全文获取类型
收费全文 | 242篇 |
免费 | 0篇 |
专业分类
化学 | 75篇 |
晶体学 | 4篇 |
力学 | 1篇 |
数学 | 33篇 |
物理学 | 129篇 |
出版年
2013年 | 5篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 14篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1996年 | 11篇 |
1995年 | 6篇 |
1994年 | 13篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1955年 | 3篇 |
1954年 | 2篇 |
1942年 | 2篇 |
1941年 | 3篇 |
1939年 | 2篇 |
1934年 | 1篇 |
1914年 | 1篇 |
1913年 | 1篇 |
1910年 | 2篇 |
1905年 | 2篇 |
1903年 | 5篇 |
1900年 | 2篇 |
1898年 | 1篇 |
1897年 | 4篇 |
排序方式: 共有242条查询结果,搜索用时 62 毫秒
131.
132.
F. Bloch J. Ahrens J. R. M. Annand R. Beck L. S. Fog D. Hornidge S. Janssen M. Kotulla B. Krusche J. C. McGeorge I. J. D. MacGregor J. G. Messchendorp V. Metag R. Novotny R. O. Owens M. Pfeiffer M. Rost R. Sanderson S. Schadmand A. Thomas D. P. Watts 《The European Physical Journal A - Hadrons and Nuclei》2007,32(2):219-228
The photoproduction of π
0
π
0 and π
0
π
± pairs off 40Ca has been investigated with the TAPS detector using the Glasgow photon tagging spectrometer at the Mainz MAMI accelerator.
Data have been taken for incident photon energies in the energy range from 200-820MeV. Total cross-sections have been extracted
from threshold up to the maximum photon energy and invariant-mass distributions of the pion pairs have been obtained for incident
photon energies between 400-500MeV and 500-550MeV. The double π
0 invariant-mass distributions show some relative enhancement with respect to the mixed charge channel at small invariant masses.
The effects are smaller than previously observed for lead nuclei and the distributions do not significantly deviate from carbon
data. The data are in good agreement with the results of recent calculations in the framework of the BUU model, with careful
treatment of final-state interaction effects but without an explicit in-medium modification of scalar, iso-scalar pion pairs.
This means that for Ca most of the experimentally observed effect can be explained by final-state interactions. Only at low
incident photon energies there is still a small low mass enhancement of the double π
0 data over the BUU results. 相似文献
133.
R.C. Weiss R.E. Anderson J.J. Kraushaar R.A. Ristinen E. Rost S. Shastry 《Nuclear Physics A》1981,355(1):45-65
The 205Tl(p, t)203Tl reaction has been used at 26.2 MeV to obtain additional information on the particle-vibration multiplets in 203Tl. Enhancement factors for the L = 0 and L = 2 transitions to the lower excited states of 203Tl were well accounted for by using enhancement factors from the 206Pb(p, t)204Pb reaction and the wave functions from the intermediate coupling calculations of Covello and Sartoris. Additional data on the 208Pb(p, t)206Pb reaction at 26.2 MeV were used along with data at other energies to examine the energy dependence of the zero-range enhancement factors. 相似文献
134.
Rost MJ 《Physical review letters》2007,99(26):266101
We report on the first atomic-scale real-time in situ investigation of the growth of a polycrystalline gold film during its deposition performed with a scanning tunneling microscope. Continuously scanning while depositing the film enables the direct observation of atomic processes. The grain boundaries play a crucial role in the evolving film structure, as they initiate mound formation, thereby significantly increasing the film roughness. A possible additional roughness increase comes from atom steering, which also can delay the film closure in the early stages during film growth. 相似文献
135.
A scheme to probe dissipative multielectron motion in time is introduced. In this context attosecond probing enables one to obtain information which is lost at later times and cannot be retrieved by conventional methods in the energy domain due to the incoherent nature of the dynamics. As a specific example we will trace the transient charging of ions in a rare-gas cluster during a strong femtosecond vacuum-ultraviolet pulse by means of delayed attosecond pulses. 相似文献
136.
Beng Sim Chuah Florence Geneste Andrew B. Holmes Rainer E. Martin Henning Rost Franco Cacialli Richard H. Friend Hans‐Heinrich Hrhold Steffen Pfeiffer Do‐Hoon Hwang 《Macromolecular Symposia》2000,154(1):177-186
The synthesis of the highly fluorescent mono‐ and bis‐silylated poly(1,4‐phenylene vinylene) derivatives 1 and 2 is reported. The Gilch dehydrohalogenation polycondensation and the Horner synthesis of strictly alternating copolymers have been used to prepare the copolymers 8‐11 and 14, 16‐18 , respectively, in which the tunability of various optoelectonic properties may be examined systematically. 相似文献
137.
M. Dubé M. Rost K.R. Elder M. Alava S. Majaniemi T. Ala-Nissila 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,15(4):701-714
The propagation and roughening of a fluid-gas interface through a disordered medium in the case of capillary driven spontaneous
imbibition is considered. The system is described by a conserved (model B) phase-field model, with the structure of the disordered
medium appearing as a quenched random field . The flow of liquid into the medium is obtained by imposing a non-equilibrium boundary condition on the chemical potential,
which reproduces Washburn's equation for the slowing down motion of the average interface position H. The interface is found to be superrough, with global roughness exponent , indicating anomalous scaling. The spatial extent of the roughness is determined by a length scale arising from the conservation law. The interface advances by avalanche motion, which causes temporal multiscaling and qualitatively
reproduces the experimental results of Horv'ath and Stanley (Phys. Rev. E 52, 5166 (1995)) on the temporal scaling of the interface.
Received 24 November 1999 相似文献
138.
139.
140.
We introduce soft recollisions in laser-matter interaction. They are characterized by the electron missing the ion upon recollision in contrast with the well-known head-on collisions responsible for high-harmonic generation or above-threshold ionization. We demonstrate analytically that soft recollisions can cause a bunching of photoelectron energies through which a series of low-energy peaks emerges in the electron yield along the laser polarization axis. This peak sequence is universal, it does not depend on the binding potential, and is found below an excess energy of one tenth of the ponderomotive energy. 相似文献