全文获取类型
收费全文 | 898篇 |
免费 | 46篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 270篇 |
金属工艺 | 12篇 |
机械仪表 | 19篇 |
建筑科学 | 31篇 |
能源动力 | 37篇 |
轻工业 | 56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 | 149篇 |
冶金工业 | 51篇 |
原子能技术 | 9篇 |
自动化技术 | 207篇 |
出版年
2024年 | 1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 | 72篇 |
2012年 | 50篇 |
2011年 | 100篇 |
2010年 | 63篇 |
2009年 | 46篇 |
2008年 | 49篇 |
2007年 | 56篇 |
2006年 | 38篇 |
2005年 | 38篇 |
2004年 | 30篇 |
2003年 | 23篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 6篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有944条查询结果,搜索用时 15 毫秒
1.
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
2.
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
3.
Hervé Barthélemy Matthieu Fillaud Sylvain Bourdel Jean Gaubert 《Analog Integrated Circuits and Signal Processing》2007,50(2):141-146
A new versatile class AB low-voltage second generation current conveyor based on CMOS inverters operating in transconductance
mode is presented in this letter. Against traditional design based on CCII+, the circuit is able to operate at low supply
voltages and offers numerous advantages like class AB operation, large voltage and current swing, synthesis from digital inverters.
Simulation results from a typical 0.35 μm CMOS process had demonstrated the circuit capability to operate at high frequency
over wide voltage and wide current swings. The proposed circuit operation has been acted from measurements with the HEF4069UBP
from Philips semiconductors [1]. 相似文献
4.
Multipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications.Our protocol, called MultiPath OLSR (MP-OLSR), is a multipath routing protocol based on OLSR [1]. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints. 相似文献
5.
Prakash Koirala Jian Li Heayoung P. Yoon Puruswottam Aryal Sylvain Marsillac Angus A. Rockett Nikolas J. Podraza Robert W. Collins 《Progress in Photovoltaics: Research and Applications》2016,24(8):1055-1067
Polycrystalline CdS/CdTe thin‐film solar cells in the superstrate configuration have been studied by spectroscopic ellipsometry (SE) using glass side illumination. In this measurement method, the first reflection from the ambient/glass interface is rejected, whereas the second reflection from the glass/film‐stack interface is collected; higher order reflections are also rejected. The SE analysis incorporates parameterized dielectric functions ε for solar cell component materials obtained by in situ and variable‐angle SE. In the SE analysis of the complete cells, a step‐wise procedure ranks the fitting parameters, including thicknesses and those defining the spectra in ε, according to their ability to reduce the root‐mean‐square deviation between the simulated and measured SE spectra. The best fit thicknesses from this analysis are found to be consistent with electron microscopy. Based on the SE results, the solar cell quantum efficiency (QE) can be simulated without any free parameters, and comparisons with measured QE enable optical model refinements as well as identification of optical and electronic losses. These capabilities have wide applications in photovoltaic module mapping and in‐line monitoring. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
6.
Jaume S Knobe K Newton RR Schlimbach F Blower M Reid RC 《IEEE transactions on bio-medical engineering》2012,59(1):35-38
Several groups in neurobiology have embarked into deciphering the brain circuitry using large-scale imaging of a mouse brain and manual tracing of the connections between neurons. Creating a graph of the brain circuitry, also called a connectome, could have a huge impact on the understanding of neurodegenerative diseases such as Alzheimer's disease. Although considerably smaller than a human brain, a mouse brain already exhibits one billion connections and manually tracing the connectome of a mouse brain can only be achieved partially. This paper proposes to scale up the tracing by using automated image segmentation and a parallel computing approach designed for domain experts. We explain the design decisions behind our parallel approach and we present our results for the segmentation of the vasculature and the cell nuclei, which have been obtained without any manual intervention. 相似文献
7.
