全文获取类型
收费全文 | 6927篇 |
免费 | 198篇 |
专业分类
化学 | 4155篇 |
晶体学 | 31篇 |
力学 | 135篇 |
数学 | 1446篇 |
物理学 | 1358篇 |
出版年
2022年 | 61篇 |
2021年 | 77篇 |
2020年 | 71篇 |
2019年 | 84篇 |
2018年 | 162篇 |
2017年 | 151篇 |
2016年 | 251篇 |
2015年 | 193篇 |
2014年 | 245篇 |
2013年 | 557篇 |
2012年 | 358篇 |
2011年 | 467篇 |
2010年 | 255篇 |
2009年 | 222篇 |
2008年 | 393篇 |
2007年 | 399篇 |
2006年 | 359篇 |
2005年 | 271篇 |
2004年 | 242篇 |
2003年 | 175篇 |
2002年 | 157篇 |
2001年 | 104篇 |
2000年 | 85篇 |
1999年 | 66篇 |
1998年 | 62篇 |
1997年 | 54篇 |
1996年 | 60篇 |
1995年 | 55篇 |
1994年 | 39篇 |
1993年 | 52篇 |
1992年 | 59篇 |
1991年 | 48篇 |
1990年 | 54篇 |
1989年 | 53篇 |
1988年 | 50篇 |
1987年 | 54篇 |
1986年 | 47篇 |
1985年 | 63篇 |
1984年 | 69篇 |
1983年 | 66篇 |
1982年 | 68篇 |
1981年 | 46篇 |
1980年 | 54篇 |
1979年 | 47篇 |
1978年 | 74篇 |
1977年 | 42篇 |
1976年 | 52篇 |
1975年 | 41篇 |
1974年 | 49篇 |
1973年 | 41篇 |
排序方式: 共有7125条查询结果,搜索用时 15 毫秒
21.
M. E. Carlotti S. Sapino R. Cavalli M. Trotta F. Trotta K. Martina 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):445-450
This work deals with the formation of inclusion complexes between cinnamaldehyde and two synthetic alkylcarbonates of γ-cyclodextrin, namely ethylcarbonate-γ-CD and octylcarbonate-γ-CD. Complexation was monitored by phase-solubility studies, by FT-IR spectroscopy and by DSC and TG analysis.
The diffusion of cinnamaldehyde through a cellulose membrane was investigated in the absence and in the presence of each of
the two γ-CD alkylcarbonates. Studies on photostability and stability over time were carried out on different cosmetic formulations
containing pure cinnamaldehyde or an equivalent amount of cinnamaldehyde complexed with the two alkylcarbonates.
Phase-solubility diagrams, DSC, FTIR and TGA analysis suggested the formation of inclusion complexes. The diffusion of cinnamaldehyde
through the cellulose membrane decreased in the presence of the two alkylcarbonates confirming the interaction of this molecule
with the inclusion agents.
Moreover the stability of cinnamaldehyde to light and heat resulted increased by complexing this fragrance material with the
two alkylcarbonates. 相似文献
22.
V. V. Panić A. B. Dekanski S. K. Milonjić V. B. Mišković-Stanković B. Ž. Nikolić 《Russian Journal of Electrochemistry》2006,42(10):1055-1060
Electrocatalytic properties of RuO2/Ti anode with different coating masses, which are prepared by the alkoxide sol-gel procedure, are investigated in chlorine
and oxygen evolution reactions by polarization measurements and electrochemical impedance spectroscopy in H2SO4 and NaCl electrolytes. According to polarization measurements, the activity of anodes at overpotentials below 100 mV is independent
of coating mass. However, impedance measurements above 100 mV reveal changes in the activity of anodes in chlorine evolution
reaction for different coating masses. The diffusion limitations related to the evolved chlorine are registered in low-frequency
domain at 1.10 V (SCE), diminishing with the increase in potential to the 1.15 V (SCE). The observed impedance behavior is
discussed with respect to the activity model for activated titanium anodes in chlorine evolution reaction involving formation
of gas channels within porous coating structure. Gas channels enhance the mass transfer rate similarly to the forced convection,
which also increases the activity of anode. This is more pronounced for the anode of greater coating mass due to its more
compact surface structure. The more compact structure appears to be beneficial for gas channels formation.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 10, pp. 1173–1179.
The text was submitted by the authors in English. 相似文献
23.
G. Bilalbegović 《Zeitschrift für Physik B Condensed Matter》1987,69(1):117-120
The interfacial tension of a three-dimensional Ising model in the whole temperature region is calculated by the real-space renormalisation group methods. The cumulant and the finite-cluster approximations with different projection rules are used. The results are consistent with expected low-temperature and global behaviour of the interfacial tension in the three-dimensional model. 相似文献
24.
The IR finite one-loop box scalar integral with massless internal lines has been recalculated. The result is very compact,
simple and valid for arbitrary values of the relevant kinematic variables. It is given in terms of only two dilogarithms and
a few logarithms, all of very simple arguments.
Received: 31 January 2002 / Published online: 26 April 2002 相似文献
25.
Dragomir Ž. Đoković 《Combinatorica》1994,14(3):375-377
No Hadamard matrices of order 956 appear in the literature. In this note we construct two such matrices. They are both of Goethals-Seidel type. As a consequence of this and of a result of Seberry and Yamada, we conclude that there exist 4-Williamson type matrices of order 1913.This work was supported by NSERC of Canada Grants A-5285 and EQP0107539. 相似文献
26.
27.
28.
Nathalie Charton Achim Feldermann Alexander Theis Martina H. Stenzel Thomas P. Davis Christopher Barner‐Kowollik 《Journal of polymer science. Part A, Polymer chemistry》2004,42(21):5559-5559
The original article to which this Erratum refers was published in J Polym Sci Part A: Polym Chem (2004) 42(20) 5170–5179. No abstract. 相似文献
29.
Oriňák Andrej Arlinghaus Heinrich Frank Vering Guido Justinová Martina Oriňáková Renáta Turčániová L’udmila Halama Maroš 《平面色谱法杂志一现代薄层色谱法》2003,16(1):23-27
JPC – Journal of Planar Chromatography – Modern TLC - Two interfaces have been tested for coupling thin-layer chromatography (TLC) with time-of-flight secondary-ion mass spectrometry... 相似文献
30.