全文获取类型
收费全文 | 378篇 |
免费 | 0篇 |
专业分类
电工技术 | 6篇 |
综合类 | 3篇 |
化学工业 | 71篇 |
金属工艺 | 11篇 |
机械仪表 | 7篇 |
建筑科学 | 33篇 |
能源动力 | 10篇 |
轻工业 | 22篇 |
水利工程 | 10篇 |
武器工业 | 1篇 |
无线电 | 35篇 |
一般工业技术 | 69篇 |
冶金工业 | 29篇 |
原子能技术 | 2篇 |
自动化技术 | 69篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 4篇 |
2014年 | 12篇 |
2013年 | 23篇 |
2012年 | 32篇 |
2011年 | 31篇 |
2010年 | 27篇 |
2009年 | 18篇 |
2008年 | 37篇 |
2007年 | 35篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 7篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有378条查询结果,搜索用时 109 毫秒
41.
Ali Nour Bruno Massicotte Renaud De Montaignac Jean-Philippe Charron 《Cement and Concrete Research》2011,(9):964-974
This study is aimed at proposing a simple analytical model to investigate the post-cracking behaviour of FRC panels, using an arbitrary tension softening, stress crack opening diagram, as the input. A new relationship that links the crack opening to the panel deflection is proposed. Due to the stochastic nature of material properties, the random fibre distribution, and other uncertainties that are involved in concrete mix, this relationship is developed from the analysis of beams having the same thickness using the Monte Carlo simulation (MCS) technique. The softening diagrams obtained from direct tensile tests are used as the input for the calculation, in a deterministic way, of the mean load displacement response of round panels. A good agreement is found between the model predictions and the experimental results. 相似文献
42.
43.
The learning of complex relationships can be decomposed into several neural networks. The modular organization is determined
by prior knowledge of the problem that permits to split the processing into tasks of small dimensionality. The sub-tasks can
be implemented with neural networks, although the learning examples cannot be used anymore to supervise directly each of the
networks. This article addresses the problem of learning in a modular context, developing in particular additive compositions. A simple rule allows defining efficient training, and combining, for example, several Supervised-SOM networks. This technique
is important because it introduces interesting generalizations in many modular compositions, permitting data fusion or sequential
combinations of neural networks.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
44.
Marquis Jean-Philippe; Goulet Sonia; Doré Fran?ois Y. 《Canadian Metallurgical Quarterly》2008,122(3):629
This research examined cognitive and motivational processes at different developmental stages in rats with neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia. In Experiment 1, performance in a T-maze alternation task was assessed on postnatal days (PNDs) 22 and 23. VH-lesioned rats displayed a severe deficit relative to controls. In Experiment 2, behaviorally naive rats were tested for spontaneous alternation at PND 29. Alternation was intact in VH-lesioned rats only when successive alternations were separated by >5 s. In Experiment 3, motivation was tested in a cost-benefit T-maze task and in a saccharine-water preference test. Between PNDs 22-37, behaviorally naive rats with neonatal VH lesions displayed weaker saccharine preference than controls, but the 2 groups did not differ on the cost-benefit task. At adulthood, between PNDs 56-72, the difference on saccharine preference persisted and an impairment on the cost-benefit task emerged. Overall, these results suggest that working memory deficits observed at the weaning stage were not secondary to spontaneous alternation or motivation dysfunctions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
45.
46.
Vincent Frick Joris Pascal Luc Hébrard Jean-Philippe Blondé 《Analog Integrated Circuits and Signal Processing》2008,57(3):161-168
This paper describes an integrated analogue instrumental chain dedicated to measuring magnetic pulses with an amplitude of
a few tens or hundreds of microteslas, superimposed to a strong static magnetic field, i.e. 1.5 T. The system features a silicon
Hall sensor with nested-chopping-like biasing circuitry, DC Hall voltage compensation, amplifying and multistage filtering.
Low-noise performances are achieved by applying 100 kHz spinning current to the Hall device and chopping at 200 kHz to the
signal conditioning blocs downstream. The microsystem achieves 20 μT resolution over a 1.6 kHz bandwidth extending from 5 Hz
to 1.6 kHz under 1.5 T static field. 相似文献
47.
Corfdir P Abid M Mouti A Stadelmann PA Papa E Ansermet JP Ganière JD Deveaud-Plédran B 《Nanotechnology》2011,22(28):285710
The design of cost-effective standards for the quality of nano-objects is currently a key issue toward their massive use for optoelectronic applications. The observation by photoluminescence of narrow excitonic and biexcitonic emission lines in semiconductor nanowires is usually accepted as evidence for high structural quality. Here, we perform time-resolved cathodoluminescence experiments on isolated ZnO nanobelts grown by chemical vapor deposition. We observe narrow emission lines at low temperature, together with a clear biexciton line. Still, drastic alterations in both the CL intensity and lifetime are observed locally along the nano-object. We attribute these to non-radiative recombinations at edge dislocations, closing basal plane stacking faults, inhomogeneously distributed along the NB length. This leads us to the conclusion that the observation of narrow excitonic and biexcitonic emission lines is far from sufficient to grade the quality of a nano-object. 相似文献
48.
Genevet P Tetienne JP Blanchard R Kats MA Müller JP Scully MO Capasso F 《Applied optics》2011,50(31):G56-G62
We present detailed experimental and numerical investigations of resonances in deep nanogroove gratings in metallic substrates. These plasmonic nanocavity gratings feature enhanced fields within the grooves that enable a large enhancement of linear and nonlinear optical processes. This enhancement relies on both localized and propagating surface plasmons on the nanopatterned surface. We show that the efficiency of optical processes such as Raman scattering and four-wave mixing is dramatically enhanced by plasmonic nanocavity gratings. 相似文献
49.
Atef Rebhi Thabet Makhlouf Yannick Champion Jean-Philippe Couzinié Nabil Njah 《Journal of Materials Science》2011,46(7):2185-2193
Microstructure evolution of 99.1% aluminum after equal-channel angular extrusion (ECAE) and subsequent heat-treatment was
investigated. After deformation the samples were annealed at different temperatures. The deformed and annealed states were
characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and microhardness tests. It was shown that
the observed microstructure changes during subsequent annealing have to be associated with recovery and cells formation. The
initial stages of recovery were investigated using weak-beam technique. The microstructure obtained after annealing for 1 h
at 100 °C consists of some arrangements of the dislocations into sub-grain boundaries within the wide preexisting grains.
Annealing at 300 °C led to the appearance of a duplex microstructure consisting of bands of slightly coarsened grains associated
with refined grains. No growth of dislocation cells was observed up to 400 °C. In XRD measurements, the lattice parameter
increase with subsequent heating. This indicates a continuous grain growth during annealing. This is due to the important
increase of coherency length, D observed parallel to a substantial decrease of rms-strain, ε. 相似文献
50.