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991.
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The single phase NH4NiPO4·6H2O was synthesized by solid‐state reaction at room temperature using NiSO4·6H2O and (NH4)3PO4·3H2O as raw materials. The NH4NiPO4·6H2O and its calcined products were characterized using X‐ray powder diffraction (XRD), thermogravimetry and differential thermal analyses (TG/DTA), Fourier transform IR (FT‐IR), ultraviolet‐visible (UV‐vis) absorption spectroscopy, and scanning electron microscopy (SEM). The results showed that the product dried at 80°C for 3 h was orthorhombic NH4NiPO4·6H2O [space group Pmm2(25)], and surfactant polyethylene glycol (PEG)‐400 can direct growth of crystal NH4NiPO4·6H2O. The thermal process of NH4NiPO4·6H2O experienced three steps, which involve the dehydration of the five crystal water molecules at first, and then deamination, dehydration of the one crystal water, intramolecular dehydration of the protonated phosphate groups together, at last crystallization of Ni2P2O7. The product of thermal decomposition at 150°C for 2 h, orthorhombic NH4NiPO4·H2O, is layered compound with an interlayer distance of 0.8370 nm. 相似文献
996.
Organometallic derivatives of 2,3-dihydroperimidine were obtained by the solid state interaction of ferrocene-, cymantrene-,
and ruthenocenecarbaldehydes with 1,8-naphthylenediamine.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 1, pp. 145–146, January, 2000. 相似文献
997.
Cadmium determination in biological samples by direct solid sampling flame atomic absorption spectrometry 总被引:1,自引:0,他引:1
rico Marlon de Moraes Flores Jos Neri Gottfried Paniz Ayrton Figueiredo Martins Valderi L. Dressler Edson Irineu Müller Adilson Ben da Costa 《Spectrochimica Acta Part B: Atomic Spectroscopy》2002,57(12):2187-2193
A direct solid sampling flame atomic absorption spectrometric procedure for trace determination of cadmium in biological samples has been developed. Test samples (0.05–2.00 mg) were ground and weighed into small polyethylene vials, which were connected to the device for solid sample introduction into a conventional air/acetylene flame. Test samples were carried as a dry aerosol to a quartz cell, placed between the burner and the optical path, which had a perpendicular entrance and a slit in the upper part. The atomic vapor generated in the flame produced a transient signal that was totally integrated within 1 s. The effect of operating conditions and the extent of grinding on the analytical signal were evaluated. Background signals were always low and a characteristic mass of 0.29 ng Cd was obtained. Calibration was performed using different masses of solid certified reference materials. Results obtained for certified and in-house reference materials were typically within the 95% confidence interval of the certified and/or reference value, and the precision, expressed as relative standard deviation, was between 3.8 and 6.7%. The proposed system is simple and it might be adapted to conventional atomic absorption spectrometers allowing the determination of Cd in more than 80 test samples per hour, excluding weighing. 相似文献
998.
本文对激光通过大气传输引起的热晕进行数值模拟,并采用相位补偿的方法对热晕进行校正,从计算结果中得到经过相位补偿后,光束质量有较好的改善,Strehl比有所提高。从模拟结果中还总结出补偿后的热晕 定标规律公式,发现热晕经补偿后的功率阈值提高3倍以上。 相似文献
999.
Al-pillared, Fe-pillared and mixed Fe-Al pillared systems have been prepared and characterized using EDX and XRD analyses,
surface area pore volume and acidity measurements. Mixed systems are found to be superior to single oxide pillared systems
in terms of acidity and aniline methylation activity.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
1000.
David Valade Frédéric Boschet Stéphanie Roualdès Bruno Ameduri 《Journal of polymer science. Part A, Polymer chemistry》2009,47(8):2043-2058
A membrane or an electrode binder to be used in a solid alkaline fuel cell (SAFC) needs to (i) be insoluble in both aqueous solutions and the required fuels, and (ii) exhibit an hydroxide ion conductivity. To achieve these goals, two pathways were employed: (i) one consists of the radical copolymerization of diallyldimethylammonium chloride (DADMAC) with chlorotrifluoroethylene (CTFE) while (ii) the other one is based on the counter‐ion exchange of a poly(DADMAC) by fluorinated anions. First, the radical copolymerization of CTFE with DADMAC under various experimental conditions was achieved in yields up to 85%, and DADMAC percentages in the copolymers were higher than those in the feed compositions. To obtain insoluble copolymers, high CTFE feed contents (>70 mol %) were required. The other route consisting in the partial replacement of the Cl? counter‐ions in the water‐soluble poly(DADMAC) by bistrifluoromethanesulfonimide (TFSI?) did confer the starting material insolubility in water while maintaining its conductivity. When the fluorinated poly(DADMAC) was obtained from concentrated solutions of fluorinated surfactant, it was observed that the amount of counter‐ions exchanged was difficult to control, which limits optimization. Nevertheless, under diluted conditions, membranes with ion exchange capacity up to 0.7 meq g?1, and conductivities close to 1 mS cm?1 were obtained. Although their conductivities were low, these membranes fulfill the requirements for a SAFC membrane in terms of solubility in DMSO, water insolubility, and thermal stability (Td,10% > 320 °C). When used in a fuel cell, as a binder in the membrane‐electrode assembly (MEA), significant improvements were noted (+50% of the open circuit voltage, +580% in current density, and +540% in accessible power). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2043–2058, 2009 相似文献