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991.
992.
O.E. Dragomir M.J. Tummers E.H. van Veen D.J.E.M. Roekaerts 《Combustion and Flame》2009,156(9):1810-1817
This paper presents the results of a series of experiments on the condensed phase decomposition and the gas phase combustion of hydrazinium nitroformate (HNF). The experiments include SEM analysis of quenched samples that showed evidence of the formation of a foam layer. FTIR spectrometry and mass spectrometry provide details on species formation during decomposition and combustion. The analysis of the results led to the identification of probable overall reactions in the low pressure regime around 0.1 MPa. It is found that decomposition of HNF takes place through formation of ammonium nitroformate, and through dissociative vaporisation. The gas phase near the surface of burning HNF is expected to contain a large amount of hydrazine, ammonia and nitrogen dioxide (as a decomposition product of nitroform). The primary reaction zone of the HNF flame is then associated with the exothermic reactions of these species. The resulting nitrogen oxide is subsequently reduced to molecular nitrogen in the secondary flame. 相似文献
993.
Zandra Arwidsson Kristin Elgh-Dalgren Thomas von Kronhelm Ragnar Sjöberg Bert Allard Patrick van Hees 《Journal of hazardous materials》2010,173(1-3):697-704
Removal of Cu, Pb, and Zn by the action of the two biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS) and methylglycinediacetic acid (MGDA), as well as citric acid, was tested. Three soil samples, which had previously been treated by conventional soil washing (water), were utilized in the leaching tests. Experiments were performed in batches (0.3 kg-scale) and with a WTC-mixer system (Water Treatment Construction, 10 kg-scale). EDDS and MGDA were most often equally efficient in removing Cu, Pb, and Zn after 10–60 min. Nonetheless, after 10 d, there were occasionally significant differences in extraction efficiencies. Extraction with citric acid was generally less efficient, however equal for Zn (mainly) after 10 d. Metal removal was similar in batch and WTC-mixer systems, which indicates that a dynamic mixer system could be used in full-scale. Use of biodegradable amino polycarboxylic acids for metal removal, as a second step after soil washing, would release most remaining metals (Cu, Pb and Zn) from the present soils, however only after long leaching time. Thus, a full-scale procedure, based on enhanced metal leaching by amino polycarboxylic acids from soil of the present kind, would require a pre-leaching step lasting several days in order to be efficient. 相似文献
994.
Liberalisation and privatisation have increased the need to gain more understanding into the management of hydro storage (HS) plants. We analyse what types of reservoir management policies enable an owner or a public authority to achieve their respective objectives. By “policy” we understand simple, easily applicable decision rules, which enable a decision maker to decide when and how much to produce based on currently available information. We use a stylised deterministic simulation model of a hydro-power producer (HP) who behaves strategically. We study a non-liberalised market, where the authorities aim to minimise the total electricity cost for customers and a liberalised market where the HP attempts to maximise his contribution. This enables us to evaluate the impact of the liberalisation of HS production decisions on production volumes and electricity prices. We conclude that imposing rigid policies with the aim of limiting the potential for strategic behaviour can create incentives to produce only at very high prices throughout the year. This can lead to very high total costs, especially when the producer has most flexibility (large reservoirs combined with large turbine capacity). More surprisingly, we observe lower total production in a non-liberalised market. 相似文献
995.
E.Y. Sako M.A.L. Braulio E. Zinngrebe S.R. van der Laan V.C. Pandolfelli 《Ceramics International》2012,38(3):2243-2251
Although the physical expansion associated with the in situ formation of magnesium–aluminate spinel (MgAl2O4) is well-reported, some questions related to this behavior, such as the different volume change values experimentally attained when compared to theoretical one and the pore generation after the reaction, remain open. Thus, the main objective of this work is to shed some light on these questions by evaluating a cement-bonded alumina–magnesia castables, designed using dead-burnt magnesia of different particle size ranges. Microstructural observations suggested that the faster Mg2+ migration during the spinel formation led to vacancy accumulation and, consequently, to pore generation, as a direct result of the Kirkendall effect. Additionally, the overall expansion of alumina–magnesia castables seemed to be ruled by two main factors: its sintering efficiency and the different possibilities of the Al2O3 and MgO interactions in the mixture. Those consequences, however, do not usually affect the castable corrosion behavior in industrial applications, due to the benefits imposed by the structural constraint. 相似文献
996.
Dan B. Jensen Mariska van der Voort Henk Hogeveen 《Journal of dairy science》2018,101(11):10428-10439
Accurate forecasting of dairy cow milk yield is useful to dairy farmers, both in relation to financial planning and for detection of deviating yield patterns, which can be an indicator of mastitis and other diseases. In this study we developed a dynamic linear model (DLM) designed to forecast milk yields of individual cows per milking, as they are milked in milking robots. The DLM implements a Wood's function to account for the expected total daily milk yield. It further implements a second-degree polynomial function to account for the effect of the time intervals between milkings on the proportion of the expected total daily milk yield. By combining these 2 functions in a dynamic framework, the DLM was able to continuously forecast the amount of milk to be produced in a given milking. Data from 169,774 milkings on 5 different farms in 2 different countries were used in this study. A separate farm-specific implementation of the DLM was made for each of the 5 farms. To determine which factors would influence the forecast accuracy, the standardized forecast errors of the DLM were described with a linear mixed effects model (lme). This lme included lactation stage (early, middle, or late), somatic cell count (SCC) level (nonelevated or elevated), and whether or not the proper farm-specific version of the DLM was used. The standardized forecast errors of the DLM were only affected by SCC level and interactions between SCC level and lactation stage. Therefore, we concluded that the implementation of Wood's function combined with a second-degree polynomial is useful for dynamic modeling of milk yield in milking robots, and that this model has potential to be used as part of a mastitis detection system. 相似文献
997.
Pieter Coenen Idsart Kingma Cécile R.L. Boot Paulien M. Bongers Jaap H. van Dieën 《Applied ergonomics》2013
Valid and reliable low-back load assessment tools that can be used in field situations are needed for epidemiologic studies and for ergonomic practice. The aim of this study was to assess the inter-rater reliability of a low-back load video-analysis method in a field setting. 相似文献
998.
A. Jokić M. Lazar P.P.J. van den Bosch 《International Journal of Electrical Power & Energy Systems》2009,31(9):522-530
This article presents a novel control scheme for achieving optimal power balancing and congestion management in electrical power systems via nodal prices. We develop a dynamic controller that guarantees economically optimal steady-state operation while respecting all line flow constraints in steady-state. A benchmark example illustrates the effectiveness of the proposed control scheme. 相似文献
999.
1000.
Jan Benjamins Monique H. Vingerhoeds Franklin D. Zoet Els H.A. de Hoog George A. van Aken 《Food Hydrocolloids》2009
This study evaluates the role of partial coalescence of whey protein-stabilized emulsions on sensory perception. The selection of fats was restricted to vegetable fats that are essentially melted at oral temperatures. The sensitivity to partial coalescence was controlled by a variation in the fat melting curve and by addition of unsaturated monoglyceride. Most fat-related sensory attributes appear to be well-correlated to an increase in viscosity and coalescence in the mouth due to partial coalescence. Moreover, it was found that in-mouth aeration induces extra coalescence, which increases the perception of fat-related sensory attributes significantly. 相似文献