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71.
BT Heelan S Osman A Blyth L Schnorr T Jones AJ George 《Canadian Metallurgical Quarterly》1998,66(8):1101-1103
BACKGROUND: We investigated the potential of predicting allograft rejection by measuring the ability of graft-infiltrating cells to take up 2-[18F]fluoro-2-deoxyglucose ([18F]FDG). This molecule is a positron emitting glucose analogue that is taken up by metabolically active cells and can be detected using positron emission tomography. METHODS: Uptake of [18F]FDG during an alloresponse was measured both in vitro in mixed lymphocyte cultures and in vivo using allogeneic and syngeneic skin grafts. RESULTS: Uptake of [18F]FDG was seen in a mixed lymphocyte reaction. Using a mouse skin graft model, we found that mean [18F]FDG uptake was 1.5-2 times higher in allografts than in syngeneic grafts; the increase in uptake correlated with the level of T-cell infiltrate seen histologically. CONCLUSION: Assessing the metabolic activity of graft-infiltrating cells with [18F]FDG may be useful in the prediction of graft rejection episodes. 相似文献
72.
Adamantios S. Diamantopoulos George N. Angelopoulos Demetrios C. Papamantellos 《国际钢铁研究》1996,67(5):179-187
Nickel losses in the slag generated at Larco electric reduction furnaces (ERF) during smelting of Greek laterites account for about 20% of the total nickel of the feed. The recovery of the nickel contained in the slag as well as in its magnetic concentrate was studied under different methods. The experimental results have shown that a nickel recovery in the range of 75-90% is possible by allowing the slag to settle. Washing by low carbon steel can be performed during the final stages of the settling process as it improves the finally attained nickel recovery up to 94.4%. The simultaneous carbon reduction and settling process do not favour the Ni- recovery as the produced carbon monoxide and dioxide cause boiling of the bath which promotes the flotation of the metallic grains. In all cases a reoxidation of nickel was observed after 20min approximately. Settling of the ferronickel grains was described by a mathematical model. The model's results are in good agreement to the experimental ones for the initial 20min of the process. A modified model was elaborated combining the settling of the metallic grains with the nickel reoxidation reaction. This model describes with adequate accuracy the whole Ni- recovery process. The developed model can be proven helpful in the design of a slag cleaning step for metal recovery utilizing a slag settling furnace operating on line to the ERF. 相似文献
73.
Water Resources Management - 相似文献
74.
Moutafis Panagiotis García-García Francisco Mavrommatis George Vassilakopoulos Michael Corral Antonio Iribarne Luis 《Distributed and Parallel Databases》2021,39(3):733-784
Distributed and Parallel Databases - Given two datasets of points (called Query and Training), the Group (K) Nearest-Neighbor (GKNN) query retrieves (K) points of the Training with the smallest sum... 相似文献
75.
A kinetic analysis of the isothermal nitridation of high-purity oxide-free silicon powder is described. The kinetic analysis suggests that the and polymorphs of Si3N4 are formed by separate and parallel reaction paths. This analysis provides for the decoupling and quantitative kinetic interpretation of- and-Si3N4 formation reactions. Consistent with existing microstructural and thermodynamic evidence, the-forming reaction is shown to obey a first-order rate law, whereas a phase-boundary controlled rate law describes the-forming reaction. A kinetic model employing these rate laws is developed and is used to predict the/ phase ratio as a function of isothermal reaction temperature and extent of reaction. The/ phase ratios so obtained are shown to be in good agreement with experimental observations made under a variety of reaction conditions. 相似文献
76.
77.
Tsan-Yue Yang George E. Klinzing Shiao-Hung Chiang Fernando J. Aguirre 《Chemical Engineering Communications》1988,64(1):1-11
In the study of mass transfer between partially miscible liquids, temperature perturbations have been found to have an important effect in the generation of interfacial activity. Micro- and macro-generated interfacial convection usually occurs in combination with one another even in fairly simple heat or mass transfer events. These combinations are responsible for the enhancement of mass transfer rates. In an effort to acquire a better understanding of the heat transfer effects in ternary liquid-liquid systems, temperature difference profiles were measured when contacting two partially miscible phases. A vertical and a rotational transfer cell were designed to contact the partially miscible phases without inducing external disturbances. Five thermocouples were immersed in the bottom liquid phase at predetermined positions below the interface. In order to understand the influence of the convection generated, the vertical cell was designed to hinder convection in one phase, while the rotational cell permits convection in both phases. The experimental results showed larger temperature differences in the rotational cell after the contact of the phases. Also, systems which were initially unsaturated presented larger heat effects than those in which the partially miscible solvents were initially saturated. Several parameters indicating the importance of heat effects in the ternary systems studied are reported. 相似文献
78.
George M. Campbell 《Chemical Engineering Communications》1990,98(1):223-230
The room temperature adsorption of PuF6(g) on a solid substrate was compared to the adsorption of UF6(g) on the same surface. Significantly more PuF6(g) was adsorbed at pressures in the range of 1.2 to 0.2torr, accompanied by the evolution of molecular fluorine. The adsorbed UF6 was easily desorbed by reducing the pressure. Most of the adsorbed PuF6 remained on the surface when subjected to the same treatment. 相似文献
79.
80.
JuvenileAplysia dactylomela were found feeding in abundance on the tropical brown algaStypopodium zonale, a seaweed previously shown to contain numerous unique terpene-quinone natural products. Lipid extracts of these herbivorous mollusks were shown by TLC and HPLC-NMR analyses to contain appreciable quantities of twoS. zonale metabolites as well as one new but closely related compound. Spectroscopic analyses of the new compound in concert with functional group modifications identified this new compound as 3-keto epitaondiol. A careful analysis of the seaweed extract failed to locate this ketone, and thus, it most likely represents anAplysia-biotransformed compound. This is the first clear reported observation of metabolite transfer between an alga of the phylum Phaeophyta and a sea hare. 相似文献