全文获取类型
收费全文 | 10538篇 |
免费 | 332篇 |
国内免费 | 2篇 |
专业分类
化学 | 5506篇 |
晶体学 | 132篇 |
力学 | 189篇 |
数学 | 2074篇 |
物理学 | 2971篇 |
出版年
2022年 | 91篇 |
2021年 | 153篇 |
2020年 | 144篇 |
2019年 | 130篇 |
2018年 | 201篇 |
2017年 | 224篇 |
2016年 | 471篇 |
2015年 | 309篇 |
2014年 | 353篇 |
2013年 | 803篇 |
2012年 | 497篇 |
2011年 | 629篇 |
2010年 | 402篇 |
2009年 | 344篇 |
2008年 | 321篇 |
2007年 | 275篇 |
2006年 | 204篇 |
2005年 | 164篇 |
2004年 | 160篇 |
2003年 | 166篇 |
2002年 | 171篇 |
2001年 | 138篇 |
2000年 | 131篇 |
1999年 | 139篇 |
1998年 | 129篇 |
1997年 | 127篇 |
1996年 | 136篇 |
1995年 | 118篇 |
1994年 | 111篇 |
1993年 | 121篇 |
1992年 | 117篇 |
1991年 | 104篇 |
1990年 | 105篇 |
1989年 | 101篇 |
1988年 | 102篇 |
1987年 | 121篇 |
1986年 | 89篇 |
1985年 | 129篇 |
1984年 | 130篇 |
1983年 | 122篇 |
1982年 | 118篇 |
1981年 | 114篇 |
1980年 | 116篇 |
1979年 | 124篇 |
1978年 | 121篇 |
1977年 | 115篇 |
1976年 | 113篇 |
1975年 | 99篇 |
1974年 | 104篇 |
1973年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
J. Ježek 《Czechoslovak Mathematical Journal》2004,54(1):233-246
We investigate congruences in one-element extensions of algebras in the variety generated by tournaments. 相似文献
33.
J. Mlynár J. Ongena The EFDA JET Contributions I. Duran M. Hron R. Pánek V. Petržílka F. Žáček 《Czechoslovak Journal of Physics》2004,54(3):C28
JET (Joint European Torus) is the largest tokamak in the world and the only fusion facility able to operate with Tritium, the fusion fuel, and Beryllium, the ITER first wall material. JET also features the most complete remote handling equipment for invessel maintenance. As a multinational research center, JET provides logistic experience in preparing for operation of the global facility, tokamak ITER.Experiments on JET are focused on ITER-relevant studies, in particular on detailing the operational scenarios (EL My H-modes and advanced regimes), on enhancing the heating systems, on developing diagnostics for burning plasmas etc. Pioneering real-time control techniques have been implemented that maximize performance and minimize internal disturbances of JET plasmas. In helium plasmas, ion cyclotron heating (ICRH) created fast α-particles, mimicking their populations in future burning plasmas. The recent successful Trace Tritium campaign provided important new data on fuel transport. Current enhancements on JET include a new ITER-like ELM-resilient high power ICRH antenna (7 MW) and over twenty new diagnostics that will further extend the JET scientific capabilities and push the facility even closer to the ITER parameters.A special mention is given to the involvement of the fusion experts from Association EURATOM-IPP.CR, who have been actively participating in the collective use of JET facility for more than three years. 相似文献
34.
35.
The rate-dependent effects in metallic ferromagnetic materials with magnetization processes attributed to domain-walls motion were studied. The experimental method for eddy-current relaxation time determination was proposed. Some discrepancies between the data and theoretical predictions were observed and discussed. The origin of these discrepancies is accounted for by the decrease of viscous-type relaxation process as the rate of change of averaged magnetization is approaching zero. 相似文献
36.
The physico-chemical properties and reactivity tested by hydrogen reduction have been studied for two series of NiO-ZnO mixed oxides of various composition. The solid nickel oxide or zinc oxide in interaction with the solution of nitrate of the second component were used as the precursors in each series. The differences in some physico-chemical parameters of the samples in both series were correlated with their reduction behaviour, followed both in iso- and non-isothermal regime. Moreower, the influence of various factors modifying the reactivity of mixed oxides was also investigated and the results were compared with those obtained from earlier studied analogous systems of quite different origin.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
37.
Július Korbaš 《Acta Mathematica Hungarica》2004,105(1-2):129-137
We prove new results about the vector field problem on the real flag manifolds O(n)/O(1) x O(1) x O(n - 2). For some infinite families of these manifolds, we completely solve the vector field problem. 相似文献
38.
Lubomír Kubáček 《Mathematica Slovaca》2007,57(6):571-588
The multivariate model, where not only parameters of the mean value of the observation matrix, but also some other parameters
occur in constraints, is considered in the paper. Some basic inference is presented under the condition that the covariance
matrix is either unknown, or partially unknown, or known.
Supported by the grant of the Council of Czech Republic MSM 6 198 959 214. 相似文献
39.
We prove that a locally compact ANR-space X is a Q-manifold if and only if it has the Disjoint Disk Property (DDP), all points of X are homological Z
∞-points and X has the countable-dimensional approximation property (cd-AP), which means that each map f: K → X of a compact polyhedron can be approximated by a map with the countable-dimensional image. As an application we prove that
a space X with DDP and cd-AP is a Q-manifold if some finite power of X is a Q-manifold. If some finite power of a space X with cd-AP is a Q-manifold, then X
2 and X × [0, 1] are Q-manifolds as well. We construct a countable family χ of spaces with DDP and cd-AP such that no space X ∈ χ is homeomorphic to the Hilbert cube Q whereas the product X × Y of any different spaces X, Y ∈ χ is homeomorphic to Q. We also show that no uncountable family χ with such properties exists.
This work was supported by the Slovenian-Ukrainian (Grant No. SLO-UKR 04-06/07) 相似文献
40.
V. D. Fedotov N. P. Obuchov R. A. Zadikhanov J. Spěváček J. Straka 《Applied magnetic resonance》1993,4(4):491-511
The combined analysis of1H and13C NMR relaxation data in solid lysozyme and some typical homopolypeptides was carried out by using “model-free” approach. Three types of relaxation transitions (γ’, γ and β) were revealed in the temperature range investigated. The microdynamical parameters of these motions were determined. From the comparison of these parameters with those of selected synthetic polymers it follows that the molecular motions in proteins and synthetic polymers are of the same nature. All these motions show pronounced anisotropic character. In the investigated temperature range no molecular motions corresponding to α-relaxation (liquid-like) transition were revealed. The hydration effects on parameters of the motions in proteins were considered. The most pronounced effect takes place for β-transition. The effect of Brownian rotation of protein molecule in solution on measured correlation function of local motions was also discussed. 相似文献