全文获取类型
收费全文 | 781篇 |
免费 | 40篇 |
国内免费 | 1篇 |
专业分类
化学 | 722篇 |
晶体学 | 4篇 |
力学 | 3篇 |
数学 | 1篇 |
物理学 | 92篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 20篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 19篇 |
2014年 | 13篇 |
2013年 | 57篇 |
2012年 | 49篇 |
2011年 | 49篇 |
2010年 | 27篇 |
2009年 | 25篇 |
2008年 | 64篇 |
2007年 | 46篇 |
2006年 | 49篇 |
2005年 | 42篇 |
2004年 | 62篇 |
2003年 | 30篇 |
2002年 | 32篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 12篇 |
1998年 | 8篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1972年 | 3篇 |
1970年 | 1篇 |
1967年 | 2篇 |
1964年 | 1篇 |
排序方式: 共有822条查询结果,搜索用时 78 毫秒
81.
82.
83.
Atsuhiro Fujimori Hiroko Hoshizawa Satoshi Kobayashi Kaname Kanai Yukio Ouchi Kazuhiko Seki 《Journal of Polymer Science.Polymer Physics》2008,46(5):534-546
Comb copolymers containing both hydrogenated and fluorinated side‐chains were prepared by copolymerization using acrylic or methacrylic monomers in several ratios. The crystal structures of these copolymers and layer structures of their organized molecular films were investigated by wide‐angle X‐ray diffraction (WAXD), small‐angle X‐ray scattering (SAXS), and out‐of plane X‐ray diffraction. Further, to selectively estimate the regularity of shorter fluorocarbon side‐chains, organized molecular films of copolymers were investigated by polarized near‐edge X‐ray adsorption fine structure (NEXAFS) spectroscopy. From the results of these measurements, it was inferred that these copolymers formed highly ordered layer structures, and a long spacing was predominantly determined by the arrangement of hydrogenated side‐chains, except in copolymers having extremely high fluorocarbon contents. In the case of the organized molecular films, the fluorinated side‐chains of methacrylate copolymers cannot form a highly ordered arrangement, whereas those of acrylate copolymers were oriented on monolayers. However, in both cases, the hydrogenated side‐chains predominantly formed layer structures in the organized films, and the fluorinated side‐chains did not contribute to the formation of the layer structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 534–546, 2008 相似文献
84.
Koji Nagahama Kanae Fujiura Shunsuke Enami Tatsuro Ouchi Yuichi Ohya 《Journal of polymer science. Part A, Polymer chemistry》2008,46(18):6317-6332
Starburst triblock copolymers consisting of 8‐arm poly(ethylene glycol) (8‐arm PEG) and biodegradable poly(L ‐lactide) (PLLA) or its enantiomer poly(D ‐lactide) (PDLA), 8‐arm PEG‐b‐PLLA‐b‐PEG ( Stri‐L ), and 8‐arm PEG‐b‐PDLA‐b‐PEG ( Stri‐D ) were synthesized. An aqueous solution of a 1:1 mixture ( Stri‐Mix ) of Stri‐L and Stri‐D assumed a sol state at room temperature, but instantaneously formed a physically crosslinked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high‐storage modulus (9.8 kPa) at 37 °C. Interestingly, once formed at the transition temperature, the hydrogel was stable even after cooling below the transition temperature. The hydrogel formation process was irreversible because of the formation of stable stereocomplexes. In aqueous solution, gradual hydrolytic erosion was observed because of degradation of the hydrogel. The combination of rapid temperature‐triggered irreversible hydrogel formation, high‐mechanical strength, and degradation behavior render this polymer mixture system suitable for use in injectable biomedical materials, for example, as a drug delivery system for bioactive reagents or a biodegradable scaffold for tissue engineering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6317–6332, 2008 相似文献
85.
A new effective copper catalyzed CO coupling reaction using excess amount of strongly coordinating monodentate ligands was successfully developed. Among the DMAP-type monodentate ligands, 4-pyrrolidinopyridine afforded the best results. The developed reaction is widely applicable for the synthesis of various hindered or acyclic secondary alkyl-aryl ethers. In this study, a novel and remarkable acceleration of the coupling reaction using excess amount of monodentate ligands was discovered. 相似文献
86.
Thomas TD Kukk E Ueda K Ouchi T Sakai K Carroll TX Nicolas C Travnikova O Miron C 《Physical review letters》2011,106(19):193009
The first experimental evidence of rotational Doppler broadening in photoelectron spectra, reported here, show good agreement with recently described theoretical predictions. The dependence of the broadening on temperature and photoelectron kinetic energy is quantitatively predicted by the theory. The experiments verify that the rotational contributions to the linewidth are comparable to those from translational Doppler broadening and must be considered in the analysis of high-resolution photoelectron spectra. A classical model accounting for this newly observed effect is presented. 相似文献
87.
88.
89.
Excimer laser‐induced photolysis of gaseous diethyl selenium and diethyl tellurium (C2H5)2M (M = Se, Te) is controlled by cleavage of both M? C bonds, it yields C1–C4 hydrocarbons (ethene as major product) and results in chemical vapour deposition of selenium films and nanosized tellurium powder. The selenium and tellurium properties were characterized by X‐ray photoelectron spectroscopy and Scanning electron Microscopy techniques. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献