全文获取类型
收费全文 | 5409篇 |
免费 | 537篇 |
国内免费 | 168篇 |
专业分类
电工技术 | 1520篇 |
综合类 | 443篇 |
化学工业 | 277篇 |
金属工艺 | 121篇 |
机械仪表 | 779篇 |
建筑科学 | 354篇 |
矿业工程 | 126篇 |
能源动力 | 249篇 |
轻工业 | 108篇 |
水利工程 | 182篇 |
石油天然气 | 190篇 |
武器工业 | 91篇 |
无线电 | 381篇 |
一般工业技术 | 407篇 |
冶金工业 | 154篇 |
原子能技术 | 89篇 |
自动化技术 | 643篇 |
出版年
2024年 | 21篇 |
2023年 | 59篇 |
2022年 | 86篇 |
2021年 | 134篇 |
2020年 | 140篇 |
2019年 | 107篇 |
2018年 | 84篇 |
2017年 | 114篇 |
2016年 | 167篇 |
2015年 | 163篇 |
2014年 | 360篇 |
2013年 | 264篇 |
2012年 | 413篇 |
2011年 | 441篇 |
2010年 | 339篇 |
2009年 | 326篇 |
2008年 | 270篇 |
2007年 | 389篇 |
2006年 | 354篇 |
2005年 | 329篇 |
2004年 | 312篇 |
2003年 | 283篇 |
2002年 | 201篇 |
2001年 | 160篇 |
2000年 | 138篇 |
1999年 | 73篇 |
1998年 | 72篇 |
1997年 | 56篇 |
1996年 | 54篇 |
1995年 | 55篇 |
1994年 | 34篇 |
1993年 | 34篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 4篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1959年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有6114条查询结果,搜索用时 15 毫秒
11.
Anne Mahoney 《Computers and the Humanities》2003,37(4):469-473
This paper describes an encoding for representing quantitativemetrical analyses in TEI SGML or XML documents, using only charactersfrom the standard keyboard set, and a system for converting thisencoding to other forms for display. 相似文献
12.
13.
Experimental and computational analysis on guide vane losses of impulse turbine for wave energy conversion 总被引:1,自引:0,他引:1
This paper deals with the detailed flow analysis of impulse turbine with experimental and computed results for wave energy power conversion. Initially, several turbulence models have been used in two-dimensional (2-D) computational fluid dynamic (CFD) analysis to find a suitable model for this kind of slow speed unconventional turbine. Experiments have been conducted to validate the CFD results and also to analyze the aerodynamics at various stations of the turbine. The three-dimensional (3-D) CFD model with tip clearance has been generated to predict the internal flow and to understand the effect of tip clearance leakage flow on behavior of the turbine in design and off-design conditions. As a result, it is found from the 2-D results that the comparison between computed and experimental data is good, qualitatively and the turbulence model, standard k–ε can predict the experimental values reasonably well, especially the efficiency of the turbine. Experimental results reveal that the downstream guide vanes are more responsible for low efficiency of the turbine and it is measured that 21% average pressure is lost due to downstream guide vanes. It is proved from the 3-D CFD model with tip clearance that it can predict the experimental values quantitatively and qualitatively. Furthermore, it is estimated from the computed results that the efficiency of the turbine has been reduced about 4%, due to tip clearance leakage flow at higher flow coefficients. 相似文献
14.
The teaching of literature through CAI raises problems of both a linguistic and instructional nature; student involvement and creativity in studying literature, and especially poetry, is difficult to build into a computer-based lesson. We have confronted these difficulties in the lessonPoetry I, which introduces undergraduates to basic concepts of poetic verse in a design using screen display, speech synthesis, and verse processing to maximize interactivity and student involvement.The lesson contains instructional modules which include the student's composition of a limerick. Computational processing of the limerick's text enables the program to offer guidance as the student composes and revises the verse and gains first-hand experience with metrical language. The significant problems inherent in processing verse are addressed by adapting Digital Equipment Corporation's DECTalk speech synthesizer as an engine converting natural language verse text into accessible strings of phonemic symbols. Although the verse processor cannot scan verse, it can interpret DECTalk's symbols reliably enough to successfully stimulate students' thinking about their verse compositions.Preliminary responses to the program have been favorable and demonstrate its effectiveness in involving students more deeply in learning about poetic verse. This suggests that the techniques of verse processing prototyped inPoetry I might be usefully extended to other types of verse and levels of study.W. Webster Newbold is an Assistant Professor of English at Ball State University, Muncie, Indiana, USA, who has recently served as English Department Computer Coordinator. His research interests include computer-assisted instruction and computer-based composition.Herbert F. W Stahlke is a Professor of English, specializing in linguistics, and currently serves as Associate Director for Academic Computing, Ball State University Computing Services. His research interests include computer-assisted instruction, natural language processing, and lexical databases. 相似文献
15.
Computational Fluid Dynamics (CFD) simulation is one of the important methods to study the performance and in-fluencing factors of turbine flow sensors. According to the working characteristics of the turbine flow sensor, the passive simulation method based on the six degrees of freedom (6-DOF) model and dynamic mesh is proposed in this paper. The reliability of the simulation method is verified by steady-state experiments and unsteady-state experiments. The results show that the trend of meter factor with flow rate acquired from the simulation is close to the experimental results, and the deviation between the simulation result and the experiment result is low with a maximum deviation of 2.88%. In the unsteady simulation study, the impeller speed changes with the inlet velocity of the turbine flow sensor, which has a good follow-up. The passive simulation method can be used to predict the dynamic performance of the turbine flow sensor. 相似文献
16.
17.
介绍一种以ARM为核心控制处理器的三相智能电表的软、硬件设计。电表集电量参数监测计量与显示为一体,其中电量参数计量设计实现采用专用的测量芯片CS5463。结果表明,所设计电表具有集成度高、功能强、成本低、抗干扰能力强、功耗低等优点,能够满足电能智能化管理的要求。电表通过MAX485芯片与主控制器通信,完成数据远传,最终实现电量数据采集与实时监测等功能,具有很好的应用前景。 相似文献
18.
20.
介绍德国E+H公司Promass流量计的结构和工作原理,该流量计以Coriolis力为基础,对流体的质量流量和密度进行测量,从而避免了般体积流量计测量结果受温度影响较大的缺点,分析了Pomass流量计用于重油测量时的影响因素及防范措施。 相似文献