全文获取类型
收费全文 | 2645篇 |
免费 | 195篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 2841篇 |
出版年
2023年 | 24篇 |
2022年 | 22篇 |
2021年 | 181篇 |
2020年 | 90篇 |
2019年 | 84篇 |
2018年 | 109篇 |
2017年 | 84篇 |
2016年 | 135篇 |
2015年 | 90篇 |
2014年 | 118篇 |
2013年 | 202篇 |
2012年 | 168篇 |
2011年 | 218篇 |
2010年 | 152篇 |
2009年 | 179篇 |
2008年 | 125篇 |
2007年 | 129篇 |
2006年 | 108篇 |
2005年 | 88篇 |
2004年 | 65篇 |
2003年 | 57篇 |
2002年 | 59篇 |
2001年 | 35篇 |
2000年 | 28篇 |
1999年 | 23篇 |
1998年 | 31篇 |
1997年 | 24篇 |
1996年 | 30篇 |
1995年 | 16篇 |
1994年 | 27篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 5篇 |
1990年 | 17篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 11篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1965年 | 2篇 |
1909年 | 2篇 |
排序方式: 共有2841条查询结果,搜索用时 31 毫秒
61.
Giuseppe Antonio Elia Krystan Marquardt Katrin Hoeppner Sebastien Fantini Rongying Lin Etienne Knipping Willi Peters Jean‐Francois Drillet Stefano Passerini Robert Hahn 《Advanced materials (Deerfield Beach, Fla.)》2016,28(35):7564-7579
A critical overview of the latest developments in the aluminum battery technologies is reported. The substitution of lithium with alternative metal anodes characterized by lower cost and higher abundance is nowadays one of the most widely explored paths to reduce the cost of electrochemical storage systems and enable long‐term sustainability. Aluminum based secondary batteries could be a viable alternative to the present Li‐ion technology because of their high volumetric capacity (8040 mAh cm?3 for Al vs 2046 mAh cm?3 for Li). Additionally, the low cost aluminum makes these batteries appealing for large‐scale electrical energy storage. Here, we describe the evolution of the various aluminum systems, starting from those based on aqueous electrolytes to, in more details, those based on non‐aqueous electrolytes. Particular attention has been dedicated to the latest development of electrolytic media characterized by low reactivity towards other cell components. The attention is then focused on electrode materials enabling the reversible aluminum intercalation‐deintercalation process. Finally, we touch on the topic of high‐capacity aluminum‐sulfur batteries, attempting to forecast their chances to reach the status of practical energy storage systems. 相似文献
62.
Giordano Maria C. Longhi Stefano Barelli Matteo Mazzanti Andrea Buatier de Mongeot Francesco Della Valle Giuseppe 《Nano Research》2018,11(7):3943-3956
Nano Research - The engineering of self-organized plasmonic metasurfaces is demonstrated using a maskless technique with defocused ion-beam sputtering and kinetically controlled deposition. The... 相似文献
63.
A case situation arising in a normal interaction among people is the baseline for discussing properties of the theory of viewpoints. In particular we consider how to ensure agreement on the meaning of certain utterances by agents who have different perspectives on the situation, while maintaning other knowledge as private. We argue that communication should be modeled as adding facts to the common knowledge of agents. We introduce the principle of 'referent sharing' in communications and argue that common knowledge resulting from communication should only use constants whose referent is manifest to the parties involved. 相似文献
64.
65.
Giuseppe DeToffol Francesco Ancilotto Flavio Toigo 《Journal of Low Temperature Physics》1996,102(5-6):381-410
Calculations are presented, based on a Density Functional approach, of the first excited states (l=1) of alkali metal atoms (Cs and Na) in liquid
4He. We find large departures from the spherical bubble in the liquid4He structure when the alkali atom is excited. The shifts from the free atom values of the excitation and emission transition lines are calculated and compared with the experimental results. According to our calculations, the so far unseen radiative deexcitation transition for light alkalis in4He may lie in an unexplored infrared region of the spectrum. 相似文献
66.
