全文获取类型
收费全文 | 334篇 |
免费 | 0篇 |
专业分类
化学 | 193篇 |
晶体学 | 3篇 |
数学 | 37篇 |
物理学 | 101篇 |
出版年
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 3篇 |
2010年 | 9篇 |
2009年 | 3篇 |
2008年 | 15篇 |
2007年 | 17篇 |
2006年 | 22篇 |
2005年 | 9篇 |
2004年 | 14篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 8篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1982年 | 4篇 |
1980年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1918年 | 6篇 |
1916年 | 5篇 |
1915年 | 3篇 |
1912年 | 4篇 |
1910年 | 3篇 |
1909年 | 2篇 |
1908年 | 4篇 |
1907年 | 4篇 |
1906年 | 3篇 |
1905年 | 6篇 |
1904年 | 3篇 |
1903年 | 6篇 |
1902年 | 4篇 |
1901年 | 8篇 |
1900年 | 4篇 |
1897年 | 6篇 |
1895年 | 2篇 |
1893年 | 3篇 |
1892年 | 2篇 |
1890年 | 2篇 |
1883年 | 2篇 |
1882年 | 2篇 |
排序方式: 共有334条查询结果,搜索用时 0 毫秒
261.
Measurements of elastic and inelastic cotunneling currents are presented on a two-terminal Aharonov-Bohm interferometer with a Coulomb-blockaded quantum dot embedded in each arm. Coherent current contributions, even in a magnetic field, are found in the nonlinear regime of inelastic cotunneling at a finite-bias voltage. The phase of the Aharonov-Bohm oscillations in the current exhibits phase jumps of pi at the onsets of inelastic processes. We suggest that additional coherent elastic processes occur via the excited state. Our measurement technique allows the detection of such processes on a background of other inelastic current contributions and contains qualitative information about the ratio of transport and inelastic relaxation rates. 相似文献
262.
263.
M. Yu. Akimov I. V. Kukushkin S. I. Gubarev S. V. Tovstonog J. Smet K. von Klitzing W. Wegscheider 《JETP Letters》2000,72(9):460-463
Dimensional magnetoplasma resonance is observed and studied in a spatially confined, two-dimensional hole system in (001) GaAs/AlGaAs single quantum wells. From the analysis of the field dependence of the magnetoplasma resonance on the diameter of the 2D system, the semiclassical cyclotron hole mass is determined. Its value is found to be equal to 0.26m 0 (m 0 is the free electron mass), which considerably exceeds the theoretically predicted value. A method is proposed for a direct determination of the concentration and mobility of 2D holes from the analysis of the magnetoplasma resonance. 相似文献
264.
Wolfhard Wegscheider 《Accreditation and quality assurance》1999,4(11):478-479
There is much discussion in chemical metrology about the definition of primary methods of measurement, just as a couple of
years ago there was debate about its predecessors, absolute methods and definitive methods. It is argued in this paper that
the designation of certain methods as being primary only makes sense if there is an outstanding property identified that is
common to all primary methods, and not present for all non-primary methods. The aim to identify primary methods should not
blur our notion that it is the good practice of analytical chemistry that produces good results, not a particular method of
analysis. 相似文献
265.
Lüscher S Heinzel T Ensslin K Wegscheider W Bichler M 《Physical review letters》2001,86(10):2118-2121
Coulomb blockade resonances are measured in a GaAs quantum dot in which both shape deformations and interactions are small. The parametric evolution of the Coulomb blockade peaks shows a pronounced pair correlation in both position and amplitude, which is interpreted as spin pairing. As a consequence, the nearest-neighbor distribution of peak spacings can be well approximated by a modified bimodal Wigner surmise, in which interactions are taken into account beyond the constant interaction model. 相似文献
266.
T. Feil H.-P. Tranitz C. Gerl W. Wegscheider 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):301
We experimentally investigate the transport through a shunted surface superlattice under the influence of a magnetic field applied perpendicular to the current direction. The current–voltage characteristics of these surface superlattices exhibit a peak which is followed by a wide region of negative differential resistance. The application of a transverse magnetic field has a profound influence on the position and height of this peak. The recorded shifts are compared to the predictions of different superlattice transport theories. Since these theories predict a different dependence on the magnetic field strength, the transport mechanism in the surface superlattice structures can be uniquely determined. 相似文献
267.
268.
269.
270.
Ohne Zusammenfassung 相似文献