全文获取类型
收费全文 | 3399篇 |
免费 | 137篇 |
国内免费 | 24篇 |
专业分类
化学 | 2618篇 |
晶体学 | 8篇 |
力学 | 64篇 |
数学 | 508篇 |
物理学 | 362篇 |
出版年
2023年 | 19篇 |
2022年 | 26篇 |
2021年 | 27篇 |
2020年 | 72篇 |
2019年 | 52篇 |
2018年 | 32篇 |
2017年 | 46篇 |
2016年 | 77篇 |
2015年 | 101篇 |
2014年 | 108篇 |
2013年 | 183篇 |
2012年 | 215篇 |
2011年 | 230篇 |
2010年 | 168篇 |
2009年 | 127篇 |
2008年 | 225篇 |
2007年 | 223篇 |
2006年 | 229篇 |
2005年 | 207篇 |
2004年 | 158篇 |
2003年 | 142篇 |
2002年 | 160篇 |
2001年 | 74篇 |
2000年 | 57篇 |
1999年 | 62篇 |
1998年 | 48篇 |
1997年 | 56篇 |
1996年 | 63篇 |
1995年 | 49篇 |
1994年 | 34篇 |
1993年 | 25篇 |
1992年 | 29篇 |
1991年 | 14篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 10篇 |
1987年 | 17篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 9篇 |
1973年 | 8篇 |
1972年 | 7篇 |
1971年 | 12篇 |
排序方式: 共有3560条查询结果,搜索用时 15 毫秒
931.
932.
933.
P. G. Verschuren Juul L. van der Baan Rolf Blaauw Dirk de Beer Johannes C. van den Heuvel 《Fresenius' Journal of Analytical Chemistry》1999,364(6):595-598
The synthesis of iodo{2,2′-[1,2-octadecanediylbis(nitrilomethylidyne)]diphenolato}cobalt is described. Liquid membrane microelectrodes
based on this carrier exhibit Nernstian behaviour with a selectivity sequence according to the Hofmeister series: I– > NO3
– > NO2
– > Cl– > HCO3
– > AcO–. The selectivity coefficient of nitrate over nitrite and chloride amounts to –1.6 and –2.7, respectively. The detection limit
for nitrate in water amounts to 10–5.2 mol/L. A nitrate profile measured in a nitrifying biofilm is presented as a practical application.
Received: 11 November 1998 / Revised: 22 January 1999 / Accepted: 27 January 1999 相似文献
934.
Consider the stochastic Swift-Hohenberg equation on a large domain near its change of stability. Under appropriate scaling its solutions are approximated by a periodic wave modulated by the solutions to a stochastic Ginzburg-Landau equation. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
935.
Federica Chiellini Ranieri Bizzarri Christopher K. Ober Dirk Schmaljiohann Tianyue Yu W. Mark Saltzman Roberto Solaro Emo Chiellini 《Macromolecular Symposia》2003,197(1):369-380
Semi-interpenetrating hydrogel networks were prepared by radical polimerization of monomer HEMA, co-monomer EGDMA as cross-linking agent and in the presence of 1 wt % of poly(alkyl β-malolactonate)s. Biological evaluation in terms of cell adhesion and proliferation of the prepared materials showed the ability of HEMA-based hydrogels to sustain a good cell adhesion and proliferation. Moreover, a method based on soft-lithography to obtained surface microstructured semi-interpenetrating hydrogel networks was developed, thus allowing for further investigation of the influence of surface topography on cell behavior. 相似文献
936.
937.
Riccardo Baron Dirk Bakowies WilfredF. vanGunsteren Xavier Daura 《Helvetica chimica acta》2002,85(11):3872-3882
The conformational spaces accessible to two β‐hexapeptides in MeOH at 298 K and 340 K are investigated by molecular‐dynamics simulation with an atomistic model of both solute and solvent. The structural properties of these peptides have been previously studied by NMR in MeOH at room temperature. The experimental data could be fitted to a model (P)‐12/10‐helix for one of the peptides and a model hairpin with a ten‐membered H‐bonded turn for the other. The goal of the present work is to determine whether the conformational spaces accessible to these two peptides of seemingly different conformational properties contain any common regions. In other words, to what extent are the evident differences found at the macroscopic level also present at the microscopic structural level? It is found that, for the two peptides studied, the conformational spaces sampled in the respective simulations show significant overlap. 相似文献
938.
939.
940.