全文获取类型
收费全文 | 2655篇 |
免费 | 55篇 |
专业分类
公路运输 | 1440篇 |
综合类 | 566篇 |
水路运输 | 172篇 |
铁路运输 | 268篇 |
综合运输 | 264篇 |
出版年
2023年 | 8篇 |
2022年 | 39篇 |
2021年 | 72篇 |
2020年 | 126篇 |
2019年 | 42篇 |
2018年 | 61篇 |
2017年 | 52篇 |
2016年 | 70篇 |
2015年 | 117篇 |
2014年 | 241篇 |
2013年 | 127篇 |
2012年 | 233篇 |
2011年 | 275篇 |
2010年 | 208篇 |
2009年 | 167篇 |
2008年 | 149篇 |
2007年 | 201篇 |
2006年 | 177篇 |
2005年 | 127篇 |
2004年 | 66篇 |
2003年 | 40篇 |
2002年 | 17篇 |
2001年 | 36篇 |
2000年 | 14篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有2710条查询结果,搜索用时 15 毫秒
101.
基于CAN总线机舱智能监控仪表的设计 总被引:2,自引:1,他引:1
针对船舶机舱温度变化大、振动强度高和控制系统复杂等特点,提出了一种基于CAN总线的机舱智能监控仪表,对机舱设备参数进行实时采集、处理和控制.该智能监控仪表主要由SJA1000和AT89S51芯片构成,其硬件电路、软件设计和智能算法在文中做了详细说明.实验表明:该智能监控仪表能较好地监控设备的运行状态,提供准确、可靠、实时的信息. 相似文献
102.
103.
104.
公交IC卡的应用,不仅方便了乘客出行,也为城市交通规划相关数据的采集提供了一种新的调查统计手段.针对当前城市公交IC卡在换乘矩阵构造过程中存在的信息量大、处理困难的问题,利用Excel软件强大的数据处理功能,对大量的IC卡信息进行了有效地处理,成功地构造了城市公交换乘矩阵,使其成为公交换乘枢纽规划的一个重要参考依据. 相似文献
105.
以C8051F单片机作为中央处理器,采集电参数计量模块和TAX2型机车安全综合监测装置的信息,生成并存储电量消耗记录;通过USB盘转储数据到地面进行处理和分析。系统整体设计具有模块化、准确可靠的特点,对电力机车节能降耗措施提供合理的依据。 相似文献
106.
107.
Sashank Musti 《Transportation Research Part A: Policy and Practice》2011,45(8):707-720
In today’s world of volatile fuel prices and climate concerns, there is little study on the relationship between vehicle ownership patterns and attitudes toward vehicle cost (including fuel prices and feebates) and vehicle technologies. This work provides new data on ownership decisions and owner preferences under various scenarios, coupled with calibrated models to microsimulate Austin’s personal-fleet evolution.Opinion survey results suggest that most Austinites (63%, population-corrected share) support a feebate policy to favor more fuel efficient vehicles. Top purchase criteria are price, type/class, and fuel economy. Most (56%) respondents also indicated that they would consider purchasing a Plug-in Hybrid Electric Vehicle (PHEV) if it were to cost $6000 more than its conventional, gasoline-powered counterpart. And many respond strongly to signals on the external (health and climate) costs of a vehicle’s emissions, more strongly than they respond to information on fuel cost savings.Twenty five-year simulations of Austin’s household vehicle fleet suggest that, under all scenarios modeled, Austin’s vehicle usage levels (measured in total vehicle miles traveled or VMT) are predicted to increase overall, along with average vehicle ownership levels (both per household and per capita). Under a feebate, HEVs, PHEVs and Smart Cars are estimated to represent 25% of the fleet’s VMT by simulation year 25; this scenario is predicted to raise total regional VMT slightly (just 2.32%, by simulation year 25), relative to the trend scenario, while reducing CO2 emissions only slightly (by 5.62%, relative to trend). Doubling the trend-case gas price to $5/gallon is simulated to reduce the year-25 vehicle use levels by 24% and CO2 emissions by 30% (relative to trend).Two- and three-vehicle households are simulated to be the highest adopters of HEVs and PHEVs across all scenarios. The combined share of vans, pickup trucks, sport utility vehicles (SUVs), and cross-over utility vehicles (CUVs) is lowest under the feebate scenario, at 35% (versus 47% in Austin’s current household fleet). Feebate-policy receipts are forecasted to exceed rebates in each simulation year.In the longer term, gas price dynamics, tax incentives, feebates and purchase prices along with new technologies, government-industry partnerships, and more accurate information on range and recharging times (which increase customer confidence in EV technologies) should have added effects on energy dependence and greenhouse gas emissions. 相似文献
108.
109.
110.