全文获取类型
收费全文 | 4884篇 |
免费 | 178篇 |
专业分类
化学 | 2486篇 |
晶体学 | 20篇 |
力学 | 100篇 |
数学 | 592篇 |
物理学 | 1864篇 |
出版年
2021年 | 46篇 |
2020年 | 55篇 |
2019年 | 45篇 |
2018年 | 50篇 |
2017年 | 53篇 |
2016年 | 143篇 |
2015年 | 93篇 |
2014年 | 113篇 |
2013年 | 217篇 |
2012年 | 219篇 |
2011年 | 273篇 |
2010年 | 128篇 |
2009年 | 102篇 |
2008年 | 202篇 |
2007年 | 198篇 |
2006年 | 169篇 |
2005年 | 173篇 |
2004年 | 118篇 |
2003年 | 114篇 |
2002年 | 81篇 |
2001年 | 88篇 |
2000年 | 75篇 |
1999年 | 66篇 |
1998年 | 45篇 |
1997年 | 60篇 |
1996年 | 65篇 |
1995年 | 70篇 |
1994年 | 53篇 |
1993年 | 69篇 |
1992年 | 75篇 |
1991年 | 54篇 |
1990年 | 52篇 |
1989年 | 46篇 |
1988年 | 49篇 |
1987年 | 49篇 |
1986年 | 46篇 |
1985年 | 52篇 |
1984年 | 55篇 |
1983年 | 48篇 |
1982年 | 57篇 |
1981年 | 58篇 |
1979年 | 52篇 |
1978年 | 52篇 |
1977年 | 45篇 |
1976年 | 50篇 |
1975年 | 55篇 |
1973年 | 43篇 |
1964年 | 44篇 |
1962年 | 43篇 |
1956年 | 45篇 |
排序方式: 共有5062条查询结果,搜索用时 31 毫秒
51.
C. Fischbacher K.-U. Jagemann K. Danzer U. A. Müller L. Papenkordt J. Schüler 《Analytical and bioanalytical chemistry》1997,359(1):78-82
Partial least-squares regression (PLS) and radial basis function (RBF) networks are used to compute calibration models for non-invasive blood glucose determination by NIR diffuse reflectance spectroscopy. A model computation shows that even extremely small deviations of the spectra induce increased prediction errors. Since the spectral contribution of blood glucose is much smaller than deviations resulting from the non-invasive measuring process a method based on Pearson’s correlation coefficient can be used for evaluating the quality of the recorded spectra during the prediction step. Another method is based on the leverage values from the hat matrix of the RBF network. Both methods lead to a significant decrease in prediction error. 相似文献
52.
53.
U. Kreibig K. Fauth M. Quinten D. Schönauer 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,12(1-4):505-514
First, some general remarks concerning macroscopic “cluster matter” are given. In the second part, three recent, mainly optically and electron-microscopically performed investigations are discussed which deal with special properties of noble metal cluster systems forming the building units of this kind of matter:(1) dressed Au-55 clusters,(2) electromagnetic coupling effects among coagulated clusters,(3) the transition towards compact inhomogeneous matter caused by coalescence of clusters. 相似文献
54.
E. Ühlein W. Scherman F. Asinger A. Warner P. Kratochvil G. Kirschstein H. Bergmann H. D. Cremer U. Grigull E. Schleitzer E. Best R. Honerjäger H. Schäfer K. -H. König A. Sippel Hj. Schönert W. Koch B. Frisch H. G. Kilian R. Hähnel H. H. Pfeiffer 《Colloid and polymer science》1966,213(1-2):157-174
Ohne Zusammenfassung 相似文献
55.
56.
Renkes T Schäfer HJ Siemens PM Neumann E 《Angewandte Chemie (International ed. in English)》2000,39(14):2512-2516
57.
58.
Summary The question of the existence of good Markov [good stationary] policies is studied for a general class of Borel [stationary] dynamic programming models. It is shown, for example, that Markov [stationary] policies are uniformly adequate if every transition law is absolutely continuous with respect to a fixed measure [and the reward function is positive or the model satisfies certain compactness and continuity conditions].Research supported by Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 72Research supported by National Science Foundation Grant MCS 8100789 相似文献
59.
C. Chr Schüler 《Zeitschrift für Physik B Condensed Matter》1987,68(2-3):325-328
The proton conductivity of three layer-type compounds was studied: H3OTi2NbO7. H2O, HTiNbO5 and HTiTaO5. Measurements were made between 20 °C and 90°C on pellets pressed from crystalline powders and soaked with pure water. The hydrated compound had the highest conductivity, (20°C)-6.3–6.9·10–4 (cm)–1. Acid ions from the exchange process were quite firmly retained in its layer structure and contributed significantly to the measured conductivity. Consistent results were obtained after prolonged washing with water.Dedicated to Professor Harry Thomas on the occasion of his 60th birthday 相似文献
60.
Christophe Reutenauer Marcel-Paul Schützenberger 《Letters in Mathematical Physics》1987,13(4):299-302
We give a formula, involving circular words and symmetric functions of the eigenvalues, for the determinant of a sum of matrices. Theorem of Hamilton-Cayley is deduced from this formula.UQAM and LITPUniversité Paris 7 and LITP. 相似文献