全文获取类型
收费全文 | 4971篇 |
免费 | 193篇 |
国内免费 | 16篇 |
专业分类
化学 | 3366篇 |
晶体学 | 42篇 |
力学 | 93篇 |
数学 | 598篇 |
物理学 | 1081篇 |
出版年
2023年 | 49篇 |
2022年 | 151篇 |
2021年 | 139篇 |
2020年 | 125篇 |
2019年 | 137篇 |
2018年 | 105篇 |
2017年 | 109篇 |
2016年 | 208篇 |
2015年 | 144篇 |
2014年 | 164篇 |
2013年 | 290篇 |
2012年 | 341篇 |
2011年 | 400篇 |
2010年 | 249篇 |
2009年 | 230篇 |
2008年 | 347篇 |
2007年 | 300篇 |
2006年 | 249篇 |
2005年 | 236篇 |
2004年 | 214篇 |
2003年 | 150篇 |
2002年 | 132篇 |
2001年 | 75篇 |
2000年 | 78篇 |
1999年 | 49篇 |
1998年 | 38篇 |
1997年 | 42篇 |
1996年 | 40篇 |
1995年 | 33篇 |
1994年 | 28篇 |
1993年 | 31篇 |
1992年 | 34篇 |
1991年 | 17篇 |
1990年 | 18篇 |
1989年 | 17篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 20篇 |
1985年 | 14篇 |
1984年 | 16篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1979年 | 7篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1967年 | 6篇 |
排序方式: 共有5180条查询结果,搜索用时 31 毫秒
1.
In this paper, we design a Branch and Bound algorithm based on interval arithmetic to address nonconvex robust optimization problems. This algorithm provides the exact global solution of such difficult problems arising in many real life applications. A code was developed in MatLab and was used to solve some robust nonconvex problems with few variables. This first numerical study shows the interest of this approach providing the global solution of such difficult robust nonconvex optimization problems.
相似文献2.
3.
4.
da Silva Andre Luis Ferreira Salas Ruben Andres Silva Emilio Carlos Nelli 《Meccanica》2021,56(2):417-437
Meccanica - Fiber reinforced materials are used in assorted engineering application and for this reason, new additive manufacturing technologies have been developed for this type of materials. With... 相似文献
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.
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.
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
8.
We analyze the dynamics of an AdS5 braneworld with matter fields when gravity is allowed to deviate from the Einstein form on the brane. We consider exact five-dimensional warped solutions which are associated with conformal bulk fields of weight –4 and describe on the brane the following three dynamics: those of inhomogeneous dust, of generalized dark radiation, and of homogeneous polytropic dark energy. We show that, with modified gravity on the brane, the existence of such dynamical geometries requires the presence of non-conformal matter fields confined to the brane. 相似文献
9.
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
10.
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