全文获取类型
收费全文 | 3551篇 |
免费 | 185篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 53篇 |
综合类 | 3篇 |
化学工业 | 998篇 |
金属工艺 | 79篇 |
机械仪表 | 87篇 |
建筑科学 | 139篇 |
矿业工程 | 6篇 |
能源动力 | 154篇 |
轻工业 | 269篇 |
水利工程 | 28篇 |
石油天然气 | 3篇 |
无线电 | 356篇 |
一般工业技术 | 703篇 |
冶金工业 | 178篇 |
原子能技术 | 32篇 |
自动化技术 | 654篇 |
出版年
2023年 | 31篇 |
2022年 | 87篇 |
2021年 | 108篇 |
2020年 | 55篇 |
2019年 | 76篇 |
2018年 | 87篇 |
2017年 | 95篇 |
2016年 | 123篇 |
2015年 | 105篇 |
2014年 | 144篇 |
2013年 | 242篇 |
2012年 | 222篇 |
2011年 | 282篇 |
2010年 | 183篇 |
2009年 | 220篇 |
2008年 | 227篇 |
2007年 | 168篇 |
2006年 | 180篇 |
2005年 | 124篇 |
2004年 | 108篇 |
2003年 | 103篇 |
2002年 | 120篇 |
2001年 | 55篇 |
2000年 | 51篇 |
1999年 | 49篇 |
1998年 | 66篇 |
1997年 | 71篇 |
1996年 | 42篇 |
1995年 | 32篇 |
1994年 | 36篇 |
1993年 | 26篇 |
1992年 | 17篇 |
1991年 | 15篇 |
1990年 | 20篇 |
1989年 | 17篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1972年 | 4篇 |
排序方式: 共有3742条查询结果,搜索用时 15 毫秒
41.
介绍了用于钨双嵌入和钨栓CMP工艺的新型CMP3200TM氧化铝浆料,测试证明,这种浆料在110nm技术节点的钨CMP工艺应用中取得了理想的效果。通过对氧化铝粒子制造工艺的有效控制,获得了可满足110nm技术节点双嵌入和栓层钨CMP工艺要求的低缺陷率,高性价比的氧化铝蛐硝酸铁浆料。从而在价格竞争激烈的半导体制造领域,特别是代工市场引起了业界越来越多的关注。 相似文献
42.
Emmanuel Defaÿ David Wolozan Jean-Pierre Blanc Emmanuelle Serret Pierre Garrec Sophie Verrun Denis Pellissier Philippe Delpech Julie Guillan Bernard Andr Laurent Ulmer Marc Aïd Pascal Ancey 《Solid-state electronics》2007,51(11-12):1624
This paper describes realization and characterization of SrTiO3 (STO) high K MIM capacitors above BiCMOS integrated circuit (IC). These capacitances are connected to IC and are used as coupling capacitors in order to realize a high pass filter. Surface capacitance achieved is 10 nF/mm2 with capacitance value of 1.2 nF. The process for STO MIM fabrication does not exceed 400 °C, which is compatible with interconnections. Typical K and dielectric losses values obtained are, respectively 110% and 2%. Yield obtained reaches 83% for capacitors. A functional high pass filter using these STO capacitors was realized in this study. It exhibits a cut-off frequency at 6.5 kHz and a constant gain at higher frequencies of −1.3 dB. 相似文献
43.
Philippe Pichot 《电子元器件资讯》2010,(8)
电源开关的使用较为复杂,甚至让大多数电子产品设计人员都感到困惑,特别是对那些非电源管理专家而言.在各种各样的应用中,例如:便携式电子产品、消费类电子产品、工业或电信系统等,广大设计人员正越来越多地使用电源开关.这些电源开关的使用方式多种多样,包括控制、排序,电路保护、配电甚至是系统电源开启管理等.当然,每一种用法都需要有不同特性的电源开关解决方案. 相似文献
44.
Beaulieu A Bossé D Micheau P Avoine O Praud JP Walti H 《IEEE transactions on bio-medical engineering》2012,59(2):323-331
This study presents a methodology for applying the forced-oscillation technique in total liquid ventilation. It mainly consists of applying sinusoidal volumetric excitation to the respiratory system, and determining the transfer function between the delivered flow rate and resulting airway pressure. The investigated frequency range was f ∈ [0.05, 4] Hz at a constant flow amplitude of 7.5 mL/s. The five parameters of a fractional order lung model, the existing "5-parameter constant-phase model," were identified based on measured impedance spectra. The identification method was validated in silico on computer-generated datasets and the overall process was validated in vitro on a simplified single-compartment mechanical lung model. In vivo data on ten newborn lambs suggested the appropriateness of a fractional-order compliance term to the mechanical impedance to describe the low-frequency behavior of the lung, but did not demonstrate the relevance of a fractional-order inertance term. Typical respiratory system frequency response is presented together with statistical data of the measured in vivo impedance model parameters. This information will be useful for both the design of a robust pressure controller for total liquid ventilators and the monitoring of the patient's respiratory parameters during total liquid ventilation treatment. 相似文献
45.
