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101.
ABSTRACT Drying studies were carried out on single droplets suspended from a rotating nozzle in a horizontal wind tunnel. Droplets were of solution of a third type of skin-forming material, namely the natural products skim milk or fructose. Droplet weight and temperature were measured during the drying process. Dried crusts were recovered and examined by Scanning Electron Microscopy. With this type of material a skin first forms at any drying condition on the surface of the droplet at a cerlain stage of drying. A crust subsequently forms beneath the skin. The final dried panicle retains the structure and properties of the original powder, unless the material is dried at very high temperatures. e.g. >300 °C. which result in burning. An increase in air temperature resulted in the formation of a smoother skin offering a higher resistance to vapour diffusion. At temperatures over 100 °C droplets exhibited puffing or ballooning phenomena; i.e. they inflated and deflated many times before forming the final dried particles. 相似文献
102.
Max Müller A. Kirsten A. Rammul A. Hebebrand A. Spieckermann C. Mai H. Will und A. Oelker 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1903,6(5):219-239
Ohne Zusammenfassung 相似文献
103.
Clive J. Oliphant Christopher J. Arendse Sara N. Prins Gerald F. Malgas Dirk Knoesen 《Journal of Materials Science》2012,47(5):2405-2410
We report on the application of electron backscatter diffraction to investigate the structural changes of a tantalum filament
operated at typical hot-wire chemical vapour deposition conditions for the synthesis of hydrogenated nanocrystalline silicon.
Various tantalum-silicides, identified by electron backscatter diffraction, form preferentially along the length of the filament.
The filament has a recrystallized Ta inner core and a TaSi2 layer encapsulated with a Si layer at the cooler ends. The αTa5Si3, metastable Ta5Si3 and Ta2Si phases formed in addition to recrystallized Ta and TaSi2 at the centre regions. Cracks and porosity were prevalent throughout the length of the filament. The microstructural evolution
of the aged tantalum filament can be ascribed to the thermal gradient along the filament length, recrystallization of Ta and
the variation of silicon content within the filament. 相似文献
104.
Clive R. Cartlidge Leisl Dukhedin-Lalla Parviz Rahimi John M. Shaw 《Petroleum Science and Technology》2013,31(1-2):163-178
ABSTRACT The phase behaviour of heavy oil mixtures was studied using an X-ray imaging system. Batch phase experiments were performed at temperatures and pressures up to 725 K and 7 MPa. Complex phase behaviour such as liquid-liquid-vapour and solid-liquid-liquid-vapour were observed and preliminary experimental phase diagrams were constructed. This observed complex phase behaviour is consistent with thermodynamic theory and such phase behaviour can be modelled using the Peng-Robinson equation of state and the tangent plane criterion. These latter points are illustrated through the phase diagram for a model reservoir fluid (ethane + propane + n-butane + phenanthrene) which exhibits solid-liquid-liquid-vapour phase behaviour. Example predicted and experimental phase diagrams are presented for this model system. 相似文献
105.
Anne Lanfer Karin Bammann Kolja Knof Kirsten Buchecker Paola Russo Toomas Veidebaum Yiannis Kourides Stefaan de Henauw Dénes Molnar Silvia Bel-Serrat Lauren Lissner Wolfgang Ahrens 《Food quality and preference》2013,27(2):128-136
The present study investigated taste preferences in a sample of 1705 children aged 6 to 9 years from survey centres in Italy, Estonia, Cyprus, Belgium, Sweden, Germany, Hungary, and Spain and aimed to identify factors correlated with taste preference. Children’s preferences for varying levels of sucrose (sweet) in apple juice and fat, sodium chloride (salt) and monosodium glutamate (umami) in crackers were assessed using paired-comparison tests. Socio-demographics (age, sex, parental education), early feeding practises (breastfeeding, introduction of fruits), parenting behaviour (TV viewing, using food as a reward) and taste threshold sensitivity for sucrose (sweet), sodium chloride (salt), caffeine (bitter) and monosodium glutamate (umami) were investigated as possible correlates of taste preferences. Parents reported on socio-demographics, early feeding and parenting behaviour. Taste thresholds were determined via a paired-comparison staircase method. Country of residence was the strongest factor related to preferences for all four tastes. Taste preferences also differed by age. Preference for sugar and salt increased between 6 and 9 years of age while preference for monosodium glutamate decreased. The age differences remained significant even after adjustment for sex, country of residence, parental education and early feeding habits. Sex, parental education, early feeding habits, TV viewing, using food as a reward and taste thresholds were not consistently related to taste preferences among the survey centres. In summary, the results highlight the importance of culture and age in taste preferences in children younger than 10 years of age. 相似文献
106.
107.
Many organic compounds including some herbicides concentrate in sediment, thus it may be expected that interstitial waters contain higher concentrations of these contaminants than the water column. To estimate benthic microalgal exposure to pesticides, sediment and interstitial water sampled in the dry season from four major rivers in north Queensland, Australia, were analysed for these contaminants. Interstitial water extracts from the sediments were tested for acute phytotoxicity to benthic microalgae using PAM fluorometry and the results were compared with chemical analyses of the same water samples. A range of pesticides were detected in both sediment and interstitial waters from all sites, notably the herbicide diuron at concentrations ranging from 0.3 to 11 μg kg−1 dry weight sediment, and up to 68 ng L−1 in interstitial waters. Herbicide concentrations estimated from partition coefficients and the sediment concentrations typically overestimated analytically determined concentrations present in interstitial water by an order of magnitude. The analytically determined herbicide concentrations in the interstitial water explained most of the phytotoxicity measured with the bioassay; however, photoinhibition was slightly higher than expected based on analytical results, indicating the presence of unidentified phytotoxins. These results demonstrate the presence of pesticides in interstitial waters in the Tropical dry season, sometimes at concentrations that may affect sensitive benthic organisms, and supports the use of the I-PAM bioassay as a valuable tool in exposure- and environmental risk- and impact-assessments. 相似文献
108.
Anton V. Polotai Tae-Hee Jeong Gai-Ying Yang Elizabeth C. Dickey Clive A. Randall Pascal Pinceloup Abhijit S. Gurav 《Journal of Electroceramics》2009,23(1):6-12
Multilayer ceramic capacitors based on BaTiO3 dielectric compositions and Ni inner electrodes have complex interfacial reactions that impact the continuity of the inner
electrode microstructure. Previously we demonstrated that through the addition of Cr to Ni, a significant improvement in the
continuity of ultra-thin Ni electrodes in Ni–BaTiO3 multilayer capacitors could be achieved. Here, the effect of the Cr addition to the nickel electrode pastes is studied with
regard to the electrical properties. Low-field electrical measurements demonstrate no major differences between Cr doped Ni
and undoped Ni. However, high-field measurements show a significant decrease to the total capacitor resistance. Under a critical
electrical bias the conductivity significantly increases due to a Fowler–Nordheim tunneling conduction though the interfacial
Schottky barrier at the dielectric–electrode interface; the onset voltage of this conduction is much lower than with the undoped
nickel. Based on these results, we evaluate criteria for the selection of an appropriate refractory metal in order to improve
the Ni electrode continuity. 相似文献
109.
A. Hasterlik G. Sonntag C. A. Neufeld A. Kirsten A. Hebebrand und A. Oelker 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1905,9(1):39-47
Ohne Zusammenfassung 相似文献
110.