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161.
Giorgio Careri 《Physics in Perspective (PIP)》2000,2(2):204-210
Lars Onsager was known for his obscure but correct predictions in several fields of science. Some scientific events, particularly
in the field of superfluidity, are recollected here by one of his old friends. 相似文献
162.
J.C. Conde P. González F. Lusquiños S. Chiussi J. Serra B. León 《Applied Physics A: Materials Science & Processing》2007,88(4):667-671
Changes in target surface morphology and ablation plume direction have been experimentally observed during the initial stages
of the silicon laser ablation process. A relationship between both phenomena can be observed upon analysing the temperature
field induced by the laser beam in a rough surface material. Theoretical studies on the deflection of the ablation plume are
presented. These analyses are based on the hypothesis that particles that reach evaporation temperature will exit normally
to the target surface with a velocity that is proportional to the surface temperature and the amount of the ablated material.
Numerical solutions and experimental results of laser ablation process of silicon targets are found to agree with theoretical
studies.
PACS 42.25.Lc; 79.20.Dc; 02.70.Dc 相似文献
163.
Salvatore Giuffrida Guglielmo G. Condorelli Lucia L. Costanzo Giorgio Ventimiglia Raffaella Lo Nigro Maria Favazza Enrico Votrico Corrado Bongiorno Ignazio L. Fragalà 《Journal of nanoparticle research》2007,9(4):611-619
Liquid Phase Photo-Deposition (LPPD) technique has been used to obtain both colloidal particles and thin films of metallic
and chloride nickel from solutions of only precursor Ni(acac)2 (acac=2,4-pentandionato). Metallic nickel was obtained from ethanol solutions by direct nickel(II) photoreduction at 254 nm
and by acetone sensitised reaction at 300 nm. In this latter process the rate was higher than in the first one. NiCl2 was formed from CCl4 solution by a solvent-initiated reaction. TEM analysis, performed on colloidal particles of nickel, showed that their dimensions
are in the range 2–4 nm. The films did not present carbon contamination and were characterized by AFM, XPS and GIXRD. Metallic
films consisted of particles of 20–40 nm that are the result of the aggregation of smaller crystallites (4–5 nm). Larger agglomerations
(around 200 nm) have been observed for NiCl2 films. 相似文献
164.
Giorgio Parisi 《Physica A》2007,386(2):611-624
Here I will review the theoretical results that have been obtained for spin glasses. I will concentrate my attention on the predictions of the mean field approach in three dimensional systems and on its numerical and experimental verifications. 相似文献
165.
Giorgio Mantica 《Numerische Mathematik》2013,125(4):705-731
We introduce a new set of algorithms to compute the Jacobi matrices associated with invariant measures of infinite iterated function systems, composed of one–dimensional, homogeneous affine maps. We demonstrate their utility in the study of theoretical problems, like the conjectured almost periodicity of such Jacobi matrices, the singularity of the measures, and the logarithmic capacity of their support. Since our technique is based on a reversible transformation between pairs of Jacobi matrices, it can also be applied to solve an inverse/approximation problem. The proposed algorithms are tested in significant, highly sensitive cases: they perform in a stable fashion, and can reliably compute Jacobi matrices of large order. 相似文献
166.
Mireia Morell Brigitte Voit Xavier Ramis Àngels Serra Albena Lederer 《Journal of polymer science. Part A, Polymer chemistry》2011,49(14):3138-3151
Well‐defined multiarm star block copolymers poly(glycidol)‐b‐poly(methyl methacrylate) (PGOHBr‐b‐PMMAx) with an average number of PMMA arms of 85, 55, and 45 have been prepared. The core‐first approach has been selected as the methodology using atom transfer radical polymerization (ATRP) of MMA from an activated hyperbranched poly(glycidol) as the core. These activated hyperbranched macroinitiators were prepared by esterification of hyperbranched poly(glycidol) (PGOH) with 2‐bromoisobutyryl bromide. The effect of monomer/initiator ratio, catalyst concentration, time, temperature, and solvent on the growing of the arms has been studied in detail in order to optimize the process and to diminish the radical‐radical coupling. The final products and intermediates were characterized by means of size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) and Fourier transform‐infrared (FTIR) spectroscopy. The length of PMMA arms was determined by SEC after cleavage of ester bond linked to PGOH core. Glass transition temperature (Tg), thermal stability and rheological properties of the multiarm star copolymers were also studied. Finally, tapping mode atomic force microscopy (TMAFM) allowed the clear visualization of nano‐sized particles (80–200 nm) corresponding to individual star molecules. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
167.
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169.
This paper investigates the topological properties of the Brazilian term structure of interest rates network. We build the minimum spanning tree (MST), which is based on the concept of ultrametricity, using the correlation matrix for interest rates of different maturities. We show that the short-term interest rate is the most important within the interest rates network, which is in line with the Expectation Hypothesis of interest rates. Furthermore, we find that the Brazilian interest rates network forms clusters by maturity. 相似文献
170.
Jan Kratochvíl Andrzej Proskurowski Oriol Serra 《Discrete Applied Mathematics》2009,157(12):2575-2576