全文获取类型
收费全文 | 422篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 205篇 |
晶体学 | 13篇 |
力学 | 13篇 |
数学 | 83篇 |
物理学 | 113篇 |
出版年
2023年 | 2篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 13篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 22篇 |
2012年 | 23篇 |
2011年 | 22篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 26篇 |
2007年 | 17篇 |
2006年 | 19篇 |
2005年 | 26篇 |
2004年 | 10篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 11篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1992年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1975年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 2篇 |
1959年 | 8篇 |
1958年 | 10篇 |
1957年 | 9篇 |
1956年 | 2篇 |
1955年 | 8篇 |
1954年 | 4篇 |
1934年 | 1篇 |
排序方式: 共有427条查询结果,搜索用时 15 毫秒
11.
Kyselová Z Kysel'ová Z Krizanová L Soltés L Stefek M 《Journal of chromatography. A》2005,1084(1-2):95-100
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of eye lens proteins showed that both progression of diabetic cataract in rats in vivo and precipitation of soluble eye lens proteins stressed by free radicals in vitro were accompanied by significant protein cross-linking. There was a noticeable contribution of disulfide bridges to protein cross-linking in diabetic eye lens in vivo. In contrast, under conditions in vitro, when eye lens proteins were exposed to hydroxyl or peroxyl radicals, we showed that the participation of reducible disulfide linkages in the formation of high molecular mass products was markedly lower. These in vivo--in vitro differences indicate that the generally accepted role of reactive oxygen species in diabetic cataractogenesis may be overestimated in connection with the processes of protein cross-linking. 相似文献
12.
Ladislav Halás Andrej Oriňák Abubaker Sharif Monika Ádámová Juraj Ladomerský 《Central European Journal of Chemistry》2005,3(3):570-582
Acrylate monomers methylmethacrylate (MMA) and cyclohexylmethacrylate (CHMA) bioaccumulation has been determined in aquatic
organism, algae (Chlorella kessleri). Algae were collected in amount of 0.4 mg and directly injected to the pyrolytical cell. In algae bodies accumulated monomers
were analysed by pyrolysis gas chromatography (Py-GC) and pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS).
Traces of the accumulated monomers in algae body can be determined after 1-, 2-, 3-weeks of incubation. Maximum content of
MMA was determined after 3-week of experiment, contrariwise in the case of CHMA after 2-week exposition. Relationship with
pyrolysis temperature has also been studied. 相似文献
13.
Solutions of the perfluoro anion-exchange membrane TosHex® in a solvent mixture composed of methanol + isopropanol + water (1:1:1) were prepared and applied in coating glassy carbon electrodes. The evaporated films were used to accumulate the Fe(CN)
6 redox couple on the electrode surface. The magnitude of the electrochemical response of the loaded films is comparable with that for Nafion® incorporated cationic redox species. The multicharged Fe(CN)
6 couple accumulated in Tosflex® film causes an ion cross-linking of the polymeric backbone, thus decreasing ion transport in the film substantially. 相似文献
14.
Stereoselectivity of reductive amination of (R)-1-hydroxy-1-phenylpropan-2-one by methylamine was studied. From the four isomers possible, only two are produced by this
reaction. These are marked as (−)-(1R,2S)-ephedrine (desired product) and (+)-(1S,2R)-ephedrine. The reaction stereoselectivity depends both on the type of the catalyst and reaction conditions. The most suitable
type is the supported platinum. However, this catalyst rapidly deactivates. With a decreasing activity of Pt catalyst, the
stereoselectivity decreases. It is also decreased during the production of the second liquid phase (water) in the reaction
mixture. 相似文献
15.
Marián Masár Pavol Kruk Milan Luc Róbert Bodor Ladislav Danč Peter Troška 《Electrophoresis》2013,34(3):432-440
Adsorption processes on a PMMA chip linked with CZE separations of a group of 13 aliphatic and aromatic mono‐ and di‐amines were studied. Due to the lack of chromophores within aliphatic amines, contact conductivity detection implemented directly onto the chip was used for monitoring of cationic CZE separations. To prevent an adsorption of studied amines to the chip channels, the surface of PMMA chip was modified by dynamic coating. Different surface modifiers, such as aliphatic oligoamines (diethylenetriamine and triethylenetetramine), were added to the BGE solutions filling the chip channels. The effect of various concentrations of surface modifiers on peak profiles and separation parameters of amines was monitored. Of these, mainly, aliphatic di‐amines and aromatic mono‐amines adversely affected the CZE resolution of a whole group of analytes by their strong adsorption to the chip channels. A propionate BGE with pH 3.2 containing 100 μM triethylenetetramine and 25 mM 18‐crown‐6‐ether was found suitable for CZE resolution of 12 from a total of 13 amines studied. Simple dynamic modification of the surface of PMMA chip enabled fast (analysis time lasted 9 min), sensitive (sub‐μM LODs reached) and reproducible (1–3% RSD of the peak areas) CZE analysis of the aliphatic and aromatic amines. 相似文献
16.
17.
18.
Ladislav Ceniga 《Meccanica》2010,45(1):73-77
The paper deals with an analytical model of thermal stresses acting in an particle-matrix system represented by one isotropic
spherical particle embedded in a triaxial-anisotropic infinite matrix, or by one triaxial-anisotropic spherical particle embedded
in an isotropic infinite matrix. The thermal stresses originate during a cooling process as a consequence of the difference
in thermal expansion coefficients between a matrix and a particle. 相似文献
19.
Costas Iliopoulos M. Sohel Rahman Michal Voráček Ladislav Vagner 《Journal of Discrete Algorithms》2010,8(2):117-130
In this paper, we present linear-time algorithms for the construction two novel types of finite automata and show how they can be used to efficiently solve the Longest Common Subsequence (LCS), Shortest Common Supersequence (SCS) and Constrained Longest Common Subsequence (CLCS) problems for degenerate strings. 相似文献
20.
Polyakov S Malendevich R Jankovic L Stegeman G Bosshard C Gunter P 《Optics letters》2002,27(12):1049-1051
The generation of multiple quadratic spatial solitons aligned approximately along a crystal axis in a biaxial noncritically phase-matched crystal is shown theoretically and experimentally to be the consequence of anisotropic diffraction. 相似文献