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991.
A scheme to execute an n-bit Deutsch-Jozsa (DJ) algorithm using n qubits has been implemented for up to three qubits on an NMR quantum computer. For the one- and the two-bit Deutsch problem,
the qubits do not get entangled, and the NMR implementation is achieved without using spin-spin interactions. It is for the
three-bit case, that the manipulation of entangled states becomes essential. The interactions through scalar J-couplings in NMR spin systems have been exploited to implement entangling transformations required for the three bit DJ algorithm. 相似文献
992.
Amorphous silicon carbide (SiC) thin films were deposited on silicon substrates by pulsed laser ablation at room temperature. Thicknesses and surface morphology of the thin films were characterized using optical profilers, atomic force and field emission scanning electron microscopy. Nanohardnes, modulus and scratch resistance properties were determined using XP nanoindenter. The results show that crack free, smooth and nanostructured thin films can be deposited using low laser energy densities. 相似文献
993.
994.
Anisotropy of magnetic susceptibility is used in the present study to reveal thedepositional fabric on the original (windblown) loess and secondary (redeposited) loess. The two kinds of sediments mentioned above can be distinguished in terms of their susceptibility anisotropy, e.g. anisotropy degree, magnetic foliation and lineation parameters. On this basis the magnetic fabric of the Pliocene red soil underlaying the loess is studied, and compared with the results of a typical residue-deposited red clay in South China. Considering its geological features, the red soil in Xifeng is regarded probably as aeolian in origin also. 相似文献
995.
A.G. Andreev M. Georgiev M.S. Mladenova V. Krastev 《International journal of quantum chemistry》2002,89(4):371-376
Off‐center impurity ions in solids often perform rotations around their regular lattice sites. Unlike quasifree rotors with rotational line spectra subject to textbook attention in quantum mechanics, the off‐center species are hindered rotors with spectra quantized in rotational bands. These bands occur because of tunneling through barriers arising along the orbital path. For an off‐center ion rotating along a planar orbit, such as the Li+ impurity nearest‐neighboring an F center in alkali halide, the hindered rotation will give rise to specific magnetic moments that couple to and quantize external magnetic fields normal to the orbital plane. We present a simple theory and estimates of Li+ magnetic dipoles and rotational bands to find conditions for an experimental verification. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
996.
Atsuya Muranaka Masaki Yokoyama Yotaro Matsumoto Masanobu Uchiyama Akihiko Tsuda Atsuhiro Osuka Nagao Kobayashi 《Chemphyschem》2005,6(1):171-179
The magnetic circular dichroism (MCD) spectra of doubly and triply linked fused bisporphyrins (2MD and 2MT, M = Ni, Zn, Cu, Pd, and H2) and triply linked higher oligomers (3ZnT and 4ZnT) have been measured, and their Q-bands assigned based on the results of INDO/s calculations. In contrast to the Faraday A term observed for the Q(0,0) band of Ni(II) tetraphenylporphyrin, a single positive Faraday B term was observed for the lowest energy transition of the fused systems. The calculations indicated that the molecular orbitals (MOs) of the directly fused porphyrins consist of linear combinations of the constituent monomeric MOs, and that the effect of lowering the symmetry is always larger on the lowest unoccupied molecular orbital (LUMO) than on the highest occupied molecular orbital (HOMO). On the basis of Michl's perimeter model, these features can be correlated with the observed positive MCD signs in the near infrared region. A weak absorption band at 600-700 nm for the fused dimers can be assigned to a short-axis polarized Q transition. 相似文献
997.
从洛仑兹力方程的旋量形式出发,讨论了电磁场中电荷运动的轴向电场和轴向磁场问题以及平面波的脉冲和Larmor功率。这些问题是研究自共振激光加速器的基础。From the spinorial form of the Lorentz force equation, the problems about axial electric field and axial magnetic field of charge motion in electromagnetic fields, as well as plane wave pulse and Larmor power have been discussed in this paper. These problems are the foundation of studying the autoresonance laser accelerator (ALA). 相似文献
998.
Victor V. Terskikh Stephen J. Lang Peter G. Gordon Gary D. Enright John A. Ripmeester 《Magnetic resonance in chemistry : MRC》2009,47(5):398-406
This work reports significantly improved spectral resolution of 13C CP MAS NMR spectra of chlorinated, brominated and iodinated solid organic compounds when such spectra are recorded at ultrahigh magnetic field strengths. The cause of this is the residual dipolar coupling between carbon atoms and quadrupolar halogen nuclides (chlorine‐35/37, bromine‐79/81 or iodine‐127), an effect inversely proportional to the magnetic field strength which declines in importance markedly at 21.1 T as compared to lower fields. In favorable cases, the fine structure observed can be used for spectral assignment, e.g. for Cl‐substituted aromatics where the substituted carbon as well as the ortho‐carbons show distinct doublets. The experimental results presented are supported by theoretical modeling and calculations. The improved spectral resolution in the studied systems and similar halogenated materials will be of particular interest and importance for polymorph identification, drug discovery and quality control in the pharmaceutical industry. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
999.
M. Biasini 《Il Nuovo Cimento D》1987,9(4):353-360
Summary The total and partial distribution functions of a metalloid/transition-metal amorphous alloy (Fe8B15) have been calculated by means of a ?nonstandard? hard-sphere dense-random-packing model. Based on these results, a comparison
with the ?canonical? dense-random-packing model is discussed.
Riassunto Si presenta un calcolo delle funzioni di distribuzione radiale parziali e totali di una lega metallo-metalloide amorfa (lega Fe-B) generate mediante simulazione numerica. La struttura viene realizzata tramite un modello ad impaccamento di sfere rigide basato su criteri di crescita probabilistici. I risultati sono confrontati con il modello ad impaccamento denso e casuale (dense random packing) ?canonico? di Bennet.
Резюме Вьічисляются полньіе и парциональньіе функции распределения для аморфного сплава ?металлоид-переходной металл? (Fe8B15), используя ?нестандартную⎴ модель плотной случайной упаковки твердых сфер. Полученные результаты сравниваются с результатами ?канонической? модели плотной случайной упаковки.相似文献
1000.
F. Hagelberg C. Xiao B. Marsen M. Lonfat P. Scheier K. Sattler 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,17(1):37-41
In a series of recent experiments, the HOMO-LUMO energy gaps of small Si clusters deposited on a graphite substrate have been
determined by Scanning Tunneling Microscopy (STM). The values obtained were found to be substantially smaller than the energy
gaps of corresponding passivated clusters. This work considers dimensional reduction as a possible mechanism for a sizeable
energy gap narrowing by the example of the system Si5. The impact of the graphite substrate on the deposited species is investigated in the framework of a pseudocluster model.
Received 30 November 2000 相似文献