Philippe Tribolet Jean-Pierre Chatard Patricia Costa Sylvain Paltrier 《Journal of Electronic Materials》2001,30(6):574-584
Second generation infrared (IR) detectors are now mature at the production level. These detectors are mostly based on HgCdTe
(MCT) materials technology. The main second generation detectors at the mass production level are the 288 4 long wave length
for most of the European forward-looking infrared (FLIR) and the 480 6 long wave length for the U.S. Army SADA applications.
As far as the 288 4 is concerned, SOFRADIR has delivered more than 3000 units already and the market is estimated to be 15,000
units at least! The market is also very large for SADA II units and SOFRADIR has produced them since the end of 1999. Thus,
SOFRADIR produces large quantities of mercury cadmium telluride (MCT) detectors and has a unique experience for MCT detectors
in mass production. MCT materials technology challenges for mass production concern the main following issues: Quality and
reproducibility, MCT wafer size increase, array yield level increase, and the collective manufacturing approach. These issues
are discussed in detail in this paper as well as future trends. 相似文献
8.
Etienne Perret Nicolas Zerounian Sylvain David Frédéric Aniel 《Microelectronic Engineering》2008,85(11):2276-2281
High-quality polymers such as the benzocyclobutene polymer (BCB) provide interesting dielectric feature for terahertz applications. Already used in silicon integrated circuit technologies, this material could become one of the most promising candidates for the realization of future THz waveguides and interconnections on a silicon substrate but also after active devices process on the top of any other technology (GaAs, InP, GaN…). A frequency-dependent complex permittivity of spin-coated thick layers of this low-k dielectric is obtained from transmittance spectra measured with Fourier transform spectroscopy in the frequency range of 0.5-5.4 THz. The dielectric constant and the loss tangent are discussed according to curing conditions of the photosensitive resin used. A low loss tangent value of 7 − 9 × 10-3 at 1 THz is obtained with polymerisation in oxygen-free atmosphere. An incomplete curing and a high dose UV exposure have a weak impact on losses. These results associated with the high compatibility of this polymer with silicon and metals make BCB layers well suited for the design of microelectronic THz devices and circuits. 相似文献
9.
Stefan Brandstetter Vincent Carreau Sylvain Maîtrejean Marc Legros 《Microelectronic Engineering》2010,87(3):383-386
The evolution of the grain structure through annealing of narrow damascene Cu interconnects is important for any further design of highly integrated circuits. Here we present a comprehensive transmission electron microscopy study of damascene lines between 80 nm and 3000 nm wide. Experimental results clearly indicate that morphology evolutions through annealing are strongly influenced by the line width. If the lines are wider than 250 nm a strong connection between the grain structure within the lines and the overburden copper is present at least after sufficient annealing. Once the lines are as small as 80 nm the grain structure within the lines are only weakly connected to the overburden copper grown above. 相似文献
10.
Sylvain Vedraine Ahmad El Hajj Philippe Torchio Bruno Lucas 《Organic Electronics》2013,14(4):1122-1129
The optical properties of ZnO/Ag/ZnO (ZAZ) multilayer structures were numerically modeled and calculated by a FDTD method. Such tri-layers were also manufactured using an ion beam sputtering plant. A good agreement is obtained between modelizations and realizations. The impact of the oxide thicknesses on the optical properties of the ZAZ structures were experimentally and numerically investigated, and allow us to adjust the spectral position of the transmission maximum. The transmission of these structures is optimized up to around 74%, on the whole absorption spectral range of the photoactive P3HT:PCBM bulk heterojunction. The best electrode design is glass/ZnO (30 nm)/Ag (14 nm)/ZnO (30 nm), which presents a sheet resistance of 7 Ω/□. The optimized ZAZ structure was successfully integrated in an organic solar cell as anode. A photovoltaic efficiency of 2.58% is obtained and is compared to an organic solar cell integrating a traditional ITO anode with an efficiency of 2.99%. Numerical calculations of the intrinsic absorption inside each layer of the organic solar cells are performed. Alternative ITO-free electrodes for organic solar cells are demonstrated. 相似文献