全文获取类型
收费全文 | 3522篇 |
免费 | 226篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 67篇 |
综合类 | 1篇 |
化学工业 | 949篇 |
金属工艺 | 43篇 |
机械仪表 | 72篇 |
建筑科学 | 154篇 |
矿业工程 | 1篇 |
能源动力 | 109篇 |
轻工业 | 285篇 |
水利工程 | 11篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 327篇 |
一般工业技术 | 623篇 |
冶金工业 | 247篇 |
原子能技术 | 29篇 |
自动化技术 | 830篇 |
出版年
2024年 | 5篇 |
2023年 | 43篇 |
2022年 | 134篇 |
2021年 | 160篇 |
2020年 | 79篇 |
2019年 | 94篇 |
2018年 | 102篇 |
2017年 | 95篇 |
2016年 | 147篇 |
2015年 | 118篇 |
2014年 | 148篇 |
2013年 | 232篇 |
2012年 | 209篇 |
2011年 | 239篇 |
2010年 | 201篇 |
2009年 | 199篇 |
2008年 | 191篇 |
2007年 | 171篇 |
2006年 | 126篇 |
2005年 | 101篇 |
2004年 | 131篇 |
2003年 | 109篇 |
2002年 | 74篇 |
2001年 | 61篇 |
2000年 | 50篇 |
1999年 | 40篇 |
1998年 | 66篇 |
1997年 | 43篇 |
1996年 | 58篇 |
1995年 | 41篇 |
1994年 | 38篇 |
1993年 | 28篇 |
1992年 | 22篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1987年 | 12篇 |
1986年 | 7篇 |
1985年 | 18篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 14篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 5篇 |
1967年 | 4篇 |
1965年 | 4篇 |
排序方式: 共有3752条查询结果,搜索用时 15 毫秒
61.
Abstract We are developing the control architecture of a portraitist artificial agent called DrawBot that reproduces the visuomotor behaviour of a human carrying out a realistic portrait. The visuomotor strategy adopted by DrawBot is based on computational models of eye movements in human beings,and one xperimental findings on eye-hand coordination in expert draughtsmen. In this paper we present a behavioural model of the visuomotor coordination adopted by a draughtsman, designed in terms of visual routines.Eventually we outline the implementation of the basic routines. 相似文献
62.
Marco Domenichini Ranjana Sahai Piero Castrataro Roberto Valsecchi Claudio Tonelli Francesco Greco Paolo Dario 《Microfluidics and nanofluidics》2013,15(6):753-762
The development of multilayer soft lithography methodology has seen polydimethysiloxane (PDMS) as the preferred material for the fabrication of microfluidic devices. However, the functionality of these PDMS microfluidic chips is often limited by the poor chemical resistance of PDMS to certain solvents. Here, we propose the use of a photocurable perfluoropolyether (PFPE), specifically FOMBLIN® MD40 PFPE, as a candidate material to provide a solvent-resistant buffer layer to make the device substantially impervious to chemically induced swelling. We first carried out a systematic study of the solvent resistance properties of FOMBLIN® MD40 PFPE as compared with PDMS. The comparison presented here demonstrates the superiority of FOMBLIN® MD40 PFPE over PDMS in this regard; moreover, the results permitted to categorize solvents in four different groups depending on their swelling ratio. We then present a step-by-step recipe for a novel fabrication process that uses multilayer lithography to construct a comprehensive solvent-resistant device with fluid and control channels integrated with a valve structure and also permitting easy establishment of outside connections. 相似文献
63.
64.
Stereo Light Probe 总被引:1,自引:0,他引:1
In this paper we present a practical, simple and robust method to acquire the spatially‐varying illumination of a real‐world scene. The basic idea of the proposed method is to acquire the radiance distribution of the scene using high‐dynamic range images of two reflective balls. The use of two light probes instead of a single one allows to estimate, not only the direction and intensity of the light sources, but also the actual position in space of the light sources. To robustly achieve this goal we first rectify the two input spherical images, then, using a region‐based stereo matching algorithm, we establish correspondences and compute the position of each light. The radiance distribution so obtained can be used for augmented reality applications, photo‐realistic rendering and accurate reflectance properties estimation. The accuracy and the effectiveness of the method have been tested by measuring the computed light position and rendering synthetic version of a real object in the same scene. The comparison with standard method that uses a simple spherical lighting environment is also shown. 相似文献
65.
