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991.
We analyze the forces on a small dipolar particle and the electromagnetic momentum density in a configuration consisting in two perpendicular circularly polarized stationary waves. The field distribution shows regions in which the electric and magnetic fields are parallel corresponding to a null Poynting vector. Although the average value of the momentum density, proportional to the Poynting vector, is zero in these regions, there are scattering forces acting on small particles due to light's spin force. The total scattering force suggests a new definition of the average value of the momentum density for free propagating electromagnetic fields. 相似文献
992.
Newton-like methods are often used for solving nonlinear equations. In the present paper, we introduce very general majorizing sequences for Newton-like methods. Then, we provide semi-local convergence results for these methods. The new convergence results can be weaker than in earlier studies. These new results are illustrated by several numerical examples and special cases of Newton-like methods, for which the older convergence conditions do not hold but for which our weaker convergence conditions are satisfied. 相似文献
993.
Eli Adjélé Wilson Françoise Bindler Eric Marchioni Martine Bergaentzlé Tamime Benrabah Saïd Ennahar 《Journal of separation science》2012,35(23):3369-3374
Several SPE sorbents were investigated for the extraction of a group of chemically diverse isothiocyanates (ITCs). They included bonded silica, carbon‐based, and polymer‐based sorbents with various functional groups. Results showed large differences in the ability of these sorbents to simultaneously extract ITCs from standard solutions. Recovery rates were on average the highest with divinylbenzene (DVB) based polymeric sorbents, especially with a DVB/N‐vinylpyrrolidone copolymer that had recovery rates ranging between 86.7 and 95.6%. These sorbents achieved the most balanced extraction efficiency between aliphatic and aromatic, polar, and nonpolar ITCs. With graphitized carbon, C18‐bonded silica, and amide‐containing sorbent, recovery levels were higher for the two least polar aromatic ITCs (benzyl ITC and phenylethyl ITC), whereas for the polar aliphatic ITCs levels were the lowest. The least retained one, was methyl ITC that is the most polar with recoveries between 0 and 31.5%. The presence of amide groups, especially in a polyamide sorbent, appeared to be particularly unsuitable for the extraction of aliphatic ITCs. A copolymer made up of DVB and N‐vinylpyrrolidone was therefore shown to be the most suited for the extraction of both aliphatic and aromatic ITCs. 相似文献
994.
Zhou L Zhao M Ennahar S Bindler F Marchioni E 《Analytical and bioanalytical chemistry》2012,403(1):291-300
A liquid chromatographic–electrospray ionization–tandem mass spectrometric (LC–ESI–MS2) method has been developed for determination of the molecular species of phosphatidylethanolamine (PE) in four food matrices
(soy, egg yolk, ox liver, and krill oil). The extraction and purification method consisted of a pressurized liquid extraction
procedure for total lipid (TL) extraction, purification of phospholipids (PLs) by adsorption on a silica gel column, and separation
of PL classes by semi-preparative normal-phase HPLC. Separation and identification of PE molecular species were performed
by reversed-phase HPLC coupled with electrospray ionization tandem mass spectrometry (ESI–MS2). Methanol containing 5 mmol L−1 ammonium formate was used as the mobile phase. A variety of PE molecular species were detected in the four food matrices.
(C16:0–C18:2)PE, (C18:2–C18:2)PE, and (C16:0–C18:1)PE were the major PE molecular species in soy. Egg yolk PE contained (C16:0–C18:1)PE,
(C18:0–C18:1)PE, (C18:0–C18:2)PE, and (C16:0–C18:2)PE as the major molecular species. Ox liver PE was rich in the species
(C18:0–C18:1)PE, (C18:0–C20:4)PE, and (C18:0–C18:2)PE. Finally, krill oil which was particularly rich in (C16:0(alkyl)–C22:6(acyl))plasmanylethanolamine
(PakE), (C16:0–C22:6)PE, and (C16:0–C20:5)PE, seemed to be an interesting potential source for supplementation of food with
eicosapentaenoic acid and docosahexaenoic acid. 相似文献
995.
