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41.
42.
包装材料和腌制溶液对半干鱼品保质效果的影响 总被引:2,自引:2,他引:0
利用聚丙烯(PP)与聚乙烯(PE)改性制作的抑菌抗氧包装袋和聚乙烯与聚对苯二甲酸乙二醇酯(PET)改性制作的生物气调保鲜包装袋,包装水分质量分数分别为20%,30%,60%的半干草鱼块,并在腌制溶液中添加磷酸二氢钠与磷酸氢二钠等品质改良剂,测试不同包装材料与腌制溶液对储藏期内半干鱼品色差、失重率、p H值、菌落总数的影响。结果表明:抑菌抗氧包装袋较生物气调保鲜包装袋更能延长半干草鱼的货架期;不同腌制溶液对半干鱼的品质影响不同,添加品质改良剂的腌制溶液更能保持半干鱼品的色泽,降低鱼品的失重率,延缓鱼品的p H值及菌落总数增长速率,其作用效果为:生理盐水磷酸二氢钠磷酸氢二钠。 相似文献
43.
Jérémie Chalopin Shantanu Das Yann Disser Matúš Mihalák Peter Widmayer 《Algorithmica》2013,65(1):43-59
We consider the problem of mapping an initially unknown polygon of size n with a simple robot that moves inside the polygon along straight lines between the vertices. The robot sees distant vertices in counter-clockwise order and is able to recognize the vertex among them which it came from in its last move, i.e. the robot can look back. Other than that the robot has no means of distinguishing distant vertices. We assume that an upper bound on n is known to the robot beforehand and show that it can always uniquely reconstruct the visibility graph of the polygon. Additionally, we show that multiple identical and deterministic robots can always solve the weak rendezvous problem in which the robots need to position themselves such that all of them are mutually visible to each other. Our results are tight in the sense that the strong rendezvous problem, where robots need to gather at a vertex, cannot be solved in general, and, without knowing a bound beforehand, not even n can be determined. In terms of mobile agents exploring a graph, our result implies that they can reconstruct any graph that is the visibility graph of a simple polygon. This is in contrast to the known result that the reconstruction of arbitrary graphs is impossible in general, even if n is known. 相似文献
44.
Angkoon Phinyomark Franck Quaine Sylvie Charbonnier Christine Serviere Franck Tarpin-Bernard Yann Laurillau 《Engineering Applications of Artificial Intelligence》2013,26(7):1681-1688
High classification accuracy has been achieved for muscle–computer interfaces (MCIs) based on surface electromyography (EMG) recognition in many recent works with an increasing number of discriminated movements. However, there are many limitations to use these interfaces in the real-world contexts. One of the major problems is compatibility. Designing and training the classification EMG system for a particular individual user is needed in order to reach high accuracy. If the system can calibrate itself automatically/semi-automatically, the development of standard interfaces that are compatible with almost any user could be possible. Twelve anthropometric variables, a measurement of body dimensions, have been proposed and used to calibrate the system in two different ways: a weighting factor for a classifier and a normalizing value for EMG features. The experimental results showed that a number of relationships between anthropometric variables and EMG time-domain features from upper-limb muscles and movements are statistically strong (average r=0.71?0.80) and significant (p<0.05). In this paper, the feasibility to use anthropometric variables to calibrate the EMG classification system is shown obviously and the proposed calibration technique is suggested to further improve the robustness and practical use of MCIs based on EMG pattern recognition. 相似文献
45.
Daniel Raucoules Damien Raffard Jérémy Rohmer Annick Loschetter Marcello De Michele Yann Le Gallo 《International journal of remote sensing》2013,34(11):2800-2815
This article proposes to test the feasibility of long-term surface deformation monitoring based on synthetic aperture radar (SAR) interferometry on carbon dioxide (CO2) storage sites with land cover representative of potential European injection sites (agricultural or forests with minimum built-up land cover). Because no operational injection site is currently active in Europe, a SAR data set (based on EnviSAT–ASAR spaceborne data) is simulated by combining SAR scenes acquired over a potential future European injection site with deformation measurements from SAR analysis carried out on the In-Salah (Algeria) CO2 injection demonstrator site. The study shows that under such conditions, both persistent scatterer interferometry (PSI) and diffuse scatterer (DS) interferometry appear insufficient to provide a sufficiently dense measurement network to characterize surface deformation correctly. Alternative solutions, to be investigated in further studies, include the use of data archives with shorter acquisition time spans (e.g. Sentinel-1 data when available) or installation of corner reflectors. The cost of the latter mixed space/ground solution must be evaluated with respect to conventional ground-based measurement methods in the proposed context. 相似文献
46.
