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41.
A Three‐Step Method for the Deposition of Large Cuboids of Organic–Inorganic Perovskite and Application in Solar Cells 下载免费PDF全文
Saeed Shahbazi Mahdi Malekshahi Byranvand Dr. Fariba Tajabadi Dr. Shahrara Afshar Dr. Nima Taghavinia 《Chemphyschem》2016,17(15):2389-2394
A three‐step method for the deposition of CH3NH3PbI3 perovskite films with a high crystalline structure and large cuboid overlayer morphology is reported. The method includes PbI2 deposition, which is followed by dipping into a solution of C4H9NH3I (BAI) and (BA)2PbI4 perovskite formation. In the final step, the poorly thermodynamically stable (BA)2PbI4 phase converts into the more stable CH3NH3PbI3 perovskite by dipping into a solution of CH3NH3I. The final product is characterized by XRD, SEM, UV/Vis, and photoluminescence analysis methods. The experimental results indicate that the prepared perovskite has cuboids with high crystallinity and large sizes (up to 1 μm), as confirmed by XRD and SEM data. Photovoltaic investigations show that the three‐step method results in higher solar cell efficiency (15 % enhancement in efficiency) with a better reproducibility than the conventional two‐step deposition method. 相似文献
42.
According to UV-visible spectroscopy, X-ray diffraction spectrometry, dynamic light scattering, Fourier transform infrared spectroscopy, electron paramagnetic resonance spectroscopy, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy, nano-sized manganese oxides are proposed as active catalysts for water oxidation in the reaction of some manganese complexes and cerium(iv) ammonium nitrate. 相似文献
43.
Cross-linked poly(diallyldimethylammonium chloride) and its derivative copolymers were synthesized and used as phase transfer
catalyst in the nucleophilic substitution reaction especially halogen exchange reactions. In addition, the effect of hydrophilic-hydrophobic
character of the polymers in the nucleophilic reactions was investigated. 相似文献
44.
Mahdi Sadeghi Zahra Alipoor Abbas Majdabadi 《Journal of Radioanalytical and Nuclear Chemistry》2011,288(3):745-751
The 82Sr/82Rb radionuclide generator is used very commonly in positron emission tomography. ALICE/ASH and TALYS 1.0 codes were used to calculate excitation functions for proton, alpha and 3He induced on various targets that lead to produce 82Sr radioisotope using intermediate energy accelerators. Recommended thickness of the targets according to SRIM code was premeditated. The application of those data, particularly in the calculation of integral yields, is discussed and theoretical integral yields for any reaction were computed. To consider precision of TALYS 1.0 code calculations, 85Rb(p,4n)82Sr process was determined as most interesting one due to radionuclide purity. The TALYS 1.0 code predicts a maximum cross-section of about 130 mb at 47 MeV for this reaction. Rubidium chloride deposition on copper substrate was carried out via sedimentation method in order to produce 82Sr. 2.98 g RbCl, 1.043 g ethyl cellulose, 10 mL acetone were used to prepare a layer of enriched rubidium chloride of 11.69 cm2 area and 0.34 g/cm2 thickness. 相似文献
45.
A new finite volume (FV) approach with adaptive upwind convection is used to predict the two-dimensional unsteady flow in a square cavity. The fluid is air and natural convection is induced by differentially heated vertical walls. The formulation is made in terms of the vorticity and the integral velocity (induction) law. Biquadratic interpolation formulae are used to approximate the temperature and vorticity fields over the finite volumes, to which the conservation laws are applied in integral form. Image vorticity is used to enforce the zero-penetration condition at the cavity walls. Unsteady predictions are carried sufficiently forward in time to reach a steady state. Results are presented for a Prandtl number (Pr) of 0-71 and Rayleigh numbers equal to 103, 104 and 105. Both 11 × 11 and 21 × 21 meshes are used. The steady state predictions are compared with published results obtained using a finite difference (FD) scheme for the same values of Pr and Ra and the same meshes, as well as a numerical bench-mark solution. For the most part the FV predictions are closer to the bench-mark solution than are the FD predictions. 相似文献
46.
