Observation of two resonant structures in e+ e- -->pi+ pi- psi(2S) via initial-state radiation at Belle

The cross section for e+ e- --> pi+ pi- psi(2S) between threshold and sqrt[s]=5.5 GeV is measured using 673 fb(-1) of data on and off the Upsilon(4S) resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the pi+ pi- psi(2S) invariant-mass distribution, one at 4361 +/- 9 +/- 9 MeV/c2 with a width of 74 +/- 15 +/- 10 MeV/c2, and another at 4664 +/- 11 +/- 5 MeV/c2 with a width of 48 +/- 15 +/- 3 MeV/c2, if the mass spectrum is parametrized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.     

One-dimensional structures of Bi2O3 synthesized via metalorganic chemical vapor deposition process

We have demonstrated the synthesis of one-dimensional (1D) structures of bismuth oxide (Bi₂O₃) by a reaction of a trimethylbismuth (TMBi) and oxygen (O₂) mixture at 450 °C. Scanning electron microscopy showed that the product consisted of 1D materials with width or diameters less than 1 μm and lengths up to several tens of micrometers. The X-ray energy dispersive spectroscopy revealed that the materials contained elements of Bi and O. The results of X-ray diffraction and selected area electron diffraction pattern indicated that the obtained Bi₂O₃ were crystalline with monoclinic structure.     

Phase transformation of Ni-B, Ni-P diffusion barrier deposited electrolessly on Cu interconnect

In this paper, we report that the phase transformation of Ni-B, Ni-P diffusion barriers deposited electrolessly on Cu, for the reason that the Ni-P layer is a more effective diffusion barrier than the Ni-B layer. The Ni₃B crystallized was decomposed to Ni and B₂O₃ above 400 °C and the Ni₃P crystallized was decomposed to Ni and P₂O₅ above 600 °C respectively in Ar atmosphere. Also, the Ni₃B was decomposed to Ni and free B above 400 °C and the Ni₃P was decomposed to Ni and free P above 600 °C respectively in H₂ atmosphere. The decomposed Ni formed a solid solution with Cu. The Cu diffusion occurred above 400 °C for Ni-B layer and above 600 °C for Ni-P layer, respectively. Because the decomposition temperature of Ni-P layer is about 200 °C higher than that of Ni-B layer, the Ni-P layer is a more effective barrier for Cu than the Ni-B layer.     

Global symmetry breaking in the nonconserved order parameter system during phase ordering

We study global symmetry breaking in the 2D system of scalar nonconserved order parameter following a quench to zero temperature. We show that the instant of time when the symmetry is broken and the final morphology is chosen corresponds to the saturation of the order parameter inside the domains. There are three possible final morphologies: the positive and negative order parameter final morphology, and the state of the coexisting positive and negative order parameter subsystems with a flat interface between them. We find also that each type of the final morphology constitutes about 1/3 of all cases, what agrees with the results obtained recently by Spirin et al. [Phys. Rev. E 65, 016119 (2001)]. Our results are pertinent for the two dimensional systems, but we suspect that there is also a way to apply similar arguments for the three dimensional ones.     

Micellar core-shell-type acrylic-polyurethane hybrid materials with self-polishing property

Abstract

Marine fouling can be a serious problem in the shipping industry, since it increases the surface roughness of the hull and hence its frictional resistance to its movement through water. Antifouling paint can be defined as preventing the attachment of marine organisms onto surfaces. However, the most commonly used antifouling coating which is the tributyltin-based self-polishing copolymer causes the severe pollution of marine environment. Ammonium salt-based paints include tertiary amines as biocides which have effective biocidal and biodegradable properties without accumulation in the sea environment. However, ammonium salt-based coatings were too sensitive to seawater and became swollen. In this study, polyurethane-acrylic copolymers were synthesized by radical polymerization. These hybrid materials were found to form core–shell structures in aqueous media. Synthesis and properties of copolymers were investigated by Fourier transform-infrared spectrometer, proton-nuclear magnetic resonance, transmission electron microscopy, and dynamic light scattering. The polishing rate of self-polishing copolymer was determined from the reduction in dry film thickness after artificial seawater immersion under a dynamic condition.     

