全文获取类型
收费全文 | 4698篇 |
免费 | 183篇 |
国内免费 | 15篇 |
专业分类
化学 | 3127篇 |
晶体学 | 45篇 |
力学 | 83篇 |
数学 | 484篇 |
物理学 | 1157篇 |
出版年
2023年 | 43篇 |
2022年 | 88篇 |
2021年 | 144篇 |
2020年 | 118篇 |
2019年 | 141篇 |
2018年 | 111篇 |
2017年 | 115篇 |
2016年 | 196篇 |
2015年 | 146篇 |
2014年 | 155篇 |
2013年 | 279篇 |
2012年 | 310篇 |
2011年 | 384篇 |
2010年 | 251篇 |
2009年 | 244篇 |
2008年 | 320篇 |
2007年 | 291篇 |
2006年 | 235篇 |
2005年 | 208篇 |
2004年 | 192篇 |
2003年 | 126篇 |
2002年 | 110篇 |
2001年 | 82篇 |
2000年 | 86篇 |
1999年 | 56篇 |
1998年 | 40篇 |
1997年 | 37篇 |
1996年 | 35篇 |
1995年 | 33篇 |
1994年 | 29篇 |
1993年 | 34篇 |
1992年 | 36篇 |
1991年 | 19篇 |
1990年 | 20篇 |
1989年 | 16篇 |
1988年 | 9篇 |
1987年 | 7篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1972年 | 5篇 |
排序方式: 共有4896条查询结果,搜索用时 15 毫秒
1.
Machado J. A. Tenreiro Rocha-Neves J. M. Azevedo Filipe Andrade J. P. 《Nonlinear dynamics》2021,106(2):1525-1555
Nonlinear Dynamics - Given a data-set of Ribonucleic acid (RNA) sequences we can infer the phylogenetics of the samples and tackle the information for scientific purposes. Based on current data and... 相似文献
2.
3.
4.
5.
Application of TiO2-nanotubes/PbO2 as an anode for the electrochemical elimination of Acid Red 1 dye
Santos José Eudes L. de Moura Dayanne Chianca da Silva Djalma Ribeiro Panizza Marco Martínez-Huitle Carlos A. 《Journal of Solid State Electrochemistry》2019,23(2):351-360
Journal of Solid State Electrochemistry - In this study, galvanostatic electrolysis, through the use of the platinum supported on Ti (Ti/Pt) and Ti/TiO2-nanotubes/PbO2 anodes, was conducted in an... 相似文献
6.
Alcindo A. Dos Santos Renan S. Ferrarini Jefferson L. Princival João V. Comasseto 《Tetrahedron letters》2006,47(50):8933-8935
A masked lithium homoenolate, generated by tellurium/lithium exchange, was reacted with epoxides. The lithium compound was also converted into other organometallics such as Grignard, and cuprates and the reactivity of those organometallics with epoxides was evaluated. The same building block was employed in the synthesis of (+/−)-frontalin. 相似文献
7.
J.-C. Thomas L. Achouri J. Äystö R. Béraud B. Blank G. Canchel S. Czajkowski P. Dendooven A. Ensallem J. Giovinazzo N. Guillet J. Honkanen A. Jokinen A. Laird M. Lewitowicz C. Longour F. de Oliveira Santos K. Peräjärvi M. Stanoiu 《The European Physical Journal A - Hadrons and Nuclei》2004,21(3):419-435
8.
YBa2Cu3O7-x (YBCO) bulk is one of the most important high temperature superconducting materials for magnetic levitation applications, because it has a high magnetic irreversibility field Hirr at liquid nitrogen temperature, and can grow into large grains. The levitation force of YBCO bulk is proportional to the critical current density (Jc) and grain radius (r)[1], so higher Jc and r are appreciated for YBCO bulks to achieve higher levitation force. Now single-domain YBCO bulks up to s… 相似文献
9.
C. M. Silva R. S. Amaral A. Amaral J. A. Santos Júnior D. C. Santos L. E. Lima S. V. Silveira 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(1):237-241
Summary Studies performed by the Brazilian Nuclear Corporation (NUCLEBRAS), in collaboration with the Geological Survey Company of
Brazil (CPRM), identified high levels of natural uranium in the districts of Pedra and Venturosa, in the rural region of the
state of Pernambuco (PE) - Brazil, where the maximum value found in rocks was 22,000 mg. 相似文献
10.
Tereza C. R. dos Santos Ricardo Q. Aucélio Reinaldo C. Campos 《Mikrochimica acta》2003,142(1-2):63-66
A simple and direct spectrofluorimetric method has been developed for the determination of aluminum using alizarin red PS
(1,2,4-trihydroxy 9,10-anthraquinone-3-sulfonic acid). The method is based on the strong fluorescence (480/564 nm) of Al3+ and alizarin red. Experimental parameters such as pH, concentration of the ligand, ionic strength of the solution, reaction
time and temperature were optimized in order to maximize the analytical signal. Interferences of several ions (anions and
cations) were studied and evaluated. The linear range of the method extends from 3 to 100 μg L−1. Limit of detection (3sb) was 0.9 μg L−1. The method was tested with a silicate certified reference material. Interferences were eliminated by a liquid extraction
with cupferron.
Author for correspondence. E-mail: aucelior@rdc.puc-rio.br
Received September 10, 2002; accepted January 15, 2003
Published online May 5, 2003 相似文献