全文获取类型
收费全文 | 402篇 |
免费 | 14篇 |
专业分类
化学 | 183篇 |
晶体学 | 2篇 |
力学 | 2篇 |
数学 | 46篇 |
物理学 | 183篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 8篇 |
2012年 | 13篇 |
2011年 | 31篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 11篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 6篇 |
1993年 | 10篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 12篇 |
1987年 | 6篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 10篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1973年 | 7篇 |
1969年 | 7篇 |
1910年 | 2篇 |
1907年 | 2篇 |
排序方式: 共有416条查询结果,搜索用时 15 毫秒
81.
F Matthaei S Heidorn K Boom C Bertram A Safiei J Henzl K Morgenstern 《J Phys Condens Matter》2012,24(35):354006
The submonolayer growth of NaCl bilayer high-rectangular shaped islands on Ag(111) is investigated at around room temperature by using low temperature scanning tunneling microscopy. The growth at the step edges is preferred. Two kinds of islands are observed. They either grow with their non-polar edge at the step edge of Ag(111) or the islands overgrow in a carpet-like mode with the polar direction parallel to the edge. In the latter case, the Ag step is rearranged and considerable, while the NaCl layer is bent. This study clarifies the nature of the interaction of an alkali halide nanostructure with a metal step edge. 相似文献
82.
The DNA base thymine is deposited at 100?K on Cu(111) and investigated and manipulated by low-temperature scanning tunneling microscopy at 5?K. At submonolayer coverage paired rows are observed. At monolayer coverage a hexagonal commensurate self-assembled layer with the methyl group pointing away from the surface forms. A reversible local manipulation of molecules within the self-assembled layer is demonstrated. This manipulation is interpreted as an out-of-plane relaxation of molecules within the layer induced by the change of the adsorption geometry of individual molecules between two meta-stable orientations. A positive field of 2-4?V leads to this local change in the molecular arrangement, while a field larger than 4?V restores the original geometry. 相似文献
83.
T. Schlathölter O. Hadjar R. Hoekstra R. Morgenstern 《Applied Physics A: Materials Science & Processing》2001,72(3):281-287
The electronic friction experienced by a multiply charged ion interacting with the valence electrons of a single fullerene
is an important aspect of the collision dynamics. It manifests itself in a considerable loss of projectile kinetic energy
transferred to the target, resulting in excitation. The latter mainly leads to direct ionization and multifragmentation and
can be recognized in specific patterns of the fragmentation spectra. These fingerprints can be used to quantify electronic
stopping and to identify its typical properties as known from particle–solid interactions, such as the oscillation of the
electronic stopping with the projectile atomic number Z. These essentially many-body effects can therefore be studied in a
well-defined system of finite size.
Received: 4 April 2000 / Accepted: 6 November 2000 / Published online: 9 February 2001 相似文献
84.
G. Rosenfeld K. Morgenstern M. Esser G. Comsa 《Applied Physics A: Materials Science & Processing》1999,69(5):489-496
Ultrathin metal films consisting of two-dimensional clusters are typically unstable: the cluster ensemble has the tendency
to reduce its total free energy via Ostwald ripening or dynamic coalescence of mobile clusters. In this paper we give an overview
of recent model experiments addressing these coarsening mechanisms. The experiments have been performed using STM on ensembles
consisting of adatom or vacancy clusters with typical diameters in the nanometer range on fcc(111)-metal surfaces. Agreement
with and deviations from conventional theories are discussed.
Received: 29 March 1999 / Accepted: 17 August 1999 / Published online: 30 September 1999 相似文献
85.
86.
87.
Mateusz Piontek Bernd Morgenstern Nils Steinbrück Bastian Oberhausen Guido Kickelbick Kaspar Hegetschweiler 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(6):678-685
Liu et al. [Chin. J. Struct. Chem. (1996). 15 , 371–373] reported the structure of 6‐hydroxy‐1,4‐diazepane di(hydrogen bromide), C5H12N2O·2HBr, which was interpreted in terms of neutral diazepane and HBr molecules. We found, however, ample evidence that the formation of an organic salt, consisting of a diammonium cation and two bromide anions, is more plausible. This interpretation is also in agreement with thermogravimetric analysis and with the observed solution behaviour. The crystal structure of 6‐hydroxy‐1,4‐diazepane‐1,4‐diium dibromide, C5H14N2O2+·2Br?, measured at 142 K, crystallized in the orthorhombic space group P212121. The structure displays O—H…Br and N—H…Br hydrogen bonding. Contact distances are given. A search in the Cambridge Structural Database for the singly‐bonded H—Br moiety revealed a total of 69 structures. The question, whether these structures really include HBr as neutral molecules or rather Br? anions and a protonated substrate such as an amine, is addressed. 相似文献
88.
Kacwin Christopher Oettershagen Jens Ullrich Mario Ullrich Tino 《Foundations of Computational Mathematics》2021,21(3):849-889
Foundations of Computational Mathematics - In this paper, we deal with several aspects of the universal Frolov cubature method, which is known to achieve optimal asymptotic convergence rates in a... 相似文献
89.
The possibility of performing in proximity of the Earth experiments to test the predictions of general relativity for the trajectories of particles and photons in weak gravitational fields is studied. Three experiments are analyzed, all based on optical detection methods. The first experiment would allow to detect the tidal acceleration using a freely-falling Michelson interferometer. In a second experiment, based on laser-ranging methods, the relativistic correction to the classical gravity acceleration could be detected. Finally, the possibility of detecting light deflection induced by space curvature in an optical cavity with high-reflectivity mirrors is discussed. 相似文献
90.
We have measured differential cross sections for scattering of laser-excited Na(32P) by Ar(1S0) at thermal collision energies with high angular resolution (0.1°). In the investigated range of scattering angles (1°–15°) the cross sections contain contributions from scattering along the excited state B2Σ potential (rainbow scattering) and the A2II potential (supernumerary rainbows). By performing fit calculations in which the spectroscopically determined A2II potential was adopted we were able to obtain information about the B2Σ potential. With the assumption of a Lennard-Jones (12.6) potential shape we obtain a well depth ?BΣ = (0.14±0.02)×10?3 au and an equilibrium distance rmBΣ = 10.4±1.0 au. This work presents the first experimental determination of the B2Σ potential well parameters. 相似文献