Finite state bilaterally deterministic strongly mixing processes

Triviality of the two-sided tail field of a stationary process is not an invariant property under factorization ([4]). In this paper we give an example of a bilaterally deterministic process with finitely many states which is strongly mixing. This extends and complements a result of Bradley ([1]).     

The millimeter wave rotational spectrum of N-cyanomethanimine,CH2NCN

The rotational spectrum of the short-lived species N-cyanomethanimine, CH₂NCN, has been measured in the frequency range 100–250 GHz. The observed transitions allow the determination of the rotational and centrifugal distortion constants and the nitrogen quadrupole coupling constants for both nitrogen nuclei. The N-cyanomethanimine spectrum was measured directly in the products of the pyrolysis of trimethylenetetrazole. The rotational constants obtained are A = 63 372.995(11) MHz, B = 5 449.347 90(28) MHz, and C = 5 009.559 86(29) MHz; the quadrupole coupling constants are χ_aa = 2.057(39) MHz and χ_bb ? χ_cc = ?7.205(21) MHz for the imine nitrogen, and χ_aa = ?3.264(33) MHz and χ_bb ? χ_cc = ?1.630(18) MHz for the cyano-group nitrogen. The accurate constants obtained allow the calculation of the line position and hyperfine structure of any rotational transition appropriate for a radioastronomical search.     

Endolaryngeal contact pressures

In this work, we present a new method for in vivo endolaryngeal contactpressure measurement with a miniature pressure transducer. Using this methodology, contact pressures can be measured during videoendoscopy at different locations between the artyenoids and also at various locations along the membranous vocal folds. Twenty adults with organic and functional voice disorders and two vocally healthy adults participated as subjects. Endolaryngeal contact pressure measures were made during a series of phonatory tasks varying pitch, loudness, and phonatory onset and offset. Measures were also made during nonphonatory tasks, including throat clearing, coughing, Valsalva maneuvres, and gagging. The most remarkable findings were: (1) interarytenoid contact pressures were considerably greater than intraglottal contact pressures; (2) interarytenoid contact pressures were greater for lower than higher pitches; (3) both interarytenoid and intraglottal contact pressures were remarkably large during hard glottal attack; and (4) overall, the largest endolaryngeal pressures were recorded between the arytenoids, during a thoracic fixation maneuver and during gag reflex.This work was supported in part by Deutsche Forschungsgemeinschaft (He 2869/1-1), by a grant from the “Verein zur Förderung hör-, sprach- und stimmgestörter Patienten an der FU Berlin e.V.” (nonprofit organization), Berlin, Germany, and by Grant No. K08 DC00139 from the National Institute on Deafness and Other Communication Disorders.     

Tailoring of high-Q-factor surface plasmon modes on silver microtubes

We investigate the excitation of surface plasmon polaritons on silver tubes with finite-difference time-domain simulations. These surface plasmon polaritons exhibit azimuthal whispering gallery modes with quality factors in the hundreds. We show that the high quality factors arise from the coupling of the surface plasmon modes to photonic modes inside the tube. We examine the influence of a gain material on the quality factors and find that for material data of rhodamine 6G, the quality factors are enhanced significantly up to values of 3000.     

Bending insensitivity of fiber Bragg gratings in suspended-core optical fibers

This Letter presents simulation and experimental results that explore bending insensitivity of fiber Bragg gratings in suspended-core optical fibers. The implementation of thin silica bridge in the fibers enhances index contrast of the fiber core and reduces bending-induced strain transfer to the fiber core. This fiber design lead to a reduction of over 7 times in strain-induced fiber Bragg grating resonant peak shifts in the suspended-core fiber compared with that in standard telecommunication fiber, and an 0.14 dB bending loss at a bending radius of 6.35 mm.     

Fe valence state at the surface of the Fe0.5Cu0.5Cr2S4 spinel

Here we present X‐ray absorption measurements of a vacuum cleaved Fe_0.5Cu_0.5Cr₂S₄ single crystal. Measurements at different positions on the cleaved sample surface clearly reveal a difference between the valence state of the Fe ions in the sur‐ face layers and the valency of the Fe ions present in the bulk. These results confirm the findings of recent measurements outlined previously. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Local optical properties, electron densities, and london dispersion energies of atomically structured grain boundaries

Quantitative analysis of spatially resolved valence electron energy-loss spectra shows strong physical property contrasts for Sigma5 and near Sigma13 grain boundaries in Fe-doped SrTiO3, resulting in London dispersion interaction energies of 14 to 50 mJ/m(2) between the adjacent grains. The determination of local physical properties of grain boundary cores and the appreciable contribution of long-range London dispersion to interface energies provides new information on formation and control of interfaces in materials.