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991.
Jia-jia Ji Hui Sun Xiang-yu Mao Wei Wang Xiao-bing Chen 《Journal of Sol-Gel Science and Technology》2012,61(2):328-331
The Bi5FeTi3O15 (BFTO) films of layered structure have been fabricated on Pt/Ti/SiO2/Si substrates by the sol–gel method. The thermal decomposition behaviors of precursor powder were examined using thermo-gravimetric
and differential scanning calorimeters analysis. The optimal heat treatment process for BFTO films were determined to be low-temperature
drying at 200 °C for 4 min and high-temperature drying at 350 °C for 5 min followed by annealing at 740 °C for 60 min, which
led to the formation of compact films with uniform grains of ~300 nm. The structural, surface topography, ferroelectric and
magnetic properties of the films were investigated. The remnant polarization (2P
r) of BFTO thin films under an applied electric field of ~550 kV/cm are determined to be 67.5 μC/cm2
. Meanwhile, the weak ferromagnetic properties of the BFTO films were observed at room temperature. 相似文献
992.
Xiaobing Cheng Mao Liang Siyuan Sun Yongbo Shi Zijian Ma Zhe Sun Song Xue 《Tetrahedron》2012,68(27-28):5375-5385
Diverse fused thiophenes with electron-rich and electron-deficient blocks have been synthesized and employed as the π-conjugated spacers of organic dyes for the dye-sensitized solar cells (DSSCs). The effects of these fused thiophenes were investigated by their absorption spectra, electrochemical and photovoltaic properties. For a typical device a maximum power conversion efficiency of 6.11% was obtained under simulated AM 1.5 irradiation (100 mW cm?2): a short-circuit current (JSC) of 14.47 mA cm?2, an open-circuit voltage (VOC) of 670 mV, and a fill factor (FF) of 0.63. 相似文献
993.
A highly efficient catalyst system assembled from enantiomerically pure diaminocyclohexane and Ni(OAc)(2) is, for the first time, used to catalyze the cascade Michael-Henry reaction of various diones and substituted nitroalkenes. A series of polyfunctionalized bicyclo[3.2.1]octane derivatives containing four stereogenic centers are prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to 50 : 1 dr) with high yields. In addition, via this chiral diamine-Ni(OAc)(2) catalyst system, the base-induced epimerization leading to the decrease of stereoselectivity can be prevented. 相似文献
994.
We prove two identities related to overpartition pairs. One of them gives a generalization of an identity due to Lovejoy, which was used in a joint work by Bringmann and Lovejoy to derive congruences for overpartition pairs. We apply our two identities on pairs of partitions where each partition has no repeated odd parts. We also present three partition statistics that give combinatorial explanations to a congruence modulo 3 satisfied by these partition pairs. 相似文献
995.
Jiayue Sun Yining Sun Jinli Lai Zhiguo Xia Haiyan Du 《Journal of luminescence》2012,132(11):3048-3052
Ce3+ and Tb3+ co-doped BaAl2B2O7 phosphors were synthesized by the solid-state method. X-ray diffraction (XRD) was used to characterize the phase structure. The photoluminescent properties of Ce3+ and Tb3+ co-doped BaAl2B2O7 phosphors were investigated by using the photoluminescence emission and excitation spectra. Under the excitation of near ultraviolet (n-UV) light, BaAl2B2O7:Ce3+,Tb3+ phosphors exhibited blue emission corresponding to the f–d transition of Ce3+ ions and green emission bands corresponding to the f–f transition of Tb3+ ions, respectively. Effective energy transfer occurred from Ce3+ to Tb3+ in BaAl2B2O7 host due to the observed spectra overlap between the emission spectrum of Ce3+ ion and the excitation spectrum of Tb3+ ion. The energy transfer efficiency from Ce3+ ion to Tb3+ ion was also calculated to be 71%. Furthermore, the concentration quenching and critical distance of BaAl2B2O7:Ce3+,Tb3+ phosphors were also discussed. The energy transfer from Ce3+ to Tb3+ in BaAl2B2O7 host was demonstrated to be resonant type via a dipole–dipole interaction mechanism with the energy transfer critical distance of 16.13 Å. 相似文献
996.
