全文获取类型
收费全文 | 92篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 32篇 |
力学 | 2篇 |
数学 | 32篇 |
物理学 | 29篇 |
出版年
2023年 | 1篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1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95条查询结果,搜索用时 31 毫秒
31.
Jean-Jacques Aaron Belkacem Laassis M. Carmen Mahedro Arsenio Muñoz de la Peña F. Salinas 《Journal of inclusion phenomena and macrocyclic chemistry》1994,18(1):69-79
The photo-oxidation reaction of phenothiazine has been studied in the presence of-cyclodextrin (-CD) and 2-hydroxypropyl-cyclodextrin (HP -CD). The influence of these organized media on the formation of the oxidation photoproduct upon UV irradiation has been investigated. Phenothiazine forms an inclusion complex with the cyclodextrins. The stoichiometry and formation constant of the complex formed with 2-hydroxypropyl -CD have been calculated using the changes of the fluorescence emission signal and of the absorbance of the drug upon inclusion. An increase of the fluorescence intensity of the photogenerated product is attained when it becomes included inside the cyclodextrin cavity. 相似文献
32.
This paper presents a new estimation procedure for the limit distribution of the maximum of a multivariate random sample. This procedure relies on a new and simple relationship between the copula of the underlying multivariate distribution function and the dependence function of its maximum attractor. The obtained characterization is then used to define a class of kernel-based estimates for the dependence function of the maximum attractor. The consistency and the asymptotic distribution of these estimates are considered. 相似文献
33.
Gael Colomines Belkacem Otazaghine Cyrille Boyer Sophie Monge Jean‐Jacques Robin 《Journal of polymer science. Part A, Polymer chemistry》2008,46(2):433-443
Valorization of poly(ethylene terephthalate) (PET) waste has been achieved using glycolysis. The resulting diols were employed for the synthesis of triblock copolymers by atom transfer radical polymerization using copper (I) bromide and (1,1,4,7,10,10)‐hexamethyltriethylenetetramine as catalyst system. Macroinitiator was obtained after depolymerization of PET waste followed by functionalization of the obtained glycolysate with 2‐bromoisobutyrate bromide. Polymerization of styrene (S) and glycidyl methacrylate (GMA) has been achieved leading to PS‐b‐PETG‐b‐PS and (PS‐stat‐PGMA)‐b‐PETG‐b‐(PS‐stat‐PGMA) triblock copolymers. Best results were obtained at 100 °C. At this temperature, termination reaction were negligible and the measured number‐average molar mass of the product increased linearly with monomer conversion in agreement with the theoretical Mn with low polydispersity products achieved. Polymers were also characterized by 1H NMR. This work presents a original valorization of PET waste as (PS‐stat‐PGMA)‐b‐PETG‐b‐(PS‐stat‐PGMA) copolymer could be used as heat curable coatings. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 433–443, 2008 相似文献
34.
35.
Belkacem Benmerad Achoura Guehria‐Laidoudi Fadila Balegroune Henrik Birkedal Gervais Chapuis 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):789-792
The structure of the title compound, [La(C5H6O4)(C5H7O4)‐(H2O)]·H2O, consists of dense layers formed by chains of one‐edge‐sharing LaO9(H2O) polyhedra, linked together by the glutarate ligand. The three‐dimensional polymeric structure, built up through connection of these layers by the hydrogen glutarate ligand, exhibits cavities accommodating a guest water molecule. The lanthanum ion is tenfold coordinated by four glutarates, acting as bridging–chelating carboxylate groups, by three hydrogen glutarates, three times monodentate, and by one water molecule. Its coordination polyhedron is highly distorted and intermediate between a bicapped dodecahedron and a tetracapped trigonal prism. Hydrogen bonding links the two water molecules and the framework built up from this polynuclear coordination polymer. A very short hydrogen bond, D?A = 2.484 (3) Å, links the protonated with the deprotonated acid groups in the hydrogen glutarate. 相似文献
36.