Kyung Hyun Choi Maria Mustafa Khalid Rahman Bum Ko Jeong Yang Hui Doh 《Applied Physics A: Materials Science & Processing》2012,106(1):165-170
A prototype memristive device has been presented in this paper, for which the top and bottom electrodes have been fabricated
through a simple and cost-effective technique, i.e. electrohydrodynamic printing. For deposition of the bottom electrode pattern,
a silver ink containing 60 wt% silver by content was subjected to controlled flow through a metal capillary exposed to an
electric field at the ambient temperature to generate an electrohydrodynamic jet, thereby depositing uniform patterns of silver
on glass substrate at a constant substrate speed. The top electrode has been deposited in a similar fashion. In between the
top and bottom electrodes, a uniform layer of ZnO is fabricated using spin-coating technique. The nanoscale ZnO memristor
stack has a channel length of 370 μm and channel width of 82 μm. A memristor thus fabricated was characterized and its current
voltage curves were analyzed. The device showed a typical nonvolatile resistive switching behavior present in memristor devices
thus highlighting the EHD printed patterning as a reliable method for the fabrication of memory devices. 相似文献
996.
Peptide-based nanomaterials have been utilized for various applications from regenerative medicine to electronics since they provide several advantages including easy synthesis methods, numerous routes for functionalization and biomimicry of secondary structures of proteins which leads to design of self-assembling peptide molecules to form nanostructures. Microscopic characterization at nanoscale is critical to understand processes directing peptide molecules to self-assemble and identify structure-function relationship of the nanostructures. Here, fundamental studies in microscopic characterization of peptide nanostructures are discussed to provide insights in widely used microscopy tools. In this review, we will encompass characterization studies of peptide nanostructures with modern microscopes, such as TEM, SEM, AFM, and advanced optical microscopy techniques. We will also mention specimen preparation methods and describe interpretation of the images. 相似文献
997.
Cr (III) sorption on microporous strong cation exchanger Amberlite.120 (Na+) is studied as a function of time and temperature. The pH changes show the co-sorption of H+ ions along with the chromium. The rate constant values for Cr (III) sorption are calculated for both film and particle diffusion processes. However, the particle diffusion is found to be more dominant than the film diffusion. The temperature is found to have a positive effect on both the diffusional processes. The low values of energy of activation also confirm the diffusional nature of the process. Equilibrium data are explained with the help of Langmuir equation. Various thermodynamic parameters (??H, ??S and ??G) for Cr (III) exchange on the resin are calculated. The ??G values are found to be negative, while both the ??H and ??S values obtained are positive. 相似文献
998.
Mahide Küçük Mustafa Soyertem Yalçın Küçük İlknur Atasever 《Journal of Mathematical Analysis and Applications》2012,385(1):285-292
As a result of our previous studies on finding the minimal element of a set in n-dimensional Euclidean space with respect to a total ordering cone, we introduced a method which we call “The Successive Weighted Sum Method” (Küçük et al., 2011 [1], [2]). In this study, we compare the Weighted Sum Method to the Successive Weighted Sum Method. A vector-valued function is derived from the special type of set-valued function by using a total ordering cone, which is a process we called vectorization, and some properties of the given vector-valued function are presented. We also prove that this vector-valued function can be used instead of the set-valued map as an objective function of a set-valued optimization problem. Moreover, by giving two examples we show that there is no relationship between the continuity of set-valued map and the continuity of the vector-valued function derived from this set-valued map. 相似文献
999.
1000.
A. Radhouane I. Bhouri Baouab N. Mahjoub Saïd H. Mhiri Ph. Bournot G. Le Palec 《Heat and Mass Transfer》2013,49(5):629-656
Consideration is given to the interaction of twin tandem jets with an oncoming uniform crossflow. A variable temperature is assumed for the emitted jets while the crossflow is maintained constant, equivalent to the ambient temperature. Both jet nozzles are elliptic, as initially inclined with an angle of 60°, placed three diameters apart in line with the crossflow and discharge a nonreactive fume. The handled configuration is numerically simulated in the present work, by means of the finite volume method together with a non uniform grid system. The model is first validated with reference to available experimental data, in the simple isothermal case of air jets in air crossflow. It is then upgraded by considering a nonreactive fume discharged at a variable temperature. The upgraded model turbulence is described by means of the Reynolds Stress Model second order turbulent closure model. The present work is to our knowledge pioneering in the introduction of this particular model is such a configuration and its introduction proved to be highly valuable since is described satisfyingly the turbulent behavior of the resulting flowfield. This behavior is, precisely, specified in terms of shear stress components whose evolutions, explored along the different directions of the domain, showed a more pronounced vertical mixing, and gave rise to more significant vortices in most characterizing zones: near the injection plane as well as within the discharging nozzles. 相似文献