全文获取类型
收费全文 | 34945篇 |
免费 | 2580篇 |
国内免费 | 22篇 |
专业分类
电工技术 | 1596篇 |
综合类 | 412篇 |
化学工业 | 11992篇 |
金属工艺 | 530篇 |
机械仪表 | 682篇 |
建筑科学 | 1740篇 |
矿业工程 | 273篇 |
能源动力 | 596篇 |
轻工业 | 3087篇 |
水利工程 | 274篇 |
石油天然气 | 262篇 |
武器工业 | 1篇 |
无线电 | 1404篇 |
一般工业技术 | 5701篇 |
冶金工业 | 4383篇 |
原子能技术 | 185篇 |
自动化技术 | 4429篇 |
出版年
2023年 | 675篇 |
2022年 | 442篇 |
2021年 | 860篇 |
2020年 | 816篇 |
2019年 | 782篇 |
2018年 | 799篇 |
2017年 | 633篇 |
2016年 | 914篇 |
2015年 | 1004篇 |
2014年 | 1174篇 |
2013年 | 2467篇 |
2012年 | 1174篇 |
2011年 | 1260篇 |
2010年 | 1419篇 |
2009年 | 1551篇 |
2008年 | 1259篇 |
2007年 | 1243篇 |
2006年 | 957篇 |
2005年 | 981篇 |
2004年 | 775篇 |
2003年 | 771篇 |
2002年 | 617篇 |
2001年 | 443篇 |
2000年 | 368篇 |
1999年 | 402篇 |
1998年 | 509篇 |
1997年 | 442篇 |
1996年 | 502篇 |
1995年 | 521篇 |
1994年 | 428篇 |
1993年 | 524篇 |
1992年 | 424篇 |
1990年 | 392篇 |
1989年 | 458篇 |
1988年 | 341篇 |
1987年 | 379篇 |
1986年 | 395篇 |
1985年 | 434篇 |
1984年 | 425篇 |
1983年 | 404篇 |
1982年 | 374篇 |
1981年 | 417篇 |
1980年 | 338篇 |
1979年 | 358篇 |
1977年 | 326篇 |
1976年 | 299篇 |
1975年 | 380篇 |
1974年 | 353篇 |
1973年 | 498篇 |
1972年 | 324篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
In this paper, we present a thorough mathematical analysis of the use of neural networks to solve a specific classification
problem consisting of a bilinear boundary. The network under consideration is a three-layered perceptron with two hidden neurons
having the sigmoid serving as the activation function. The analysis of the hidden space created by the outputs of the hidden
neurons will provide results on the network’s capacity to isolate two classes of data in a bilinear fashion, and the importance
of the value of the sigmoid parameter is highlighted. We will obtain an explicit analytical function describing the boundary
generated by the network, thus providing information on the effect each parameter has on the network’s behavior. Generalizations
of the results are obtained with additional neurons, and a theorem concerned with analytical reproducibility of the boundary
function is established. 相似文献
143.
144.
Richard Baskerville 《欧洲信息系统杂志》2011,20(3):251-254
145.
146.
Some students (base group) played the Circuit Game, a 10-level computer-based learning activity intended to help students learn how electrical circuits work. Other students (competition group) played the same game but with competition features added - including a score bar showing performance on each level, the opportunity to earn one ticket per level if a performance criterion is met, and the opportunity to win a prize based on the number of tickets earned. On a retention test given after the game, the competition group remembered significantly more than the base group (d = 0.47). On an embedded transfer test constituting the final level of the game, the groups did not differ significantly. However, on the transfer test there was a significant gender by group interaction in which men performed worse in the competition group than the base group (d = −0.54) and women performed better in the competition group than the base group (d = 0.24). Overall, adding game-like features to a computer-based learning activity caused students to pay attention to game details but did not motivate students - particularly men - to learn more deeply. 相似文献
147.
Semiconductor wafer fabrication system (SWFS) is the most complex and capital-intensive phase in the entire semiconductor manufacturing cycle. With characteristics of re-entrant processing routes, equipment uncertainty, product diversity and improving technologies, great challenges are presented in SWFS’s modeling, scheduling and simulation. To implement efficient production control, this paper provides a timed extended object-oriented Petri nets (TEOPNs) approach to performance modeling, real-timed dispatching and simulation of SWFSs. The TEOPNs models are constructed in a hierarchy to accord with the real-world SWFS’s organization, and a new type of signal place is added into the TEOPNs to respond the dynamic states of all processing facilities. A novel autonomy and coordination-based real-time dispatching mechanism (A&C-RDM) is developed in this paper, which executes under the support of the TEOPNs-based hybrid real-time dispatching control system (HRDCS). Owning to the ability of gathering dynamic real-time information of all production facilities and WIP products, the HRDCS can make adaptive dispatching decisions according to the local and global real-time processing status. Two sets of key elements of real-time dispatching, i.e. the state thresholds and dispatching rules, are defined in the HRDCS so that the A&C-RDM can integrate different types of dispatching rules. A set of simulation experiments prove the efficiency of the proposed modeling and dispatching algorithm. In summary, the proposed TEOPNs, HRDCS and A&C-RDM form the cornerstones of a real-time dispatching simulation prototype of SWFS, and the work described in this paper carries out an advanced integrated “modeling–dispatching–simulation” methodology. 相似文献
148.
This paper introduces the concept of the temporal think tank™ (T3™), a temporary in-house research center, based on case studies with a highly automated global manufacturer and in various small-sized manufacture (SME's). The T3™ brings individuals from across the organization together in a team setting in which they are charged to look at the future, develop their decision-making skills, and use entrepreneurial thinking to incubate new processes and/or products. After an appropriate time in the temporal think tank™, the individuals are asked to return to their regular positions to implement the best practices and best ideas and doing so spur the organization forward. At intervals, the temporal think tanks™ can be reconvened, or reconstituted with new participants. This approach prepares technology champions for the SME, who can return to the organization with a fresh outlook and renewed energy to keep the enterprise at the peak of efficiency and effectiveness. 相似文献
149.
Prof. Dr. Jarke 《WIRTSCHAFTSINFORMATIK》2009,51(1):154-155
Ohne Zusammenfassung
This article is also available in English via http://www.springerlink.com and http://www.bise-journal.org: BISE – Call for
Papers, Issue 3/2010, High-Impact Requirements Engineering. Bus Inf Syst Eng. doi: . 相似文献
150.
Zusammenfassung Der Beitrag basiert auf der Annahme, dass das IT-Controlling in zweifacher Hinsicht unter einem Integrationsdefizit leidet.
Dies gilt zum einen für die unbefriedigende Synchronisation der Forschung mit Entwicklungen in der Praxis, zum anderen für
die unzureichende Verzahnung mit den Methoden der Wirtschaftsinformatik. Ausgehend von dieser Annahme untersucht der Beitrag
die historische Entwicklung des IT-Controllings, um daraus Thesen zum Integrationsstand abzuleiten. Die Untersuchung kommt
zu dem Ergebnis, dass Hinweise auf – nach wie vor – ungenutzte Integrationspotenziale vorliegen und identifiziert Potenziale
einer weiter gehenden Integration. Aus der Analyse identifizierter Integrationspotenziale werden Anforderungen an eine methodenbezogene
Integration abgeleitet und die Realisierung von Integrationspotenzialen an zwei Beispielen illustriert.
This article is also available in English via and : Strecker S, Kargl H (2009) Integration Deficits of IT Controlling – Historical Background, Analysis of Integration Potentials
and Method Integration. Bus Inf Syst Eng. doi: 10.1007/s12599-009-0053-4. 相似文献