全文获取类型
收费全文 | 2807篇 |
免费 | 62篇 |
国内免费 | 13篇 |
专业分类
化学 | 1731篇 |
晶体学 | 22篇 |
力学 | 74篇 |
数学 | 412篇 |
物理学 | 643篇 |
出版年
2023年 | 15篇 |
2022年 | 47篇 |
2021年 | 54篇 |
2020年 | 50篇 |
2019年 | 36篇 |
2018年 | 46篇 |
2017年 | 32篇 |
2016年 | 84篇 |
2015年 | 62篇 |
2014年 | 70篇 |
2013年 | 139篇 |
2012年 | 126篇 |
2011年 | 143篇 |
2010年 | 102篇 |
2009年 | 97篇 |
2008年 | 139篇 |
2007年 | 115篇 |
2006年 | 118篇 |
2005年 | 118篇 |
2004年 | 94篇 |
2003年 | 92篇 |
2002年 | 71篇 |
2001年 | 60篇 |
2000年 | 50篇 |
1999年 | 30篇 |
1998年 | 38篇 |
1997年 | 43篇 |
1996年 | 39篇 |
1995年 | 28篇 |
1994年 | 27篇 |
1993年 | 36篇 |
1992年 | 23篇 |
1991年 | 17篇 |
1990年 | 21篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 32篇 |
1984年 | 41篇 |
1983年 | 20篇 |
1982年 | 21篇 |
1981年 | 23篇 |
1980年 | 22篇 |
1979年 | 24篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 22篇 |
1973年 | 13篇 |
1972年 | 14篇 |
1901年 | 11篇 |
排序方式: 共有2882条查询结果,搜索用时 15 毫秒
1.
2.
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
3.
4.
We study a class of nonlinear regression models for scalar or vectorial response when the explanatory variable is a function. We introduce a consistent estimator of the parameters of models in this class when functions are evaluated at randomly chosen observation points. To cite this article: F. Rossi, B. Conan-Guez, C. R. Acad. Sci. Paris, Ser. I 340 (2005). 相似文献
5.
Ornella Azzolina Simona Collina Daniela Rossi Enrica Lanza 《Tetrahedron letters》2004,45(7):1355-1357
The diastereoselective synthesis of naphthyl amino alcohols via nucleophilic addition to racemic 1-dimethylamino-2-methylpentan-3-one was studied. The use of the appropriate experimental conditions allowed the synthesis of both diastereoisomers. The relative configurations were established via NOESY experiments. 相似文献
6.
For ϕ a δ-subharmonic function, sharp results are obtained that connectA(r, ϕ), B(r, ϕ) andT(r, ϕ), whereA(r, ϕ)=inf|z|=r
ϕ(z),B(r, ϕ)=sup|z|=r
ϕ(z), andT(r, ϕ) is the Nevanlinna characteristics. 相似文献
7.
Viviane Van Hoof Hugo Cluckers Vera Verhaeghe An Hennebel Marleen Truyens Edith Van Loock Pierre Rombouts Dirk Maes Jan Van Elven Katrien Lesage Mark Flothmann Lieve Nijs Filip Colpaert Werner Vercammen Dominique Bolain 《Accreditation and quality assurance》2004,10(1-2):55-59
In response to a change of the Belgian National Directives whereby hospital laboratories became responsible for all point-of-care testing (POCT) performed within hospital walls a standardized and automated POC glucose-testing system was implemented in our hospital. The system consists of 50 AccuCheck Inform instruments (Roche Diagnostics, Vilvoorde, Belgium), 50 docking stations, a DataCare Server, and connections to the medical laboratory information system (MOLIS, Sysmex, Barchon, Belgium) and to the hospital information system. Implementation involved many parties and extensive preparation and communication. Key issues were bar-coded patient and user identification, training, and responsibilities. One year after the hospital wide implementation of this system the quality of POC glucose testing has significantly increased, thereby improving patient safety. This study describes a stepwise change over involving the medical laboratory and with a focus on hands-on quality.Presented at the ninth conference on Quality in the Spotlight, 18–19 March 2004, Antwerp, Belgium. 相似文献
8.
Jun Fujii Giancarlo Panaccione Giorgio Rossi Giancarlo Trimarchi 《Surface science》2006,600(18):3884-3887
Bulk carbon impurities segregate at the Fe(1 0 0) surface and, upon thermal annealing, can form metastable surface phases with local and long range order and peculiar electronic properties. We present a surface science study of C-segregated Fe(1 0 0) with scanning tunneling microscopy, angle resolved photoemission, and ab initio calculations of the surface structure and electron states. In particular the c(3√2 × √2) structure, observed for 0.67 atomic layers of C segregated at the iron surface, is found to be due to self-organized carbon stripes made of zig-zag chains. The strong hybridization between C and Fe was observed in ARPES spectra. 相似文献
9.
Particle filters are presently among the most powerful tools for filtering discrete time non linear systems. However the presence of unknown parameters in the system equations makes their use more complex and can even impair their convergence properties. This Note shows how an on-line consistent estimation of these parameters can be obtained simultaneously to that of the state variables to be filtered. This approach relies upon a kernel-based non parametric estimation of conditional probability densities from successive Monte Carlo generations of system particles. To cite this article: V. Rossi, J.-P. Vila, C. R. Acad. Sci. Paris, Ser. I 340 (2005). 相似文献
10.
Giorgio AbbiatiAntonio Arcadi Egle BeccalliElisabetta Rossi 《Tetrahedron letters》2003,44(28):5331-5334
Intramolecular cyclization of 2-acyl-1-propargyl-1H-indoles in the presence of ammonia provides an easy entry to pyrazino[1,2-a]indole nucleus. 相似文献