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We conduct both simulation and experiment studies of impacts of simultaneously varying the thicknesses of transparent bottom electrodes and semi-transparent top thin metal electrodes on optical characteristics (e.g., transmission, reflection) and efficiencies of transparent organic light-emitting devices (OLEDs). For the thickness range of both electrodes studied, the total electroluminescent (EL) efficiencies (including both bottom and top emission), EL spectra, and emission patterns remain similar; yet the ratio of top to bottom emission would be modulated by the semi-transparent top metal electrode thickness. The thickness of the transparent bottom electrode has weak effects on the efficiencies of top/bottom/total emission, but it does have definite effects on optical transmission/reflection spectra (e.g. peak/valley wavelengths). Meanwhile, the thickness of semi-transparent top metal electrodes mainly affect magnitudes of the optical transmission/reflection. Transmissive/reflective hues and appearances of the transparent OLEDs can thus be tuned by the thicknesses of bottom/top electrodes. Overall, we demonstrated efficient transparent green phosphorescent OLEDs exhibiting a high peak transmittance of up to 81% and rather high total external quantum efficiencies of up to 21–21.5% (corresponding to a total current efficiency of 80–82 cd/A and total power efficiency of 95–99 l m/W), among the highest (if not the highest) for planar transparent OLEDs using no other optical out-coupling structures. By varying the thicknesses of transparent bottom electrodes and semi-transparent top metal electrodes, the ratio of top to bottom emission, and the transmissive or reflective hues/appearances of transparent OLEDs in the off state can be tuned, yet without sacrificing total EL efficiencies or changing their EL colors/patterns. Such tunable optical characteristics of transparent OLEDs may find some interesting applications. 相似文献
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A completely automated flow-injection system was developed for the monitoring of biosorption studies of Cu(II) ion on vegetable waste by-products. The system employed flow-through Cu(II)-selective electrodes, of epoxy-resin-CuS/Ag2S heterogeneous crystalline type, and computer controlled pumps and valves for the flow operation. Computer automation was done through a specially devised virtual instrument, which commanded and periodically calibrated the system, allowing for the monitoring of Cu(II) ions between 0.6 and 6530 mg L−1 at a typical frequency of 15 h−1. Grape stalk wastes were used as biosorbent to remove Cu(II) ions in a fixed-bed column with a sorption capacity of 5.46 mg g−1, obtained by the developed flow system, while the reference determination performed by FAAS technique supplied a comparable value of 5.41 mg g−1. 相似文献
906.
In this paper a carbon ionic liquid electrode (CILE) was fabricated by using ionic liquid 1‐ethyl‐3‐methylimidazolium ethylsulphate ([EMIM]EtOSO3) as the modifier and further used as the working electrode for the sensitive anodic stripping voltammetric detection of Pb2+. The characteristics of the CILE were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In pH 4.5 NaAc‐HAc buffer Pb2+ was accumulated on the surface of CILE due to the extraction effect of IL and reduced at a negative potential (‐1.20 V). Then the reduced Pb was oxidized by differential pulse anodic stripping voltammetry with an obvious stripping peak appeared at ?0.67 V. Under the optimal conditions Pb2+ could be detected in the concentration range from 1.0 × 10?8 mol/L to 1.0 × 10?6 mol/L with the linear regression equation as Ip(μA) = ?0.103 C (μmol/L) + 0.0376 (γ = 0.999) and the detection limit as 3.0 × l0?9 mol/L (3σ). Interferences from other metal ions were investigated and Cd2+ could be simultaneously detected in the mixture solution. The proposed method was further applied to the trace levels of Pb2+ detection in water samples with satisfactory results. 相似文献
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Tomasz Gubica Jadwiga Stroka Andrzej Temeriusz Marianna Kańska 《Journal of Physical Organic Chemistry》2011,24(12):1229-1234
Ten nitrophenyl N‐glycosides have been studied electrochemically in neutral (at pH 7) water–organic solutions by cyclic voltammetry using static mercury drop electrode. For all compounds under investigation the two electrochemical processes have been observed: the four‐electron irreversible reduction of their nitro groups to the corresponding phenylhydroxylamine derivatives, as well as the two‐electron quasi‐reversible process between phenylhydroxylamine and nitroso derivatives. For three compounds the additional electrochemical processes have been also observed, which can be connected with the formation of azoxybenzene derivatives. The potentials of both redox processes: a two‐electron quasi‐reversible R? NHOH/R? NO (Ef) and four‐electron irreversible R? NO2/R? NHOH (Epc(I)) systems have been determined and discussed according to crystal structures of selected compounds. Ef and Epc(I) depended strongly on the positive mesomeric effect (caused by glycosidic nitrogen atom), as well as on the intramolecular hydrogen bond between electroactive nitro group and the hydrogen atom at the glycosidic atom observed in N‐o‐nitrophenyl‐2,3,4,6‐tetra‐O‐acetyl‐β‐D ‐glucopyranosylamine. Moreover, the chirality of selected reactants has had the pronounced effect on the Epc(I). Copyright © 2011 John Wiley & Sons, Ltd. 相似文献