Intensional query answering by partial evaluation 总被引:1,自引:0,他引:1
Giuseppe de Giacomo 《Journal of Intelligent Information Systems》1996,7(3):205-233
67.
Giuseppe Ascia Vincenzo Catania Alessandro G. Di Nuovo Maurizio Palesi Davide Patti 《Applied Soft Computing》2011,11(1):382-398
Multi-objective evolutionary algorithms (MOEAs) have received increasing interest in industry because they have proved to be powerful optimizers. Despite the great success achieved, however, MOEAs have also encountered many challenges in real-world applications. One of the main difficulties in applying MOEAs is the large number of fitness evaluations (objective calculations) that are often needed before an acceptable solution can be found. There are, in fact, several industrial situations in which fitness evaluations are computationally expensive and the time available is very short. In these applications efficient strategies to approximate the fitness function have to be adopted, looking for a trade-off between optimization performance and efficiency. This is the case in designing a complex embedded system, where it is necessary to define an optimal architecture in relation to certain performance indexes while respecting strict time-to-market constraints. This activity, known as design space exploration (DSE), is still a great challenge for the EDA (electronic design automation) community. One of the most important bottlenecks in the overall design flow of an embedded system is due to simulation. Simulation occurs at every phase of the design flow and is used to evaluate a system which is a candidate for implementation. In this paper we focus on system level design, proposing an extensive comparison of the state-of-the-art of MOEA approaches with an approach based on fuzzy approximation to speed up the evaluation of a candidate system configuration. The comparison is performed in a real case study: optimization of the performance and power dissipation of embedded architectures based on a Very Long Instruction Word (VLIW) microprocessor in a mobile multimedia application domain. The results of the comparison demonstrate that the fuzzy approach outperforms in terms of both performance and efficiency the state of the art in MOEA strategies applied to DSE of a parameterized embedded system. 相似文献
68.
Vincenza Carchiolo Michele Malgeri Giuseppe Mangioni Vincenzo Nicosia 《Journal of Parallel and Distributed Computing》2010
Nature is a great source of inspiration for scientists, because natural systems seem to be able to find the best way to solve a given problem by using simple and robust mechanisms. Studying complex natural systems, scientists usually find that simple local dynamics lead to sophisticated macroscopic structures and behaviour. It seems that some kind of local interaction rules naturally allow the system to auto-organize itself as an efficient and robust structure, which can easily solve different tasks. Examples of such complex systems are social networks, where a small set of basic interaction rules leads to a relatively robust and efficient communication structure. In this paper, we present PROSA, a semantic peer-to-peer (P2P) overlay network inspired by social dynamics. The way queries are forwarded and links among peers are established in PROSA resemble the way people ask other people for collaboration, help or information. Behaving as a social network of peers, PROSA naturally evolves to a small world, where all peers can be reached in a fast and efficient way. The underlying algorithm used for query forwarding, based only on local choices, is both reliable and effective: peers sharing similar resources are eventually connected with each other, allowing queries to be successfully answered in a really small amount of time. The resulting emergent structure can guarantee fast responses and good query recall. 相似文献
69.
Giuseppe Della Penna Daniele Magazzeni Sergio Orefice 《Journal of Visual Languages and Computing》2010,21(1):23-32
In this paper we present a graphical software system that provides an automatic support to the extraction of information from web pages. The underlying extraction technique exploits the visual appearance of the information in the document, and is driven by the spatial relations occurring among the elements in the page. However, the usual information extraction modalities based on the web page structure can be used in our framework, too. The technique has been integrated within the Spatial Relation Query (SRQ) tool. The tool is provided with a graphical front-end which allows one to define and manage a library of spatial relations, and to use a SQL-like language for composing queries driven by these relations and by further semantic and graphical attributes. 相似文献
70.