全文获取类型
收费全文 | 109篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
化学 | 84篇 |
力学 | 2篇 |
数学 | 12篇 |
物理学 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有116条查询结果,搜索用时 62 毫秒
51.
52.
Bush CE Goldston RJ Scott SD Fredrickson ED McGuire K Schivell J Taylor G Barnes CW Bell MG Boivin RL Bretz N Budny RV Cavallo A Efthimion PC Grek B Hawryluk R Hill K Hulse RA Janos A Johnson DW Kilpatrick S Manos DM Mansfield DK Meade DM Park H Ramsey AT Stratton B Synakowski EJ Towner HH Wieland RM Zarnstorff MC Zweben S 《Physical review letters》1990,65(4):424-427
53.
54.
55.
Single-crystal-to-single-crystal (SCSC) transformations represent some of the most fascinating phenomena in chemistry. They are not only intriguing from a basic science point of view but also provide a means to modify or tune the properties of the materials via the postsynthetic introduction of suitable guest molecules or organic functional groups into their structures. Here, we describe UCY-2, a new flexible Nd(3+) metal-organic framework (MOF), which exhibits a unique capability to undergo a plethora of SCSC transformations with some of them being very uncommon. These structural alterations involve the replacement of coordinating solvent molecules of UCY-2 by terminally ligating solvents and organic ligands with multiple functional groups including -OH, -SH, -NH-, and -NH(2) or their combinations, chelating ligands, anions, and two different organic compounds. The SCSC coordinating solvent exchange is thus demonstrated as a powerful method for the functionalization of MOFs. 相似文献
56.
57.
Manos Gkikas Biswa P. Das Marina Tsianou Hermis Iatrou Georgios Sakellariou 《European Polymer Journal》2013
Ring-opening surface initiated polymerization of l-proline N-carboxyanhydride was performed from amine functionalized single (SWNTs) and multi walled carbon nanotubes (MWNTs). The primary amines were grafted on the surfaces via a well-studied Diels–Alder cycloaddition. The initiator attachment helped the debundling of carbon nanotubes as shown by atomic force microscopy (AFM) studies where only small aggregates were observed. Thermogravimetric analysis revealed high wt% of grafted polyproline on the carbon nanotubes surface after the ring-opening polymerization. AFM studies showed a rather uniform layer of grafted polyproline from both MWNTs and SWNTs. The grafting of PLP on the surface was also verified by FTIR and Raman spectroscopy as well as 1H NMR in CDCl3/d-TFA. The polyproline grafted carbon nanotubes (CNTs) were readily dissolved in organic solvents in contrast to the insoluble pristine and amine-functionalized CNTs. 相似文献
58.
Brandon J. O'Neill David H. K. Jackson Dr. Anthony J. Crisci Carrie A. Farberow Fengyuan Shi Dr. Ana C. Alba‐Rubio Dr. Junling Lu Dr. Paul J. Dietrich Dr. Xiangkui Gu Dr. Christopher L. Marshall Prof. Peter C. Stair Dr. Jeffrey W. Elam Dr. Jeffrey T. Miller Prof. Fabio H. Ribeiro Prof. Paul M. Voyles Prof. Jeffrey Greeley Prof. Manos Mavrikakis Prof. Susannah L. Scott Prof. Thomas F. Kuech Prof. James A. Dumesic 《Angewandte Chemie (International ed. in English)》2013,52(51):13808-13812
Atomic layer deposition (ALD) of an alumina overcoat can stabilize a base metal catalyst (e.g., copper) for liquid‐phase catalytic reactions (e.g., hydrogenation of biomass‐derived furfural in alcoholic solvents or water), thereby eliminating the deactivation of conventional catalysts by sintering and leaching. This method of catalyst stabilization alleviates the need to employ precious metals (e.g., platinum) in liquid‐phase catalytic processing. The alumina overcoat initially covers the catalyst surface completely. By using solid state NMR spectroscopy, X‐ray diffraction, and electron microscopy, it was shown that high temperature treatment opens porosity in the overcoat by forming crystallites of γ‐Al2O3. Infrared spectroscopic measurements and scanning tunneling microscopy studies of trimethylaluminum ALD on copper show that the remarkable stability imparted to the nanoparticles arises from selective armoring of under‐coordinated copper atoms on the nanoparticle surface. 相似文献
59.
Bernhard G. Bodmann Manos Papadakis Qiyu Sun 《Journal of Fourier Analysis and Applications》2006,12(2):181-211
This article introduces an inhomogeneous uncertainty principle for digital lowpass filters. The measure for uncertainty is
a product of two factors evaluating the frequency selectivity in comparison with the ideal filter and the effective length
of the filter in the digital domain, respectively. We derive a sharp lower bound for this product in the class of filters
with so-called finite effective length and show the absence of minimizers. We find necessary and certain sufficient conditions
to identify minimizing sequences. When the class of filters is restricted to a given maximal length, we show the existence
of an uncertainty minimizer. The uncertainty product of such minimizing filters approaches the unrestricted infimum as the
filter length increases. We examine the asymptotics and explicitly construct a sequence of finite-length filters with the
same asymptotics as the sequence of finite-length minimizers. 相似文献