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201.
The ISO 9001 standard is considered as an effective tool to support a quality management system (QMS). A steady growth in the number of ISO 9001 issued certificates is observed worldwide, confirming the interest of companies in this approach. However, information regarding this behaviour over time in the American Continent is scarce. This paper presents a set of qualitative and quantitative analyses related to the ISO 9001 certification (globally and at the country level of the Americas), the use of this standard in countries that were part of the ISO Survey 2011 and modelling the ISO 9001 certification for American countries, in order to characterise through mathematical models, the evolution of the certification process and to identify factors that influence the ISO 9001 issued certificates in the various countries analysed. Based on the work developed, a positive relationship was found between the number of issued certificates in each country per 1000 inhabitants and the indicators of economic development (Gross National Income Per Capita). It is determined that the total reserves of a country is an economic variable that directly affects the number of issued certificates, a finding not observed in other forecasting models.  相似文献   
202.
In this work, supported ionic liquid (IL) phases catalysts were prepared based on Pd dispersed in IL phases supported on magnetic particles of nickel/molybdenum covered with carbon (NiMo/C). The magnetic support was prepared via CVD method at 800 °C. XRD analysis showed the phases of metallic nickel and molybdenum carbide. The presence of carbon in these materials was confirmed by TEM/EDS and thermogravimetric analysis (TG) analysis. Pd particles were dispersed in 1 and 2.5 wt% of the IL 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm·BF4), which were immobilized on the support surface via impregnation method. TG analysis shows a weight loss between 300 and 420 °C attributed to the BMIm·BF4, confirming the existence of IL on the support surface. The prepared materials were investigated in hydrogenations reactions of 1,5-cyclooctadiene and nitrobenzene, and the influence of IL on the activity and selectivity of these catalysts were observed. These materials have great potential for catalysis applications, because they bring together the advantages of the IL in the catalyst surface and the facility of magnetic materials separation.  相似文献   
203.
Thin-walled steel cold-formed members usually display local–global buckling interaction which strongly affects the structural strength of columns and beams. The local bucking of slender folded sections develops in analogy with single plate buckling, including the interaction between the plate elements of the cross-section and can be identified with appropriate first-order stability analysis and the consequent results of the critical buckling loads and the associated modes. The effective section method, ESM, as an extension of the original effective area method, EAM, was conceived for the design of cold-formed members on the basis of the actual local buckling results of the section, together with calibrated formulations for column and beam resistance. The strength equations were taken from the direct strength method, DSM, as it is presented in the North American AISI standard. In addition, as a consequence of its proposed formulation the effective section method is able to be applied side-by-side with the traditional effective width method, EWM, allowing its inclusion in the main part of the codes and specifications for the design of cold-formed members and improving its dissemination. The ESM was proposed in combination with equations and tables that enables designers to directly access the critical local buckling compressive force and bending moment of usual sections, resulting in a contribution that improves the attractiveness of the method.  相似文献   
204.
This paper describes a methodology to establish an optimal process design for prickly pear wine production that preserves the peculiar and unique traits of traditional products, generating at the same time, technical information for appropriate design of both bioreactor and overall process. The strategy includes alcoholic fermentation optimization by the mixed native culture composed by Pichia fermentans and Saccharomyces cerevisiae, followed by malolactic fermentation optimization by Oenococcus oeni. The optimization criteria were based on multiple output functions: alcohol content, volatile compounds profile, organic acids profile, and compound contents related to color, which were analyzed by spectroscopy–chromatography methods and sensory analysis. The results showed that the mixed culture inoculated into a bioreactor containing prickly pear juice with 20 °Bx of fermentable sugars concentration, processed at a constant temperature of 20 °C for 240 h, leads to a fermented product with 9.93% (v/v) total alcohol content, and significant abundance of volatile compounds, which provide fruity and ethereal aromatic notes, complemented by a lively but not unpleasant acidity. This young wine was further subjected to malolactic fermentation at constant temperature (16 °C) for 192 h, decreasing malic acid, and balancing volatile compounds contents, thus resulting in a product with better aroma and flavor perception, and a velvety feeling of long aftertaste. Repeated assays showed that the process is stable, predictable, controllable, and reproducible. These results were used for process design and spreadsheet construction in order to simulate the process, and properly select and size the equipment required for such process.  相似文献   
205.
