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41.
A black-box methodology of a parallel generation of adaptive anisotropic meshes is described. A control of mesh adaptation, important for robustness and flexibility, may effect parallel properties of the methodology. This is demonstrated with a 3D example. 相似文献
42.
Lead-acid cells evolve hydrogen and oxygen gasses during the charging mode, which results in a water loss. Gas recombination devices extend the water refilling periods due to the recombination reactionH2 + O2 → H2O The recombination devices consist of: aerosol retainer, charcoal filter, catalyst, condenser, gas storage and vents. Theoretical models describing the self-limiting behaviour of the catalyst and the heat flow conditions in the device were developed.Design specifications of component requirements for a 435-W recombination device, which is capable of recombining 182 l/h stoichiometric oxyhydrogen gas, were also developed. Tests with the system (recombination device-lead-acid cell) showed that a maintenance-free and nearly gastight operation was achieved. The use of catalytic recombination devices improves the economy and safety of battery operation. 相似文献
43.
Khoruzhaya Vera G. Meleshevich Konstantin A. 《Powder Metallurgy and Metal Ceramics》2003,42(5-6):268-273
Phase equilibria in the ternary system Mg – Al – Ca in the composition range 50-100 mass% Mg were studied by the methods of differential thermal, xray diffraction, electron-probe and microscopic analysis. The projection of the liquidus surface on the concentration triangle, isothermal section at 150°C and polythermal sections at 4.5, 8.5, and 16 mass% Al were constructed. It was determined that additions of Al and Ca decrease the liquidus temperature of magnesium alloys (from 650 to 438°C). It is shown that the three-phase region + 2Ca> + 17Al12> exists at 150°C with the corresponding two-phase fields. The temperature dependence of the homogeneity range of the Mgbased solid solution was determined, and also the temperatures of the phase transformations which occur in the investigated range of compositions in the system. 相似文献
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Ioannis Rigopoulos Basilios Tsikouras Panagiotis Pomonis Konstantin Hatzipanagiotou 《International Journal of Rock Mechanics and Mining Sciences》2010,47(1):69-80
The influence of alteration on the physico-mechanical properties of dolerites from the Pindos and Vourinos ophiolites, northern Greece, is investigated. Quantitative petrographic analysis shows that the samples display various percentages of secondary minerals. Two new micropetrographic indices are calculated from the results of petrographic modal analysis for the engineering assessment of dolerites: the micropetrographic strength index Ips and the replacement index Irep. The samples are also tested to determine water absorption, apparent density, total porosity, sand equivalent, uniaxial compressive strength, Los Angeles abrasion value, aggregate impact value, aggregate abrasion value and polished stone value. The influence of alteration on the rock quality and especially the relationships between the proposed micropetrographic indices and the engineering parameters are determined using regression analysis and the derived equations were verified by the t-test and the F-test. The relationships between the Ips and Irep indices and the engineering properties show that alteration products generally result in mechanically weaker rocks. However, the results of the physico-mechanical tests indicate that dolerites retain their strength and durability due to the low proportions of soft minerals and microcracks, along with the preservation of their igneous textures. The polishing resistance is the only engineering parameter that is positively affected by alteration processes, as expressed by the Ips index. Particularly, the replacement of the primary mafic minerals by secondary minerals, expressed by the Irep index, can enhance the polishing resistance of dolerites when used in the wearing surface of a road. The results also indicate strong positive correlations between the chlorite content and the water absorption and total porosity values. 相似文献
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47.
Self-citation can inflate h-index 总被引:1,自引:1,他引:0
48.
Konstantin L. Gavrilov Stephen J. Bennison Kurt R. Mikeska Jan M. Chabala Riccardo Levi-Setti 《Journal of the American Ceramic Society》1999,82(4):1001-1008
Trace SiO2 and MgO additive distributions in sintered alumina have been studied using high-resolution scanning secondary ion mass spectrometry (SIMS). When doped with each additive individually, evidence is seen for both strong silicon segregation to grain boundaries ( C gb / C grain similar/congruent 300) in SiO2 -doped alumina and strong magnesium segregation to grain boundaries ( C gb / C grain similar/congruent 400) in MgO-doped alumina. When codoped with both SiO2 and MgO, segregation of both ions to grain boundaries is reduced by a factor of 5 or more over single doping. The additive concentrations increase proportionally in the grains, and both dopants become more uniformly distributed throughout the bulk. It is concluded that codoping with these additives increases their mutual bulk solid solubility and decreases their interfacial segregation over single doping. The beneficial effect of MgO additions in controlling microstructure development in alumina and improving corrosion resistance to aqueous HF stems from its ability to redistribute silicon ions from grain boundaries into the bulk. 相似文献
49.
Dmitry Elnyakov Konstantin Kalmykov Sergey Dunaev 《Journal of Phase Equilibria and Diffusion》2018,39(2):204-211
The isothermal section of the Er-Ag-Sn system at 873 K was constructed with the use of scanning electron microscopy, energy-dispersive x-ray microanalysis and x-ray powder diffraction. Two ternary compounds were confirmed at this temperature: ErAgSn (LiGaGe structure type, P63mc, Z = 2, a = 4.6595(2) Å, c = 7.2872(3) Å) and non-stoichiometric phase ErAg1?xSn2+x (Cu3Au structure type, Pm-3m, Z = 1). For the last one homogeneity range was established (0.08 < x < 0.24) and lattice parameters were determined (a = 4.5007(4), 4.5040(2), 4.5107(1), 4.5412(1) Å for the compositions Er25.4Ag23.4Sn51.2, Er25.7Ag23.0Sn51.3, Er25.7Ag21.7Sn52.6, Er25.2Ag18.6Sn56.2 (at.%) respectively). Melting point of the phase Er25.7Ag21.7Sn52.6 (at.%) was determined to be 1199 K by differential thermal analysis. 相似文献
50.
Aryl Bis‐Sulfonamide Inhibitors of IspF from Arabidopsis thaliana and Plasmodium falciparum 下载免费PDF全文
Jonas Thelemann Dr. Boris Illarionov Dr. Konstantin Barylyuk Dr. Julie Geist Prof. Dr. Johannes Kirchmair Dr. Petra Schneider Lucile Anthore Katharina Root Dr. Nils Trapp Prof. Dr. Adelbert Bacher Dr. Matthias Witschel Prof. Dr. Renato Zenobi Prof. Dr. Markus Fischer Prof. Dr. Gisbert Schneider Prof. Dr. François Diederich 《ChemMedChem》2015,10(12):2090-2098
2‐Methylerythritol 2,4‐cyclodiphosphate synthase (IspF) is an essential enzyme for the biosynthesis of isoprenoid precursors in plants and many human pathogens. The protein is an attractive target for the development of anti‐infectives and herbicides. Using a photometric assay, a screen of 40 000 compounds on IspF from Arabidopsis thaliana afforded symmetrical aryl bis‐sulfonamides that inhibit IspF from A. thaliana (AtIspF) and Plasmodium falciparum (PfIspF) with IC50 values in the micromolar range. The ortho‐bis‐sulfonamide structural motif is essential for inhibitory activity. The best derivatives obtained by parallel synthesis showed IC50 values of 1.4 μm against PfIspF and 240 nm against AtIspF. Substantial herbicidal activity was observed at a dose of 2 kg ha?1. Molecular modeling studies served as the basis for an in silico search targeted at the discovery of novel, non‐symmetrical sulfonamide IspF inhibitors. The designed compounds were found to exhibit inhibitory activities in the double‐digit micromolar IC50 range. 相似文献