全文获取类型
收费全文 | 6634篇 |
免费 | 322篇 |
国内免费 | 27篇 |
专业分类
化学 | 4826篇 |
晶体学 | 20篇 |
力学 | 164篇 |
数学 | 982篇 |
物理学 | 991篇 |
出版年
2024年 | 9篇 |
2023年 | 55篇 |
2022年 | 108篇 |
2021年 | 115篇 |
2020年 | 124篇 |
2019年 | 123篇 |
2018年 | 119篇 |
2017年 | 89篇 |
2016年 | 238篇 |
2015年 | 199篇 |
2014年 | 227篇 |
2013年 | 429篇 |
2012年 | 483篇 |
2011年 | 529篇 |
2010年 | 319篇 |
2009年 | 297篇 |
2008年 | 464篇 |
2007年 | 442篇 |
2006年 | 330篇 |
2005年 | 364篇 |
2004年 | 326篇 |
2003年 | 235篇 |
2002年 | 230篇 |
2001年 | 123篇 |
2000年 | 121篇 |
1999年 | 89篇 |
1998年 | 67篇 |
1997年 | 40篇 |
1996年 | 71篇 |
1995年 | 53篇 |
1994年 | 53篇 |
1993年 | 42篇 |
1992年 | 45篇 |
1991年 | 52篇 |
1990年 | 51篇 |
1989年 | 25篇 |
1988年 | 37篇 |
1987年 | 22篇 |
1986年 | 24篇 |
1985年 | 37篇 |
1984年 | 29篇 |
1983年 | 9篇 |
1982年 | 29篇 |
1981年 | 19篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1975年 | 8篇 |
1973年 | 7篇 |
排序方式: 共有6983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.
Biodistribution study of free and microencapsulated 6‐methylcoumarin in Wistar rats by HPLC 下载免费PDF全文
Aura Rocío Hernández Luis Fernando Ospina Diana Marcela Aragón 《Biomedical chromatography : BMC》2015,29(2):176-181
A sensitive, specific and reproducible HPLC method has been developed and validated for the quantitative determination of 6‐methylcoumarin (6MC) in plasma and other tissues in Wistar rats. A C18 column was used with UV detection at 321 nm and a gradient system consisting of methanol‐deionized water was used as mobile phase. The retention time for 6MC was 14.921 min and no interfering peaks were observed for any of the matrices. Linear relationships (r2 > 0.997) were obtained between the peak height ratios and the corresponding biological sample concentrations over the range 0.4–12.8 µg/mL. Precision and accuracy were evaluated; the coefficient of variation and the relative error for all of the organs were <2 and 7%, respectively. The limit of quantitation was 0.20 µg/mL for the heart and 0.30 µg/mL for the other tissues evaluated. This HPLC method was successfully used in the determination of 6MC in the biodistribution study after administration of 200 mg/kg of both 6MC‐free and 6MC‐loaded polymeric microparticles. In this study, extensive 6MC was found, in both free and microencapsulated forms, in all the organs tested. The 6MC‐free showed a range of between 1.7 and 11.5 µg/g, while the microencapsulated 6MC showed concentrations of between 6.35 and 17.7 µg/g, suggesting that 6MC improved absorption rate. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
4.
5.
6.
Mejía Hugo Fernando Giraldo Jiménez-Piqué Emilio Valdés Matías Procaccini Raúl Pellice Sergio 《Journal of Solid State Electrochemistry》2020,24(10):2451-2460
Journal of Solid State Electrochemistry - A novel material was developed using sol-gel chemistry and an environmental-friendly grafting process of clay nanoparticles. In a previous work of our... 相似文献
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.
A. Baeza M. Fernández M. Herranz F. Legarda C. Miró A. Salas 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(2):321-326
We studied the effectiveness of potable water treatment processes that consist of the stages of coagulation-flocculation-decantation,
using iron-based coagulants, in eliminating gamma-emitting man-made radioisotopes of cesium, strontium, and americium from
two natural waters with different degrees of mineralization. The resulting decontamination was found to depend on the chemical
behavior of each of the radionuclides considered, on the pH at which the process of coagulation is carried out, and on the
concentration of the other stable cations present.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献