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排序方式: 共有137条查询结果,搜索用时 140 毫秒
91.
92.
Jihen Mahfoudh Slim Salhi Aurélie Auguste Christelle Delaite Rachid El Gharbi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(4):280-285
A series of random polyesteramides (PEAs) within a range of molar composition from 90/10 to 10/90 were synthesized by a direct melt polycondensation of glycolic acid and β-alanine. Their structures were fully characterized by NMR spectroscopy. The resulting copolymers are amorphous and present increasing glass transition temperatures at increasing β-alanine contents. The copolymers were also characterized by, FTIR, TGA and viscosimetry measurements. 相似文献
93.
Removal of bromide and iodide anions from drinking water by silver-activated carbon aerogels 总被引:1,自引:0,他引:1
Sánchez-Polo M Rivera-Utrilla J Salhi E von Gunten U 《Journal of colloid and interface science》2006,300(1):437-441
The aim of this study is to analyze the use of Ag-doped activated carbon aerogels for bromide and iodide removal from drinking water and to study how the activation of Ag-doped aerogels affects their behavior. It has been observed that the carbonization treatment and activation process of Ag-doped aerogels increased the surface area value ( [Formula: see text] ), whereas the volume of meso-(V(2)) and macropores (V(3)) decreased slightly. Chemical characterization of the materials revealed that carbonization and especially activation process considerably increased the surface basicity of the sample. Original sample (A) presented acidic surface properties (pH(PZC)=4.5) with 21% surface oxygen, whereas the sample that underwent activation showed mainly basic surface chemical properties (pH(PZC)=9.5) with only 6% of surface oxygen. Carbonization and especially, activation process considerable increased the adsorption capacity of bromide and iodide ions. This would mainly be produced by (i) an increase in the microporosity of the sample, which increases Ag-adsorption sites available to halide anions, and (ii) a rise of the basicity of the sample, which produces an increase in attractive electrostatic interactions between the aerogel surface, positively charged at the working pH (pH(solution)相似文献
94.
In physical distribution the location of depots and vehicle routes are interdependent problems, but they are usually treated
independently. Location-routing is the study of solving locational problems such that routing considerations are taken into
account. We present an iterative heuristic for the location-routing problem on the plane. For each depot the Weber problem
is solved using the end-points of the routes found previously as input nodes to the Weiszfeld procedure. Although the improvements
found are usually small they show that it pays not to ignore the routing aspects when solving continuous location problems.
Possible research avenues in continuous location-routing will also be suggested. 相似文献
95.
F. Amrani A. Haboucha M. Salhi H. Leblond A. Komarov F. Sanchez 《Applied physics. B, Lasers and optics》2010,99(1-2):107-114
We investigate experimentally ordered and disordered pattern formation of solitons in a double-clad fiber laser. We point out an analogy between the different states of matter and the states of a set of dissipative solitons. In particular, we have identified a gas, a supersonic gas flow, a liquid, a polycrystal and a crystal of solitons. The different states are obtained only by adjustment of the intracavity phase plates. 相似文献
96.
We report the observation of bound states of 350 pulses in a ring fiber laser mode locked by nonlinear rotation of the polarization. The phenomenon is described theoretically using a multiscale approach to the gain dynamics; the fast evolution of a small excess of gain is responsible for the stabilization of a periodic pattern, while the slow evolution of the mean value of gain explains the finite length of the quasiperiodic soliton train. 相似文献
97.
M. Bardoux A. Bousseksou G. Tessier S. Bouchoule D. Fournier A. Salhi Y. Rouillard F. Genty 《Optics and Lasers in Engineering》2009,47(3-4):473-476
Thermal characterization of semiconductor lasers is an important issue for optoelectronics. This paper presents our thermoreflectance measurements on two different types of laser diodes: classical ridge laser diodes and vertical cavity surface emitting lasers (VCSELs). We first studied the external temperature increase in ridge diodes in order to determine inhomogeneity. Then, we tried to determine the inner temperature of the VCSELs. 相似文献
98.
Let T be a bounded operator and let \(k \ge 2\) be an integer. We study in this paper the following question: T is a partial isometry implies that \(T^k\) is a partial isometry and conversely. 相似文献
99.
[structure: see text] Oligothienyl-substituted paracyclophanes bearing alpha-thienyl substituents, which block polymerization at these sites, undergo oxidation to form stable radical cations and dications. Splitting of the first voltammetric oxidation wave of stacked dimers into two single-electron processes corresponding to formation of the stacked mono(radical cation) and the stacked bis(radical cation) illustrates the influence of pi-stacking on the behavior of conjugated chains, which serve as models for stacked polarons in conjugated polymers. 相似文献
100.