We proposed a geometrical form factor (GFF) calculation using Monte Carlo integration (GFF–MC) for lidar that is practical and can be applied to any laser intensity distribution. Theoretical results have been calculated with our method based on the functions of measured, uniform and Gaussian laser intensity distribution. Two experimental GFF traces on clear days are obtained to verify the validity of the theoretical results. The results indicated that the measured distribution function outperformed the Gaussian and uniform functions. That means that the deviation of the measured laser intensity distribution from an ideal one can be too large to neglect. In addition, the theoretical GFF of the uniform distribution had a larger error than that of the Gaussian distribution. Furthermore, the effects of the inclination angle of the laser beam and the central obstruction of the support structure of the second mirror of the telescope are discussed in this study. 相似文献
997.
A series of novel (Z)‐1‐tert‐butyl (or phenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐ethanone O‐[2,4‐dimethylthiazole (or 4‐methyl‐1,2,3‐thiadiazole) ?5‐carbonyl] oximes 5a – 5c and (1Z, 3Z)‐4,4‐dimethyl‐1‐substitutedphenyl‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐pent‐1‐en‐3‐one O‐[2,4‐dimethylthiazole (or 4‐methyl‐1,2,3‐thiadiazole)‐5‐carbonyl] oximes 6a – 6e were synthesized by the condensations of (Z)‐1‐tert‐butyl (or phenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐ethanone oximes 3 or (1Z, 3Z)‐4,4‐dimethyl‐1‐substitutedphenyl‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐pent‐1‐en‐3‐one oximes 4 with 2,4‐dimethylthiazole‐5‐carbonyl chloride or 4‐methyl‐1,2,3‐thiadiazole‐5‐carbonyl chloride in the basic condition. Their structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays showed the title compounds 5 and 6 exhibited moderate to good fungicidal activities. For example, compound 6c possessed 86.4% inhibition against Fusarium oxysporum, and compound 6b exhibited 86.4 and 100% inhibition against Fusarium oxysporum and Cercospora arachidicola Hori at the concentration of 50 mg/L, respectively. 相似文献
998.
A. Zanella J. Astor W. Kim J. Mao K. Pinnock A. F. Fucaloro 《Journal of solution chemistry》2012,41(6):965-975
The partial molar volumes (V 2) for hexaamminecobalt(III) nitrate in proteated and deuterated water were determined at 0.00 (for H2O only), 5.00, 10.00, 15.00, and 20.00?°C. The increase of the solute??s partial molar volume with increasing concentration and the negative second derivative of the solute??s partial molar volume at infinite dilution with respect to temperature were interpreted in terms of the solvent structure breaking property of the solute. In addition, the difference at each temperature between the solute??s partial molar volume at infinite dilution for proteated and deuterated water was used to estimate the solvent coordination number at each temperature. 相似文献
999.
Joseba Irigoyen Lulu Han Irantzu Llarena Zhenwei Mao Changyou Gao Sergio E. Moya 《Macromolecular rapid communications》2012,33(22):1964-1969
Responsive polyelectrolyte multilayers (PEMs) of poly(diallyl dimethyl ammonium chloride) (PDADMAC) and poly(styrene sodium sulfonate) (PSS) with thicknesses between 350 and 400 nm for 11 deposited polyelectrolyte layers were fabricated assembling the polyelectrolytes at 3 M NaCl. When the 3 M NaCl bulk solution is replaced by water, the PEMs release water, approximately a 46% of the total mass, and experience a thickness reduction of more than 200 nm. Changes in thickness and water content are fully reversible. The film recovers its original thickness and water content when it is exposed again to a 3 M NaCl solution. A responsive polymer film is achieved with the capability of swelling at high ionic strength and collapsing in water with variations in thickness of hundred of nanometers. 相似文献
1000.
本文主要从数字矩阵具有的合同关系和相似关系等性质入手,定义并讨论λ-矩阵的合同关系和相似关系,并讨论它们的性质. 相似文献