全文获取类型
收费全文 | 549篇 |
免费 | 9篇 |
专业分类
化学 | 302篇 |
晶体学 | 3篇 |
力学 | 33篇 |
数学 | 88篇 |
物理学 | 132篇 |
出版年
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 29篇 |
2011年 | 22篇 |
2010年 | 14篇 |
2009年 | 18篇 |
2008年 | 31篇 |
2007年 | 19篇 |
2006年 | 31篇 |
2005年 | 20篇 |
2004年 | 15篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 11篇 |
1997年 | 10篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 11篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1971年 | 4篇 |
1966年 | 3篇 |
1906年 | 2篇 |
排序方式: 共有558条查询结果,搜索用时 31 毫秒
551.
The deformation and breakup of a drop in an immiscible equiviscous liquid undergoing unbounded shear flow has been extensively investigated in the literature, starting from the pioneering work of Taylor. In this Letter, we address the case of microconfined shear flow, a problem which is relevant for microfluidics and emulsion processing applications. The main effects of confinement include complex oscillating transients and drop stabilization against breakup. In particular, very elongated drop shapes are observed, which would be unstable in the unbounded case and can be explained in terms of wall-induced distortion of the shear flow field. We show that wall effects can be exploited to obtain nearly monodisperse emulsions in microconfined shear flow. 相似文献
552.
553.
Sarah Goler Jun Yan Vittorio Pellegrini Aron Pinczuk 《Solid State Communications》2012,152(15):1289-1293
The magneto-phonon resonance or MPR occurs in semiconductor materials when the energy spacing between Landau levels is continuously tuned to cross the energy of an optical phonon mode. MPRs have been largely explored in bulk semiconductors, in two-dimensional systems and in quantum dots. Recently there has been significant interest in the MPR interactions of the Dirac fermion magneto-excitons in graphene, and a rich splitting and anti-crossing phenomena of the even parity long wavelength optical phonon mode have been theoretically proposed and experimentally observed. The MPR has been found to crucially depend on disorder in the graphene layer. This is a feature that creates new venues for the study of interplays between disorder and interactions in the atomic layers. We review here the fundamentals of MRP in graphene and the experimental Raman scattering works that have led to the observation of these phenomena in graphene and graphite. 相似文献
554.
Andrea Francesca Quivelli Federico Vittorio Rossi Chiara Alario Francesco Sannicol Paola Vitale Joaquín García-lvarez Filippo Maria Perna Vito Capriati 《Molecules (Basel, Switzerland)》2022,27(21)
Dimethindene is a selective histamine H1 antagonist and is commercially available as a racemate. Upon analyzing the synthetic pathways currently available for the industrial preparation of dimethindene, we set up a sustainable approach for the synthesis of this drug, switching from petroleum-based volatile organic compounds (VOCs) to eco-friendly solvents, such as 2-methyltetrahydrofuran (2-MeTHF) and cyclopentyl methyl ether (CPME) belonging to classes 3 and 2, respectively. Beyond decreasing the environmental impact of the synthesis (E-factor: 24.1–54.9 with VOCs; 12.2–22.1 with 2-MeTHF or CPME), this switch also improved the overall yield of the process (from 10% with VOCs to 21–22% with 2-MeTHF or CPME) and remarkably simplified the manual operations, working under milder conditions. Typical metrics applied at the first and second pass, according to the CHEM21 metrics toolkit, were also calculated for the whole synthetic procedure of dimethindene, and the results were compared with those of the classical procedure. 相似文献
555.
Ranieri Bizzarri Vittorio Pellegrini Caterina Arcangeli Aldo Ferrari Riccardo Nifosì Pasqualantonio Pingue Valentina Tozzini Mauro Giacca Fabio Beltram 《Macromolecular Symposia》2004,218(1):283-292
The discovery of the photochromic characteristics of engineered green fluorescent proteins (GFPs) allows new proteomics and biomolecular electronic applications. In particular, photoreversibility among two distinct optical states can lead to the realization of a bio-optical high density storage memory. Here we review our recent work on an optically bistable GFP and we report the recent developments of self-assembly methods for spatial immobilization of proteins into well-definite 2D patterns. 相似文献
556.
557.
558.
Debora Bontempo Nicola Tirelli Giancarlo Masci Vittorio Crescenzi Joffrey A. Hubbell 《Macromolecular rapid communications》2002,23(7):417-422
Atom‐transfer radical polymerization has been used for polymerizing water‐soluble monomers from solid polymeric particles, intended as a model for any polymeric functional surface. Depending on the polarity of substrate and solvent, homogeneous initiation throughout the particles or pure surface initiation could be obtained. In the last case, polymer layers were obtained with thicknesses up to several tens of microns, still active for block copolymerization. 相似文献