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41.
利用动力学蒙特卡罗方法模拟了异质外延超薄膜生长中的成核过程.研究了薄膜与衬底的晶格失配对超薄膜生长中成核密度、平均核尺寸、标度关系及生长模式的影响.结果发现产生压(张)应变的晶格负(正)失配使生长过程更早(迟)从成核区进入过渡区,失配越大,这一效应越明显.在相同的沉积条件下,负失配导致超薄膜形成较低的成核密度与较大的平均核尺寸,而正失配则相反.成核密度满足标度关系Ns≈(F/D)χ,随着失配度从-0.04增加到0.02,标度系数χ从0.37逐渐减小到0.33,对应超薄膜生长过程从包含二聚体扩散模式转变到无
关键词:
薄膜生长
成核
晶格失配
蒙特卡罗模拟 相似文献
42.
研究了利用磁性薄膜构造Salisbury屏的可能性及其在微波频段的反射率频率特性.结果表明,利用铁磁性材料在铁磁共振频率附近磁化率具有χ″>χ′的特性,可以构造出对电磁波有良好吸收性能的磁性Salisbury屏.通过对铁磁材料高频磁谱物理机理的分析后指出,具有弛豫型共振磁谱的铁磁材料可以构造出薄膜型Salisbury屏,其厚度为微米甚至亚微米量级.反射率的频率特性与磁性材料的特征阻抗z-r有关,它取决于铁磁共振频率和静态磁化率.反射率的频率响应显示磁性薄膜Salisbury屏具有较宽的吸收带宽.
关键词:
磁性Salisbury屏
反射率
频带响应
磁性薄膜 相似文献
43.
报道了新合成的二氰基二硫纶·菲咯啉-5,6-二酮合铜(Ⅱ)配合物CuLL′(L=mnt2-, 1,2-dicyano-1,2-ethylenedithiolate; L′=phen-5,6-dione, 1,10-phenanthroline-5,6-dione)的变温磁化率和电子顺磁共振波谱表征结果. 发现微晶粉体型的标题配合物CuLL′具有一定的顺磁性,形成四配位的近似于方形的结构. 探讨了这种配合物磁学特性与结构的关系. 相似文献
44.
Fe2(CO)6(μ-S2) was used as a single source precursor in attempt to produce FeS film via MOCVD. Pyrolysis of Fe2(CO)6(μ-S2) at temperature below 500℃ produced Fe1-xS or Fe7S8 powder as indicated by its powder X-ray spectra. At 750 ℃, polycrystalline FeS powder was obtained. In film deposition, polycrystalline Fe1-xS or Fe7Ss films were obtained on Si(100) and Ag/Si(100) substrates below 500 ℃. SEM micrographs showed the film on Si(100) substrate containing whisker like grains. However, pillar like grains were obtained on Ag/Si(100) substrate.Deposition rates are also different for different substrates as evaluated by the thickness of the films, which were obtained by SEM micrographs of the cross section of the films. At 750℃, similar polycrystalline Fe1-xS or Fe7S8 film was obtained. 相似文献
45.
The electronic structure and chemical bonding in a recently synthesized inorganic fullerene-like molecule, [CuCl]20[Cp*FeP5]12[Cu-(CH3CN) +
2Cl−]5 has been studied by a density functional approach. Geometrical optimization of the three basic structural units of the molecule
is performed with Amsterdam Density Functional Program. The results are in agreement with the experiment. Localized MO’s obtained
by Boys-Foster method give a clear picture of the chemical bonding in this molecule. The reason why CuCl can react with Cp*FeP5 in solvent CH3CN to form the fullerene-like molecule is explained in terms of the soft-hard Lewis acid base theory and a new concept of
covalence. 相似文献
46.
WANG Bingwu XU Guangxian & CHEN Zhida State Key Laboratory of Rare Earth Materials Chemistry Applications College of Chemistry Molecular Engineering Peking University Beijing China 《中国科学B辑(英文版)》2004,47(2)
The titled inorganic fullerene-like molecule (hereafter abbreviated as IFM) was recently synthe-sized by Bai et al.[1], which attracts a lot of interests from inorganic and organometallic chemists, and questions are raised for this smart molecule: (ⅰ) Why CuCl can react with Cp*FeP5 in solvent CH3CN to form IFM? (ⅱ) What is the nature of chemical bond-ing? (ⅲ) What is the covalence of Cu in this mole-cule? In this paper we intend to answer these questions in terms of the soft-hard … 相似文献
47.
B. Amaziane M. Goncharenko L. Pankratov 《Mathematical Methods in the Applied Sciences》2005,28(15):1847-1865
We study the asymptotic behaviour of the solution of a stationary quasilinear elliptic problem posed in a domain Ω(ε) of asymptotically degenerating measure, i.e. meas Ω(ε) → 0 as ε → 0, where ε is the parameter that characterizes the scale of the microstructure. We obtain the convergence of the solution and the homogenized model of the problem is constructed using the notion of convergence in domains of degenerating measure. Proofs are given using the method of local characteristics of the medium Ω(ε) associated with our problem in a variational form. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
48.
Changes in thin zinc-sulfide films under the action of the γ-radiation of Co60 are studied by investigating electroluminescence spectra of terbium embedded in these films as a luminescent probe. It is
shown that changes in the relation of the intensities of bands, a decrease in their halfwidth and the background component,
and simplification of the spectrum are observed in a short-wave region of the Tb radiation spectrum that corresponds to5D3→7Fj transitions. The same modification of the radiation spectrum is characteristic of ZnS films whose crystalline structure is
ordered in the course of thermal annealing at a temperature of 350°C. Based on the analysis of the data obtained it is inferred
that irradiating the ZnS films with small radiation doses of 104–105 rad leads to the ordering of their crystalline structure due to the elimination of one of the types of structural defects.
Institute of Physics of Semiconductors, National Academy of Sciences of Ukraine, 45, Nauka Ave., Kiev-28, 252650. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 338–341, May–June, 1997. 相似文献
49.
50.
L.-H. Tang P. Smilauer D.D. Vvedensky 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(3):409-412
Two types of mechanisms are proposed for mound coarsening during unstable epitaxial growth: stochastic, due to deposition
noise, and deterministic, due to mass currents driven by surface energy differences. Both yield the relation H=(RWL)2 between the typical mound height W, mound size L, and the film thickness H. An analysis of simulations and experimental data shows that the parameter R saturates to a value which discriminates sharply between stochastic () and deterministic () coarsening. We derive a scaling relation between the coarsening exponent 1/z and the mound-height exponent which, for a saturated mound slope, yields .
Received: 11 November 1997 / Revised in final form: 28 November 1997 /
Accepted: 28 November 1997 相似文献