Recreational runners with patellofemoral pain exhibit elevated patella water content

Increased bone water content resulting from repetitive patellofemoral joint overloading has been suggested to be a possible mechanism underlying patellofemoral pain (PFP). To date, it remains unknown whether persons with PFP exhibit elevated bone water content. The purpose of this study was to determine whether recreational runners with PFP exhibit elevated patella water content when compared to pain-free controls. Ten female recreational runners with a diagnosis of PFP (22 to 39 years of age) and 10 gender, age, weight, height, and activity matched controls underwent chemical-shift-encoded water-fat magnetic resonance imaging (MRI) to quantify patella water content (i.e., water-signal fraction). Differences in bone water content of the total patella, lateral aspect of the patella, and medial aspect of the patella were compared between groups using independent t tests. Compared with the control group, the PFP group demonstrated significantly greater total patella bone water content (15.4 ± 3.5% vs. 10.3 ± 2.1%; P = 0.001), lateral patella water content (17.2 ± 4.2% vs. 11.5 ± 2.5%; P = 0.002), and medial patella water content (13.2 ± 2.7% vs. 8.4 ± 2.3%; P < 0.001). The higher patella water content observed in female runners with PFP is suggestive of venous engorgement and elevated extracellular fluid. In turn, this may lead to an increase in intraosseous pressure and pain.     

Superhigh numerical aperture (NA > 1.5) micro gradient-index lens based on a dual-material approach

We describe a novel scheme for obtaining a superhigh numerical aperture gradient-index (SHNA GRIN) lens from multiple thin layers of two or more materials with large refractive-index contrast. Design procedures for the lens are described, including variation of the layer thickness to achieve focusing and of the thickness limit to reduce scattering loss. We use an exact numerical solution by the finite-difference time-domain method to evaluate the lens's performance. Specific examples of a SHNA GRIN lens with a SiO2-TiO2 material system designed for fiber coupling to a nanowaveguide are shown to have focusing FWHM spot sizes of 0.53-0.7 microm at lambda =1.55 microm (corresponding to a NA of approximately 1.6-1.1) with 2.7-2.4% more loss than an ideal continuous index profile GRIN lens. With this approach, a SHNA GRIN lens with a NA of > 1.5 and a length of <20 microm can be achieved with currently available thin-film deposition techniques.     

The SN3–SN2 spectrum. Rate constants and product selectivities for solvolyses of benzenesulfonyl chlorides in aqueous alcohols

Rate constants for a wide range of binary aqueous mixtures and product selectivities (S) in ethanol–water (EW) and methanol–water (MW) mixtures, are reported at 25 °C for solvolyses of benzenesulfonyl chloride and the 4‐chloro‐derivative. S is defined as follows using molar concentrations: S = ([ester product]/[acid product]) × ([water solvent]/[alcohol solvent]). Additional selectivity data are reported for solvolyses of 4‐Z‐substituted sulfonyl chlorides (Z = OMe, Me, H, Cl and NO₂) in 2,2,2‐trifluoroethanol–water. To explain these results and previously published data on kinetic solvent isotope effects (KSIEs) and on other solvolyses of 4‐nitro and 4‐methoxybenzenesulfonyl chloride, a mechanistic spectrum involving a change from third order to second order is proposed. The molecularity of these reactions is discussed, along with new term ‘S_N3–S_N2 spectrum’ and its connection with the better established term ‘S_N2–S_N1 spectrum’. Copyright © 2009 John Wiley & Sons, Ltd.     

Luminescence enhancement of Eu-doped calcium magnesium silicate blue phosphor for UV-LED application

(Ca_1−x,Eu_x)MgSi_2yO_6+δ blue phosphor was prepared by spray pyrolysis and the photoluminescence properties were optimized by controlling concentration of Si element and the activator content. At y=1.0, the concentration quenching in the luminescent intensity appeared when the Eu²⁺ content (x) was 0.01 (1 at%). Such quenching concentration was changed with the concentration of silicon (y), which was increased with an increase in the quantity of excess Si (y>1.0). The highest luminescent intensity was achieved when the Eu²⁺ content (x) and the Si concentration (y) were 0.04 and 1.3, respectively. According to X-ray diffraction (XRD) analysis, the tetragonal SiO₂ phase was formed as a minor phase when the y value was larger than 1.3. The formation of SiO₂ phase, however, did not reduce but increased the luminescent intensity when the Eu²⁺ content was optimized again. As a result, the luminescent intensity of the phosphor particles optimized in the content of both Si and Eu²⁺ was about 150% improved compared with that of the CaMgSi₂O₆:Eu sample (x=0.01, y=1.0).