全文获取类型
收费全文 | 1128篇 |
免费 | 32篇 |
国内免费 | 4篇 |
专业分类
化学 | 609篇 |
晶体学 | 5篇 |
力学 | 29篇 |
数学 | 192篇 |
物理学 | 329篇 |
出版年
2021年 | 9篇 |
2019年 | 12篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 27篇 |
2015年 | 23篇 |
2014年 | 13篇 |
2013年 | 40篇 |
2012年 | 55篇 |
2011年 | 56篇 |
2010年 | 44篇 |
2009年 | 39篇 |
2008年 | 39篇 |
2007年 | 47篇 |
2006年 | 40篇 |
2005年 | 37篇 |
2004年 | 38篇 |
2003年 | 28篇 |
2002年 | 29篇 |
2001年 | 30篇 |
2000年 | 32篇 |
1999年 | 18篇 |
1998年 | 25篇 |
1997年 | 21篇 |
1996年 | 17篇 |
1995年 | 12篇 |
1994年 | 17篇 |
1993年 | 20篇 |
1992年 | 17篇 |
1991年 | 21篇 |
1990年 | 16篇 |
1989年 | 12篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 17篇 |
1984年 | 20篇 |
1983年 | 15篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1976年 | 8篇 |
1975年 | 16篇 |
1974年 | 10篇 |
1973年 | 11篇 |
1972年 | 7篇 |
1970年 | 8篇 |
1969年 | 9篇 |
排序方式: 共有1164条查询结果,搜索用时 31 毫秒
91.
Roman Gumeniuk Dr. Miriam Schmitt Walter Schnelle Ulrich Burkhardt Helge Rosner Andreas Leithe‐Jasper 《无机化学与普通化学杂志》2010,636(6):954-961
Two new intermetallic alkaline‐earth palladium borides, SrPd4B and BaPd4B were synthesised and their physical properties were investigated. The crystal structure of SrPd4B was solved from powder X‐ray diffraction data: new structure type, space group Pnma, a = 6.0014(1) Å, b = 5.5041(1) Å, c = 11.8723(2) Å, RI = 0.065, RP = 0.093. BaPd4B is isostructural with a = 6.0883(1) Å, b = 5.6066(1) Å, c = 12.0050(2) Å, RI = 0.062, RP = 0.097. The relationship of this structure type with the series of derivatives of the CaCu5 type is discussed. Calculated electronic band structures for palladium, Pd3B, SrPd5, SrPd4B and SrPd3B are compared. The role of boron and strontium for the electronic properties is discussed in detail. SrPd4B shows metallic behaviour with a DOS(EF) ≈? 1.7 eV–1 · f.u.–1 at the Fermi level. Magnetic properties, electrical resistivity and specific heat capacity measurements reveal that the two compounds are diamagnetic metallic conductors with low electronic density of states, in agreement, with the electronic structure calculations. 相似文献
92.
93.
Thin gadolinium nitride (GdN) films deposited on a glass surface may serve as excellent substrates for uniform growth of gadolinium metal layers. We have deposited GdN films on glass substrates at room temperature by Ar/N2 mixed gas-plasma-radio frequency sputtering method. An improvement of the optical properties and the lifetime of switchable mirrors is obtained by placing a thin GdN buffer layer between the glass substrate and the optically active, rare earth layer. The GdN buffer layer affects the structural properties of the Gd films, and enhances the switching properties of Gd switchable mirrors. 相似文献
94.
95.
Regina Schmitt Patrick Mayer Benjamin Kirsch Jan Aurich Charlotte Kuhn Ralf Müller Kaushik Bhattacharya 《PAMM》2014,14(1):383-384
This work is motivated by cryogenic turning which allows end shape machining and simultaneously attaining a hardened surface due to deformation induced martensitic transformations. To study the process on the microscale, a multivariant phase field model for martensitic transformations in conjunction with a crystal plastic material model is introduced. The evolution of microstructure is assumed to follow a time-dependent Ginzburg-Landau equation. To solve the field equations the finite element method is used. Time integration is performed with Euler backward schemes, on the global level for the evolution equation of the phase field, and on the element level for the crystal plastic material law. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
96.
Regina Schmitt Ralf Müller Charlotte Kuhn Herbert M. Urbassek 《Archive of Applied Mechanics (Ingenieur Archiv)》2013,83(6):849-859
A phase field model approach for multivariant martensitic transformations of stable and metastable phases is introduced. The evolution of the microstructure is examined with respect to elastic energy minimization in which one or two martensitic orientation variants are considered. In this context, the martensitic nucleation behavior is simulated for different activation barriers. Furthermore, the influence of time-dependent external loads on the formation of the different phases is studied. The numerical implementation is performed with finite elements and an implicit time integration scheme. 相似文献
97.
98.
99.
100.
Asymptotic behavior of positive solution branches of elliptic problems with linear part at resonance
Renate Schaaf Klaus Schmitt 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1992,43(4):645-676
We consider Dirichlet problems for semilinear elliptic equations whose linear part is at resonance. For various types of nonlinearities we provide sufficient conditions for the solvability of these problems for certain types of forcing terms. Depending upon the dimension of the independent variable and the shape of the domain, we obtain multiple existence results and show that in some cases infinitely many solutions may exist.Dedicated to Klaus Kirchgässner on the occasion of his 60th birthdayThe authors' work on this project has been supported by several institutions and thanks are due to the University of Utah for granting Schaaf a one year's visiting professorship during 1989–1990, to the DFG and the University of Stuttgart for providing Schmitt with the opportunity to visit that institution during the summer semester 1989. Final preparation was supported by a grant from NSF. 相似文献