In this work, we have prepared electrochemically and studied a composite materials based on an organic conducting polymer, polyaniline (PANI), in which inorganic semiconductor titanium dioxide (TiO2) particles were incorporated with different concentrations. The polyaniline/titanium dioxide composite material which had been deposited by cyclic voltammetry on substrates of indium tin oxide was then characterized. The cyclic voltammogram showed one redox couple characteristic of the oxidation and reduction states of the produced composite material. The impedance spectroscopy study showed that the resistance of the film increases with the TiO2 cocntent incorporated in the polymer. The incorporation of TiO2 in PANI covering the surfaces was confirmed by the scanning electron microscopy and the energy dispersive X-ray analysis. The morphological analysis of the film surfaces showed that the TiO2 nanoparticle increased the roughness. These observations allow to consider a new approach to improve the physicochemical properties of the interface between the organic and inorganic material. The I–V characteristics of PANI+TiO2 heterostructure diode showed the nonlinear nature of the I–V curve of PANI+TiO2 heterostructure device. 相似文献
37.
Salim A. Messaoudi Belkacem Said‐Houari 《Mathematical Methods in the Applied Sciences》2005,28(2):205-232
In this paper, we consider a one‐dimensional non‐linear system of thermoelasticity with second sound. We establish an exponential decay result for solutions with small ‘enough’ initial data. This work extends the result of Racke (Math. Methods Appl. Sci. 2002; 25 :409–441) to a more general situation. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
38.
Belkacem Otazaghine Cyrille Boyer Jean‐Jacques Robin Bernard Boutevin 《Journal of polymer science. Part A, Polymer chemistry》2005,43(11):2377-2394
Different acrylate oligomers were synthesized by atom transfer radical polymerization in the presence of a transfer agent and CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine. The functionality in bromine was determined by 1H NMR. These oligomers were coupled in the presence of Cu(0) and the ligand 2,2′‐bipyridine. The coupling yield was determined by size exclusion chromatography and NMR analysis and depended on the nature of the monomer and not on the molecular weight. In other words, the preliminary functionalization of the brominated chain end with styrene increased the coupling yield. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2377‐2394, 2005 相似文献
39.
Faiza Nessark Ahmed Zouaoui Alvaro Garcia-Cruz Anne Bonhomme Michael Lee Belkacem Nessark 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(11):827-834
In this research, an efficient fabrication process of conducting polypyrrole (PPy)/silicon nitride (Si3N4) hybrid materials were developed in order to be employed as transducers in electrochemical sensors used in various environmental and biomedical applications. The fabrication process was assisted by oxidative polymerization of pyrrole (Py) monomer on the surface of Si/SiO2/Si3N4 substrate in presence of FeCl3 as oxidant. To improve the adhesion of PPy layer to Si3N4 surface, a pyrrole-silane (SPy) was chemically bonded through silanization process onto the Si3N4 surface before deposition of PPy layer. After Py polymerization, Si/SiO2/Si3N4-(SPy-PPy) substrate was formed. The influence of SPy concentration and temperature of silanization process on chemical composition and surface morphology of the prepared Si/SiO2/Si3N4-(SPy-PPy) substrates was studied by FTIR and SEM. In addition, the electrical properties of the prepared substrates were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that the best silanization reaction conditions to get Si/SiO2/Si3N4-(SPy-PPy) substrate with high PPy adhesion and good electrical conductivity were obtained by using SPy at low concentration (4.3 mM) at 90°C. These promising findings open the way for fabrication of new hybrid materials which can be used as transducers in miniaturized sensing devices for various environmental and biomedical applications. 相似文献
40.
Belkacem Chaouchi Rabah Labbas Boubaker-Khaled Sadallah 《Mediterranean Journal of Mathematics》2013,10(1):157-175
In this paper, we give new results about existence, uniqueness and regularity properties for solutions of Laplace equation $$\Delta u = h \quad {\rm in} \, \Omega$$ where Ω is a cusp domain. We impose nonhomogeneous Dirichlet conditions on some part of ?Ω. The second member h will be taken in the little Hölder space ${h^{2 \sigma}(\bar{\Omega})}$ with ${\sigma \, \in \, ]0, \, 1/2[}$ . Our approach is based essentially on the study of an abstract elliptic differential equation set in an unbounded domain. We will use the continuous interpolation spaces and the generalized analytic semigroup theory. 相似文献