全文获取类型
收费全文 | 1413篇 |
免费 | 132篇 |
国内免费 | 2篇 |
专业分类
化学 | 966篇 |
晶体学 | 12篇 |
力学 | 22篇 |
数学 | 345篇 |
物理学 | 202篇 |
出版年
2024年 | 5篇 |
2023年 | 19篇 |
2022年 | 24篇 |
2021年 | 38篇 |
2020年 | 44篇 |
2019年 | 64篇 |
2018年 | 52篇 |
2017年 | 38篇 |
2016年 | 92篇 |
2015年 | 99篇 |
2014年 | 83篇 |
2013年 | 235篇 |
2012年 | 141篇 |
2011年 | 132篇 |
2010年 | 73篇 |
2009年 | 51篇 |
2008年 | 46篇 |
2007年 | 23篇 |
2006年 | 42篇 |
2005年 | 23篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 21篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 5篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 2篇 |
1958年 | 2篇 |
1955年 | 2篇 |
1922年 | 1篇 |
排序方式: 共有1547条查询结果,搜索用时 328 毫秒
991.
992.
Synthesis of (E)‐4‐Bromo‐3‐methoxybut‐3‐en‐2‐one,the Key Fragment in the Polyhydroxylated Chain Common to Oscillariolide and Phormidolides A–C
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alejandro Gil Dr. Janire Lamariano‐Merketegi Dr. Adriana Lorente Prof. Fernando Albericio Prof. Mercedes Álvarez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(21):7033-7035
The terminal bromomethoxydiene (BMD) moiety of the polyhydroxylated chain present in phormidolides and oscillariolides has been synthesized for first time. Several strategies for the stereoselective synthesis of the 4‐bromo‐3‐methoxybut‐3‐en‐2‐ones are described. Furthermore, a preliminary study to successfully introduce the BMD within the polyol chain and the fatty acid allowed us to corroborate the end structure of the polyol. 相似文献
993.
994.
VÍT JIRÁSEK STANISLAV LABÍK ANATOL MALIJEVSKÝ MARTIN LÍSAL 《Molecular physics》2013,111(24):2033-2043
Square-well homo-nuclear and hetero-nuclear diatomic fluids are studied using the Ornstein-Zernike equation and the recently proposed RHNC-VM closure. Monte Carlo canonical simulations have been performed to complete recent literature simulation data. The integral equation thermodynamic and structural results are compared with these and literature simulation data at three elongations over a large range of densities and temperatures. The RHNC-VM theory agrees excellently with the simulation thermodynamic and structural results. Its accuracy revealed slight errors in simulation data in work by Lisal and Nezbeda [1999, Molec. Phys., 96, 335]. The data have been re-simulated. 相似文献
995.
Pt—Sn supported on alumina was characterized before and after treatment with hydrogen by Mössbauer spectroscopy and X-ray diffraction. For the calcined sample tin is present as SnO2 and platinum as metal. After reduction with hydrogen, Sn(IV), Sn(II), Sn(0), Pt, Pt3Sn, PtSn alloys are formed. SnO interacts strongly with the support. 相似文献
996.
We present a new semilocal convergence analysis for Newton-like methods in order to approximate a locally unique solution of an equation in a Banach space setting. This way, we expand the applicability of these methods in cases not covered in earlier studies. The advantages of our approach include a more precise convergence analysis under the same computational cost on the Lipschitz constants involved. Applications are also given in this study to show that our estimates on the distances involved are tighter than the older ones. 相似文献
997.
Competitive retro‐cycloaddition reactions in heterocyclic fullerene bis‐adducts ions: selective removal of the heterocyclic moieties
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)
998.
Gutierrez Luisa F. Nope Eliana Rojas Hugo A. Cubillos Jairo A. Sathicq Ángel G. Romanelli Gustavo P. Martínez José J. 《Research on Chemical Intermediates》2018,44(9):5559-5568
Research on Chemical Intermediates - This study focuses on the search of new applications of polyoxometalates known as decaniobate ions [Nb10O28]6?. The decaniobates can be used as basic... 相似文献
999.
JPC – Journal of Planar Chromatography – Modern TLC - The antibacterial effect of the components of clary sage (Salvia sclarea L.) and spearmint (Mentha spicata L. var. crispa (Bentham)... 相似文献
1000.
A detailed survey of reduced SnO2-(110) surfaces is presented including novel and disordered reconstructions with cation surface interstitials as essential building block. Our results consistently explain the experimentally observed (1 × 1) and (1 × 2) reconstructions. A revised surface phase diagram containing all observed equilibrium reconstructions is proposed. 相似文献