sensing to coastal area management (CAM) in China. These applications include the coastal resource and island mapping, coastal environmental change and coastal hazard monitoring, oceanographic parameter measurement, and coastal process restudy. Future applications are also discussed.  相似文献   
60.
A data and dynamics driven approach to estimate, decompose, organize and analyze the evolving three-dimensional variability of ocean fields is outlined. Variability refers here to the statistics of the differences between ocean states and a reference state. In general, these statistics evolve in time and space. For a first endeavor, the variability subspace defined by the dominant eigendecomposition of a normalized form of the variability covariance is evolved. A multiscale methodology for its initialization and forecast is outlined. It combines data and primitive equation dynamics within a Monte-Carlo approach.The methodology is applied to part of a multidisciplinary experiment that occurred in Massachusetts Bay in late summer and early fall of 1998. For a 4-day time period, the three-dimensional and multivariate properties of the variability standard deviations and dominant eigenvectors are studied. Two variability patterns are discussed in detail. One relates to a displacement of the Gulf of Maine coastal current offshore from Cape Ann, with the creation of adjacent mesoscale recirculation cells. The other relates to a Bay-wide coastal upwelling mode from Barnstable Harbor to Gloucester in response to strong southerly winds. Snapshots and tendencies of physical fields and trajectories of simulated Lagrangian drifters are employed to diagnose and illustrate the use of the dominant variability covariance. The variability subspace is shown to guide the dynamical analysis of the physical fields. For the stratified conditions, it is found that strong wind events can alter the structures of the buoyancy flow and that circulation features are more variable than previously described, on multiple scales. In several locations, the factors estimated to be important include some or all of the atmospheric and surface pressure forcings, and associated Ekman transports and downwelling/upwelling processes, the Coriolis force, the pressure force, inertia and mixing.  相似文献   
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