全文获取类型
收费全文 | 396篇 |
免费 | 31篇 |
国内免费 | 18篇 |
专业分类
化学 | 276篇 |
晶体学 | 1篇 |
力学 | 39篇 |
数学 | 46篇 |
物理学 | 83篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 23篇 |
2019年 | 25篇 |
2018年 | 36篇 |
2017年 | 20篇 |
2016年 | 43篇 |
2015年 | 25篇 |
2014年 | 32篇 |
2013年 | 45篇 |
2012年 | 27篇 |
2011年 | 24篇 |
2010年 | 19篇 |
2009年 | 17篇 |
2008年 | 17篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 6篇 |
1999年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有445条查询结果,搜索用时 46 毫秒
341.
Closing the Nanographene Gap: Surface‐Assisted Synthesis of Peripentacene from 6,6′‐Bipentacene Precursors 下载免费PDF全文
Cameron Rogers Chen Chen Zahra Pedramrazi Dr. Arash A. Omrani Hsin‐Zon Tsai Han Sae Jung Dr. Song Lin Prof. Dr. Michael F. Crommie Prof. Dr. Felix R. Fischer 《Angewandte Chemie (International ed. in English)》2015,54(50):15143-15146
The thermally induced cyclodehydrogenation reaction of 6,6′‐bipentacene precursors on Au(111) yields peripentacene stabilized by surface interactions with the underlying metallic substrate. STM and atomic‐resolution non‐contact AFM imaging reveal rectangular flakes of nanographene featuring parallel pairs of zig‐zag and armchair edges resulting from the lateral fusion of two pentacene subunits. The synthesis of a novel molecular precursor 6,6′‐bipentacene, itself a synthetic target of interest for optical and electronic applications, is also reported. The scalable synthetic strategy promises to afford access to a structurally diverse class of extended periacenes and related polycyclic aromatic hydrocarbons as advanced materials for electronic, spintronic, optical, and magnetic devices. 相似文献
342.
343.
344.
In this paper we obtain various approximation theorems by means of k-positive linear operators defined on the space of all analytic functions on a bounded domain of the complex plane. 相似文献
345.
Arash Mouradzadegun Nargess Gheitasvand 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1385-1388
Abstract A solvent-free reduction of 2,4,6-triarylthiopyrylium with NaBH4/alumina is described. The regioselectivity of these reductions were compared with those obtained in solution experiments. 相似文献
346.
A copper catalyzed one-pot protocol for the preparation of aryl alkyl thioethers and diaryl disulfides using carbon disulfide as the sulfur source and diethylamine in polyethylene glycol (PEG200) is described. 相似文献
347.
For aromatic polymers, the out-of-plane oscillations of aromatic groups limit the maximum accessible time step in a molecular dynamics simulation. We present a systematic approach to removing such high-frequency oscillations from planar groups along aromatic polymer backbones, while preserving the dynamical properties of the system. We consider, as an example, the industrially important polymer, polyether ether ketone (PEEK), and show that this coarse graining technique maintains excellent agreement with the fully flexible all-atom and all-atom rigid bond models whilst allowing the time step to increase fivefold to 5 fs. 相似文献
348.
Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately at mild condition and high yields in suitable times were obtained. 相似文献
349.
350.