Traditional multivariate control charts such as Hotelling’s χ 2 and T 2 control charts are designed to monitor vectors of variable quality characteristics. However, in certain situations, data are expressed in linguistic terms and, under these circumstances, variable or attribute multivariate control charts are not suitable choices for monitoring purposes. Fuzzy multivariate control charts such as fuzzy Hotelling’s T 2 could be considered as efficient tools to overcome the problems of linguistic observations. The purpose of this paper is to develop a fuzzy multivariate exponentially weighted moving average (F-MEWMA) control chart. In this paper, multivariate statistical quality control and fuzzy set theory are combined to develop the proposed method. Fuzzy sets and fuzzy logic are powerful mathematical tools for modeling uncertain systems in industry, nature, and humanity. Through a numerical example, the performance of the proposed control chart was compared to the fuzzy Hotelling’s T 2 control chart. Results indicate uniformly superior performance of the F-MEWMA control chart over Hotelling’s T 2 control chart.  相似文献   
206.
207.
The evaluation of the effects of sugars, metals, acids and other antioxidants on the in vitro antioxidant capacity of purified anthocyanin extract by different techniques was the purpose of this study. Three methods and the ways of expressing their results were evaluated: ABTSTEAC (capacity equivalent to Trolox, by ABTS (2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid))), DPPHTEAC (capacity equivalent to Trolox, by DPPH (2,2‐diphenyl‐1‐picrylhydrazyl)), DPPHEC50 (50% reduction in the radical, by DPPH), DPPH%Sca (reduction in the scavenging capacity, by DPPH), FRAPTEAC (capacity equivalent to Trolox, by FRAP (reduction power of iron)) and FRAPEC50 (50% reduction in the radical, by FRAP). The way of expressing DPPH and FRAP results as EC50 showed the greater interfering extent, mainly when the medium contained tartaric and ascorbic acids. The most coherent method was ABTSTEAC in which only ascorbic acid interfered. Ascorbic acid was shown to interfere in all methods; thus, it must be removed prior to determining the in vitro antioxidant capacity of anthocyanins in food materials.  相似文献   
208.
Navigation through large microscopical images demands special characteristics like flexibility to access image data and progressive recovery or relevant information, i.e., several qualities, magnifications, and random accesses to any desired Window of Interest in the Virtual Slide (VS). Nowadays there exist systems that allow such interaction, but with a certain delay, which is dependent on the application. It has been shown that caching or prefetching policies can speed up interaction with these systems. This article presents an optimal soft‐cache strategy, which improves the navigation times in virtual microscopy. The entire method includes an optimal soft‐cache strategy and a dynamical probabilistic model of a pathologist's navigation. This strategy was implemented as a Client‐Server application, using the JPEG2000‐JPIP standard and evaluated using different navigation patterns, namely, four different pathologists exploring 10 VS, stained with different dyes. The present approach was compared with a conventional soft‐cache method and the cache performance improved, in average, in about a 10%. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.  相似文献   
209.
210.
In this work, a novel sol-gel-based procedure to obtain solid carbon composite electrodes is proposed. The procedure is based on the use of sonocatalysis to apply high-energy ultrasound directly to the precursors; this way, ultrasonic cavitation is achieved so that hydrolysis with acidic water is promoted in the absence of any additional solvent and the time needed to get a unique phase is reduced drastically. The mix of sonogel with spectroscopic grade graphite leads to a new type of sol-gel electrode: the Sonogel-Carbon electrode. The amount of water, necessary for hydrolysis to occur, has been studied, as well as the sol pH value and the electrochemical behavior of the Sonogel-Carbon electrode in Britton-Robinson buffer. Mechanical renewal of the electrodes surfaces and background signal stability for at least 42 days have been also tested. We have carried out some tests to check the ability of the synthesized material to give electrochemical response when redox species are present in the background electrolyte. Mechanical and electrochemical studies indicate that the Sonogel-Carbon electrode shows good properties for use as an electrochemical sensor.  相似文献   
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