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771.
This article draws lessons about recent innovations in decision support for coping with challenges in integrated infrastructure planning strategies. After setting up a conceptual framework for the scope of analysis and the use of information in infrastructure planning, the empirical section explores the introduction of early-stage sustainability assessment tools. Data collection draws on experiences gained in the Netherlands with a new tool: ‘Sustainability Check’. We conclude that such instruments have a number of capacities that address the challenges of area-oriented planning: (a) bringing together information about the comprehensive value of alternatives, (b) facilitating the generation of alternatives, (c) addressing institutional fragmentation by learning about referential frames, and (d) adding contextual perspectives to the ‘hard’ outcomes of conventional tools. We also conclude that tools such as Sustainability Check should not be seen as a replacement for conventional decision support tools, but rather as complementary to them.  相似文献   
772.
This paper addresses a fundamental question related to nearly all container liner shipping planning models: whether the implicit assumption of identical container delivery pattern every week is valid in a situation of identical shipping services and identical cargo demand every week. We prove that when the number of containers transported from one port to the next is formulated as a continuous variable, the resulting mathematical model with an identical container delivery pattern is equivalent to the model with general container delivery patterns which can be different in different weeks. When the number of containers transported is formulated as an integer variable, the model with an identical container delivery pattern is not equivalent to the model with general container delivery patterns. However, the difference between the optimal objective values of the two models is negligible for practical applications. In sum, little, if not nothing, is lost by assuming an identical container delivery pattern in liner shipping planning models.  相似文献   
773.
Given a fleet of container ships of varying capacity, a cost-efficient approach for improving fleet utilization and reducing the number of delayed containers is to optimize the sequence of container ships in a given string, a problem which belongs to the large ship-deployment class. A string sequence with ‘uniformly’ distributed ship capacity is more likely to accommodate a random container shipment demand. The number of one’s total ship slots acts as a gauge of the capacity of the container ships. Meanwhile, there are two types of ship slots: dry slots and reefer slots. A dry slot only accommodates a dry container, while a reefer slot can accommodate either a dry or a reefer container. The numbers of dry and reefer slots for ships in a string are different. Therefore, in this study, we propose a model that considers both dry and reefer slots and use it to elucidate the optimal ship-deployment sequence. The objective is to minimize the delay of dry and reefer containers when the demand is uncertain. Furthermore, based on the optimal sequence deduced, the study also investigates the need to convert some dry slots to reefer slots for the container ships.  相似文献   
774.
Climate change adaptation presents a difficult challenge for coastal towns around the world, forcing local governments to plan for sea level rise in a contentious decision-making space. The concept of “adaptation pathways,” a diagnostic and analytical tool to assist in adaptive planning and decision-making, is gaining traction as a way of framing and informing climate adaptation. It provides decisionmakers a way to acknowledge the inter-temporal complexities and uncertainties associated with the novel dynamics of climate change and a mechanism to manage these challenges in the local context. In 2012, the Australian Government funded an 18-month program to provide decisionmakers in the coastal zone an opportunity to test the utility of the adaptation pathways concept for coastal climate adaptation. Using a selection of completed projects as case studies, we performed a document analysis to better understand the learnings from the projects. The main themes surrounded: (1) the utility of the adaptation pathway framework in developing options, (2) decision-making rationale and criteria, and (3) stakeholder participation in pathway development. A project participant survey was developed to further understand these themes. Our analysis reveals that “adaptation pathways” was generally framed narrowly and conservatively to emphasize extant economic, administrative and legal considerations over community, participatory, or exploratory ones. Although some case study projects were able to reach a point in the pathway discussion to actively involve stakeholders in their decision-making process, many case studies continued to build technical data as a method for defending policies and actions. These results indicate that coastal adaptation can take-up adaptation pathways as a useful concept for decision-making and planning; however, many councils may still require assistance in stakeholder communication processes in order to develop sociallyacceptable plans that take into account the full range of values affecting local coastal environments.  相似文献   
775.
基于国内外生态港口发展历史和实践,提出生态型港口规划的愿景、原则,结合传统港口规划理念,分析生态型港口规划技术路线,丰富了港口规划体系。并以大连港太平湾港区规划为例,提出生态型港口规划概念性方案,明确了港口开发建设与生态要素协同发展的规划理念,为我国探索生态型港口规划提供了新思路。  相似文献   
776.
文章针对连续曲率路径,用一种简单的几何方法生成连续曲率的路径.基于该几何方法生成的连续路径,文中利用line-of-sight(LOS)引导律解决了循迹控制中横向偏差最小的问题.为了减弱控制输出的振荡和获得平滑的控制输出,一种基于动态执行机构的改进反步积分控制器在过驱动船舶循迹控制中得到了应用.值得注意的是,文中用积分操作来抵抗风浪流环境力.数值分析结果展示了该控制器的有效性.  相似文献   
777.
将多维动态规划法应用于1条无人帆船从上海到青岛的长途路径规划,在当前位置以外引入已航行路径长度作为第三维状态变量,以相邻路径点之间的短途路径规划方案作为决策变量,可以规划出一组随路径总长度变化的航行时间最短路径。结果显示,增加状态变量维度后,规划结果保留了更多备选方案,起到了很好的决策辅助作用。  相似文献   
778.
综合保税区是设立在内陆地区具有保税港区功能的海关特殊监管区域,是一个相对封闭、完整的城市空间,其规划策略与其他城市空间存在巨大差异。分析了综合保税区政策属性、产业功能、空间形态等特性,采用"目标导向"的思维方式提出了综合保税区的规划目标。围绕规划目标的实现过程从协调外部限制要素、符合监管要求、内外交通组织、确定建设用地指标、协调城市景观等方面提出了综合保税区的规划策略,并以徐州综合保税区为例进行了实例分析。  相似文献   
779.
针对宜昌庙嘴长江大桥西坝锚碇区极软岩和深厚卵石层发育、地下水作用影响大等突出问题,从工程地质和水文地质角度重点论述了锚碇区岩土层工程特性、水文地质特征。采用工程地质综合评价方法,得出了极软岩遇水软化易导致槽壁垮塌、深厚卵石层成槽难度大易导致槽段倾斜、地下水渗流破坏易形成管涌等影响槽壁稳定等工程地质问题的结果。提出了地连墙槽段加固与施工工艺、基坑降水的建议措施,为优化基坑施工方案提供了可靠依据,可供类似工程借鉴。  相似文献   
780.
The optimal allocation of multiple land uses constitutes a complex multi-objective optimization problem with unknown feasible objective space and optimal planning alternatives. Despite the effectiveness of evolutionary algorithms to capture the underlying Pareto set of optimum maps, land use planners are bound to pursue the best possible spatial allocation of each use within an enormous population of non-dominated solutions. This article presents a novel post-processing methodology enhancing the comparative evaluation of alternative planning approaches without making any assumptions about the (relative) importance of each objective function. The proposed consolidated post-processing module is applied in a land use planning paradigm, revealing: (a) the existence of substantial planning guidelines whose validity is not affected by the relative significance of each criterion and (b) the variable planning component emerging from the (varying) relative importance of objective functions. Such planning feedback could not be extracted by the exhaustive review of non-dominated maps.  相似文献   
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