全文获取类型
收费全文 | 106篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 31篇 |
力学 | 5篇 |
数学 | 31篇 |
物理学 | 42篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 10篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 15 毫秒
1.
2.
T. Kubo M. Belkacem V. Latora A. Bonasera 《Zeitschrift für Physik A Hadrons and Nuclei》1995,352(2):145-148
Intermittent behaviour of fragment multiplicity distributions in the nuclear liquid-gas phase transition is studied in terms of the droplet model of Fisher. The anomalous fractal dimensions are compared with data on heavy ion reactions and classical molecular dynamics simulations. A signature of the transition in the anomalous fractal dimensions is shown.We thank Profs. S. Ayik, M. Di Toro and V. Kondratyev for discussions. One of us (T.K.) acknowledges the support of INFN-LNS. 相似文献
3.
Liebich HM Müller-Hagedorn S Klaus F Meziane K Kim KR Frickenschmidt A Kammerer B 《Journal of chromatography. A》2005,1071(1-2):271-275
4.
Mounir Maafi Belkacem Laassis Jean-Jacques Aaron M. Carmen Mahedero Arsenio Muñoz De La Peña Francisco Salinas 《Journal of inclusion phenomena and macrocyclic chemistry》1995,22(3):235-247
The photooxidation of Azure A and fluorescence properties of Azure A and its photoproduct have been investigated in aqueous media and in the presence of-cyclodextrin (-CD). The fluorescence intensity of the complex formed between the photoproduct and -CD was found to be three times higher than that of the uncomplexed Azure A photoproduct. A complex formation constant of 110±40 M–1 was calculated using the Benesi-Hildebrand treatment of the fluorescence emission data. Although the stoichiometry of the Azure A photoproduct: -CD complex was found to be 1: 1, it seems that the Azure A structure is only partially included. Calibration graphs were plotted for the free Azure A photoproduct and the photogenerated product included in -CD. The analytical parameters and quantification limits were determined. 相似文献
5.
Leila Hasniou Belkacem Nessark Naima Maouche 《Russian Journal of Applied Chemistry》2017,90(4):633-640
In the present work, a new composite material poly(3T + 6T + TiO2) was electrochemically synthesized. This composite material was synthesized in a solution of (CH2Cl2/TBAP) containing the monomers (terthiophene), (sexithiophene) and semiconductor (TiO2) particles. The preparedsamples were characterized electrochemically by cyclic voltamperometry (CV) and spectrometry analysis by scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis) absorption spectroscopy, energy dispersive X-ray spectroscopy (EDX) and fourier transform infrared spectroscopy (FTIR), respectively. The effect of TiO2 concentration in the solution on dispersed microparticle entity and on the photocurrent response was investigated. The results showed that TiO2 particles were dispersed and codeposited into the copolymer poly(3T + 6T + TiO2) matrix, and titanium atom was confirmed by EDX spectra. From SEM images, the TiO2 has a spherical shape and micrometer size. The FTIR spectrum indicated that titanium dioxide do not show a significant modification in terms of band shape and no interaction between polymers and TiO2 particles. Furthermore, the results showed that the composite films with different amounts of TiO2 exhibit good photocurrent properties which imply that these composites films can be used in various fields, such as photoelectrochemical applications as photovoltaic cells. 相似文献
6.
Mostefa Sayhi Nasreddine Haine Belkacem Belaabed Valérie Vigneras 《Journal of Macromolecular Science: Physics》2015,54(10):1183-1195
Conducting polymer blends were prepared using polyaniline doped with para- toluene sulfonic acid (PTSA-PANI) and a polyester polyol-based polyurethane (PU). The morphological, thermal and dielectric properties of the PTSA-PANI/PU blends in the frequency range of 1–5 GHz (S band) were investigated. It was found that the morphology of the samples was affected by the PTSA-PANI loading, resulting in the formation of agglomerates and pathways when above 10 wt%. The thermal stability of the composites was improved with increased PTSA-PANI loading. The electrical conductivity percolation threshold was obtained at 2.5% of PTSA-PANI loading and the electrical conductivity reached the value of 0.13 S/m at a PTSA-PANI loading of 30 wt%. The obtained results for the PTSA-PANI/PU blends prepared indicate a high potential for their successful use in electrical and electromagnetic applications. 相似文献
7.
Belkacem Meziane 《Optical and Quantum Electronics》2014,46(2):305-317
This paper is intended to show that laser-intensity-output versus excitation characteristics of bad-cavity configured lasers deviate from the linearly expected evolution when these are driven beyond the instability threshold. These deviations result in collapsed curves with marked and discernible intensity-reduction at the onset of instability. Such behaviors are shown to be rooted in the fundamental and intrinsic aspects of both the single mode homogeneously-broadened laser and the inhomogeneously-broadened system. In addition, we clarify, for the first example, the physical origin of a hysteresis effect which is known to occur when the pump-input power is scanned from levels above to levels below the instability threshold. As for the inhomogeneous case, a lateral hole-burning effect, which takes place in the spectral profile at high excitations, is shown to shift the output-intensity towards higher levels, with respect to the steady-state values. Simple theoretical elements are put forward to identify the physical origin of these features. 相似文献
8.
The response to pump-power modulation of Nd-doped fibre lasers with lengths in the kilometre range is reported. The timescales involved are close to those of subcritical regimes so that the transient relaxation oscillations are strongly damped. Furthermore, no competing effects (antiphase dynamics) occur between the two polarization eigenstates of the laser. Simple rate equations are shown to predict these behaviours. The experimental side of this study furnishes a definite demonstration of the importance of timescales in the dynamical properties of nonlinear and nonautonomous physical systems. 相似文献
9.
Armspach D Poorters L Matt D Benmerad B Balegroune F Toupet L 《Organic & biomolecular chemistry》2005,3(14):2588-2592
1,3-Bis[bis(4-tert-butylphenyl)chloromethyl]benzene and 1,3-bis[bis(4-anisyl)chloromethyl]benzene were employed as regioselective capping reagents for the preparation of C-6A,C-6B-bridged, permethylated alpha- and beta-CD derivatives; isolated yields up to 55% of proximally capped, methylated CDs were obtained, thus opening the way to the straightforward preparation of a wide range of A,B-functionalised CDs. As revealed by a single crystal X-ray diffraction study, the benzene-1,3-bis[bis(4-tert-butylphenyl)methyl] spacer is perfectly suited for A,B-capping of beta-cyclodextrin. 相似文献
10.