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21.
Ohne Zusammenfassung 相似文献
22.
C Baeken H D'haenen P Flamen J Mertens D Terriere K Chavatte R Boumon A Bossuyt 《Canadian Metallurgical Quarterly》1998,25(12):1617-1622
5-HT2A receptors have been implicated in the pathophysiology of mood disorders and in the therapeutic effect of the so-called atypical antipsychotics. Recently, a new radioiodinated ligand with high affinity and selectivity for serotonin 5-HT2A receptors, 123iodinated 4-amino-N-1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl] 5-iodo-2-methoxybenzamide (123I-5-I-R91150), has been developed and has been shown to be suitable for single-photon emission tomography (SPET) imaging. In this study the influence of age and gender on the ligand binding was investigated in normal volunteers. One hundred and fifty MBq of 123I-5-I-R91150 was administered to 26 normal volunteers (13 females and 13 males) with an age range of 23-60 years. SPET imaging was performed with a triple-headed gamma camera. For semi-quantitative analysis, ratios of ligand binding in different regions of interest to the binding in the cerebellum were calculated. Mean ratios of 1.7 were obtained. No gender difference was demonstrated. 5-HT2A binding was shown to decline with age. Over an age range of 40 years a reduction in ligand binding of 42% +/- 7% was found. These results are in agreement w in vitro and positron emission tomography findings of a decline in 5-HT2A receptor binding with age. The findings confirm the suitability of 123I-5-I-R91150 for SPET imaging of 5-HT2A receptors, and highlight the necessity for age-matched controls in clinical studies. 相似文献
23.
The shapes of our cities change very frequently. These changes have to be reflected in data sets representing urban objects.
However, it must be assured that frequent updates do not affect geometric-topological consistency. This important aspect of spatial data quality guarantees essential assumptions on which users and applications of 3D city
models rely: viz. that objects do not intersect, overlap or penetrate mutually, or completely cover one another. This raises
the question how to guarantee that geometric-topological consistency is preserved when data sets are updated. Hence, there
is a certain risk that plans and decisions which are based on these data sets are erroneous and that the tremendous efforts
spent for data acquisition and updates become vain. In this paper, we solve this problem by presenting efficient transaction rules for updating 3D city models. These rules guarantee that geometric-topological consistency is preserved (Safety) and allow for the generation of arbitrary consistent 3D city models (Completeness). Safety as well as completeness is proven with mathematical rigor, guaranteeing the reliability of our method. Our method
is applicable to 3D city models, which define—besides the terrain surface—complex spatial objects like buildings with rooms
and storeys as interior structures, as well as bridges and tunnels. Those objects are represented as aggregations of solids,
and their surfaces are complex from a topology point of view. 3D GIS models like CityGML, which are widely used to represent cities, provide the means to define semantics, geometry and topology, but do not address
the problem of maintaining consistency. Hence, our approach complements CityGML. 相似文献
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25.
Mertens W. G. Rubin L. J. Teasdale B. F. 《Journal of the American Oil Chemists' Society》1961,38(6):286-289
A fractional crystallization method for the winterization of cottonseed oil with solvents was developed in our laboratories
and pilot plant.
Small amounts of solvent (e.g., 10% by weight of acetone) were mixed with the oil. This mixture was rapidly chilled to 0°C. and kept at this temperature
for 3–4 hrs.; the liquid portion was separated from the solids.
After solvent evaporation a salad oil of good quality was obtained. The yield is equal to or better than that obtained with
conventional methods.
The method is suitable for a continuous operation since rapid chilling can be used, and only a short over-all time is necessary.
Great advantages of the process are the use of low amounts of solvent and of a refrigeration system not requiring temperatures
below 0°C. 相似文献
26.
Ekkehard H. Lutz 《Journal of the American Ceramic Society》1994,77(5):1274-1280
Plasma spraying, originally a surfacing technology used for ceramic coating of metal and nonmetal substrates, is suitable for producing large, full ceramic bodies, such as plates and tubes, in situ to almost the desired dimensions; i.e., conventional methods of designing by molding and casting green bodies followed by sintering are not required. These "plasma ceramics" exhibit characteristic mechanical and thermomechanical properties. Their porous laminar grain structure results in low E -modulus and strength, and in extreme thermal shock resistance, which is enhanced by the comparably high fracture resistance of the material. Because of these properties and their low hardness, plasma ceramics can be easily machined with almost conventional methods of metal processing. 相似文献
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30.
Wey Yang Teoh Frans Denny Rose Amal Donia Friedmann Lutz Mädler Sotiris E. Pratsinis 《Topics in Catalysis》2007,44(4):489-497
A comparative photocatalytic analysis was carried out on TiO2 made in a Flame Spray Pyrolysis (FSP) process and flame-made Degussa P25. Both have similar crystallinity, phase composition,
phase segregation and a non-porous surface. Hence comparison was made based on their difference in specific surface area,
organic adsorption and the amount of OH• generated upon illumination. The photocatalytic activity tests were carried out using
the following series of organic compounds: sucrose, glucose, fructose, maleic acid, glyoxylic acid, oxalic acid, isobutyric
acid, phenol and methanol. FSP-made TiO2 outperformed P25 for saccharides mineralisation, while for phenol and methanol mineralisation P25 was better than FSP-made
TiO2. Similar mineralisation rates were observed for both FSP-made and P25 TiO2 for the mineralisation of carboxylic acids. This shows that the relative performance of the photocatalysts depends on the
type of organic compounds to be degraded. The high surface area and possibly a more efficient interfacial charge transfer
of FSP-made TiO2 provided an efficient pathway for saccharides mineralisation. As for phenol and methanol, the mineralisation rates were higher
when using P25 due to the greater amount of OH• radicals generated by this photocatalyst. The fast mineralisation rates of
carboxylic acids made degradation of these organic compounds to be less affected by the TiO2 photocatalyst properties and conditions tested in this work. 相似文献