全文获取类型
收费全文 | 87篇 |
免费 | 1篇 |
专业分类
公路运输 | 24篇 |
综合类 | 19篇 |
水路运输 | 20篇 |
铁路运输 | 18篇 |
综合运输 | 7篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 2篇 |
2012年 | 6篇 |
2011年 | 12篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1994年 | 2篇 |
1992年 | 2篇 |
排序方式: 共有88条查询结果,搜索用时 31 毫秒
71.
Yu-Chiun Chiou Chieh-Hua Wen Shih-Hsun Tsai Wei-Ying Wang 《Transportation Research Part A: Policy and Practice》2009,43(7):665-684
Devising effective management strategies to relieve dependency on private vehicles, i.e. cars and motorcycles, depends on the ability to accurately and carefully examine the effects of corresponding strategies. Disaggregate choice models regarding the ownership, type and usage of cars and motorcycles are required to achieve this. Consequently, this study proposes integrated car and motorcycle models based on a large-scale questionnaire survey of Taiwanese owners of cars and motorcycles, respectively. Incorporating gas mileage and emission coefficients for different types of cars and motorcycles into the proposed models can enable the estimation and comparison of reductions in energy consumption and emissions under various management strategies. To demonstrate the applicability of the proposed integrated models, scenarios involving 10% and 30% increases in gas prices are analyzed and compared. The results indicate that gas price elasticities of cars and motorcycles are low, ranging from 0.47 to 0.50 for cars and 0.11 for motorcycles. Additionally, a high ratio of discouraged car users shifting to use of motorcycles neutralizes the effects of increased gas price in reducing energy consumption and emissions. Pollution of CO and HC even slightly increased because motorcycles are much more polluting in terms of CO and HC. At last, the reductions of energy consumption and emissions under 10% and 30% increase (or decrease) in other manipulating variables are also estimated and compared. The countermeasures for reducing ownership and usage of cars and motorcycles are then recommended accordingly. 相似文献
72.
进口原油运输船型经济性分析 总被引:8,自引:0,他引:8
石油是世界海上运量最大的货种之一,约占海上总运输量的三分之一。加入WTO后,中国石油海上运输量,特别是进口原油运输量将大幅度地增加。针对这一现实情况,本文对世界原油运输船队的技术经济作了概括性分析,对原油进口航线作了介绍。建立了单船运输经济性测算模型。基于实船经济指标测算结果,以必要运费率为主,通过比较选出了优良船型。并定量测算出不同类型船舶在同一航线上营运的必要运费率及其差异。研究结果指出,随着进口原油量的大幅度增加,中国应大力发展VLCC和Suezmax船队,重点建设大型深水油轮码头。 相似文献
73.
74.
This paper presents the World-wide harmonized Light duty Test Cycle (WLTC), developed under the Working Party on Pollution and Energy (GRPE) and sponsored by the European Union (with Switzerland) and Japan. India, Korea and USA have also actively contributed. The objective was to design the harmonized driving cycle from “real world” driving data in different regions around the world, combined with suitable weighting factors. To this aim, driving data and traffic statistics of light duty vehicles use were collected and analyzed as basic elements to develop the harmonized cycle. The regional driving data and weighting factors were then combined in order to develop a unified database representing the worldwide light duty vehicle driving behavior. From the unified database, short trips were selected and combined to develop a driving cycle as representative as possible of the unified database. Approximately 765,000 km of data were collected, covering a wide range of vehicle categories, road types and driving conditions. The resulting WLTC is an ensemble of three driving cycles adapted to three vehicle categories with different power-to-mass ratio (PMR). It has been designed as a harmonized cycle for the certification of light duty vehicles around the world and, together with the new harmonized test procedures (WLTP), will serve to check the compliance of vehicle pollutant emissions with respect to the applicable emissions limits and to establish the reference vehicle fuel consumption and CO2 performance. 相似文献
75.
从桥梁护栏防撞等级、护栏结构设计、细节优化设计、护栏颜色四个方面入手,利用结构力学、材料力学、色彩心理学等基础学科,结合规范条文要求,提出一种比较实用的设计方法,供护栏设计参考。 相似文献
76.
针对我处各船闸维修情况实例,对船闸阀门目前技术状况及各部件磨损原因进行分析和探讨。一些体会可供参考,所提的技术要求和问题也有一定现实参考价值。 相似文献
77.
78.
文章重点介绍了美国公路的公示速度概念和种类、基本速度原则及超速范围,分析了提高公示速度的原因,并针对美国公路公示速度的特点,探讨了中美两国在公路设计速度、设计理念和公示速度管理方式上的差别,同时提出了美国公路公示速度的借鉴学习要点。 相似文献
79.
80.
中小型LNG船C型独立液货舱蒸发率计算 总被引:2,自引:0,他引:2
C型独立液货舱是中小型LNG船的主要液货舱形式,通常为单圆筒或双圆筒。根据IGC规则,利用简化算法,对C型独立液货舱和138000m3 LNG运输船液舱的蒸发率进行了计算。计算结果表明:该方法是有效的,能快速应用于液货舱保温层的设计。 相似文献