全文获取类型
收费全文 | 463篇 |
免费 | 9篇 |
国内免费 | 4篇 |
专业分类
化学 | 235篇 |
晶体学 | 2篇 |
力学 | 13篇 |
数学 | 112篇 |
物理学 | 114篇 |
出版年
2022年 | 4篇 |
2021年 | 4篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 6篇 |
2013年 | 21篇 |
2012年 | 16篇 |
2011年 | 30篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 18篇 |
2007年 | 22篇 |
2006年 | 14篇 |
2005年 | 20篇 |
2004年 | 21篇 |
2003年 | 14篇 |
2002年 | 22篇 |
2001年 | 11篇 |
2000年 | 17篇 |
1998年 | 7篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1970年 | 5篇 |
1967年 | 3篇 |
1915年 | 4篇 |
排序方式: 共有476条查询结果,搜索用时 15 毫秒
51.
H. Huppert E. Salkowski H. Strauss R. Burián H. Schurr und E. Riegler 《Fresenius' Journal of Analytical Chemistry》1897,36(1):546
Ohne Zusammenfassung 相似文献
52.
Konstantin Dirian Susanne Backes Claudia Backes Volker Strauss Fabian Rodler Frank Hauke Andreas Hirsch Dirk M. Guldi 《Chemical science》2015,6(12):6886-6895
A water soluble naphthalenebisimide derivative (NBI) was synthesized and probed to individualize, suspend, and stabilize single wall carbon nanotubes (SWCNTs). Besides a comprehensive photophysical and electrochemical characterization of NBI, stable suspensions of SWCNTs were realized in buffered D2O. Overall, the dispersion efficiency of the NBI surfactant was determined by comparison with naphthalene based references. Successful individualization of SWCNTs was corroborated in several microscopic assays. In addition, emission spectroscopy points to the strong quenching of SWCNT centered band gap emission, when NBIs are immobilized onto SWCNTs. The origin of the quenching was found to be strong electronic communication, which leads to charge separation between NBIs and photoexcited SWCNTs, and, which yields reduced NBIs as well oxidized SWCNTs. Notably, electrochemical considerations revealed that the energy content of these charge separated states is one of the highest reported for SWCNT based electron donor–acceptor hybrids so far. 相似文献
53.
Shustova NB Kuvychko IV Peryshkov DV Whitaker JB Larson BW Chen YS Dunsch L Seppelt K Popov AA Strauss SH Boltalina OV 《Chemical communications (Cambridge, England)》2011,47(3):875-877
High-temperature syntheses of the new C(60)(i-C(3)F(7))(2,4,6) and C(70)(i-C(3)F(7))(2,4) isomers and their characterization by spectroscopic methods, X-ray crystallography, cyclic voltammetry and density functional theory provide compelling evidence that they are superior electron acceptors than trifluoromethylfullerenes. 相似文献
54.
We show that there exist relatively small subsemigroupsM ofβℕ with the property that ifp+q andq+p are inM then bothp andq are inM + ℤ. We also show that it is consistent with the usual axioms of set theory that there is some idempotent e inβℕ such that ifp+q=e, then bothp andq are ine + ℤ.
The first author acknowledges support received from the National Science Foundation (USA) via grant DMS90-25025. 相似文献
55.
On interpolation with products of positive definite functions 总被引:1,自引:0,他引:1
Hans Strauss 《Numerical Algorithms》1997,15(2):153-165
In this paper we consider the problem of scattered data interpolation for multivariate functions. In order to solve this problem, linear combinations of products of positive definite kernel functions are used. The theory of reproducing kernels is applied. In particular, it follows from this theory that the interpolating functions are solutions of some varational problems. 相似文献
56.
Metal/superconductor/semiconductor (Ag/Hg-1212/CdSe) hetero-nanostructures have been fabricated using pulse-electrodeposition
technique and are characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The junction capacitance of Ag/Hg-1212, Hg-1212/CdSe and Ag/Hg-1212/CdSe heterojunctions is measured in dark
and under laser irradiation at room temperature. The nature of the junction formed and built-in-junction potentials were determined.
The increase in carrier concentration across the junction due to photo-irradiation has been observed. 相似文献
57.
We discuss some of the experimental motivation for the need for semigroup decay laws and the quantum Lax-Phillips theory of scattering and unstable systems. In this framework, the decay of an unstable system is described by a semigroup. The spectrum of the generator of the semigroup corresponds to the singularities of the Lax-Phillips S-matrix. In the case of discrete (complex) spectrum of the generator of the semigroup, associated with resonances, the decay law is exactly exponential. The states corresponding to these resonances (eigenfunctions of the generator of the semigroup) lie in the Lax-Phillips Hilbert space, and, therefore, all physical properties of the resonant states can be computed. We show that the parametrized relativistic quantum theory is a natural setting for the realization of the Lax-Phillips theory. 相似文献
58.
We study a simplified mean field model of superconductor dynamics in the
presence of impurities or for variable superconductor depth. This model is
given by the gradient-flow version of the Ginzburg-Landau equations
(Gorkov-Eliashberg equations) with an addition of a potential term. We find
a dynamical law of motion of the vortex center, involving the potential, such
that for datum close to a (static) magnetic vortex the solution
is close, for all times, to a magnetic vortex whose center obeys this law. 相似文献
59.
One of the innovative technological directions for the high-temperature superconductors has been persued by fabricating the
heteroepitaxial multilayer structures such as superconductor-semiconductor heterostructures. In the present investigation,
metal/superconductor/semiconductor (Ag/Tl-2223/CdSe) hetero-nanostructures have successfully been fabricated using dc electrodeposition
technique and were characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The measurement of junction capacitance as a function of biasing voltage was used for the estimation of junction
built-in-potential (V
D) and to study the charge distribution in a heterojunction. The Mott-Schottky plots were measured for each junction in dark
and under the photo-irradiation. The effect of laser irradiation on C-V characteristics of hetero-nanostructure has been studied. 相似文献
60.