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61.
The propagation of a semi-infinite line defect, contained in an infinite square-cell lattice is considered. The defect is composed of particles lighter than those in the ambient lattice and it is assumed this defect propagates with constant speed. Dispersion properties of the lattice are related to waves generated by the propagating defect. In order to determine these properties, the Wiener–Hopf technique is applied. Additional features, related to localisation along the defect are also identified. Analysis of the dispersion relations for this lattice, from the kernel function inside the Wiener–Hopf equation, is carried out. The solution of the Wiener–Hopf equation is presented for the case when an external load is applied corresponding to an energy flux at infinity. 相似文献
62.
Isovalent cation substitution into rocksalt oxides, MO, has been investigated using atomistic simulation. A strain related parameter, ε, is established that relates the size of a substitutional cation to the host lattice ion for which it has been substituted. This has allowed us to identify relationships between solution energy, defect volume and a strain parameter, which are general for any rocksalt oxide host lattice and as such are predictive for any combination of a divalent cation and rocksalt host lattice. 相似文献
63.
《Microelectronics Journal》2015,46(5):398-403
Bridge defects are an important manufacturing defect that may escape test causing reliability issues. It has been shown that in nanometer regime, process variations pose important challenges for traditional delay test methods lowering test quality. Therefore, advances in test methodologies to enhance bridge detection are required. In this work a Statistical Timing Analysis Framework (STAF) is used to compute the probability of detection of bridge defects for different VDD and RBB values. The detection of the bridge defects of a circuit is computed by the Statistical Fault Coverage (SFC). The STAF allows to capture properly the behavior of the mean and a standard circuit delay when VDD and RBB change. Furthermore, the STAF uses a realistic bridge defect model suitable to consider appropriately the impact of VDD and RBB on delay increase. This methodology is applied to some ISCAS benchmark circuits implemented in a commercial 65 nm CMOS technology. The obtained results of several ISCAS benchmark circuits show clearly that the Statistical Fault Coverage (SFC) increases significantly when VDD is lowered, and increases even more when RBB is applied at Low VDD. The test conditions to improve resistive bridge detection combining Low VDD and Reverse Body Bias (RBB) under a delay based test are determined. It is shown that the impact of RBB on bridge detection improves significantly for a sufficient low value of VDD. The values of Low VDD and RBB can be selected considering the tradeoff between fault coverage and test time penalization. 相似文献
64.
65.
Yiliang Wu Jun-Ichi Mamiya Osamu Tsutsumi Akihiko Kanazawa Takeshi Shiono Tomiki Ikeda 《Liquid crystals》2013,40(6):749-753
Photoinduced alignment in a polymer liquid crystal prepared from 6-{1-[4-(2-cyano-4-nitrophenylazo)phenyl]piperazino}hexyl acrylate and 4'-[6-(methacryloyloxy)hexyloxy]-4-cyanobiphenyl was investigated for the first time on irradiation with a polarized He-Ne laser beam at 633 nm. The azobenzene moieties as well as the inert cyanobiphenyl mesogenic units were aligned with the molecular long axis perpendicular to the polarization direction of the irradiation light. Alignment induced on short irradiation was reversible, while that induced under prolonged irradiation was irreversible due to the occurrence of crosslinking which might be caused by photoinduced decomposition of the azobenzene moieties during the photoirradiation process. 相似文献
66.
The assembly of colloidal particles in a nematic liquid crystal has been investigated using small-angle X-ray scattering. The structure and orientation of nanoparticle assemblies in bulk samples of aligned nematic liquid crystal have been determined. The method offers some advantages over optical microscopy, which is usually restricted to investigations of thin cells and micron-sized particles. The scattering from chains of particles has been calculated, and comparison with experimental results has shown that suspensions of 48 and 105 nm diameter silica nanoparticles formed highly ordered structures perpendicular to the liquid crystal director, consistent with quadrupolar defect-induced assembly. 相似文献
67.
Cryo-TEM studies on two smectic phases of an asymmetric bent-core liquid crystal material are presented and compared to prior X-ray results obtained in bulk samples. While the bulk samples have layer-modulated structures, those modulations are not observable in the 100-nm-thick TEM samples, indicating surface-induced suppression of the layer modulations. The observed layer spacing is in agreement with the X-ray results in the lower temperature smectic phase, but distinctly larger in the higher temperature phase. This indicates surface-induced suppression of the director tilt. Cryo-TEM textures resolve the profiles of individual smectic layers at the scales down to few nanometres and reveal the presence of edge and screw dislocations, twist grain boundaries, small-angle and large-angle tilt grain boundaries. 相似文献
68.
Shao‐Bo Mi 《Surface and interface analysis : SIA》2014,46(2):102-105
Structural properties of YBa2Cu3O7‐δ/PrBa2Cu3O7‐δ heterointerfaces have been investigated by aberration‐corrected electron microscopy. Experimental evidence shows that c‐axis‐oriented YBa2Cu3O7‐δ/PrBa2Cu3O7‐δ heterostructures with atomically sharp interface epitaxially grow on SrTiO3(001) substrates. In terms of the contrast analysis, no apparent interdiffusion between YBa2Cu3O7‐δ and PrBa2Cu3O7‐δ occurs at the interface. In addition, stand‐off misfit dislocations and planar faults appear within PrBa2Cu3O7‐δ layer near the interface. Both misfit dislocations and interfacial dislocations resulting from the termination of planar faults contribute to misfit relaxation at the YBa2Cu3O7‐δ/PrBa2Cu3O7‐δ interface. The defect configuration of planar faults and stand‐off misfit dislocations is explored. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
69.
We investigated the face-stabilized Open-Hole Compression (OHC) test method for evaluating the effects of fiber waviness on the compression strength of continuous carbon fiber reinforced polymer composites. Temporal evaluations of the load-deformation response, acoustic emissions and optical microscopy are used to understand the failure modes and damage progression in the OHC specimen. The failure modes observed are structurally correlated to matrix failure and kink zone formation leading to fiber fracture. The results show how the resin pocket plays a more critical role than the layup in influencing the initiation of damage in the composite specimens. 相似文献
70.
Koki Ikemoto Shotaro Harada Seungmin Yang Taisuke Matsuno Hiroyuki Isobe 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2022,134(1):e202114305
A 3-nm molecule comprising a cylindrical core and cross-shaped rims was designed and synthesized by developing a modular synthetic route. By using a cyclic precursor from previous studies as a starting material, multiple carbazole units were installed at the rims of the defective cylinder. The defective cylinder was synthetically doped with two types of nitrogen atoms, that is, pyridinic and pyrrolic nitrogen atoms, which resulted in solvatochromic shifts in fluorescence by charge-transfer interactions. The structure of the large, C552H496N24 molecule was fully disclosed by crystallographic analyses, and the unique helical arrangement of nitrogen-doped cylinders in the crystal was revealed. 相似文献