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101.
Planar laser polarization spectroscopy has recently been used to image the hydroxyl radical in combustion for small intersection angles of pump and probe beams. We report an experimental configuration that allows planar laser polarization imaging for perpendicular intersection of pump and probe beams. We demonstrate what to our knowledge is the first planar laser polarization spectroscopy imaging at a 90 degree intersection of pump and probe beams for both linearly and circularly polarized pump beams. 相似文献
102.
We describe a middleware framework for the adaptive delivery of context information to context-aware applications. The framework
abstracts the applications from the sensors that provide context. Further applications define utility functions on the quality
of context attributes that describe the context providers. Then, given multiple alternatives for providing the same type of
context, the middleware applies the utility function to each alternative and choose the one with maximum utility. By allowing
applications to delegate the selection of context source to the middleware, our middleware can implement autonomic properties,
such as self-configuration when new context providers appear and resilience to failures of context providers.
相似文献
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103.
Jichun Ye Leonardo Ajdelsztajn Julie M. Schoenung 《Metallurgical and Materials Transactions A》2006,37(8):2569-2579
Dense, bulk nanocrystalline aluminum 5083 alloy was fabricatedvia a combined technique: cryomilling (mechanical milling at cryogenic temperature) to achieve the nanocrystalline Al 5083 powder
and spark plasma sintering (SPS) to consolidate the cryomilled powder. The results of X-ray diffraction analysis indicate
that the average grain size in the SPS consolidated material is 51 nm, one of the smallest grain sizes ever reported in bulk
Al alloys produced by powder metallurgy derived methods. In contrast, transmission electron microscopy (TEM) analysis revealed
a bimodal grain size distribution, with an average grain size of 47 nm in the fine-grained regions and approximately 300 nm
in the coarse-grained regions. Nanoindentation was used to evaluate the mechanical properties and the uniformity of the consolidated
nanocrystalline Al 5083. The hardness of the material is greatly improved over that of the conventional equivalent, due to
the fine grain size. The mechanisms for spark plasma sintering and the microstructural evolution are discussed on the basis
of the experimental findings. 相似文献
104.
Abstract: Picture sorts were used to investigate perceptions of women's office clothes, with a sample of ten male and ten female subjects who normally worked in an office environment. The pictures on the cards were taken from catalogues, and showed women's outfits which might be worn in an office. The subjects sorted the cards repeatedly and generated criteria and categories of their own choice. Some of the criteria and categories had not been previously reported in the clothing research literature. Over half of the male subjects, but none of the female subjects, used ‘married/unmarried woman’ as a sorting criterion, although only one of the images sorted showed a wedding ring. A significantly higher proportion of male than of female subjects used dichotomous categorization (i.e. sorting the cards into two piles for one or more of the criteria). The reasons for this are obscure, but do not appear to be a simple outcome of males not knowing much about female clothing. Previous research into clothing has tended to involve researcher‐centred approaches such as semiotics; the results from this study suggest that there would be advantages in wider use of subject‐centred approaches such as card sorts, both in this domain and elsewhere. It was concluded that card sorts were a useful method and should be more widely used. 相似文献
105.
Pan Du Jian Gong Eve Syrkin Wurtele Julie A Dickerson 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2005,35(6):1351-1359
Gene regulatory networks model regulation in living organisms. Fuzzy logic can effectively model gene regulation and interaction to accurately reflect the underlying biology. A new multiscale fuzzy clustering method allows genes to interact between regulatory pathways and across different conditions at different levels of detail. Fuzzy cluster centers can be used to quickly discover causal relationships between groups of coregulated genes. Fuzzy measures weight expert knowledge and help quantify uncertainty about the functions of genes using annotations and the gene ontology database to confirm some of the interactions. The method is illustrated using gene expression data from an experiment on carbohydrate metabolism in the model plant Arabidopsis thaliana. Key gene regulatory relationships were evaluated using information from the gene ontology database. A new regulatory relationship concerning trehalose regulation of carbohydrate metabolism was also discovered in the extracted network. 相似文献
106.
We present a noniterative image cross-correlation approach to track translation and rotation of crawling cells in time-lapse video microscopy sequences. The method does not rely on extracting features or moments, and therefore does not impose specific requirements on the type of microscopy used for imaging. Here we use phase-contrast images. We calculate cell rotation and translation from one image to the next in two stages. First, rotation is calculated by cross correlating the images' polar-transformed magnitude spectra (Fourier magnitudes). Rotation of the cell about any center in the original images results in translation in this representation. Then, we rotate the first image such that the cell has the same orientation in both images, and cross correlate this image with the second image to calculate translation. By calculating the rotation and translation over each interval in the movie, and thereby tracking the cell's position and orientation in each image, we can then map from the stationary reference frame in which the cell was observed to the cell's moving coordinate system. We describe our modifications enabling application to nonidentical images from video sequences of moving cells, and compare this method's performance with that of a feature extraction method and an iterative optimization method. 相似文献
107.
