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61.
We study the phase diagram of the strongly interacting matter at finite temperatures and densities including 2SC, uniform chiral and non-uniform chiral phases within the Nambu–Jona-Lasinio model in the mean field approximation. 相似文献
62.
Synthesis of multi-walled carbon nanotubes using CoMnMgO catalysts through catalytic chemical vapor deposition 下载免费PDF全文
The Co Mg O and Co Mn Mg O catalysts are prepared by a co-precipitation method and used as the catalysts for the synthesis of carbon nanotubes(CNTs) through the catalytic chemical vapor deposition(CCVD). The effects of Mn addition on the carbon yield and structure are investigated. The catalysts are characterized by temperature programmed reduction(TPR) and X-ray diffraction(XRD) techniques, and the synthesized carbon materials are characterized by transmission electron microscopy(TEM) and thermo gravimetric analysis(TG). TEM measurement indicates that the catalyst Co Mg O enclosed completely in the produced graphite layer results in the deactivation of the catalyst. TG results suggest that the Co Mn Mg O catalyst has a higher selectivity for CNTs than Co Mg O. Meanwhile, different diameters of CNTs are synthesized by Co Mn Mg O catalysts with various amounts of Co content, and the results show that the addition of Mn avoids forming the enclosed catalyst, prevents the formation of amorphous carbon, subsequently promotes the growth of CNTs, and the catalyst with decreased Co content is favorable for the synthesis of CNTs with a narrow diameter distribution.The Co Mn Mg O catalyst with 40% Co content has superior catalytic activity for the growth of carbon nanotubes. 相似文献
63.
利用第一性原理中的DFT理论研究了Fe/A1界面的能量学和电子结构,讨论了替位型掺杂的元素Zn、Mn、Ni在Fe/A1界面处的作用.结果表明:元素Zn、Mn、Ni都会优先替换界面处的Fe原子,使得界面结合能增加,体系更稳定,有利于界面的结合;跨界面的Fe原子与Al原子之间的电荷布居、键长以及差分电荷密度图的计算表明:掺杂后有利于跨界面的Fe-Al间成键,从而加强了Al层与Fe基体的结合,且结合强度由强到弱依次为:掺Zn〉掺Mn〉掺Ni;与实验比较吻合.最后对掺杂Zn的增韧机理加以解释. 相似文献
64.
K shell fluorescence parameters of pure Ti and some of its compounds have been determined experimentally using an Ultra-LEGe detector with resolution 150 eV at 5.9 keV. The samples were excited 5.96 keV photons emitted from a 55Fe radioisotope source with 50 mCi activity. The experimental values of the K shell fluorescence parameters have been compared with the experimental and theoretical values available in the literature for pure Ti. 相似文献
65.
66.
Yoichi Sakai Ryo Omatsuzawa Iwao Sakazaki Sayaka Suzuki Hayato Hashino Takanobu Saito Takahiko Iriyama 《Hyperfine Interactions》2005,166(1-4):483-487
Samarium–iron intermetallic compounds were prepared by a melt spinning method with low and high wheel speeds, which resulted in a Th2Zn17-type and a TbCu7-type structure, respectively. Structure comparison between these types was investigated for Sm–Fe intermetallic compounds and their nitrides by 57Fe-Mössbauer spectroscopy. 相似文献
67.
68.
Reactivities of mixed organozinc and mixed organocopper reagents. Part 13 Kinetic study for phosphine‐catalyzed acylation of alkylarylzincs and effect of residual group on the transfer rate of alkyl group 下载免费PDF全文
Özgen Ömür Pekel 《Journal of Physical Organic Chemistry》2016,29(4):190-195
Kinetics of reactions of di‐n‐butylzinc, n‐Bu2Zn, and mixed n‐butyl(substituted phenyl)zinc reagents and n‐Bu(functional group (FG)?C6H4)Zn with benzoyl chloride in the presence of tri‐n‐butylphosphine have been investigated. Reaction rates of transferable n‐butyl group have been determined in tetrahydrofuran at 0 °C to compare the transfer rate of n‐butyl group in homo and mixed diorganozincs. Rate law is consistent with a third‐order reaction, which is first order in diorganozinc, benzoyl chloride, and n‐Bu3P, and a mechanism was proposed. The lower reaction rate of n‐BuPhZn than that of n‐Bu2Zn and negative reaction constant in Hammett plot are in accordance with the carbanionic charge of transferable n‐butyl group in the acylation reaction. These findings support the hypothesis that the reaction rate of transferable group, RT, changes depending upon the residual group, RR, in RRRTZn reagents. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
69.
Ming Wen Kejia E Haiquan Qi Lujiang Li Juan Chen Ying Chen Qingsheng Wu Tao Zhang 《Journal of nanoparticle research》2007,9(5):909-917
Dispersed-well FePt nanoparticles with particle size ~5 nm have been prepared by hydrazine hydrate reduction of H2PtCl6·6H2O and FeCl2·4H2O in ethanol–water system. By employing as-synthesized FePt nanoparticles, the monolayer can be formed by LB Technique. The
structural, magnetic properties and electrochemical properties of FePt monolayer were respectively studied by XRD, TEM, VSM
and CHI 820 electrochemical workstation. The as-synthesized particle has a chemically disordered fcc structure and can be
transformed into chemically ordered fct structure after annealing treatment above 400°C. The coercivity of ordered fct FePt
phase can be up to 2515Oe. CVs of 0.5 M H2SO4/0.5M CH3OH on GCE modified with FePt nanoparticles monolayer films illustrate that the as-synthesized FePt is a kind of active electrochemical
catalyst. 相似文献
70.
G. Pancheri O. Shekhovtsova G. Venanzoni 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):458-460
Effects due to the non-pointlike behaviour of pions in the process e
+
e
-→π
+
π
-
γ can arise for hard photons in the final state. By means of a Monte Carlo event generator, which also includes the contribution
of the direct decay φ→π
+
π
-
γ, we estimate these effects in the framework of the resonance perturbation theory. We consider angular cuts used in the KLOE
analysis of the pion form factor at threshold. A method to reveal the effects of the non-pointlike behaviour of pions in a
model-independent way is proposed. 相似文献