全文获取类型
收费全文 | 8571篇 |
免费 | 218篇 |
国内免费 | 69篇 |
专业分类
电工技术 | 88篇 |
技术理论 | 2篇 |
综合类 | 936篇 |
化学工业 | 320篇 |
金属工艺 | 80篇 |
机械仪表 | 167篇 |
建筑科学 | 2988篇 |
矿业工程 | 240篇 |
能源动力 | 96篇 |
轻工业 | 94篇 |
水利工程 | 399篇 |
石油天然气 | 222篇 |
武器工业 | 5篇 |
无线电 | 265篇 |
一般工业技术 | 240篇 |
冶金工业 | 1559篇 |
原子能技术 | 22篇 |
自动化技术 | 1135篇 |
出版年
2024年 | 9篇 |
2023年 | 58篇 |
2022年 | 96篇 |
2021年 | 98篇 |
2020年 | 94篇 |
2019年 | 76篇 |
2018年 | 80篇 |
2017年 | 71篇 |
2016年 | 140篇 |
2015年 | 155篇 |
2014年 | 475篇 |
2013年 | 533篇 |
2012年 | 525篇 |
2011年 | 741篇 |
2010年 | 626篇 |
2009年 | 577篇 |
2008年 | 510篇 |
2007年 | 584篇 |
2006年 | 462篇 |
2005年 | 450篇 |
2004年 | 411篇 |
2003年 | 402篇 |
2002年 | 347篇 |
2001年 | 202篇 |
2000年 | 187篇 |
1999年 | 246篇 |
1998年 | 156篇 |
1997年 | 102篇 |
1996年 | 79篇 |
1995年 | 63篇 |
1994年 | 55篇 |
1993年 | 30篇 |
1992年 | 15篇 |
1991年 | 7篇 |
1990年 | 18篇 |
1989年 | 16篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 40篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 32篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有8858条查询结果,搜索用时 15 毫秒
41.
This study is concerned with the assessment of risk for major construction activities. Risk has been defined as a measure of the probability, the severity, and the exposure of all hazards of an activity. A risk assessor model (RAM) was developed and computerized to determine the risk associated with a particular activity and the justification factor for a proposed remedy. Knowing the value of risk would help contractors identify the high risk of major construction activities and would enable them to allocate safety precautions in a more efficient manner. 相似文献
42.
This paper discusses the need for interface management within construction, with particular reference to building facade interfaces. It categorizes the three different types of interface management—physical, contractual, and organizational. The implication of interface management in construction contracting is discussed; it is explained how the U.K. procurement trends have changed, affecting the interface management within projects. U.K. cladding procurement is very fragmented, and the paper maps the development of a typical cladding system showing the complexities of interface management. Finally, the paper discusses CladdISS, a U.K. government funded research project to develop a standardized strategy for the design and management of window and cladding interfaces. It explains the principles of CladdISS with reference to process maps, action plans, management strategy, bibliography, advice on standards, materials, maintenance, joints, movement, and tolerances. This will enable strategies to be developed to avoid the endemic interface problems occurring on-site. It will also guide the management of the interfaces throughout the project. 相似文献
43.
Various ways of quantifying damages have been applied to productivity loss claims in construction. All of the ways attempt to be as objective as possible based on the extent of information available in a particular case. The measured mile, a widely accepted method, is employed when an unimpacted baseline period of production can be identified. Although that approach is considered to be the most objective method available in such cases, the method is limited and does not directly account for variation in individual productivity values about a normal or natural level of productivity. A gap exists between the use of existing methods and the availability of an appropriate methodology that specifically addresses variation in productivity. The key lies in the way baseline productivity is measured, which is inherently statistical, yet no truly statistical methods are used to establish such a baseline. Using the measured mile as a backdrop, this article provides an objective, measurement-based approach that can be used to establish a productivity baseline applied to construction productivity loss claims, based on the application of statistical methods aided by a process control chart. The focus is on providing the basic principles and concepts underlying the approach presented. 相似文献
44.
45.
扣件式钢管脚手架应用代表着建筑工业化的一个重要发展方向 ,如何安全、规范地使用扣件式钢管脚手架将是我们标准化施工的新课题 相似文献
46.
We investigated the factors that facilitated the fast adoption and utilization of Technology-Mediated Distance Education (TMDE) among higher education institutions. Our analysis was based on a rich data set on the utilization of TMDE between the 1997–1998 and 2000–2001 academic years. The analysis showed that size, public/private status, and location significantly predicted its actual adoption. Being in an urban location negatively affected enrollment in the courses at the undergraduate but not at the graduate level. While the intent to adopt TMDE correlated significantly with actual adoption, many schools that were not interested in TMDE in 1997–1998 adopted it by 2000–2001. Interestingly, late adopters utilized certain technologies as frequently as early adopters, such as synchronous Internet-based instruction and the use of CD-ROMs. 相似文献
47.
Potential applications of knowledge based expert systems in the area of construction project monitoring and control are described. Originally developed from research in artificial intelligence, these systems are computer programs that can undertake intelligent tasks currently performed by highly skilled people. While some project monitoring can be accomplished by algorithmic procedures, the capability of knowledge based expert systems to deal with illstructured problems and to be extensively modified over time make them desirable for application in this area. Sample applications and heuristic rules in scheduling and inventory control are provided. 相似文献
48.
山西水资源可持续利用的对策与措施 总被引:1,自引:0,他引:1
本文从切实认清山西水资源的现状入手指出,建立水务一体化运作机制,是山西水资源可持续利用的现实需求,发挥水利职教功能,提高行业职工素质,是其技术支撑,建立健全水利建设机制,是其重要保证。 相似文献
49.
介绍了长江江新洲堤段应用软体排护岸新型技术的情况,结合长江江新洲护岸工程对软体排施工、工艺、设备作简要叙述。 相似文献
50.
一氧化碳对聚丙烯收率、结构的影响 总被引:1,自引:0,他引:1
胡蔚鸽 《石油化工安全环保技术》2002,18(4):32-33
分析研究了Montell(Himont)聚丙烯工艺中CO对聚丙烯收率、产品结构的影响。 相似文献