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951.
Taxamairin B, a novel rearranged 9(10→20)-abeo-8,11,13-triene diterpene, has been synthesized by a short and efficient route. A friedal-Crafts annunation and the oxidation of the allylic and benzylic methene group are the key steps. 相似文献
952.
953.
Naturally Occurring Ferritin as a Novel Catalyst for Selective Hydroxylation of Phenol 总被引:2,自引:0,他引:2
Ning Zhang Fengyi Li Qi jia Fu Shik Chi Tsang 《Reaction Kinetics and Catalysis Letters》2000,71(2):393-404
Ferritin, a naturally occurring protein cage molecule containing interior inorganic iron oxide/hydroxide nano-crystallites was used for the first time as a catalyst for selective hydroxylation of phenol with using hydrogen peroxide as an oxidant. 相似文献
954.
We report two synthetic systems, Cu(Bpy)2+ and Cu(Phen)2+, for catalytic hydrogenation of steroidal haloalkenes in the presence of hydrazine and air. Thesestudies demonstrated that the selective hydrogenation is faster for the 1,10‐phenanthroline–Cu(II) system because forming more stable copper complex are formed, leaving fewer free copper ions in solution. Evidence also supports that the catalytic power of Cu(II) ions can be tuned moderately through the addition of bidentate ligand, Bpy or Phen. 相似文献
955.
956.
957.
Strongly Phosphorescent Neutral Rhenium(I) Isocyanoborato Complexes: Synthesis,Characterization, and Photophysical,Electrochemical, and Computational Studies
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Wing‐Kin Chu Xi‐Guang Wei Dr. Shek‐Man Yiu Dr. Chi‐Chiu Ko Dr. Kai‐Chung Lau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2603-2612
A new series of neutral isocyanoborato rhenium(I) diimine complexes [Re(CO)3(N^N)(CNBR3)], where N^N=bpy, 4,4′‐Me2bpy, phen, 4,7‐Me2phen, 2,9‐Me2phen, 3,4,7,8‐Me4phen; R=C6F5, C6H5, Cl, 4‐ClC6H4, 3,5‐(CF3)2C6H3, with various isocyanoborate and diimine ligands of diverse electronic and steric nature have been synthesized and characterized. The X‐ray crystal structures of six complexes have also been determined. These complexes displayed intense bluish green to yellow phosphorescence at room temperature in dichloromethane solution. The photophysical and electrochemical properties of these complexes had been investigated. To elucidate the electronic structures and transitions of these complexes, DFT and TD‐DFT calculations have been performed, which revealed that the lowest‐energy electronic transition associated with these complexes originates from a mixture of MLCT [dπ(Re)→π*(N^N)] and LLCT [π(CNBR3)→π*(N^N)] transitions. 相似文献
958.
通过掺杂金属的方式实现了双金属同构金属-有机框架材料的制备, 采用X射线粉末衍射(PXRD)确定了多种金属在双金属CAU-21材料中的最大掺杂量, 使用扫描电子显微镜(SEM)观察了掺杂金属对材料形貌的影响. 热重分析(TGA)结果表明, CAU-21系列材料均具有较好的热稳定性. 氮气气体吸附测试及以CAU-21-Al/M为填料的混合基质膜对N2气的渗透实验结果与掺杂金属离子尺寸大小呈相反的关系, 证实了双金属可实现对孔道结构及气体吸附性能的调控. 相似文献
959.
Fu Yuwei Luo Santu Li Xingdi Chen Chi Wang Chuang Zhang Zaiqin Liu Dingxin 《Plasma Chemistry and Plasma Processing》2022,42(6):1265-1278
Plasma Chemistry and Plasma Processing - C5F10O-insulated environmental-friendly power equipment has great potential to be used in the near future to reduce greenhouse effect. During maintenance,... 相似文献
960.
Aseries of Ni catalysts supported on alumina with different Ce contents(1.0%-6.0%, mass fraction) was prepared by the impregnation method and used for dry reforming of methane(DRM) at a relatively low temperature of 650 oC. The promotion effect of Ce with different loading amounts on the physicochemical properties of the catalysts was systematically characterized by transmission electron microscopy(TEM), X-ray diffraction(XRD), N2 adsorption-desorption, thermo elemental IRIS Intrepid inductively coupled plasma atomic emission spectrometer (ICP-AES), UV-visible diffuse reflectance spectroscopy(UV-Vis DRS), Fourier transformation infrared(FTIR) spectra, H2-temperature programmed reduction(H2-TPR) analysis, H2-temperature programmed desorption(H2-TPD), and the X-ray photoelectron spectroscopy(XPS) techniques. The results indicate that all the catalysts mainly exist in the NiAl2O4 phase after being calcined at 750 oC with small Ni particle sizes due to the strong metal-support interaction derived from the reduction of the NiAl2O4 phase. The Ce-promoted catalysts show better catalytic performance as well as the resistance against sintering of Ni particles and deposition of carbon compared to the Ni/Al2O3 catalyst. The Ni-6Ce/Al2O3 exhibits the best catalytic stability and coke resistance among the four catalysts studied, which is due to its small Ni nanoparticles sizes, excellent reducibility as well as high amount of active oxygen species. In a 400 h stability test for DRM reaction at 650 oC, Ni-6Ce/Al2O3 exhibits less coke deposition and small growth of Ni nanoparticles. This work provides a simple way to preparing the Ni-Ce/Al2O3 catalyst with enhanced catalytic performance in DRM. The Ni-6Ce/Al2O3 catalyst has great potential for industrial application due to its anti-sintering ability and resistance to carbon deposition. 相似文献