全文获取类型
收费全文 | 473篇 |
免费 | 19篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 10篇 |
综合类 | 22篇 |
化学工业 | 14篇 |
金属工艺 | 1篇 |
机械仪表 | 5篇 |
建筑科学 | 90篇 |
矿业工程 | 27篇 |
能源动力 | 26篇 |
轻工业 | 37篇 |
水利工程 | 12篇 |
石油天然气 | 19篇 |
武器工业 | 1篇 |
无线电 | 6篇 |
一般工业技术 | 36篇 |
冶金工业 | 147篇 |
原子能技术 | 8篇 |
自动化技术 | 36篇 |
出版年
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 15篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 10篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 44篇 |
2012年 | 8篇 |
2011年 | 23篇 |
2010年 | 32篇 |
2009年 | 17篇 |
2008年 | 24篇 |
2007年 | 21篇 |
2006年 | 32篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 12篇 |
2001年 | 8篇 |
2000年 | 8篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 11篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 8篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1972年 | 7篇 |
1971年 | 11篇 |
1970年 | 9篇 |
1969年 | 2篇 |
1968年 | 4篇 |
排序方式: 共有497条查询结果,搜索用时 140 毫秒
11.
Susan L. Bradbury 《International Planning Studies》2016,21(1):64-80
Creating a continental transportation system that supports the efficient movement of goods between Canada and the United States is essential to the economies of both countries. However, 25 years after the passage of the Canada–US Free Trade Act and many agreements and accords later, poor connectivity, congestion and delays still plague many transborder corridors. Recent attempts to improve this situation involving several proposed new bridge projects have either been halted or significantly delayed over the last decade. This paper will review and critically examine the bi-national planning process that has been followed in an attempt to build a new bridge across the Detroit River, known as the Detroit River International Crossing (DRIC) project. 相似文献
12.
Roberta L Bondar 《Architectural Design》2015,85(4):98-99
‘By 2050 we will have probed the universe even further, peeling back time as we strive for some sense of creation and meaning.’ The world's first neurologist in space, Roberta L Bondar , who conducted international experiments on space mission STS 42 and has subsequently undertaken neurological research with NASA, urges us to look up and into space, which is set to remain a rich area of exploration, scientific investigation and wonder, with the discovery of new planets, light, patterns and materials on the not-so-distant horizon. 相似文献
13.
世界未来石油工业的过渡化发展方向--以加拿大油砂石油生产和煤层气开发利用为例 总被引:2,自引:2,他引:2
加拿大是一个石油天然气净出口国.是美国最重要的能源进口国之一。随着西部省区油田的成熟化,加拿大自1999年实施开发油砂和海域石油资源项目后,石油产量开始增长。业内人士分析预测,加拿大油砂石油的产量在不久将会有更显著的提高,并可以补偿上其常规原油递减的产量。加拿大油砂石油生产和煤层气开发所取得的成功.很可能是今后世界石油工业的过渡发展方向。 相似文献
14.
I. C. Goulter 《Civil Engineering and Environmental Systems》2013,30(1):50-54
The systems theory component in the undergraduate and graduate programs in civil engineering at the University of Manitoba is reviewed. Proposals for increasing the systems theory content in the undergraduate program arediscussed. The primary element in the proposals is the 'lowering' of the basic civil engineering systems course currently in the graduate program, into the undergraduate program. It is anticipated that this course will first be introduced as a technical elective in the fourth year of the program. The long range plan is to place this course in the second year of the program. The implications of this approach for the graduate and undergraduate programs are analysed. 相似文献
15.
16.
Estimation of the costs of acute gastrointestinal illness in British Columbia, Canada 总被引:1,自引:0,他引:1
Henson SJ Majowicz SE Masakure O Sockett PN MacDougall L Edge VL Thomas MK Fyfe M Kovacs SJ Jones AQ 《International journal of food microbiology》2008,127(1-2):43-52
The costs associated with gastrointestinal infection (GI) in the province of British Columbia, Canada, were estimated using data from a population-based survey in three health service delivery areas, namely Vancouver, East Kootenay and Northern Interior. The number of cases of disease, consequent expenditure of resources and associated economic costs were modeled as probability distributions in a stochastic model. Using 2004 prices, the estimated mean annual cost per capita of gastrointestinal infection was CAN$128.61 (euro207.96), with a mean annual cost per case of CAN$1,342.57 (euro2,170.99). The mean estimate of the overall economic burden to British Columbia was CAN$514.2 million (euro831.5 million) (95% CFI CAN$161.0 million to CAN$5.8 billion; euro260.3 million to euro9.38 billion). The major element of this cost was the loss of productivity associated with time away from paid employment by both the sick and their caregivers. Sensitivity analysis suggested that the uncertainty associated with the base model assumptions did not significantly affect the estimates. The results are comparable to those obtained in an earlier study using a similar analytical framework and data from the city of Hamilton, Ontario, Canada. 相似文献
17.
Luo Minghai 《工程勘察》2008,(5)
基础地图系统是一种地籍管理信息系统,通过基础地图信息的生产、维护和管理,提供地产注册、权属查询、地址查询、税收评估等基于宗地的地理空间分析。本文介绍了卡尔加里基础地图系统的主要内容,包括法律测量模块LSF、地籍边界模块OPF、道路数据库Roadnet和航测数据库DAS,分析了其管理方法,包括数据管理、数据更新、数据维护和数据分发。 相似文献
18.
对加拿大公众参与的理论基础、价值理念、发展历程和主要技术手段进行了总结.接着,以新斯科舍省“志愿规划”和哈利法克斯地区“社区远景规划”为例,分析了加拿大公众参与规划的典型模式.最后,针对我国公众参与规划现状,提出了加拿大公众参与理论和实践对我国的启示与借鉴. 相似文献
19.
矿床模型表现为矿床的描述性特征和依据地质作用对这些特征所作的解释两部分,前者用作选区准则,后者则反映了选区准则和金属成矿之间的成因联系。模型的建立和使用直接影响矿产的勘查,加拿大金矿勘探的历史即为典型实例。 相似文献
20.
Canadians' support for the underlying values and structures of medicare still remains extremely high, according to all recent public opinion studies. However, their confidence is being tested by the persistent advocacy that increased private-for-profit payment and delivery be introduced in order to guarantee medicare's future sustainability. Patience is further being challenged as the public eagerly awaits (but does not yet sees) productive reforms actually being implemented into the system. Delay erodes public support. Alternative "solutions" gain currency. Thus, the public-private debate must be engaged fully and emerge from the shadows of public policy so that Canadians can determine its efficacy and its compatibility with our society's values. Therefore, the long overdue reforms also need to be advanced. One of the most urgent reforms to medicare should address mental health needs and concerns, which I have described as being "an orphan of medicare." An essential first step would be to construct a basic platform of care and research on issues of mental health. This platform would provide necessary, immediate services for those in need and, at another level, would provide the impetus for further solutions to the wide-ranging needs in this field. Overall, the snail's pace of reforms has caused many Canadians to speculate that the future of medicare is at the crossroads on mental health policies and other issues, like accountability, quality, adequate reporting and health outcomes. The time to act is now. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献