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71.
R. Boutami M. J.G. Borge H. Mach L. M. Fraile K. Gulda A. J. Aas L. M. García-Raffi E. Hagebø W. Kurcewicz G. Løvhøiden T. Martínez B. Rubio J. L. Taín O. Tengblad 《The European physical journal. Special topics》2007,150(1):87-88
There is lack of knowledge of the structure of the 231Ac
nucleus located in the upper border of the
island of octupole deformation centered around A = 225.
We have populated the excited states in 231Ac by beta-decay from the parent 231Ra
produced at ISOLDE, CERN.
The low-energy structure of 231Ac has been investigated by
means of γ, conversion electrons, γ-γ and γ-e-
spectroscopy. We report here in the precise
determination in 231Ac of the half-life of the most intensively populated states
by the Advanced Time Delayed ββγ(t) technique. 相似文献
72.
Suresh N. Thennadil Luis H. Garcia‐Rubio 《Particle & Particle Systems Characterization》2007,24(6):402-410
The problem of extracting quantitative information on individual particle properties from spectroscopic measurements conducted at concentrations where particle interactions become significant is of great industrial and theoretical importance. For dispersions of charged particles, this can happen at fairly low concentrations. The effect of the fluid (slurry) structure has to be taken into account to interpret the light scattering spectra of such dispersions. In this paper, a hybrid method that addresses the effect of the fluid structure is proposed. The hybrid approach describes the fluid structure by relating the “effective” Percus‐Yevick hard‐sphere parameters to the system parameters using empirical models. The feasibility of this approach is examined through a theoretical study with data generated by Monte Carlo simulations of a monodisperse dispersion of charged spherical particles using realistic interaction potentials under single scattering conditions. 相似文献
73.
Ana Egatz-Gómez P. Aella P. Domínguez-García S.T. Picraux Miguel A. Rubio Manuel Marquez Antonio A. García 《Applied Surface Science》2007,254(1):330-334
A microfluidic method to manipulate small drops of water is studied on two different superhydrophobic surfaces. Using this digital magnetofluidic method, water drops containing paramagnetic carbonyl-iron microparticles were displaced on silicon nanowire (Si NW) and low-density polyethylene (LDPE) superhydrophobic surfaces using magnetic fields. Horizontal, vertical, or upside-down drop movement is made possible by the action of capillary forces induced by paramagnetic particles aligning and following a magnetic field, indicating that three-dimensional digital microfluidics is possible. Also, both Si NW and LDPE superhydrophobic surfaces combine surface chemistry with nano and microscale surface roughness to make drop movement possible. Si NW superhydrophobic surfaces were prepared using vapor-liquid-solid growth systems followed by coating with a perfluorinated hydrocarbon. LDPE superhydrophobic surfaces were prepared by growing polyethylene crystals on a polyethylene substrate through careful rate control. 相似文献
74.
Brandon J. O'Neill David H. K. Jackson Dr. Anthony J. Crisci Carrie A. Farberow Fengyuan Shi Dr. Ana C. Alba‐Rubio Dr. Junling Lu Dr. Paul J. Dietrich Dr. Xiangkui Gu Dr. Christopher L. Marshall Prof. Peter C. Stair Dr. Jeffrey W. Elam Dr. Jeffrey T. Miller Prof. Fabio H. Ribeiro Prof. Paul M. Voyles Prof. Jeffrey Greeley Prof. Manos Mavrikakis Prof. Susannah L. Scott Prof. Thomas F. Kuech Prof. James A. Dumesic 《Angewandte Chemie (International ed. in English)》2013,52(51):13824-13824
75.
By means of a local integral formula on a maximal surface, which involves the hyperbolic angle between the unit normal vector
field and a fixed timelike direction, we give a new proof of the parametric Calabi-Bernstein theorem. A suitable modification
of the integral formula gives an independent proof to the non-parametric case of this result. 相似文献
76.
Silver was introduced into medieval glass by an ancient painting process using different clay minerals (ochre, illitic, montmorillonitic, and kaolinitic clays). The colorimetric properties, studied by UV-Vis spectroscopy, were dependent on the clay mineral as a result of different concentration of Ag ions diffused into the glass surface. TEM results showed the well known formation of silver nanoclusters which give the yellow coloration of the glass. The obtained results showed that clay properties such as specific surface area, pore volume and iron concentration (Fe2O3), are important factors that affect the yellow coloration. It is also observed that Fe2O3 acts as an oxidant agent for silver atoms providing the Ag2O formation. This oxide cannot diffuse into the glass structure and avoid the ion-exchanged process. After Ag ion diffusion some structural changes occur in the glass as it has been shown by Raman spectroscopy. It is observed that the diffusion process leads to depolymerization of the glass network as it is determined by analyzing the Qn components of Raman spectra. Two Raman bands at 148 and 244 cm−1 assigned to Ag-O bonds can be associated to the presence of Ag2O on the glass painted surface. 相似文献
77.
Alan R. Katritzky Kenneth C. Caster Olga Rubio Otto Schwarz 《Journal of heterocyclic chemistry》1986,23(5):1315-1325
Derivatives of four series of compounds derived from isomers of indoxyl with the nitrogen at the bridgehead and two further series of aza-analogues are prepared and their absorption properties studied. 相似文献
78.
Cristina Santamaría Beln García-Mora Gregorio Rubio Enrique Navarro 《Mathematical and Computer Modelling》2009,50(5-6):726
A Markovian approach to analyze different states of the superficial vesical carcinoma is considered, taking into account up to two recurrences and the possibility of progression. So, three transient states are considered: free of disease, first, and second recurrence; and an absorbent state, the progression. A methodology based in phase-type distributions is also used, that allows the usual quantities of interest in survival studies to be expressed in a well-structured form. This type of distribution has shown its utility in queue theory, and has the advantage that mathematical expressions can be presented in a closed form that allows algebraic treatment. 相似文献
79.
The objective of this work is to investigate through the numeric simulation, the effects of the weakly viscoelastic flow within a rotating rectangular duct subject to a buoyancy force due to the heating of one of the walls of the duct. A direct velocity–pressure algorithm in primitive variables with a Neumann condition for the pressure is employed. The spatial discretization is made with finite central differences on a staggered grid. The pressure field is directly updated without any iteration. Numerical simulations were done for several Weissemberg numbers (We) and Grashof numbers (Gr) . The numerical results show that for high Weissemberg numbers (We>7.4 × 10?5) and for ducts with aspect ratio 2:1 and 8:1, the secondary flow is restabilized with a stretched double vortex configuration. It is also observed that when the Grashof number is increased (Gr>17 × 10?4) , the buoyancy force neutralizes the effects of the Coriolis force for ducts with aspect ratio 8:1. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献