全文获取类型
收费全文 | 4652篇 |
免费 | 220篇 |
国内免费 | 7篇 |
专业分类
化学 | 3520篇 |
晶体学 | 21篇 |
力学 | 90篇 |
数学 | 645篇 |
物理学 | 603篇 |
出版年
2024年 | 3篇 |
2023年 | 34篇 |
2022年 | 43篇 |
2021年 | 66篇 |
2020年 | 81篇 |
2019年 | 73篇 |
2018年 | 92篇 |
2017年 | 63篇 |
2016年 | 174篇 |
2015年 | 152篇 |
2014年 | 149篇 |
2013年 | 298篇 |
2012年 | 367篇 |
2011年 | 358篇 |
2010年 | 207篇 |
2009年 | 169篇 |
2008年 | 312篇 |
2007年 | 329篇 |
2006年 | 247篇 |
2005年 | 259篇 |
2004年 | 230篇 |
2003年 | 178篇 |
2002年 | 162篇 |
2001年 | 100篇 |
2000年 | 100篇 |
1999年 | 75篇 |
1998年 | 57篇 |
1997年 | 29篇 |
1996年 | 57篇 |
1995年 | 29篇 |
1994年 | 36篇 |
1993年 | 35篇 |
1992年 | 37篇 |
1991年 | 38篇 |
1990年 | 25篇 |
1989年 | 14篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 18篇 |
1985年 | 29篇 |
1984年 | 30篇 |
1983年 | 11篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 13篇 |
1975年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有4879条查询结果,搜索用时 31 毫秒
1.
Peralta Cecilia Mariana Acosta Gimena Henestrosa Cecilia Gil Raúl Andrés Fernández Liliana Patricia 《Journal of Analytical Chemistry》2022,77(3):308-317
Journal of Analytical Chemistry - The present development involved a flow injection strategy using a mini-column of multiwalled carbon nanotubes and fluorescent detection (λex of 283 nm,... 相似文献
2.
Bazarra Noelia Castejón Alberto Fernández José R. Quintanilla Ramón 《Meccanica》2021,56(12):3025-3037
Meccanica - In this work we study, from the numerical point of view, a one-dimensional thermoelastic problem where the thermal law is of type III. Quasi-static microvoids are also assumed within... 相似文献
3.
Ana-Maria Udrea Andra Dinache Jean-Marie Pags Ruxandra Angela Pirvulescu 《Molecules (Basel, Switzerland)》2021,26(8)
Multidrug resistance of bacteria is a worrying concern in the therapeutic field and an alternative method to combat it is designing new efflux pump inhibitors (EPIs). This article presents a molecular study of two quinazoline derivatives, labelled BG1189 and BG1190, proposed as EPIs. In silico approach investigates the pharmacodynamic and pharmacokinetic profile of BG1189 and BG1190 quinazolines. Molecular docking and predicted ADMET features suggest that BG1189 and BG1190 may represent attractive candidates as antimicrobial drugs. UV-Vis absorption spectroscopy was employed to study the time stability of quinazoline solutions in water or in dimethyl sulfoxide (DMSO), in constant environmental conditions, and to determine the influence of usual storage temperature, normal room lighting and laser radiation (photostability) on samples stability. The effects of irradiation on BG1189 and BG1190 molecules were also assessed through Fourier-transform infrared (FTIR) spectroscopy. FTIR spectra showed that laser radiation breaks some chemical bonds affecting the substituents and the quinazoline radical of the compounds. 相似文献
4.
Development of biocompatible porous supports is a promising strategy in the field of tissue engineering for the repair and regeneration of bone tissues with severe damage. Graphene oxide aerogels (GOAs) are excellent candidates for the manufacture of these systems due to their porosity, ability to imitate bone structure, and mechanical resistance, and according to their surface chemical reactivity, they can facilitate osseointegration, osteogenesis, osteoinduction and osteoconduction. In this review, synthesis of GOAs from the most primary source is described, and recent studies on the use of these functionalized carbonaceous foams as scaffolding for bone tissue regeneration are presented. 相似文献
5.
Carello Giuliana Landa Paolo Tnfani Elena Testi Angela 《Central European Journal of Operations Research》2022,30(1):159-187
Central European Journal of Operations Research - In the past years, the number of patients in need of chemotherapy treatments has been constantly increasing. Chemotherapy treatments must be... 相似文献
6.
7.
8.
Possible Loss and Recovery of Gibbsianness¶During the Stochastic Evolution of Gibbs Measures 总被引:1,自引:1,他引:0
A.C.D. van Enter R. Fernández F. den Hollander F. Redig 《Communications in Mathematical Physics》2002,226(1):101-130
We consider Ising-spin systems starting from an initial Gibbs measure ν and evolving under a spin-flip dynamics towards a
reversible Gibbs measure μ≠ν. Both ν and μ are assumed to have a translation-invariant finite-range interaction. We study
the Gibbsian character of the measure νS(t) at time t and show the following:
(1) For all ν and μ, νS(t) is Gibbs for small t.
(2) If both ν and μ have a high or infinite temperature, then νS(t) is Gibbs for all t > 0.
(3) If ν has a low non-zero temperature and a zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t and non-Gibbs for large t.
(4) If ν has a low non-zero temperature and a non-zero magnetic field and μ has a high or infinite temperature, then νS(t) is Gibbs for small t, non-Gibbs for intermediate t, and Gibbs for large t.
The regime where μ has a low or zero temperature and t is not small remains open. This regime presumably allows for many different scenarios.
Received: 26 April 2001 / Accepted: 10 October 2001 相似文献
9.
Enrique Fernández-Cara Sergio Guerrero Oleg Yurievich Imanuvilov Jean-Pierre Puel 《Comptes Rendus Mathematique》2004,338(5):375-380
This Note deals with the controllability of Stokes and Navier–Stokes systems with distributed controls with support in possibly small subdomains. We first present a new global Carleman inequality for the solutions to Stokes-like systems that leads to the null controllability at any time T>0. Then, we present a local result concerning exact controllability to trajectories of the Navier–Stokes system. To cite this article: E. Fernández-Cara et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
10.
Alberto Plaza Sonia Piacente Angela Perrone Arafa Hamed Cosimo Pizza Giuseppe Bifulco 《Tetrahedron》2004,60(52):12201-12209
Stemmosides C and D, two novel pregnane glycosides characterized by an unusual C-17 side chain were isolated from the pericarps of Solenostemma argel. In addition, stemmoside D displays an uncommon 14β proton configuration, apparently being the first pregnane isolated from plants known to have a 15 keto, cis CD ring junction. Their structures have been established by ESIMS and NMR experiments. The relative configuration of the molecules was determined using a strategy based on the simulation of 1H, 13C, and J coupling NMR parameters. DFT calculations of 1H and 13C chemical shifts, and of the 1H homonuclear spin–spin coupling constants were performed with the mPW1PW91 functional using the 6-31G(d,p) basis set on the fully optimized geometries of all the possible stereoisomers. 相似文献