全文获取类型
收费全文 | 148篇 |
免费 | 0篇 |
专业分类
化学 | 86篇 |
力学 | 10篇 |
数学 | 37篇 |
物理学 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 8篇 |
2013年 | 14篇 |
2012年 | 13篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 11篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1987年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 15 毫秒
81.
Luciano Miozzo Nicolas Battaglini Daniele Braga Loïg Kergoat Clément Suspène Abderrahim Yassar 《Journal of polymer science. Part A, Polymer chemistry》2012,50(3):534-541
Random regioregular copolymers of 3‐hexylthiophene and 3,4‐ethylenedioxythiophene were synthesized by grignard metathesis polymerization. Soluble copolymers were obtained with a high degree of regioregularity and with a monomer ratio close to the feed ratio. A comparison between the optical properties and the thin film morphologies of these copolymers and poly(3‐hexylthiophene) is also presented. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
82.
In this paper, we study an implicit version of the sweeping process. Based on methods of convex analysis, we prove the equivalence of the implicit sweeping process with a differential equation, which enables us to show the existence and uniqueness of the solution to the implicit sweeping process in a very general framework. Moreover, this equivalence allows us to give a characterization of nonsmooth Lyapunov pairs and invariance for implicit sweeping processes. The results of the paper are illustrated with two applications to quasistatic evolution variational inequalities and electrical circuits. 相似文献
83.
Ahmed El Akkaoui Ibtissam Bassoude Jamal Koubachi Sabine Berteina-Raboin Abderrahim MouaddibGérald Guillaumet 《Tetrahedron》2011,67(37):7128-7138
New and efficient regioselective Sonogashira and Suzuki-Miyaura palladium-catalyzed coupling reactions of 3,6-dihalogenoimidazo[1,2-a]pyridines followed by another cross-coupling has been successfully developed. Various solvents, palladium species and bases were tested. Scope and limitations of this regiocontrolled palladium-catalyzed reaction were investigated. The synthesis of 3,6-disubstituted imidazo[1,2-a]pyridine derivatives using one-pot regioselective double-coupling approach was developed. This procedure affords convergent syntheses of polysubstituted compounds in high yields in a very few steps. 相似文献
84.
A. Hajri R. Abderrahim 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):520-525
Abstract The reaction of thionyl chloride with amidines 2, derived from N-benzimidazol-2-yl imidates 1, leads to [1,2,4,6]thiatriazino[2,3-a][1,3]benzimidazol-1(2H)-one 3 in good yields. [1,3,5]Thiadiazino[3,4-a][1,3]benzimidazol-2-imine 4 was prepared by condensation of NaSCN with benzimidazol-2-yl imidate 1. The isolated compounds 3 and 4 were identified by spectroscopic methods including IR, 1H NMR, and 13C NMR as well as elemental analyses and MS of 3d and 4b. GRAPHICAL ABSTRACT 相似文献
85.
Mostafa Adimy Fabien Crauste Abderrahim El Abdllaoui 《Comptes Rendus Mathematique》2010,348(7-8):373-377
We investigate a system of nonlinear differential equations with distributed delays, arising from a model of hematopoietic stem cell dynamics. We state uniqueness of a global solution under a classical Lipschitz condition. Sufficient conditions for the global stability of the population are obtained, through the analysis of the asymptotic behavior of the trivial steady state and using a Lyapunov function. Finally, we give sufficient conditions for the unbounded proliferation of a given cell generation. 相似文献
86.
Abderrahim Dinane 《Journal of solution chemistry》2007,36(11-12):1421-1436
A hygrometric method has been used to measure water activities for the quaternary aqueous system NaCl-CsCl-LiCl-H2O as a function of the solutes concentrations at T=298.15 K. The measurements were performed by measuring the diameter of solution droplets as a function of the surrounding relative humidity. The total ionic strength range covered in this study was about 0.6 to 6 mol?kg?1 for different ionic strength fractions y of one of the three solutes ranging from y=1/3 to 1/2, whereas the constant ratio r of molalities of the two other solutes was fixed at unity. The osmotic coefficients of these aqueous mixtures were calculated over this ionic strength range. The obtained data were treated by the ECA I and ECA II rules, and the Pitzer and Kim, and Pitzer-Dinane models. The solute activity coefficients of components in the studied mixtures were also determined for different ionic strength fractions of the different solutes. 相似文献
87.