Y. G. Shee M. A. Mahdi M. H. Al-Mansoori A. Ismail N. A. M. A. Hambali A. K. Zamzuri R. Mohamad S. Yaakob 《Laser Physics》2009,19(12):2194-2196
A simple configuration for the reduction of stimulated Brillouin scattering threshold in photonic crystal fiber is presented.
The threshold reduction is contributed by the bidirectional pumping scheme through the reflection of transmitted Brillouin
pump back to the gain medium. The pump recycling scheme has greatly reduced the Brillouin threshold of a 200-m long of photonic
crystal fiber from 50 to 30 mW of Brillouin pump power. 相似文献
47.
Hossein Mahdavi B. O. Mahdi Sadeghzadeh Nader Taheri Qazvini 《Journal of Polymer Science.Polymer Physics》2009,47(5):455-462
The phase behavior of poly(N‐tertbutylacrylamide‐co‐acrylamide) (PNTBAM) in pure water and mixture of water–methanol is studied at different temperatures. The different compositions of PNTBAM are prepared by free‐radical polymerization technique and their phase behavior is studied by turbidimetry. The effects of copolymer and solvent composition on the phase behavior of the copolymers are discussed. It has been suggested that the inhomogenities in polymer chains are responsible for lowering the rate of phase transition by increasing the N‐tertbutylacrylamide (NTBAM) and methanol contents in copolymer and mixture, respectively. For the first time we have revealed that there are second‐order binary interactions in the water–methanol which are dominant in the special range of copolymer composition. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 455–462, 2009 相似文献
48.
Mahdi Zarghami Ferenc Szidarovszky Reza Ardakanian 《Fuzzy Optimization and Decision Making》2008,7(1):1-15
All realistic Multi-Criteria Decision Making (MCDM) problems face various kinds of uncertainty. Since the evaluations of alternatives
with respect to the criteria are uncertain they will be assumed to have stochastic nature. To obtain the uncertain optimism
degree of the decision maker fuzzy linguistic quantifiers will be used. Then a new approach for fuzzy-stochastic modeling
of MCDM problems will be introduced by merging the stochastic and fuzzy approaches into the OWA operator. The results of the
new approach, entitled FSOWA, give the expected value and the variance of the combined goodness measure for each alternative.
Robust decision depends on the combined goodness measures of alternatives and also on the variations of these measures under
uncertainty. In order to combine these two characteristics a composite goodness measure will be defined. The theoretical results
will be illustrated in a watershed management problem. By using this measure will give more sensitive decisions to the stakeholders
whose optimism degrees are different than that of the decision maker. FSOWA can be used for robust decision making on the
competitive alternatives under uncertainty. 相似文献
49.
We propose an exact branch-and-bound algorithm for the problem of maximizing the minimum machine completion time on identical
parallel machines. The proposed algorithm is based on tight lower and upper bounds as well as an effective symmetry-breaking
branching strategy. Computational results performed on a large set of randomly generated instances attest to the efficacy
of the proposed algorithm.
相似文献
50.
In this paper, an experimental study and modeling by artificial neural networks were carried out to predict the generated microdroplet dimensionless size in a microfluidic system in order to formulate a water-in-oil emulsion. The various parameters that affect the size of microdroplets (flow rates, viscosities, surface tensions of both the two phases and the diameter of the microchannel) are studied and further grouped into dimensionless numbers; we used these numbers as input to the neural network and the dimensionless length as output. The better neural network architecture has 10 neurons in the hidden layer with a mean square error of 1.4 10?6 and a determination’s coefficient near 1 value. The relative importance of inputs on the size of the microdroplets has been determined using the Garson algorithm and the results are in good agreement with other works. 相似文献