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Umakoshi K Yamasaki T Fukuoka A Kawano H Ichikawa M Onishi M 《Inorganic chemistry》2002,41(16):4093-4095
Treatment of pyridine-2-thiol (pytH) with H(2) (60 atm) in the presence of 5-methylpyridine-2-thiolate (5-mpyt)-bridged dinuclear Pt(III), Pt(II), or Pd(II) complexes (1 mol %) in DMF at 150 degrees C for 72 h leads to the formation of pyridine in 3-51% yield. From the (1)H NMR study of the exchange reactions and of the products under D(2) pressure, it is suggested that the catalytic reaction involves bimetallic activation of the pyt ligand followed by the liberation of pyridine and H(2)S. 相似文献
53.
Toriya S Tamura Y Takei T Fuji M Watanabe T Chikazawa M 《Journal of colloid and interface science》2002,255(1):171-176
The silica-pillared derivatives from kanemite (NaHSi(2)O(5).3H(2)O) were prepared by intercalation of dialkyldimethylammonium (DADMA) ion and pillaring with tetraethylorthosilicate. The formation of silica pillars between the silicate sheets was demonstrated by X-ray diffraction, (29)Si CP/MAS NMR, and TEM observation. The basal spacing depended on the chain length of DADMA. Nitrogen adsorption study showed that the specific surface area was enlarged over 1000 m(2) g(-1) by the pillaring and that the pore size was in the micropore region. Water and benzene adsorption isotherms revealed that the surface properties of the pillared derivatives show hydrophobic character. 相似文献
54.
Harano Azuchi Shimada Koji Okubo Tatsuya Sadakata Masayoshi 《Journal of nanoparticle research》2002,4(3):215-219
Titanium dioxide ultrafine particles (UFPs) are produced by pulsed laser ablation of titanium or titanium dioxide (anatase and rutile) rods in an atmosphere of He or O2/He mixture. The collected UFPs on cellulose membrane filters at the exit of the ablation chamber are analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The TiO2 particles produced are composed of very small particles (diameter: 10–50nm) that are completely anatase, irrespective of the rod material, and relatively large particles (diameter: 100nm–1m) that are a mixture of anatase and rutile. The large particles consist of the direct strip-off fragments coming from the rod surface. The particles obtained from the laser ablation on TiO2 rods in an atmosphere of He contains gray particles that are supposed to be amorphous TiO2 (x < 2). In the presence of O2 in the ablation chamber, these oxygen defects in amorphous TiO2 are stabilized and anatase UFPs are formed. These results suggest that the crystal phase of the products can be controlled by adjusting the rod material and the gases used in the ablation process. 相似文献
55.
Anek Charoenphakdee Ken Kurosaki Hiroaki Muta Masayoshi Uno Shinsuke Yamanaka 《固体物理学:研究快报》2008,2(2):65-67
High‐density polycrystalline samples (above 98% of the theoretical density) of Ag8GeTe6 were prepared by solid‐state reactions of Ag2Te, GeTe, and Te, followed by hot‐pressing. The thermoelectric properties were measured at temperatures ranging from room temperature to around 700 K. The thermal conductivity values were extremely low (0.25 Wm–1 K–1 at room temperature), and consequently Ag8GeTe6 exhibited a relatively high thermoelectric figure of merit, ZT = 0.48 at 703 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
56.
We propose a method for estimating the amplitude of measurement noise present in chaotic time series. This method is based on the evaluation of initial errors for a given time series and for a new one synthesized by adding an adequate amount of noise to the given one. The method is valid over a much wider range of noise levels than the previous methods are because it is not based on the detail of dynamical structure which generates the data. In addition, it is possible to check if the method is valid for the given data prior to its application. To confirm the effectiveness of the method we show the results of numerical experiments and apply the method to chaotic data obtained from an electrochemical experiment. (c) 1999 American Institute of Physics. 相似文献
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The effects of drawing temperature on the physical and mechanical properties of poly(p-phenylene sulfide) have been studied. A melt-quenched film was drawn by solid-state coextrusion both below (75°C) and above (95 and 110°C) the glass transition temperature Tg (85°C) of PPS. The maximum extrusion draw ratio (EDRmax) increased from 3.4 to 5.6 with increasing extrusion temperature Te from 75 to 110°C. It was found that extrusion drawing just above the Tg of PPS (95°C) produced more stress-induced crystals. A high efficiency of draw in the amorphous region was achieved by extrusion at Te-75°C. The tensile modulus at EDRmax decreased from 5.1 to 3.5 GPa with increasing Te from 75 to 110°C. The low efficiency of draw for the samples extruded at 110°C is explained in terms of disentanglement and chain slippage during drawing due to a less effective network. 相似文献
60.
Mori S Endo M Furukawa S Sunaoka M Nonaka H Ishii T Ikehira H 《Magnetic resonance imaging》2005,23(5):691-694
We developed a high radiation sensitive polymer gel by modifying the amounts of the gel components and the temperature for the gel preparation. We evaluated its relaxation time linearity against dose and compared the measured dose distribution with the calculated one. For the relaxation time-dose linearity, irradiations were carried out with a linear accelerator using 6 MV photons and doses ranging from 0-5.0 Gy. The relationship between dose and R(2) value (reciprocal of T(2) relaxation time) was measured and it had good linearity over a wide range (0.3-5 Gy). The measured dose distributions were in good agreement with calculated ones. Since the present gel has higher sensitivity and it is synthesized more easily at lower cost than conventional polymer gels, we expect to see improved three-dimensional (3D) dosimetry using it. 相似文献