Diffraction theory of an anisotropic circular cylinder

A fully analytical theory is developed to derive the field diffracted by an infinitely long circular cylinder made of an arbitrary anisotropic homogeneous material, illuminated by an arbitrary plane wave.     

Simulation of two-dimensional Kerr photonic crystals via fast Fourier factorization

We present an adaptation of the fast Fourier factorization method to the simulation of two-dimensional (2D) photonic crystals with a third-order nonlinearity. The algorithm and its performance are detailed and illustrated via the simulation of a Kerr 2D photonic crystal. A change in the transmission spectrum at high intensity is observed. We explain why the change does not reduce to a translation (redshift) but rather consists in a deformation and why one side of the bandgap is more suited to a switching application than the other one.     

Analytical expressions for the longitudinal evolution of nondiffracting pulses truncated by finite apertures

Starting from some general and plausible assumptions based on geometrical optics and on a common feature of the truncated Bessel beams, a heuristic derivation is presented of very simple analytical expressions capable of describing the longitudinal (on-axis) evolution of axially symmetric nondiffracting pulses truncated by finite apertures. The analytical formulation is applied to several situations involving subluminal, luminal, or superluminal localized pulses, and the results are compared with those obtained by numerical simulations of the Rayleigh-Sommerfeld diffraction integrals. The results are in excellent agreement. The present approach can be rather useful, because it yields, in general, closed-form expressions, avoiding the need for time-consuming numerical simulations, and also because such expressions provide a powerful tool for exploring several important properties of the truncated localized pulses, such as their depth of fields, the longitudinal pulse behavior, and the decaying rates.     

Extracellular and intracellular volume variations during postural change measured by segmental and wrist-ankle bioimpedance spectroscopy

Extracellular (ECW) and intracellular (ICW) volumes were measured using both segmental and wrist-ankle (W-A) bioimpedance spectroscopy (5-1000 kHz) in 15 healthy subjects (7 men, 8 women). In the 1st protocol, the subject, after sitting for 30 min, laid supine for at least 30 min. In the second protocol, the subject, who had been supine for 1 hr, sat up in bed for 10 min and returned to supine position for another hour. Segmental ECW and ICW resistances of legs, arms and trunk were measured by placing four voltage electrodes on wrist, shoulder, top of thigh and ankle and using Hanai's conductivity theory. W-A resistances were found to be very close to the sum of segmental resistances. When switching from sitting to supine (protocol 1), the mean ECW leg resistance increased by 18.2%, that of arm and W-A by 12.4%. Trunk resistance also increased but not significantly by 4.8%. Corresponding increases in ICW resistance were smaller for legs (3.7%) and arm (-0.7%) but larger for the trunk (21.4%). Total body ECW volumes from segmental measurements were in good agreement with W-A and Watson anthropomorphic correlation. The decrease in total ECW volume (when supine) calculated from segmental resistances was at 0.79 l less than the W-A one (1.12 l). Total ICW volume reductions were 3.4% (segmental) and 3.8% (W-A). Tests of protocol 2 confirmed that resistance and fluid volume values were not affected by a temporary position change.     

Pulsed Laser Deposition of Zr1-xCexO2 and Ce1-xLaxO2-x/2 for Buffer Layers and Insulating Barrier in Oxide Heterostructures

We have studied the pulsed laser deposition (PLD) of Zr_1-xCexO₂ and Ce_1-xLa_xO₂-x/2 initially to grow buffer layers for perovskite films deposited on Si, LaAlO₃, SrTiO₃ and MgO and then to produce tunneling barriers for cuprate or manganite heterostructures. On (1 0 0) Si, the deposition of Zr_1-xCexO₂ (x = 0.12) produces a smooth epitaxial layer (R _RMS = 0.25/1m²), which allows the further deposition of high quality YBa₂Cu₃O₇ (Tc 88 K) and La_0.7Sr_0.3MnO₃ films. On the other hand, the use of Ce_1-xLa_xO_2-x/2 (0 x 0.4) makes it possible to match the YBa₂Cu₃O₇ and La_0.7Sr_0.3MnO₃ layers to various substrates. The buffer layers are epitaxially grown with a 45° rotation of the in-plane axes with respect to those of the substrate, and the smoothness is high (R _RMS = 0.25/1m²). In the case of an ultra-thin barrier (2.5 nm) of Ce_1-xLa_xO_2-x/2 sandwiched in a La_0.7Sr_0.3MnO₃, the out-of-plane mismatch of 2 induces distortions at the interface steps, which propagate into the topmost La_0.7Sr_0.3MnO₃ layer. This is in contrast to the case of SrTiO₃ barriers where an ideal crystal continuity in the growth direction is observed.     

Reactive and proactive aggression: Evidence of a two-factor model.

This article examines the construct validity of reactive and proactive aggression, as assessed by the teacher-rating scale developed by K. A. Dodge and J. D. Coie (1987). In Study 1 (n?=?149 boys), confirmatory factor analyses revealed that a 2-factor model, in which a substantial correlation was observed between the 2 latent factors, presented a better fit than a single-factor model. Study 2 (n?=?193 boys) examined the relations presented by the 2 forms of aggression with peer status, leadership, social withdrawal, and victimization by peer. Reactive and proactive aggressive behaviors presented distinct patterns of relations consistent with the theoretical definitions. The results of these studies suggest that the questionnaire measures 2 forms of aggressive behavior that, although being substantially related, have a unique discriminant dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Er-doped polycrystalline silicon for light emission at λ=1.54 µm

We deposited amorphous silicon films, implanted them with erbium/oxygen, and then recrystallized them with a series of thermal treatments. Recrystallization is necessary to remove implantation damage and optically activate Er/O complexes for light emission at 1.54 μm. Photoluminescence and glancing angle x-ray diffraction were used to characterize the polycrystalline Si:Er. Following 30-minute isochronal anneals and isothermal anneals at 575°C and 600°C, the erbium luminescence intensity was observed to increase in direct relation to the degree of recrystallization during the anneal. Hydrogen passivation of dangling bonds further increased the luminescence intensity to about one half of the intensity found in a comparable single crystal material. The optically active Er is shown to be located within the recrystallized grains, and it exhibits a de-excitation (backtransfer) mechanism similar to that of single crystal Si:Er.