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991.
Rendiconti del Circolo Matematico di Palermo Series 2 - In this paper we compute the line integral of a complex function on a rectifiable cycle homologous to zero obtaining a Green’s formula... 相似文献
992.
We use a recently obtained generalization of the weighted Montgomery identity to obtain new sharp weighted generalizations of Ostrowski type in- equalities, as well as weighted 2-point Radau and Gauss and 3-point Lobatto quadrature formulae for functions whose first derivative belong to the L p spaces. 相似文献
993.
994.
Josep Batle 《Annalen der Physik》2020,532(6):2000118
Several magnetic compounds owe their properties to the particular nature of the dipole–dipole interaction. Changes induced in their structure will vary the total interaction energy in nontrivial fashions. In the present work, systems of identical particles possessing dipole moments arranged on various types of 2D structures are studied. By continuously varying a structural parameter, the state of minimum energy will favor distinct dipole configurations, giving rise to different phases. The ultimate goal is to quantitatively address the relation existing between the minimum possible energy for different systems of classic dipoles and the concomitant dipole phases that appear. The systems of dipoles considered here are studied in detail for the first time. With the exploration, new light will be shed on the existence of structural phase transitions in classical systems even at zero temperature, changes induced by the variation of a continuous parameter, and not the temperature, that resemble the ones occurring in quantum phase transitions. 相似文献
995.
Servín-Campuzano H. González-Avilés M. Sobral H. Peña-Gomar M. López-Miranda A. 《Journal of Thermal Analysis and Calorimetry》2019,138(1):153-162
Journal of Thermal Analysis and Calorimetry - Different kinds of soot were evaluated as selective coverings for use in solar cookers. The coatings were analyzed by measuring their thermal... 相似文献
996.
997.
Josué D. Mota‐Morales María C. Gutiérrez M. Luisa Ferrer Isaac C. Sanchez Eduardo A. Elizalde‐Peña John A. Pojman Francisco Del Monte Gabriel Luna‐Bárcenas 《Journal of polymer science. Part A, Polymer chemistry》2013,51(8):1767-1773
The deep eutectic solvents (DESs) based on the mixtures of a variety of ammonium salts and hydrogen bond donors containing acrylic acids and acrylamides are capable of sustaining frontal polymerization (FP). The selection of ammonium salt affects the reactivity and allows FP at relatively low temperature but with full conversion. Also, full conversion allows us to use these polymers for biomedical applications (e.g., drug delivery systems) as the unreactive ammonium salts can be released from the resulting polymer without by‐products. We call these components “active fillers,” which can be ammonium salts with biological or pharmaceutical importance. For instance, we prepared poly(acrylic acid) loaded with lidocaine hydrochloride (a common anesthetic), the release of which was found to occur in a controlled fashion. The ammonium salts also create a sufficiently high viscosity to suppress buoyancy‐driven convection without additional materials. The DES here described played an all‐in‐one role, providing the monomer, the active filler, and the polymerization medium for FPs. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
998.
Eladia María Peña‐Méndez Beatriz González Pablo Lorenzo Antonio Romerosa Josef Havel 《Rapid communications in mass spectrometry : RCM》2009,23(23):3831-3836
Ruthenium(II) complexes are of great interest as a new class of cancerostatics with advantages over classical platinum compounds including lower toxicity. The stability of the [RuClCp(mPTA)2](OSO2CF3)2 complex (I) (Cp cyclopentadienyl, mPTA N‐methyl 1,3,5‐triaza‐7‐phosphaadamantane) in aqueous solution was studied using spectrophotometry, matrix‐assisted laser desorption/ionization (MALDI) and laser desorption/ionization (LDI) time‐of‐flight (TOF) mass spectrometry (MS). Spectrophotometry proves that at least three different reactions take place in water. Dissolution of I leads to fast coordination of water molecules to the Ru(II) cation and then slow hydrolysis and ligand exchange of chloride and mPTA with water, hydroxide or with trifluoromethane sulfonate itself. Via MALDI and LDI of the hydrolyzed solutions the formation of singly positively charged ions of general formula RuClp(Cp)q(mPTA)r(H2O)s(OH)t (p = 0–1, q = 0–1, r = 0–2, s = 0–5, t = 0–2) and of some fragment ions was shown. The stoichiometry was determined by analyzing the isotopic envelopes and computer modelling. The [RuClCp(mPTA)2](OSO2CF3)2 complex can be stabilized in dilute hydrochloric acid or in neutral 0.15 M isotonic sodium chloride solution. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
999.
Maria Fernandez-Alvarez Marta Lores Eric Jover Carmen Garcia-Jares Josep M. Bayona Maria Llompart 《Journal of chromatography. A》2009,1216(51):8969-8978
Photo-solid-phase microextraction (photo-SPME) has been employed to study the photolysis of three common indoor air pollutants: coumarin, butylated hydroxytoluene, 2,6-diisopropylnaphthalene. Analytes were first extracted by SPME, and the fibre was subsequently exposed to an irradiation source (i.e. xenon arc or low-pressure mercury lamp) for the selected time (from 2 to 120 min). Analyses of the irradiated fibres were carried out by gas chromatography–mass spectrometry (GC–MS) detection. Photodecay kinetics exhibited a first-order behaviour and their rate constants and half-life times were estimated. Twenty-five photoproducts have been tentatively identified by means of their mass spectra. On the basis of the identified transformation compounds, some photodegradation pathways were proposed. The photoformation–photodecay kinetics of the identified by-products were also monitored by photo-SPME. To the best of our knowledge, photolytic routes for coumarin, butylated hydroxytoluene and 2,6-diisopropylnaphthalene have not been previously investigated. 相似文献
1000.
In this paper we will focus on power series expansions around special surfaces of codimension two, in particular around spheres and products of spheres. This will include a version of the Cauchy–Kowalewski extension theorem around these surfaces. This higher codimension result was only obtained so far in the flat case (see Partial Differential Equations with Complex Analysis. Pitman Research Notes Mathematical Series, vol. 262. Longman Science and Technology: Harlow, 1992; 61–92; Mathematics and its Applications, vol. 53. Kluwer Academic Publishers Group: Dordrecht, 1992). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献