Yves Richard Nadège Martiny Mathieu Rouault Nathalie Philippon Yann Tracol Thierry Castel 《International journal of remote sensing》2013,34(21):6763-6782
In semi-arid African regions (annual rainfall between 200 and 600 mm), variability of vegetative activity is mainly due to the rainfall of the current rainy season. In most of South Africa, the rainy season occurs from October to March. On average, vegetative activity lags rainfall by 1 to 2 months. The interannual variability in early summer (December to September) normalized difference vegetation index (NDVI) depends primarily on precipitation at the beginning (October to November) of the rainy season. However, once this primary control is removed, the residual interannual variability in NDVI highlights a double memory effect: a 1-year effect, referred to as Mem1, and a 7- to 10-month effect, referred to as Mem2. This article aims at better describing the influence of soil and vegetation characteristics on these two memory effects. The data sets used in this study are as follows: (1) a 19-year NDVI time series from National Oceanic and Atmospheric Administration (NOAA) satellites, (2) rainfall records from a network of 1160 rain-gauge stations compiled by the Water Research Commission (WRC), (3) vegetation types from Global Land Cover (GLC) 2000 and (4) soil characteristics from the soil and terrain database for Southern Africa (SOTERSAF). Results indicate that among 20–30% of NDVI variance that is not explained by the concurrent rainfall, one-third is explained by the two memory effects. Mem1 is found to have maximum effect in the northwest of our study domain, near the Botswana boundary, in the South Kalahari. Associated conditions are open grasslands growing on Arenosols. Mem1 is less important in the southeast, particularly in open grassland with shrubs growing on Cambisols. Thus, Mem1 mainly depends on soil texture. Mem2 is more widespread and its influence is the greatest in the centre, the south and the east of our domain. It is related to rainfall from January to April, which controls, beyond the intervening dry season, the interannual variations of NDVI (December to September) at the beginning of the next rainy season. Through these new findings, this article emphasizes again the high potential of remote-sensing techniques to monitor and understand the dynamics of semi-arid environments. 相似文献
47.
48.
This paper introduces a new texture analysis scheme, which is invariant to local geometric and radiometric changes. The proposed
methodology relies on the topographic map of images, obtained from the connected components of level sets. This morphological
tool, providing a multi-scale and contrast-invariant representation of images, is shown to be well suited to texture analysis.
We first make use of invariant moments to extract geometrical information from the topographic map. This yields features that
are invariant to local similarities or local affine transformations. These features are invariant to any local contrast change.
We then relax this invariance by computing additional features that are invariant to local affine contrast changes and investigate
the resulting analysis scheme by performing classification and retrieval experiments on three texture databases. The obtained
experimental results outperform the current state of the art in locally invariant texture analysis. 相似文献
49.
50.
Angelo Esposito Aaron D. Montello Yann G. Guezennec Cesare Pianese 《Journal of power sources》2010,195(9):2691-2699
It has been well documented that water production in PEM fuel cells occurs in discrete locations, resulting in the formation and growth of discrete droplets on the gas diffusion layer (GDL) surface within the gas flow channels (GFCs). This research uses a simulated fuel cell GFC with three transparent walls in conjunction with a high speed fluorescence photometry system to capture videos of dynamically deforming droplets. Such videos clearly show that the droplets undergo oscillatory deformation patterns. Although many authors have previously investigated the air flow induced droplet detachment, none of them have studied these oscillatory modes. The novelty of this work is to process and analyze the recorded videos to gather information on the droplets induced oscillation. Plots are formulated to indicate the dominant horizontal and vertical deformation frequency components over the range of sizes of droplets from formation to detachment. The system is also used to characterize droplet detachment size at a variety of channel air velocities. A simplified model to explain the droplet oscillation mechanism is provided as well. 相似文献