全文获取类型
收费全文 | 879篇 |
免费 | 46篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 269篇 |
金属工艺 | 11篇 |
机械仪表 | 20篇 |
建筑科学 | 29篇 |
能源动力 | 35篇 |
轻工业 | 55篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 91篇 |
一般工业技术 | 146篇 |
冶金工业 | 44篇 |
原子能技术 | 9篇 |
自动化技术 | 206篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 19篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 25篇 |
2018年 | 27篇 |
2017年 | 34篇 |
2016年 | 37篇 |
2015年 | 26篇 |
2014年 | 52篇 |
2013年 | 70篇 |
2012年 | 50篇 |
2011年 | 100篇 |
2010年 | 63篇 |
2009年 | 44篇 |
2008年 | 48篇 |
2007年 | 57篇 |
2006年 | 38篇 |
2005年 | 38篇 |
2004年 | 30篇 |
2003年 | 22篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1985年 | 7篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有925条查询结果,搜索用时 15 毫秒
11.
Ba2(Zn0.5Ti0.5X)O6 compounds from the general ABO3 perovskite family were synthesized by the classical solid-state route for X = Nb and Ta with various A/B ratios (1.005, 1 and 0.995). After the calcination step at 1100 °C, both compounds (X = Nb and Ta) contain mainly the cubic disordered ‘Ba2(Zn0.5Ti0.5X)O6’ phase but traces of BaTiO3 and secondary phases are often detectable. Nevertheless, after the sintering stage at higher temperature (from 1300 to 1500 °C) and for all A/B ratios investigated, Ti enters into the cubic perovskite structure, resulting in the formation of a unique ‘Ba2(Zn0.5Ti0.5X)O6’ phase. Attractive dielectric properties have been measured on the tantalum-based compound for A/B = 0.995 (Q ∼2000 at 7.4 GHz and ? = 39.6) as well as on the niobium-based phase for A/B = 1.005 (Q ∼2200 at 6.1 GHz and ? = 54.8). All these characteristics were confirmed at 1 MHz and a linear dependence of the permittivity versus temperature from −60 to 180 °C has also been evidenced for both formulations. Sinterability, dielectric properties and microstructure of such compounds are discussed with respect to the stoichiometry. 相似文献
12.
This paper's object is to present the results of the GEAMAS project which aims at modeling and simulating natural complex systems. GEAMAS is a generic architecture of agents used to study the behavior emergence in such systems. It is a multiagent program meant to develop simulation applications. Modeling complex systems requires to reduce, to organize the system complexity and to describe suitable components. Complexity of the system can then be tackled with an agent-oriented approach, where interactions lead to a global behavior. This approach helps in understanding how non-determinist behavior can emerge from interactions between agents, which is near of self-organized criticality used to explain natural phenomena. In the Applied Artificial Intelligence context, this paper presents an agent software architecture using a model of agent. This architecture is composed of three abstract levels over which the complexity is distributed and reduced. The architecture is implemented in ReActalk, an open agent-oriented development tool, which was developed on top of Smalltalk-80. To illustrate our purpose and to validate the architecture, a simulation program to help in predicting volcanic eruptions was investigated. This program was run over a period of one year and has given many satisfying results unattainable up to there with more classical approaches. 相似文献
13.
The current schemes of quantification of x-ray microanalysis in the SEM [ZAF and σ(ρZ) methods] are valid for specimens of homogeneous composition. The determination of the chemical composition of small inclusions using these techniques is impossible because the volume of x-ray emission is not of homogeneous composition. A scheme of quantification to determine the composition of small inclusions embedded in a matrix has been developed using Monte Carlo simulations. This scheme is similar to that developed by Kyser and Murata (1974) for the quantification of thin foils deposited on a substrate using x-ray microanalysis in the SEM. 相似文献
14.
Sylvain Fleury Éric Jamet Achraf Ghorbel Aurélie Lemaitre Eric Anquetil 《Human-Computer Interaction》2013,28(2):103-121
The present study was designed to ascertain how far flagging up potential errors can improve the automatic interpretation of technical documents. We used the resources model to analyze the supervised retro-conversion of architectural floor plans from the perspective of distributed cognition. Results showed that automated assistance helps users to correct errors spotted by the system and saves time. Surprisingly, they also showed that flagging up possible errors may make users less effective in identifying and correcting errors that go unnoticed by the system. Responses to a questionnaire probing the participants’ confidence in the system suggested that they were so trusting that they lowered their vigilance in those areas that had not been signaled by the system, leading to the identification of fewer errors there. Thus, although the participants’ confidence in the automated assistance system led to improved performances in those areas it highlighted, it also meant that areas to which the system did not draw attention were less thoroughly checked. 相似文献
15.
Pressurized pipe networks used for fresh-water distribution can take advantage of recent advances in sensing technologies and data-interpretation to evaluate their performance. In this paper, a leak-detection and a sensor placement methodology are proposed based on leak-scenario falsification. The approach includes modeling and measurement uncertainties during the leak detection process. The performance of the methodology proposed is tested on a full-scale water distribution network using simulated data. Findings indicate that when monitoring the flow velocity for 14 pipes over the entire network (295 pipes) leaks are circumscribed within a few potential locations. The case-study shows that a good detectability is expected for leaks of 50 L/min or more. A study of measurement configurations shows that smaller leak levels could also be detected if additional pipes are instrumented. 相似文献
16.
17.
18.
19.
Sylvain Lamoine Mlissa Cumenal David A. Barriere Vanessa Pereira Mathilde Fereyrolles Laëtitia Prival Julie Barbier Ludivine Boudieu Emilie Brasset Benjamin Bertin Yoan Renaud Elisabeth Miot-Noirault Marie-Ange Civiale David Balayssac Youssef Aissouni Alain Eschalier Jrme Busserolles 《International journal of molecular sciences》2022,23(1)
20.
Fernández-Godino M. Giselle Dubreuil Sylvain Bartoli Nathalie Gogu Christian Balachandar S. Haftka Raphael T. 《Structural and Multidisciplinary Optimization》2019,60(6):2205-2220
Structural and Multidisciplinary Optimization - When simulations are very expensive and many are required, as for optimization or uncertainty quantification, a way to reduce cost is using... 相似文献