全文获取类型
收费全文 | 230434篇 |
免费 | 1550篇 |
国内免费 | 476篇 |
专业分类
化学 | 104916篇 |
晶体学 | 3610篇 |
力学 | 12134篇 |
综合类 | 5篇 |
数学 | 37178篇 |
物理学 | 74617篇 |
出版年
2018年 | 10138篇 |
2017年 | 11053篇 |
2016年 | 5623篇 |
2015年 | 1942篇 |
2014年 | 1459篇 |
2013年 | 4909篇 |
2012年 | 8021篇 |
2011年 | 17730篇 |
2010年 | 10456篇 |
2009年 | 10334篇 |
2008年 | 15291篇 |
2007年 | 19177篇 |
2006年 | 4254篇 |
2005年 | 11413篇 |
2004年 | 7198篇 |
2003年 | 6776篇 |
2002年 | 4560篇 |
2001年 | 3744篇 |
2000年 | 2999篇 |
1999年 | 2238篇 |
1998年 | 1933篇 |
1997年 | 1892篇 |
1996年 | 1982篇 |
1995年 | 1878篇 |
1994年 | 1639篇 |
1993年 | 1615篇 |
1992年 | 1821篇 |
1991年 | 1822篇 |
1990年 | 1752篇 |
1989年 | 1766篇 |
1988年 | 1778篇 |
1987年 | 1765篇 |
1986年 | 1667篇 |
1985年 | 2229篇 |
1984年 | 2364篇 |
1983年 | 1979篇 |
1982年 | 2297篇 |
1981年 | 2112篇 |
1980年 | 2159篇 |
1979年 | 2165篇 |
1978年 | 2296篇 |
1977年 | 2123篇 |
1976年 | 2183篇 |
1975年 | 2103篇 |
1974年 | 1944篇 |
1973年 | 2196篇 |
1972年 | 1322篇 |
1971年 | 1001篇 |
1968年 | 1152篇 |
1967年 | 1133篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
161.
E. Ritsert und W. Lenz 《Fresenius' Journal of Analytical Chemistry》1889,28(1):749-750
Ohne Zusammenfassung 相似文献
162.
Ohne Zusammenfassung
übersetzt von H. Kauffmann (Leipzig). 相似文献
163.
Dimitar I. Pushkarov 《Central European Journal of Physics》2004,2(3):420-455
Basic ideas and results which characterize quantum diffusion of defects in quantum crystals like solid helium as a new phenomenon
are presented. Quantum effects in such media lead to a delocalization of point defects (vacancies, impurities etc.) and they
turn into quasiparticles of a new type—defectons, which are characterized not by their position in the crystal lattice but
by their quasimomentum and dispersion law. Defecton-defecton and defecton-phonon scattering are considered and an interpolation
formula for the diffusion coefficient valid in all interesting temperature and concentration regions is presented. A comparison
with the experimental data is made. Some alternative points of view are discussed in detail and the inconsistency of the Kisvarsanyi-Sullivan
theory is shown. 相似文献
164.
165.
We compute neutral Higgs and Z0-boson couplings to quarks in a model with three quark-lepton families and one mirror family. Mixing between ordinary and mirrorquarks leads to flavour-changing couplings which are negligible for the known quarks. However, t-quark couplings are sizeable and the branching ratio for the decay
can be as large as 10−4. 相似文献
166.
Blood serum samples were irradiated by monochromatic synchrotron radiation (15 keV) and by 2.4-MeV protons to compare their performance for the detection of trace elements by x-ray fluorescence (XRF) spectrometry. Absolute concentration assignment was based on the addition of an internal standard and on a method which uses the incoherent and coherent radiation as a flux monitor of the incoming beam. Preliminary experiments with a synchrotron XRF microprobe are reported. 相似文献
167.
P.A. Grillet 《Acta Mathematica Hungarica》2005,106(4):301-315
Summary Three weak variants of compactness which lie strictly between compactness and quasicompactness, are introduced. Their basic properties are studied. The interplay with mapping and their direct and inverse preservation under mappings are investigated. In the process three decompositions of compactness are observed. 相似文献
168.
169.
A mixed problem is considered for a system of partial differential equations modeling the process of adsorption dynamics. An existence and uniqueness theorem is proved for this problem, and the solution properties are investigated. The inverse problem is posed, involving the determination of the system coefficient given additional information about the solution. A uniqueness theorem is proved for the solution of the inverse problem.__________Translated from Prikladnaya Matematika i Informatika, No. 16, pp. 5 – 14, 2004. 相似文献
170.
In this paper we obtain a number of Maharam-type slice integral representations, with respect to scalar measures, for positive
projections in Dedekind complete vector lattices and f-algebras.
AMS Classification: 47B65, 46A40, 06F25 相似文献