全文获取类型
收费全文 | 177篇 |
免费 | 0篇 |
专业分类
化学 | 88篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 18篇 |
物理学 | 68篇 |
出版年
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 1篇 |
2008年 | 9篇 |
2007年 | 13篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1958年 | 1篇 |
1948年 | 2篇 |
1939年 | 2篇 |
1925年 | 1篇 |
1874年 | 1篇 |
1873年 | 1篇 |
排序方式: 共有177条查询结果,搜索用时 359 毫秒
71.
Hoover S Nam J Gorham PW Grashorn E Allison P Barwick SW Beatty JJ Belov K Besson DZ Binns WR Chen C Chen P Clem JM Connolly A Dowkontt PF DuVernois MA Field RC Goldstein D Vieregg AG Hast C Israel MH Javaid A Kowalski J Learned JG Liewer KM Link JT Lusczek E Matsuno S Mercurio BC Miki C Miočinović P Naudet CJ Ng J Nichol RJ Palladino K Reil K Romero-Wolf A Rosen M Ruckman L Saltzberg D Seckel D Varner GS Walz D Wu F 《Physical review letters》2010,105(15):151101
We report the observation of 16 cosmic ray events with a mean energy of 1.5 × 101? eV via radio pulses originating from the interaction of the cosmic ray air shower with the Antarctic geomagnetic field, a process known as geosynchrotron emission. We present measurements in the 300-900 MHz range, which are the first self-triggered, first ultrawide band, first far-field, and the highest energy sample of cosmic ray events collected with the radio technique. Their properties are inconsistent with current ground-based geosynchrotron models. The emission is 100% polarized in the plane perpendicular to the projected geomagnetic field. Fourteen events are seen to have a phase inversion due to reflection of the radio beam off the ice surface, and two additional events are seen directly from above the horizon. Based on a likelihood analysis, we estimate angular pointing precision of order 2° for the event arrival directions. 相似文献
72.
Gabrielse G Kolthammer WS McConnell R Richerme P Wrubel J Kalra R Novitski E Grzonka D Oelert W Sefzick T Zielinski M Borbely JS Fitzakerley D George MC Hessels EA Storry CH Weel M Müllers A Walz J Speck A;ATRAP Collaboration 《Physical review letters》2010,105(21):213002
Centrifugal separation of antiprotons and electrons is observed, the first such demonstration with particles that cannot be laser cooled or optically imaged. The spatial separation takes place during the electron cooling of trapped antiprotons, the only method available to produce cryogenic antiprotons for precision tests of fundamental symmetries and for cold antihydrogen studies. The centrifugal separation suggests a new approach for isolating low energy antiprotons and for producing a controlled mixture of antiprotons and electrons. 相似文献
73.
Two spirodiaza intermediates have been made and employed in the synthesis of 4-anilinopiperidine methyl esters. These intermediates can be utilized in the production of commercial synthetic analgesics carfentanil, sufentanil, and remifentanil. 相似文献
74.
Laser cooling in a CO2-laser optical lattice 总被引:1,自引:0,他引:1
S. Friebel R. Scheunemann J. Walz T.W. Hänsch M. Weitz 《Applied physics. B, Lasers and optics》1998,67(6):699-704
Received: 19 June 1998 相似文献
75.
76.
77.
Guido Walz 《Numerical Algorithms》1994,7(2):161-171
It is a well-known fact that the classical (i.e. polynomial) divided difference of orderm, when applied to a functiong, converges to themth-derivative of this function, if the evaluation points all collapse to a single one.In the first part of this paper we shall sharpen this result in the sense that we prove the existence of an asymptotic expansion with limitg
(m)
/m!. This result allows the application of extrapolation methods for the numerical differentiation of funtions.Moreover, in the second and main part of the paper we study generalized divided differences, which were introduced by Popoviciu [10] and further investigated for example by Karlin [2], Walz [15] and, mainly, Mühlbach [6–8]; we prove the existence of an asymptotic expansion also for these generalized divided differences, if the underlying function space is a Polya space. As a by-product, our results show that the generalized divided difference of orderm converges to the value of a certainmth order differential operator. 相似文献
78.
79.
80.
Clark SC Walz JY Ducker WA 《Langmuir : the ACS journal of surfaces and colloids》2004,20(18):7616-7622
We describe the use of evanescent wave scattering to measure the separation between the surface of a solid and a particle that is attached to an atomic force microscope (AFM) cantilever. Termed evanescent wave atomic force microscopy, our approach involves measuring the intensity of the light scattered from an evanescent field formed by the total internal reflection of a laser beam at a solid/fluid interface. In a conventional AFM "colloid probe" measurement, this separation must be inferred from an examination of the surface forces. Direct measurement of this separation with an evanescent wave atomic force microscope (EW-AFM) removes some ambiguity in the surface force measurement and, in addition, allows new types of measurements. For example, the force can be monitored at a constant separation. Our evanescent scattering apparatus is essentially identical to that used in total internal reflection microscopy (TIRM), except that we collect the light that scatters back into the incident medium, because the AFM partly obscures the forward scattered light (i.e., light scattered into the transmitted region). Compared to a conventional TIRM measurement, where the particle moves freely, attaching the particle to the cantilever in an EW-AFM gives much greater control of the particle position. 相似文献