全文获取类型
收费全文 | 636篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
化学 | 405篇 |
晶体学 | 17篇 |
力学 | 4篇 |
数学 | 52篇 |
物理学 | 185篇 |
出版年
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 26篇 |
2015年 | 20篇 |
2014年 | 28篇 |
2013年 | 21篇 |
2012年 | 37篇 |
2011年 | 35篇 |
2010年 | 25篇 |
2009年 | 36篇 |
2008年 | 29篇 |
2007年 | 35篇 |
2006年 | 40篇 |
2005年 | 33篇 |
2004年 | 24篇 |
2003年 | 18篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1980年 | 2篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 3篇 |
1942年 | 3篇 |
1939年 | 2篇 |
1932年 | 2篇 |
1908年 | 1篇 |
排序方式: 共有663条查询结果,搜索用时 15 毫秒
101.
Christopher J. Burns Robert D. Groneberg Joseph M. Salvino Gerard McGeehan Stephen M. Condon Robert Morris Matthew Morrissette Rose Mathew Shelley Darnbrough Kent Neuenschwander Anthony Scotese Stevan W. Djuric John Ullrich Richard Labaudiniere 《Angewandte Chemie (International ed. in English)》1998,37(20):2848-2850
One common synthetic route creates small-molecule libraries directed toward two functionally distinct target families. The novel structural template 1 can independently display the necessary pharmacophore patterns for inhibition of members of two different biomolecular target families, the matrix metalloproteinases (MMPs) or the phosphodiesterases (PDEs). The incorporation of multiple target family directed design elements into combinatorial library design could help expedite the pharmaceutical lead discovery process. Z=OR′ (PDE4), H (MMPs). 相似文献
102.
103.
In 1996, we performed the first measurements of residual stresses by using synchrotron excited Kossel diffraction (at the beamline L of the HASYLAB, Hamburg). Our first findings as well as the principle of the determination procedure for obtaining residual stresses from Kossel lines are presented. The Kossel technique is a very suitable method for fast measurements of local residual stresses in micron regions. Because of the high lateral resolution even residual stresses of third order (inhomogeneities of the stress state within a grain) can be proved and calculated. 相似文献
104.
F. Welsch J. Ullrich H. Ossmer M. Schmidt M. Kohl C. Chluba E. Quandt A. Schütze S. Seelecke 《Continuum Mechanics and Thermodynamics》2018,30(1):53-68
The exploitation of the elastocaloric effect in superelastic shape memory alloys (SMA) for cooling applications shows a promising energy efficiency potential but requires a better understanding of the non-homogeneous martensitic phase transformation. Temperature profiles on sputter-deposited superelastic \({\mathrm {Ti_{55.2}Ni_{29.3}Cu_{12.7}Co_{2.8}}}\) shape memory alloy thin films show localized release and absorption of heat during phase transformation induced by tensile deformation with a strong rate dependence. In this paper, a model for the simulation of the thermo-mechanically coupled transformation behavior of superelastic SMA is proposed and its capability to reproduce the mechanical and thermal responses observed during experiments is shown. The procedure for experiment and simulation is designed such that a significant temperature change from the initial temperature is obtained to allow potential cooling applications. The simulation of non-local effects is enabled by the use of a model based on the one-dimensional Müller–Achenbach–Seelecke model, extended by 3D mechanisms such as lateral contraction and by non-local interaction, leading to localization effects. It is implemented into the finite element software COMSOL Multiphysics, and comparisons of numerical and experimental results show that the model is capable of reproducing the localized transformation behavior with the same strain rate dependency. Additionally to the thermal and the mechanical behavior, the quantitative prediction of cooling performance with the presented model is shown. 相似文献
105.
106.
107.
108.
Fernando Cobos Luz M. Fernández-Cabrera Thomas Kühn Tino Ullrich 《Journal of Functional Analysis》2009,256(7):2321-3722
We investigate the limit class of interpolation spaces that comes up by the choice θ=0 in the definition of the real method. These spaces arise naturally interpolating by the J-method associated to the unit square. Their duals coincide with the other extreme spaces obtained by the choice θ=1. We also study the behavior of compact operators under these two extreme interpolation methods. Moreover, we establish some interpolation formulae for function spaces and for spaces of operators. 相似文献
109.
110.
Juan Peris-Vicente Jaume Albiol-Chiva Pasqual Roca-Genovés Josep Esteve-Romero 《液相色谱法及相关技术杂志》2016,39(7):325-338
Melamine is a toxic triazine which has been recently proven as a threat to human health. It can be ingested by several methods, being the most important the unethical adulteration of protein-rich foodstuff for economic reasons. This review presents several analytical methods, taken from the literature studies, devoted to the determination of melamine in milk, dietetic supplements, drinking and wastewater, swine kidney, plasma, and urine, using micellar liquid chromatography (MLC). We consider that the control of these samples is crucial to prevent and manage melamine intoxication. This technique has been demonstrated as an excellent tool to determine organic compounds in these matrices. We detail the optimization strategy and the obtained results in the different steps of method development, such as sample pretreatment, chromatographic separation, and validation process. The similarities and differences of the procedures have been described and discussed, as well as their advantages. The main ones were the possibility of direct injection and the efficient chromatographic elution, in spite of the complexity of the samples. Besides, it was found that the MLC procedures were fast, easy-to-handle, inexpensive, eco-friendly, safe, and useful for routine analysis. Therefore, they represent an excellent alternative to reliably evaluate the melamine concentration in that kind of samples. 相似文献