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81.
O. Manuel 《Physics of Atomic Nuclei》2004,67(11):1959-1962
Measurements are needed of low-energy antineutrinos generated by possible neutron decay at the core of the Sun. The measurement will test the validity of a proposal that solar luminosity, solar neutrinos, and the outpouring of H+ ions from the solar surface are the products of a chain of reactions triggered by neutron emission from the solar core. Inverse β decay of 87-d 35S, induced by capture of low-energy antineutrinos on 35Cl, is a likely candidate for this measurement. 相似文献
82.
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
83.
A numerical investigation has been carried out to examine the electrostatic loss of nanoparticles in a corona needle charger.
Two-dimensional flow field, electric field, particle charge, and particle trajectory were simulated to obtain the electrostatic
deposition loss at different conditions. Simulation of particle trajectories shows that the number of charges per particle
during the charging process depends on the particle diameter, radial position from the symmetry axis, applied voltage, Reynolds
number, and axial distance along the charger. The numerical results of nanoparticle electrostatic loss agreed fairly well
with available experimental data. The results reveal that the electrostatic loss of nanoparticles increases with increasing
applied voltage and electrical mobility of particles; and with decreasing particle diameter and Reynolds number. A regression
equation closely fitted the obtained numerical results for different conditions. The equation is useful for directly calculating
the electrostatic loss of nanoparticles in the corona needle charger during particle-charging process. 相似文献
84.
Guadalupe Valverde-Aguilar Jorge A. García-Macedo Víctor M. Rentería-Tapia Raúl W. Gómez Manuel Quintana-García 《Journal of nanoparticle research》2011,13(10):4613-4622
Hexagonal mesostructured films containing silver ions were obtained by sol–gel method. Brij 58 was used to produce channels
into the film, which house these ions. The films were exposure to UV radiation to produced silver metallic nanoparticles.
The presence of the metallic nanoparticles was determined by infrared spectroscopy and optical absorption. Besides, these
nanoparticles and core–shell structures of silver–silver oxide nanoparticles were identified by high-resolution transmission
electronic microscopy. From these measurements, the obtained size range for silver nanoparticles was 6.1 nm. The absorption
spectrum located at 440 nm was modelled and well fitted with the Gans theory considering refractive index higher than the
one coming from host matrix. This index is explained because the silver oxide shell modifies the local surrounding medium
of the metallic nanoparticles. 相似文献
85.
Accurate control of a liquid-crystal display to produce a homogenized Fourier transform for holographic memories 总被引:1,自引:0,他引:1
Márquez A Gallego S Méndez D Alvarez ML Fernández E Ortuño M Neipp C Beléndez A Pascual I 《Optics letters》2007,32(17):2511-2513
We show an accurate procedure to obtain a Fourier transform (FT) with no dc term using a commercial twisted-nematic liquid-crystal display. We focus on the application to holographic storage of binary data pages, where a drastic decrease of the dc term in the FT is highly desirable. Two different codification schemes are considered: binary pi radians phase modulation and hybrid ternary modulation. Any deviation in the values of the amplitude and phase shift generates the appearance of a strong dc term. Experimental results confirm that the calculated configurations provide a FT with no dc term, thus showing the effectiveness of the proposal. 相似文献
86.
Given a Kähler manifold M endowed with a Hamiltonian Killing vector field Z, we construct a conical Kähler manifold ${\hat{M}}$ such that M is recovered as a Kähler quotient of ${\hat{M}}$ . Similarly, given a hyper-Kähler manifold (M, g, J 1, J 2, J 3) endowed with a Killing vector field Z, Hamiltonian with respect to the Kähler form of J 1 and satisfying ${\mathcal{L}_ZJ_2 = -2J_3}$ , we construct a hyper-Kähler cone ${\hat{M}}$ such that M is a certain hyper-Kähler quotient of ${\hat{M}}$ . In this way, we recover a theorem by Haydys. Our work is motivated by the problem of relating the supergravity c-map to the rigid c-map. We show that any hyper-Kähler manifold in the image of the c-map admits a Killing vector field with the above properties. Therefore, it gives rise to a hyper-Kähler cone, which in turn defines a quaternionic Kähler manifold. Our results for the signature of the metric and the sign of the scalar curvature are consistent with what we know about the supergravity c-map. 相似文献
87.
88.
José Maria Esbrí Anna Bernaus Marta ávila David Kocman Eva M. García‐Noguero Beatriz Guerrero Xavier Gaona Rodrigo álvarez Gustavo Perez‐Gonzalez Manuel Valiente Pablo Higueras Milena Horvat Jorge Loredo 《Journal of synchrotron radiation》2010,17(2):179-186
The mobility, bioavailability and toxicity of mercury in the environment strongly depend on the chemical species in which it is present in soil, sediments, water or air. In mining districts, differences in mobility and bioavailability of mercury mainly arise from the different type of mineralization and ore processing. In this work, synchrotron‐based X‐ray absorption near‐edge spectroscopy (XANES) has been taken advantage of to study the speciation of mercury in geological samples from three of the largest European mercury mining districts: Almadén (Spain), Idria (Slovenia) and Asturias (Spain). XANES has been complemented with a single extraction protocol for the determination of Hg mobility. Ore, calcines, dump material, soil, sediment and suspended particles from the three sites have been considered in the study. In the three sites, rather insoluble sulfide compounds (cinnabar and metacinnabar) were found to predominate. Minor amounts of more soluble mercury compounds (chlorides and sulfates) were also identified in some samples. Single extraction procedures have put forward a strong dependence of the mobility with the concentration of chlorides and sulfates. Differences in efficiency of roasting furnaces from the three sites have been found. 相似文献
89.
José Ernesto Falcón Dieguez Pablo Rodi Manuel A. Lores Guevara Ana Maria Gennaro 《Applied magnetic resonance》2010,38(4):443-453
An enhanced hemoglobin–membrane association has been previously documented in sickle cell anemia. However, it is not known
how this interaction is modified during the hemoglobin S polymerization process. In this work, we use a model of reconstituted
erythrocytes from ghost membranes whose cytoskeleton proteins had been previously labeled with the 4-maleimido Tempo spin
label, and that were subsequently resealed with hemoglobin S or A solutions. Using electron paramagnetic resonance spectroscopy,
we studied the time dependence of the spectral W/S parameter, indicative of the conformational state of cytoskeleton proteins
(mainly spectrin) under spontaneous deoxygenation, with the aim of detecting the eventual effects due to hemoglobin S polymerization.
The differences observed in the temporal behavior of W/S in erythrocytes reconstituted with both hemoglobins were considered
as experimental evidence of an increment in hemoglobin S–membrane interaction as a result of the polymerization process of
hemoglobin S under spontaneous deoxygenation. 相似文献
90.
Antonio Ramos Pablo García-Sánchez Andrea Robles Manuel J. Freire 《Journal of Electrostatics》2009,67(2-3):377-380
AC electric fields are of increasing importance for the generation of fluid flows in microsystems. We analyse numerically the use of AC electric fields at microwave frequencies for electro-thermal actuation of water in microdevices. Water is heated because of its significant dielectric loss at microwave frequencies. Buoyancy and dielectric forces actuate in the liquid bulk, and the relative importance between them is studied. The microwave liquid actuation can be used for pure water as well as for water saline solutions, such as bio-fluids. Therefore, it is of interest for the Lab-on-a-Chip technology. 相似文献