Abderrahim Boudenne Laurent Ibos Magali Fois Evelyne Gehin Jean‐Charles Majeste 《Journal of Polymer Science.Polymer Physics》2004,42(4):722-732
This article is dedicated to the study of the thermal parameters of composite materials. A nonlinear least‐squares criterion is used on experimental transfer functions to identify the thermal conductivity and the diffusivity of aluminum‐polymer composite materials. The density measurements were achieved to deduce the specific heat and thereafter they were compared to values given by differential scanning calorimetry measurement. The thermal parameters of the composite material polypropylene/aluminum were investigated for the two different types of aluminum filler sizes. The experimental data were compared with several theoretical thermal conductivity prediction models. It was found that both the Agari and Bruggeman models provide a good estimation for thermal conductivity. The experimental values of both thermal conductivity and diffusivity have shown a better heat transport for the composite filled with large particles. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 722–732, 2004 相似文献
88.
Mohammad Jouni Abderrahim Boudenne Gisèle Boiteux Valérie Massardier Bertrand Garnier 《先进技术聚合物》2014,25(9):1054-1059
Electrically and thermally conductive high‐density polyethylene composites filled with hybrid fillers, multiwall carbon nanotubes (MWCNTs) and silver nanoparticles (Ag‐NPs), have been prepared in the melt state. The investigation of their electrical and thermal conductivities while comparing with high‐density polyethylene/MWCNT binary composites shows that the addition of only 3 vol% of Ag‐NPs does not reduce the electrical percolation threshold (Pc) that remains as low as 0.40 vol% of MWCNTs but leads to an increase in the maximum dc electrical conductivity of PE/MWCNT composites by two orders of magnitudes. Moreover, the association of both Ag‐NPs and carbon nanotube particles improved our composite's thermal conductivity. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
89.
Benaissa Esma Abderrahim Omar Didi Mohamed Amine 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(1):439-446
Batch experiments are carried out for the sorption of La(III) onto commercial macroporous resins containing iminodiacetic (Lewatit TP 207) and aminomethylphosphonic acid groups (Lewatit TP 260). The operating variables studied are initial La(III) concentration, pH, temperature and contact time. Since the extraction kinetics were fast, with a mixture of 0.1 g of resin and 5 mL of lanthanum ions 0.5 × 10?3 mol L?1 solution, extraction equilibrium was reached within 30 min of mixing. The optimum pH values level for quantitative sorption were between 1.5 and 4.6 with Lewatit 207 and about 5.2 with Lewatit TP 260. The sorption capacities of Lewatit TP 207 and Lewatit TP 260 resins are 114.7 and 106.7 mg g?1, respectively. Adsorption equilibrium data were calculated for Langmuir and Freundlich isotherms. It was found that the sorption of La(III) on Lewatit TP 207 was better suited to the Langmuir adsorption model while Freundlich adsorption model fitted better sorption on Lewatit TP 260. Thermodynamics data leads to endothermic and spontaneous process. ΔG° decreases with increasing temperature indicating that sorption process of La(III) on both Lewatit TP 207 and Lewatit TP 260 was more favored at high temperature. 相似文献
90.
Mohamed Amine Didi Didier Villemin Omar Abderrahim Abdelkrim Azzouz 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(3):1191-1198
In this paper, extractants that have the potential to be sustainably regenerated, are proposed for thorium(IV) removal from nitrate aqueous phases. These extractants are oleic (OA), palmitic (PA) and lauric (LA) acids. The advantages of using these acids are their sustainability, their biocompatibility and their non-toxicity, this makes these simpler and greener compared to other extractants (organophosphorus, azote derivatives, macrocyclic crown, etc…) used for metal extraction. These acids were applied as chelating agent for Th(IV) liquid–liquid extraction. The extractions were carried out in chloroform as an organic phase through the formation of thorium–OA, thorium–PA and thorium–LA complexes. The synergistic extraction of Th(IV) with these extractants in the presence of tributhylphosphine (TBP) has been investigated. The effect of different variables, such as time contact, pH of the aqueous phase, concentration of fatty acid, TBP addition on fatty acids, ionic strength and temperature, is reported. The results showed that the extraction kinetics using LA and OA were fast than with PA. The KNO3 addition does not seem to highly influence the extraction yield, and no important synergy effect was noticed in the presence of TPB. Thermodynamic data for Th(IV) solvent extraction are also reported in this paper. 相似文献