Favaro P Soatto S Burger M Osher SJ 《IEEE transactions on pattern analysis and machine intelligence》2008,30(3):518-531
Defocus can be modeled as a diffusion process and represented mathematically using the heat equation, where image blur corresponds to the diffusion of heat. This analogy can be extended to non-planar scenes by allowing a space-varying diffusion coefficient. The inverse problem of reconstructing 3-D structure from blurred images corresponds to an "inverse diffusion" that is notoriously ill-posed. We show how to bypass this problem by using the notion of relative blur. Given two images, within each neighborhood, the amount of diffusion necessary to transform the sharper image into the blurrier one depends on the depth of the scene. This can be used to devise a global algorithm to estimate the depth profile of the scene without recovering the deblurred image, using only forward diffusion. 相似文献
66.
Cecilia Laschi Gioel Asuni Eugenio Guglielmelli Giancarlo Teti Roland Johansson Hitoshi Konosu Zbigniew Wasik Maria Chiara Carrozza Paolo Dario 《Autonomous Robots》2008,25(1-2):85-101
This paper presents a sensory-motor coordination scheme for a robot hand-arm-head system that provides the robot with the capability to reach an object while pre-shaping the fingers to the required grasp configuration and while predicting the tactile image that will be perceived after grasping. A model for sensory-motor coordination derived from studies in humans inspired the development of this scheme. A peculiar feature of this model is the prediction of the tactile image. The implementation of the proposed scheme is based on a neuro-fuzzy module that, after a learning phase, starting from visual data, calculates the position and orientation of the hand for reaching, selects the best-suited hand configuration, and predicts the tactile feedback. The implementation of the scheme on a humanoid robot allowed experimental validation of its effectiveness in robotics and provided perspectives on applications of sensory predictions in robot motor control. 相似文献
67.
Andrea Bettidi Antonio Cetronio Walter Ciccognani Marco De Dominicis Claudio Lanzieri Ernesto Limiti Antonio Manna Marco Peroni Claudio Proietti Paolo Romanini 《国际射频与微波计算机辅助工程杂志》2009,19(5):598-606
In this article, the design, fabrication, and on‐wafer test of X‐Band and 2–18 GHz wideband high‐power SPDT MMIC switches in AlGaN/GaN technology are presented. The switches have demonstrated state‐of‐the‐art performance and RF fabrication yield better than 65%. Linear and power measurements for different control voltages have been reported and an explanation of the dependence of the power performances on the control voltage is given. In particular, the X‐band switch exhibits a 0.4 dB compression level at 10 GHz when driven by a 38 dBm input signal. The wideband switch shows a compression level of 1 dB at an input drive higher than 38 dBm across the entire bandwidth. © 2009 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2009. 相似文献
68.
This paper describes the development of a system for measuring surface coordinates (commonly known as "shape measurements") which is able to give the temporal evolution of the position of the tire sidewall in transient conditions (such as during braking, when there are potholes or when the road surface is uneven) which may or may not be reproducible. The system is based on the well-known technique of projecting and observing structured light using a digital camera with an optical axis which is slanted with respect to the axis of the projector. The transient nature of the phenomenon has led to the development of specific innovative solutions as regards image processing algorithms. This paper briefly describes the components which make up the measuring system and presents the results of the measurements carried out on the drum bench. It then analyses the performance of the measuring system and the sources of uncertainty which led to the development of the system for a specific dynamic application: impact with an obstacle (cleat test). The measuring system guaranteed a measurement uncertainty of 0.28 mm along the Z axis (the axial direction of the tire) with a measurement range of 250(X) x 80(Y) x 25(Z) mm(3), with the tire rolling at a speed of up to 30 km/h. 相似文献
69.
Oleuropein protects low density lipoprotein from oxidation 总被引:1,自引:0,他引:1
The Mediterranean diet, rich in fruit, vegetables, grain, and vegetable oil (mainly olive oil) is correlated with a lower incidence of coronary heart disease (CHD). Natural antioxidants contained in the Mediterranean diet might also play a role in the prevention of cardiovascular diseases, through inhibition of LDL oxidation. We tested this hypothesis "in vitro" by inducing LDL oxidation with copper sulphate and preincubating the samples with oleuropein, the bitter principle of olives, that is one of the major components of the polyphenolic fraction of olive oil. Oleuropein 10(-5) M effectively inhibited CuSO4-induced LDL oxidation, as assessed by various parameters. We demonstrate in this investigation that polyphenolic components of the Mediterranean diet interfere with biochemical events that are implicated in atherogenetic disease, thus proposing a new link between the Mediterranean diet and prevention of CHD. 相似文献
70.
Influence of religiosity and spiritual coping on health‐related quality of life in Saudi haemodialysis patients
下载免费PDF全文
![点击此处可从《Hemodialysis international. International Symposium on Home Hemodialysis》网站下载免费的PDF全文](/ch/ext_images/free.gif)