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Performance of dairy cattle fed citrus pulp or corn products as sources of neutral detergent-soluble carbohydrates 总被引:1,自引:0,他引:1
The effects of modifying the dietary profile of neutral detergent-soluble carbohydrates (NDSC) on milk production and rumen fermentation were determined. Corn silage and alfalfa hay-based diets were formulated to contain 40% calculated NDSC supplied primarily by dried citrus pulp as a source of neutral detergent-soluble fiber (NDSF), or corn products as sources of starch. Diets were compared within cow with reversal experiments with two periods. In experiment 1, 11 multiparous Holstein cows including three ruminally cannulated animals were individually fed diets containing 23.6% citrus pulp (diet CPD) or 25.3% corn hominy (diet HD) on a dry matter basis. In experiment 2, 184 animals fed as two groups received diets containing 20.5% citrus pulp (diet CPD) or 19.5% cornmeal (diet CMD). Diets CPD provided more dietary NDSF and HD and CMD more starch. In experiment 1, cows fed HD had a greater milk protein percentage (+0.12%), and tended to yield more milk protein (0.08 kg/d) than cows fed CPD. Although ruminal H+ concentrations did not differ between diets, diet x time postfeeding interactions were significant. Ruminal organic acid concentrations did not differ between diets. In experiment 2, cows fed CMD yielded more milk (3.9 kg/d), 3.5% fat- and protein-corrected milk (2.6 kg/d), fat (0.05 kg/d), and protein (0.08 kg/d), whereas cows fed CPD produced greater concentrations of fat (+0.18%), and milk urea nitrogen (0.76 mg/dl). Modifying the proportions of NDSC in the diet can alter milk production and composition, the pattern of ruminal fermentation, and N utilization in dairy cows. 相似文献
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Gourovitch Monica L.; Kirkby Brenda S.; Goldberg Terry E.; Weinberger Daniel R.; Gold James M.; Esposito Giuseppe; Van Horn John D.; Berman Karen Faith 《Canadian Metallurgical Quarterly》2000,14(3):353
To evaluate the functional neuroanatomies underlying letter and category fluency, 18 normal controls were studied with oxygen-15 water regional cerebral blood flow positron emission tomography. Three counterbalanced conditions each consisted of 6 trials (45 s each): letter fluency (generating words when cued with a particular letter), semantic fluency (generating words when cued with a particular category), and a control condition (generating days of the week and months of the year). Relative to the control, participants activated similar brain regions during both fluency tasks, including the anterior cingulate, left prefrontal regions, thalamus, and cerebellum; reductions were found in parietal and temporal regions. In a direct comparison of the 2 fluency tasks, inferior frontal cortex and temporoparietal cortex (hypothesized to participate in a phonologic loop for accessing word pronunciation) were activated more during letter than semantic fluency, whereas left temporal cortex (associated with access to semantic storage) was activated more during semantic than letter fluency. This study identifies subtle differences in the neural networks underlying letter and semantic fluency that may underlie the dissociation of these abilities in patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
145.
2nd generation European Standards for insulating materials and products: test methods for the determination of emissions of volatile organic compounds (VOC) In October 2001 ten “first generation” standards (EN 13162 through EN 13171) were introduced in Europe dealing with insulating materials and products. The new standards now in effect had to be based on the European Construction Products Directive (CPD) and conceptual details had been mandated by the European Commission to the standardization body CEN. Among other properties like thermal conductivity and fire performance the mandate requested to standardize a so called “initial type test (ITT)” for the release of dangerous substances (also called “regulated substances”) to be performed by an independent testing laboratory on behalf of the manufacturer before placing the product onto the market. However, due to the lack of experience and due to a non‐existing European harmonized common method for testing and classification, this property could not be included in the standards in due time and reference was only made to national regulations. Because of this shortcoming, a research project, started in 2003, developed a cost effective and very practical test method based on the emission cell device with a subunit that proved suitable for an initial type test (ITT) for the determination of emissions from thermal insulation materials and products – in particular volatile organic compounds (VOC). 相似文献
146.
虽然细胞分子生物学近年来发展很快,但是细胞培养的方法变化很慢.将近一个世纪以前发明的有盖培养皿至今仍在常规使用,但它已经不适合许多用来观察和分析活体细胞内发生的变化的现代光学分析方法.这篇文章描述了一种细胞培养芯片装置,它能有效地用于细胞培养和随后的高端光学分析,比如荧光和共焦显微镜方法. 相似文献
147.
Industrial gas separation membranes have selective dense layers with thicknesses around 100 nm. It has long been assumed that these thin layers have the same properties as thick (bulk) films. However, recent research has shown that thin films with such thickness experience accelerated physical aging relative to bulk films and, thus, their permeation properties can differ significantly from the bulk. Thin films made from Extem® XH 1015, a new commercial polyetherimide, have been investigated by monitoring their gas permeability. The permeability of the thin films is originally greater than the thick films but eventually decreases well below the permeability of the thick film. The CO2 plasticization of Extem thin films is explored using a series of exposure protocols that indicate CO2 plasticization is a function of film thickness, aging time, exposure time, pressure and prior history. 相似文献
148.
Influence of growth conditions on biofilm development and mass transfer at the bulk/biofilm interface 总被引:8,自引:0,他引:8
In a long-term study on heterotrophic biofilms in tube reactors, this investigation focused on mass transfer at the bulk/biofilm interface, biofilm density and substrate conversion rates. Several biofilms were cultivated under different substrate and hydrodynamic conditions. Oxygen concentration profiles were measured with microelectrodes in the biofilm and in the boundary layer directly in the biofilm tube reactors. The thickness of the concentration boundary layer was found to depend on the surface structure of the biofilm. The hydrodynamic conditions and the substrate load during the growth phase of the biofilm in biofilm systems are two key parameters that influence the biofilm growth, particularly the structure, density and thickness. The measured substrate conversion rates, biofilm densities and the boundary layer thickness were used to formulate an equation for the mass transfer in biofilm tube reactors. 相似文献
149.
A. J. Prieto V. Vásquez A. Silva A. Horn F. J. Alejandre J. M. Macías-Bernal 《Building Research & Information》2019,47(5):567-584
ABSTRACTThe development of objective methodologies for the preventive conservation of historic buildings is extremely relevant to mitigate the deterioration of buildings and sites with exceptional cultural value. In this sense, there is a growing need to develop comprehensive, coherent plans to manage, preserve and protect heritage buildings in areas that are extremely susceptible to natural disasters, such as the case of the Pacific coast of South America. Two methodologies are presented in this study to assess the functional service life and protection level of cultural heritage in Chile. This research intends to establish a correlation between the functional performance of heritage buildings and the Chilean code related to the definition of the preservation of historic heritage buildings. This study applies both methodologies to 25 heritage buildings (timber housing) located in the city of Valdivia, Chile. A multiple linear regression analysis is applied in order to rank the influence of the variables used to define the protection level, according to the Chilean standard, in the functionality index of timber heritage constructions. The information obtained in this study is exceptionally relevant for the researchers and stakeholders responsible for the definition and implementation of maintenance programmes in building stocks. 相似文献
150.