Edge-preserving smoothers need not be taxed by a severe computational cost. We present, in this paper, a lean algorithm that is inspired by the bi-exponential filter and preserves its structure-a pair of one-tap recursions. By a careful but simple local adaptation of the filter weights to the data, we are able to design an edge-preserving smoother that has a very low memory and computational footprint while requiring a trivial coding effort. We demonstrate that our filter (a bi-exponential edge-preserving smoother, or BEEPS) has formal links with the traditional bilateral filter. On a practical side, we observe that the BEEPS also produces images that are similar to those that would result from the bilateral filter, but at a much-reduced computational cost. The cost per pixel is constant and depends neither on the data nor on the filter parameters, not even on the degree of smoothing. 相似文献
46.
Rafael Krummenauer Rafael Ferrari Ricardo Suyama Romis Attux Cynthia Junqueira Pascal Larzabal Philippe Forster Amauri Lopes 《Circuits, Systems, and Signal Processing》2013,32(5):2423-2443
This paper addresses the problem of direction-of-arrival (DOA) parameter estimation in array processing when the signals are inherently discrete, which is the case mainly in the digital communication context. Based on the particular structure of the signal space in the data model, a maximum likelihood-based approach is introduced. The strategy consists in transforming the parameter estimation problem into a decision task. It is shown through numerical simulations that the proposed solution closely follows the performance limit given by the Cramér–Rao bound. Some important features of the technique are as follows: (i) it is capable of handling any number of sources, provided that the number of sensors is greater than or equal to two and the number of snapshots is sufficiently greater than the cardinality of the signal space; (ii) the estimation quality is not affected by the angle and phase separation; and (iii) it offers the possibility to deal with uncalibrated arrays. 相似文献
47.
Prasad Rohit Das Satyajit Martin Kevin J. M. Coussy Philippe 《Journal of Signal Processing Systems》2021,93(10):1159-1171
Journal of Signal Processing Systems - Coarse Grained Reconfigurable Arrays (CGRAs) are emerging as energy efficient accelerators providing a high grade of flexibility in both academia and... 相似文献
48.
Mourad Loulou Dominique Dallet Nouri Masmoudi Philippe Marchegay Lotfi Kamoun 《Analog Integrated Circuits and Signal Processing》2004,39(1):81-87
This article presents a low-pass sigma-delta modulator for Analogue-to-Digital conversion. The circuit uses a switched-current technique which presents a well known drawback called clock feedthrough. This phenomenon induces an error on the output signal value. In order to cancel the clock feedthrough effect, we use a new method based on a current feedback loop. The circuit is designed in 0.8 μm AMS “Austria Mikro Systems” single poly CMOS process. Measurements of the modulator are performed under A/D converters characterisation system, and show 55 dB dynamic range at 2.048 MHz sampling rate with 8 kHz input frequency bandwidth. These characteristics are suitable for audio applications. 相似文献
49.
Masanari Okuno Hideaki Kano Philippe Leproux Vincent Couderc Hiro-o Hamaguchi 《Optical Fiber Technology》2012,18(5):388-393
We describe and characterize a multiplex CARS microspectroscopic system that uses a nanosecond supercontinuum generated from a photonic crystal fiber and a sub-nanosecond pulse laser. This system has a high spectral resolution (<0.1 cm?1) and an ultrabroadband spectral coverage (>2500 cm?1). The estimated spatial resolutions are 0.45 μm (lateral) and 4.5 μm (axial), respectively. This system enables us to obtain CARS spectra and corresponding images in the fingerprint region as well in the CH stretch region. Using this system, we have successfully obtained label-free and multi-mode vibrational images of a yeast cell. 相似文献
50.
移动运营商在过去的12年中经历了一个爆发性增长的“火山期”和一个低增长的-一冰河期”。起落之间反映的是运营商在人才上的缺失,这一来自欧洲电信市场上的教训值得全球所有运营商警惕。 相似文献