全文获取类型
收费全文 | 557篇 |
免费 | 6篇 |
国内免费 | 5篇 |
专业分类
化学 | 377篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 135篇 |
物理学 | 52篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2018年 | 12篇 |
2017年 | 4篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 9篇 |
2013年 | 32篇 |
2012年 | 14篇 |
2011年 | 34篇 |
2010年 | 16篇 |
2009年 | 23篇 |
2008年 | 24篇 |
2007年 | 36篇 |
2006年 | 28篇 |
2005年 | 28篇 |
2004年 | 38篇 |
2003年 | 21篇 |
2002年 | 30篇 |
2001年 | 14篇 |
2000年 | 14篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1977年 | 4篇 |
1974年 | 2篇 |
1965年 | 2篇 |
1963年 | 2篇 |
1958年 | 4篇 |
1933年 | 2篇 |
1929年 | 2篇 |
排序方式: 共有568条查询结果,搜索用时 15 毫秒
461.
Our paper aims to show what to do in material modeling for an inelastic body. The method we use is based on the virtual work σ ′δε and on the variation of some function W with respect to the strain tensor. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
462.
463.
Kalechits G. V. Ol'khovik V. K. Kalosha I. I. Skakovskii E. D. Pap A. A. Zenyuk A. A. Matveenko Yu. V. 《Russian Journal of General Chemistry》2001,71(8):1257-1260
Condensation of 3-acetyl-4-hydroxy-2-quinolone with aromatic aldehydes gave substituted 3-cynnamoyl-4-hydroxy-2-quinolones that luminesce in the solid state in the visible spectral range. 相似文献
464.
A cyclic ordering of the vertices of a k‐uniform hypergraph is called a hamiltonian chain if any k consecutive vertices in the ordering form an edge. For k = 2 this is the same as a hamiltonian cycle. We consider several natural questions about the new notion. The main result is a Dirac‐type theorem that provides a sufficient condition for finding hamiltonian chains in k‐uniform hypergraphs with large (k − 1)‐minimal degree. If it is more than than the hypergraph contains a hamiltonian chain. © 1999 Wiley & Sons, Inc. J Graph Theory 30: 205–212, 1999 相似文献
465.
Lutz F. Tietze Gyula Schneider Jnos Wlfling Thomas Nbel Christian Wulff Ingrid Schubert Angela Rübeling 《Angewandte Chemie (International ed. in English)》1998,37(18):2469-2470
Numerous pharmacologically interesting compounds are available by the synthesis of hybrid natural products. Thus, for instance, the estrone–talaromycin hybrid 2 , which is synthesized in a few steps from the estrone derivative 1 by a sequence in which a hetero-Diels–Alder reaction is the key step, exhibits notable cytotoxic activity. 相似文献
466.
467.
468.
Equilibrium Swelling of an Epoxy‐Resin in Contact with Water – A Molecular Dynamics Simulation Study
Full Paper: We have studied the equilibrium swelling of an idealized model network based on a realistic epoxy‐resin in contact with water using the molecular dynamics simulation method. We use a novel method to measure the water chemical potential inside the network as function of water concentration. The equality of the water chemical potential computed in this fashion with the bulk water chemical potential under the same thermodynamic conditions determines the equilibrium water content and the swelling ratio. We study the dependence of the water content as function of temperature and as function of the size of the atomic partial charges.
469.
470.
Approaching the Kinetic Inertness of Macrocyclic Gadolinium(III)‐Based MRI Contrast Agents with Highly Rigid Open‐Chain Derivatives 下载免费PDF全文
Dr. Gyula Tircsó Dr. Martín Regueiro‐Figueroa Viktória Nagy Zoltán Garda Tamás Garai Dr. Ferenc Krisztián Kálmán Dr. David Esteban‐Gómez Dr. Éva Tóth Dr. Carlos Platas‐Iglesias 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):896-901
A highly rigid open‐chain octadentate ligand (H4cddadpa) containing a diaminocylohexane unit to replace the ethylenediamine bridge of 6,6′‐[(ethane‐1,2 diylbis{(carboxymethyl)azanediyl})bis(methylene)]dipicolinic acid (H4octapa) was synthesized. This structural modification improves the thermodynamic stability of the Gd3+ complex slightly (log KGdL=20.68 vs. 20.23 for [Gd(octapa)]?) while other MRI‐relevant parameters remain unaffected (one coordinated water molecule; relaxivity r1=5.73 mm ?1 s?1 at 20 MHz and 295 K). Kinetic inertness is improved by the rigidifying effect of the diaminocylohexane unit in the ligand skeleton (half‐life of dissociation for physiological conditions is 6 orders of magnitude higher for [Gd(cddadpa)]? (t1/2=1.49×105 h) than for [Gd(octapa)]?. The kinetic inertness of this novel chelate is superior by 2–3 orders of magnitude compared to non‐macrocyclic MRI contrast agents approved for clinical use. 相似文献