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401.
Sijun Li Guanghao Lu Hui Li Yunpeng Qu Ligui Li Joachim Loos Xiaoniu Yang 《Macromolecular rapid communications》2012,33(21):1882-1887
A series of block copolymers with fixed length of the semiconductor‐block poly(3‐butylthiophene) (P3BT) and varying length of the insulator‐block polystyrene (PS) are synthesized. These copolymers are blended with phenyl‐C61‐butyric acid methyl ester (PCBM) for the bulk heterojunction photoactive layers. With appropriate insulator‐block length and donor–acceptor ratio, the power conversion efficiency increases by one order of magnitude compared with reference devices with pure P3BT/PCBM. PS blocks improve the miscibility of the active layer blends remarkably. The P3BT‐b‐PS crystallizes as nanorods with the P3BT core covered with the PS‐block, which creates a nanoscale tunneling barrier between donor and acceptor leading to more efficient transportation of charge carriers in the semiconductors. 相似文献
402.
Jia‐Hsien Lin E. M. Woo Yin‐Ping Huang 《Journal of Polymer Science.Polymer Physics》2006,44(23):3357-3368
Effects of a strong‐interacting amorphous polymer, poly(4‐vinyl phenol) (PVPh), and an alkali metal salt, lithium perchlorate (LiClO4), on the amorphous and crystalline domains in poly(ethylene oxide) (PEO) were probed by differential scanning calorimetry (DSC), optical microscopy (OM), and Fourier transform infrared spectroscopy (FTIR). Addition of lithium perchlorate (LiClO4, up to 10% of the total mass) led to enhanced Tg's, but did not disturb the miscibility state in the amorphous phase of PEO/PVPh blends, where the salt in the form of lithium cation and ClO anion was well dispersed in the matrix. Competitive interactions between PEO, PVPh, and Li+ and ClO ions were evidenced by the elevation of glass transition temperatures and shifting of IR peaks observed for LiClO4‐doped PEO/PVPh blend system. However, the doping distinctly influenced the crystalline domains of LiClO4‐doped PEO or LiClO4‐doped PEO/PVPh blend system. LiClO4 doping in PEO exerted significant retardation on PEO crystal growth. The growth rates for LiClO4‐doped PEO were order‐of‐magnitude slower than those for the salt‐free neat PEO. Dramatic changes in spherulitic patterns were also seen, in that feather‐like dendritic spherulites are resulted, indicating strong interactions. Introduction of both miscible amorphous PVPh polymer and LiClO4 salt in PEO can potentially be a new approach of designing PEO as matrix materials for electrolytes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3357–3368, 2006 相似文献
403.
François Constantin Françoise Fenouillot Jean-Luc Guillaume Raymond Koenig Jean-Pierre Pascault 《Macromolecular Symposia》2003,198(1):335-344
Properties of thermoplastic modified epoxy network have been studied. The particularity of this work is the use of new thermoplastic epoxies whose structure is close to the final matrix. Blends of thermoset epoxy (Diglycidyl Ether of Bisphenol A/4-4′ methylenebis [3-chloro 2,6-diethylaniline]) with a thermoplastic content from 5 to 40%w have been realised. Initial miscibility in the thermoset precursors shows an UCST behaviour with a maximal value near 130°C for a thermoplastic content of 10%. Due to the presence of tertiary amine and pendant hydroxyl groups on the thermoplastic backbone, epoxy amine reactions are faster than for the neat system but the thermoplastic seems not to have reacted with the thermoset network. The final blends are transparent but toughening increase is rather low. 相似文献