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91.
Viologen-benzocrown ether conjugate (1) was prepared, in which a phenyl unit in benzocrown ether was incorporated into the nitrogen atom of a bypiridinium unit through a sigma bond. 1 showed a yellow color associated with an intramolecular charge transfer (CT) that responds to alkali and alkaline earth metal ions, especially to Ca2+. 相似文献
92.
多孔有限大弹性薄板弯曲应力集中问题 总被引:3,自引:0,他引:3
应用弹性力学的复变函数理论,采用多保角变换的方法,推出了含有任意多孔有限大弹性薄板弯曲的多复变量应力函数的表达式.在内边界上进行复Fourier级数展开,在外边界采用配点法来确定应力函数的未知系数,从而计算有限大弹性薄板的应力场.本文以外边界为矩形,内边界为任意多椭圆孔的有限薄板为例,编制了相应的计算程序,进行了算例分析.结果表明本方法对处理多孔有限大弹性平面问题是简单且行之有效的. 相似文献
93.
The major results of a series of our recent investigations on the adsorption of eight amino acids on Cu(001) and (111) surfaces are reviewed in the present paper. In all studied cases the molecules adsorb onto the surface in their anionic form. With the increase of the coverage three different 2D phases of the adsorbates, that is, the 2D lattice gas, intermediate, and solid phases, appear sequentially, although for few systems one or two of them do not appear. In both the 2D lattice gas and intermediate phases the molecules "stand" with their two oxygen "feet" on the surface and the intermolecular interactions are repulsive, although in the former they can diffuse frequently whereas in the latter they are discommensurate in one direction with the substrate. In the solid phase the molecules "lie" down on the surface to form commensurate superstructures. Adsorption of amino acids may often induce step faceting as well as bunching to form facets. Adsorption of L-lysine on Cu(001) may cause steps bunching to form facets with all the same chirality. Our preliminary results show that it is possible to manipulate individual molecules with the STM tip even at room temperature. These results may have applications in nano-materials, nano-technology, and very likely also in chiral separations or enantioselective heterogeneous catalysis. 相似文献
94.
借助边界元法设计了一种迭代修正方法来求解单侧界面裂纹模型与弹性波的相互作用问题,作为对算法的检验,用这种方法我们具体地分析了平面简谐弹性波对一个单侧界面裂纹的入射,给出了裂纹面的接触形态及应力场. 相似文献
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97.
本文阐述了Flash cs3 AcdonScript课件的优势及如何利用Flashcs3中具有的强大编程功能的AetionScript脚本语言制作大学物理CAI课件。 相似文献
98.
A new strategy for the generation of the active Pd-alkyl species from aminal via C-N bond activation has been established,in which the formation of zwitterionic... 相似文献
99.
100.
In the present study, metallophthalocyanines were modified with NIT nitroxide radicals through chemical bonds to prepare a series of metallophthalocyanines–NIT catalysts (MPcTcCl8-NIT, M=Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) applied for oxidative desulfurization of thiophene (T) in model fuel. The MPcTcCl8-NIT catalysts were characterized by FTIR, UV-Vis, ESR, and XPS spectra. The oxidative desulfurization activity of MPcTcCl8-NIT catalysts was studied in a biomimetic catalytic system using molecular O2 as the oxidant. The MPcTcCl8-NIT catalysts exhibited high catalytic activities for the oxidation of thiophene in model fuel. The desulfurization rate of ZnPcTcCl8-NIT for thiophene reached to 99.61%, which was 20.53% higher than that of pure ZnPcTcCl8 (79.08%) under room temperature and natural light. The results demonstrated that MPcTcCl8-NIT catalysts could achieve more effective desulfurization rate under milder conditions than that of the metallophthalocyanines. The NIT nitroxide radicals also could improve the catalytic activity of metallophthalocyanine based on the synergistic oxidation effect. The stability experiments for ZnPcTcCl8-NIT showed that the catalyst still had a high desulfurization rate of 92.37% after five times recycling. All these findings indicate that the application of MPcTcCl8-NIT catalysts provides a potential new way for the desulfurization performance of thiophene in fuel. 相似文献