全文获取类型
收费全文 | 152篇 |
免费 | 7篇 |
专业分类
化学 | 59篇 |
晶体学 | 3篇 |
力学 | 1篇 |
数学 | 41篇 |
物理学 | 55篇 |
出版年
2022年 | 2篇 |
2020年 | 2篇 |
2016年 | 1篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 9篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1970年 | 5篇 |
1965年 | 1篇 |
1964年 | 3篇 |
1963年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 0 毫秒
41.
B. Wiedemann K. Bethge W. Schütze U. Lambert S. Pahlke T. Reinhold B. Weinert T. Flade 《Fresenius' Journal of Analytical Chemistry》1994,350(4-5):319-322
Radiofrequency spark source mass spectrometry is a reliable and precise analytical method to measure the amount of oxygen in silicon grown by the Czochralski technique from SiO2 crucibles in the common range from 2ppm(atomic) to 20ppm(atomic) and in silicon grown by the floating zone technique below 0.1ppm(atomic). The technique is also excellent for the measurement of the amount of carbon in semi-insulating gallium arsenide grown under low and high pressure N2 ambient gas by the B2O3 encapsulated Czochralski technique from pyrolytic BN crucibles in the common range from 0.02ppm(atomic) to 0.4ppm(atomic). The results are in rather good agreement with concentrations measured by charged particle activation analysis and consistent with those obtained using other methods. 相似文献
42.
43.
Lazarov VK Zimmerman J Cheung SH Li L Weinert M Gajdardziska-Josifovska M 《Physical review letters》2005,94(21):216101
Selected molecular beam epitaxy of zinc blende (111) or wurtzite (0001) GaN films on polar MgO(111) is achieved depending on whether N or Ga is deposited first. The cubic stacking is enabled by nitrogen-induced polar surface stabilization, which yields a metallic MgO(111)-(1 x 1)-ON surface. High-resolution transmission electron microscopy and density functional theory studies indicate that the atomically abrupt semiconducting GaN(111)/MgO(111) interface has a Mg-O-N-Ga stacking, where the N atom is bonded to O at a top site. This specific atomic arrangement at the interface allows the cubic stacking to more effectively screen the substrate and film electric dipole moment than the hexagonal stacking, thus stabilizing the zinc blende phase even though the wurtzite phase is the ground state in the bulk. 相似文献
44.
Using full-potential electronic structure calculations, we predict that the (111) surface of the cubic Laves phase Pauli paramagnet YCo2 is ferromagnetic. The magnetism of the (111) surface is independent of the termination of the surface, does not extend beyond two Co layers, and is related to the field-induced metamagnetism of the bulk. YCo2 appears to be a prominent candidate to demonstrate the phenomenon of surface-induced itinerant magnetism localized in two dimensions. 相似文献
45.
46.
A.J. Freeman H. Krakauer S. Ohnishi Ding-Sheng Wang M. Weinert E. Wimmer 《Journal of magnetism and magnetic materials》1983,38(3):269-272
The current state-of-the-art of ab-initio calculations of the magnetic structures of surfaces and interfaces is highlighted by presenting results obtained with the recently developed full-potential linearized augmented plane wave method for thin films. In particular, spin density maps, (induced) magnetic moments and hyperfine-fields are presented for the clean metal surfaces Fe(001), Ni(001) and Pt(001). The magnetic moments on an interface are discussed for the prototypical case Ni/Cu. 相似文献
47.
The behaviour ofS-matrix for potentials generating bound states in continuum in the neighbourhood of the positive bound state energies is studied.
It is shown that unlike the case of usual negative energy bound states, theS-matrix does not have a pole at the positive bound state energy but becomes unity at the energy corresponding to bound states
in continuum. Calculations ofS-waveS-matrix for a local potential constructed by Stillinger and Herrick and a separable nonlocal potential constructed by the
present authors verify these results. Our results indicate that the bound states embedded in continuum constructedvia the von Neumann and Wigner procedure cannot be interpreted as resonances with zero width. 相似文献
48.
Acta Mathematica Hungarica - 相似文献
49.
Christian R. Samanamu Monika L. Amadoruge Charles S. Weinert James A. Golen Arnold L. Rheingold 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1389-1395
Abstract We have employed the hydrogermolysis reaction for the preparation of rare branched oligogermanes, and have obtained for the first time the X-ray crystal structures of several branched tetragermanes, including (Ph3Ge)3GePh, (Ph3Ge)3GeH, and (Ph3Ge)3GeX (X = Cl or Br). We also have at our disposal branched tetragermanes having the formula (EtOCH2CH2Bu n 2Ge)3GePh, where the ethoxyethyl substituent serves as a protecting group for a germanium–hydride active site. These reagents have been employed for the stepwise synthesis of higher branched systems having up to 13 bonded germanium atoms in the oligomer backbone. The synthesis, structures, and physical characteristics of these systems are described. GRAPHICAL ABSTRACT 相似文献
50.