全文获取类型
收费全文 | 338篇 |
免费 | 4篇 |
专业分类
电工技术 | 56篇 |
化学工业 | 34篇 |
金属工艺 | 6篇 |
机械仪表 | 2篇 |
建筑科学 | 5篇 |
矿业工程 | 4篇 |
能源动力 | 7篇 |
轻工业 | 19篇 |
水利工程 | 1篇 |
无线电 | 23篇 |
一般工业技术 | 43篇 |
冶金工业 | 76篇 |
自动化技术 | 66篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 43篇 |
2012年 | 21篇 |
2011年 | 23篇 |
2010年 | 28篇 |
2009年 | 25篇 |
2008年 | 21篇 |
2007年 | 16篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有342条查询结果,搜索用时 0 毫秒
1.
2.
Temperature control offers benefits in land‐based marine aquaculture: stock growth rates may be enhanced by heating in winter; mortality rates in summer may be reduced by cooling. However, if the plant is not well designed, temperature control may create very large energy demands. This paper describes the application of temperature control in abalone aquaculture in New Zealand, with a focus on energy considerations in plant design. An abalone farm using a semi‐closed water conditioning system is used as a case study for which an energy model, based on a heat pump system, is developed. The model is used to determine the impact of plant design and tank conditions on the economics of the operation. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
3.
4.
5.
Kim Khoa Nguyen Mohamed Cheriet Mathieu Lemay Victor Reijs Andrew Mackarel Alin Pastrama 《Computer Networks》2012,56(10):2538-2550
Cloud computing services have recently become a ubiquitous service delivery model, covering a wide range of applications from personal file sharing to being an enterprise data warehouse. Building green data center networks providing cloud computing services is an emerging trend in the Information and Communication Technology (ICT) industry, because of Global Warming and the potential GHG emissions resulting from cloud services. As one of the first worldwide initiatives provisioning ICT services entirely based on renewable energy such as solar, wind and hydroelectricity across Canada and around the world, the GreenStar Network (GSN) was developed to dynamically transport user services to be processed in data centers built in proximity to green energy sources, reducing Greenhouse Gas (GHG) emissions of ICT equipments. Regarding the current approach, which focuses mainly in reducing energy consumption at the micro-level through energy efficiency improvements, the overall energy consumption will eventually increase due to the growing demand from new services and users, resulting in an increase in GHG emissions. Based on the cooperation between Mantychore FP7 and the GSN, our approach is, therefore, much broader and more appropriate because it focuses on GHG emission reductions at the macro-level. This article presents some outcomes of our implementation of such a network model, which spans multiple green nodes in Canada, Europe and the USA. The network provides cloud computing services based on dynamic provision of network slices through relocation of virtual data centers. 相似文献
6.
The direct conversion of methane to higher hydrocarbons over a silica-supported Ru catalyst has been investigated via an oxygen free, two-step route. The reaction consists of decomposition of methane over a 3% silica-supp orted Ru catalyst at temperatures
between 400 and 800 K to produce surface carbonaceous species followed by rehydrogenation of these species to higher hydrocarbons at
of 368 K. It was found that the Ru/SiO2 catalyst exhibits a trend similar to that for single-crystal Ru catalysts. However, the temperature at which a maximum in ethane selectivity occurs shifts toward a higher temperature. It was also found that the ethane yield can be optimized by changing the surface carbon coverage. Under optimum conditions a net ethane yield of about 13–15% has been realized. For this two-step reaction sequence, only a few reaction cycles could be operated without intermediate high temperature rehydrogenation and without significant loss in ethane yield. This is attributed to large amounts of inactive carbon that could not be hydrogenated at 368 K. Higher methane partial pressures were found to be desirable for this reaction. The activity of the catalyst could also be maintained at total pressures up to 10 atm. 相似文献
7.
8.
9.
10.
Software organizations can significantly improve the quality of their output if they have a defined and documented software process, together with the appropriate techniques and tools to measure its effectiveness. Without a defined process it is impossible to measure success or focus on how development capability can be enhanced. To date, a number of software process improvement frameworks have been developed and implemented. However, most of these models have been targeted at large-scale producers. Furthermore, they have applied to companies who use traditional development techniques. Smaller companies and those operating in development areas where speed of delivery is paramount have not, as yet, had process improvement paradigms available for adoption.This study examined the software process in a small company and emerged with the recommendation of the use of the Dynamic Systems Development Method (DSDM) and the Personal Software Process (PSP) for achieving software process improvement. 相似文献