全文获取类型
收费全文 | 1171篇 |
免费 | 92篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 16篇 |
化学工业 | 343篇 |
金属工艺 | 23篇 |
机械仪表 | 39篇 |
建筑科学 | 28篇 |
矿业工程 | 1篇 |
能源动力 | 61篇 |
轻工业 | 138篇 |
水利工程 | 8篇 |
石油天然气 | 3篇 |
无线电 | 93篇 |
一般工业技术 | 225篇 |
冶金工业 | 38篇 |
原子能技术 | 4篇 |
自动化技术 | 245篇 |
出版年
2024年 | 1篇 |
2023年 | 18篇 |
2022年 | 78篇 |
2021年 | 77篇 |
2020年 | 36篇 |
2019年 | 64篇 |
2018年 | 52篇 |
2017年 | 54篇 |
2016年 | 59篇 |
2015年 | 48篇 |
2014年 | 43篇 |
2013年 | 76篇 |
2012年 | 92篇 |
2011年 | 101篇 |
2010年 | 75篇 |
2009年 | 73篇 |
2008年 | 61篇 |
2007年 | 66篇 |
2006年 | 25篇 |
2005年 | 27篇 |
2004年 | 27篇 |
2003年 | 13篇 |
2002年 | 13篇 |
2001年 | 10篇 |
2000年 | 3篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有1265条查询结果,搜索用时 12 毫秒
101.
102.
Vasco Furtado Leonardo Ayres Eurico Vasconcelos Johnatas D’Orleans 《Information Sciences》2010,180(1):4-70
Collaboration is on the rise, primordially leveraged by the Web 2.0 in which the difference between information producer and consumer decreases significantly. In this paper we describe WikiCrimes, an example of a Web 2.0 application that offers a collaborative environment based on the use and direct manipulation of maps, in order to register and research criminal events. WikiCrimes is driven by three goals: (i) to give more transparency and publicity to criminal information, (ii) to provide means for citizen prevention, and (iii) to reduce the phenomenon of under-reporting (crimes that are not notified to authorities). In the paper we pay particular attention to the fact that in this context, finding the equilibrium between people’s participation and information credibility is crucial. Anonymous mass collaboration is the easiest way to receive information; however, the credibility of the received information is depreciated, because the source of information is unknown. We particularly concentrate on the ways we have created to keep the “participation vs. reliability of information” trade-off at good level. The reputation model is the main component created with this purpose. The experiences and the obstacles we are facing in the implementation of the project are the subjects of discussion and analyses. 相似文献
103.
We derive a simple analytical correction of a well-known standard formulation of the gravity wave height produced in a prismatic channel due to a sudden discharge stoppage at the downstream end of the channel. The proposed analytical correction considers the vertical growth of the wave and, as a result, takes into account the effect of the channel bed slope on the wave height. This simple correction is useful to be considered in preliminary designs of relatively long channels subject to unsteady flow conditions. 相似文献
104.
The aim of this paper is to obtain an explicit expression, instead of using a recursive method, for the nth term coefficient of the generalized Baker–Campbell–Hausdorff–Dynkin (gBCHD) formula. The gBCHD formula has been applied to control theory, specially to nonholonomic motion planning. 相似文献
105.
A number of techniques that infer finite state automata from execution traces have been used to support test and analysis activities. Some of these techniques can produce automata that integrate information about the data-flow, that is, they also represent how data values affect the operations executed by programs.The integration of information about operation sequences and data values into a unique model is indeed conceptually useful to accurately represent the behavior of a program. However, it is still unclear whether handling heterogeneous types of information, such as operation sequences and data values, necessarily produces higher quality models or not.In this paper, we present an empirical comparative study between techniques that infer simple automata and techniques that infer automata extended with information about data-flow. We investigate the effectiveness of these techniques when applied to traces with different levels of sparseness, produced by different software systems. To the best of our knowledge this is the first work that quantifies both the effect of adding data-flow information within automata and the effectiveness of the techniques when varying sparseness of traces. 相似文献
106.
Dias Menezes Leonardo de Araújo Luciano Vieira Nishijima Marislei 《International Journal of Information Security》2023,22(4):869-880
International Journal of Information Security - This paper proposes a blockchain solution for some activities currently performed by notary offices under the Civil Law judiciary that is technically... 相似文献
107.
Rosamaria W.C. Leonardo Jonas Yoshio Lilian R.F. 《Sensors and actuators. B, Chemical》2008,131(2):646-651
A novel poly(p-xylylene), PPX, derivative bearing alkoxyphenyl side groups was electrochemically synthesized in 87% yield. The polymer, poly(4′-hexyloxy-2,5-biphenyleneethylene) (PHBPE), presented a fraction (92%) soluble in common organic solvents. It showed to be thermally resistant up to 185 °C. UV–vis analysis revealed an Egap of 3.5 eV. Gas sensors made from thin films of 10-camphorsulfonic acid-doped PHBPE deposited on interdigitated electrodes exhibited significant changes in electrical conductance upon exposure to five VHOCs: 1,2-dichloroethane, bromochloromethane, trichloromethane, dichloromethane and tetrachloromethane. The conductance decreased after exposure to tetrachloromethane and increased after exposure to all the other VHOCs. Three-dimensional plots of relative response versus time of half response versus time of half recovery showed good discrimination between the five VHOCs tested. 相似文献
108.
This paper describes a state space representation for sequencing and routing flexibility in manufacturing systems. Routing flexibility is represented using five different stages as follows: (i) Precedence Graph of Operations; (ii) State Transition Graph of Manufacturing Operation Sequences; (iii) State Transition Graph of Manufacturing Operation Routes; (iv) Disjunctive Normal Form (DNF) Representation of Manufacturing Sequences; and (v) DNF Representation of Manufacturing Routes. Each representation is able to represent sequencing and routing flexibility at different levels of detail. The third representation is capable of enumerating all possible manufacturing operation routes that can be applied to a certain part, being the most complete representation. Bounds for computation of some of the representations are presented to help users select the most suitable for a specific problem context. The efficacy of the representation is demonstrated through its application to problems such as job route selection and routing flexibility measure. 相似文献
109.
The Journal of Supercomputing - The design and tuning of parallel programs is known to be a hard and error-prone process. Structured parallel programming helps overcoming part of the related... 相似文献
110.
João Gustavo PrudêncioAuthor Vitae Leonardo MurtaAuthor Vitae 《Journal of Systems and Software》2012,85(2):277-289
Mechanisms to control concurrent access over project artefacts are needed to execute the software development process in an organized way. These mechanisms are implemented by concurrency control policies in version control systems that may inhibit (i.e. ‘to lock’) or allow (i.e., ‘not to lock’) parallel development. This work presents a novel approach named Orion that analyzes the project's historical changes and suggests the most appropriate concurrency control policy for each software element. This suggestion aims at minimizing conflict situations and thus improving the productivity of the development team. In addition, it identifies critical elements that do not work well with any of these policies and are candidates to refactoring. We evaluated Orion through two experimental studies and the results, which indicated it was effective, led us to a prototype implementation. Apart from the Orion approach this paper also presents the planning, execution, and analysis stages of the evaluation, and details of prototype internals. 相似文献