Ruckart PZ Borders J Villanacci J Harris R Samples-Ruiz M 《Journal of hazardous materials》2004,115(1-3):27-31
High winds, flooding, lightning, and other phenomena associated with adverse weather can cause power failures, equipment damage, and process upsets resulting in chemical releases. Of the 5000 events in Texas that were reported to the Hazardous Substances Emergency Events Surveillance (HSEES) system during 2000-2001, adverse weather conditions contributed to 110 (2%) events. Rain was the most frequent adverse weather condition. Most events to which adverse weather conditions contributed occurred during June or September; these months correspond with the high temperature and hurricane season in Texas. Most events occurred in coastal counties with large numbers of industrial facilities. Three industries reported the majority of events: industrial and miscellaneous chemicals manufacturing; petroleum refining; and plastics, synthetics, and resin manufacturing. Power failures were associated more often with adverse weather-related events than with nonweather-related events. Releases occurred most commonly from ancillary process equipment and process vessels. Events associated with adverse weather-related conditions involved nine victims. System and process design improvements, such as improved backup power generation and redesigned secondary containment systems, could be explored to reduce the potential negative effects of severe weather. 相似文献
108.
Dark-capacitance transients in MIS tunnel diodes switched from accumulation to deep depletion depend on the interface state occupancy. This time dependent function is derived and its behavior described for electron emission and electron-hole pair generation with tunneling and thermally controlled occupancies. A new method of determining the tunneling relaxation time constant τT from the electron emission transient at low temperature is described. Measurements of MIS tunnel diodes with oxide thickness dox = 17 to 80 Å agree with theory and the resultant values of τT compare with previously reported results from photocapacitance[2]. 相似文献
109.
Exploratory spatial data analysis of the distribution of regional per capita GDP in Europe, 1980−1995 总被引:9,自引:0,他引:9
The aim of this paper is to study the space-time dynamics of European regional per capita GDP. A sample of 138 European regions
over the 1980–1995 period provides clear evidence of global and local spatial autocorrelation as well as spatial heterogeneity
in the distribution of regional per capita GDP. The detection of spatial clusters of high and low per capita GDP throughout
the period is an indication of the persistence of spatial disparities among European regions. The dynamism of European regions
is investigated by exploring the spatial pattern of regional growth. Implications for applied econometric work on the convergence
of European regions are then suggested.
Received: 11 September 2000 / Accepted: 11 March 2002
RID="*"
ID="*"Previous versions of this article were presented at the 6th RSAI World Congress 2000 “Regional Science in a Small World”,
Lugano, Switzerland, May 16–20, 2000 and the 40th ERSA Congress “European Monetary Union and Regional Policy”, Barcelona,
Spain, August 29 – September 1, 2000. We would like to thank L. Anselin, R.J.G.M. Florax, A. Getis, C. Baumont, an and suggestions.
We would also like to thank Eurostat: G. Decand and A. Behrens from the regional statistics section (division E4) as well
as J. Recktenwald and I. Dennis for the help they provided on the Eurostat-Regio database. The usual disclaimer applies. 相似文献
110.
The respective influences of exposure and inborn neural networks on conspecific and nonconspecific face processing remain unclear. Although the importance of exposure in the development of object and face recognition in general is well documented, studies explicitly comparing face recognition across species showed a species-specific effect. For instance, laboratory monkeys exposed daily to human faces were better at discriminating monkeys than humans, suggesting that the role of exposure may not be the only factor affecting cross-species recognition. In the present study, the authors investigated conspecific and nonconspecific face recognition in chimpanzees (Pan troglodytes) from 2 primate centers that provided different exposure to chimpanzee and human faces. The authors showed that the chimpanzees from the center providing more exposure to human faces than to chimpanzee faces were better at discriminating human faces than they were at discriminating chimpanzee faces. The chimpanzees from the other center did not show the same effect. A computational simulation was developed to evaluate the average similarities among human pictures and among chimpanzee pictures. Both categories were comparable. Chimpanzees' scores were significantly correlated with the similarity coefficients. Overall, the results show that exposure is a critical determinant in conspecific and nonconspecific face recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献