Properties of the scalar mesons f0(1370)f_0(1370), f0(1500)f_0(1500) and f0(1710)f_0(1710)

In the three-state mixing framework, considering the possible glueball components of $\eta$ and $\eta^\prime$, we investigate the hadronic decays of $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ into two pseudoscalar mesons. The quarkonia-glueball content of the three states is determined from the fit to the new data presented by the WA102 Collaboration. We find that these data are insensitive to the possible glueball components of $\eta$ and $\eta^\prime$. Furthermore, we discuss some properties of the mass matrix describing the mixing of the isoscalar scalar mesons.Comment: Latex 14 pages including 1 eps figur

Phenylboronic acid-diol crosslinked 6-<i>O</i>-vinylazeloyl-d-galactose nanocarriers for insulin delivery

A new block polymer named poly 3-acrylamidophenylboronic acid-b-6-O–vinylazeloyl-d-galactose (p(AAPBA-b-OVZG)) was prepared using 3-acrylamidophenylboronic acid (AAPBA) and 6-O-vinylazeloyl-D-galactose (OVZG) via a two-step procedure involving S-1-dodecyl-S-(α', α'-dimethyl-α″-acetic acid) trithiocarbonate (DDATC) as chain transfer agent, 2,2-azobisisobutyronitrile (AIBN) as initiator and dimethyl formamide (DMF) as solvent. The structures of the polymer were examined by Fourier transform infrared spectroscopy (FT-IR) and 1H NMR and the thermal stability was determined by thermal gravimetric analysis (TG/DTG). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were utilized to evaluate the morphology and properties of the p(AAPBA-b-OVZG) nanoparticles. The cell toxicity, animal toxicity and therapeutic efficacy were also investigated. The results indicate the p(AAPBA-b-OVZG) was successfully synthesized and had excellent thermal stability. Moreover, the p(AAPBA-b-OVZG) nanoparticles were submicron in size and glucose-sensitive in phosphate-buffered saline (PBS). In addition, insulin as a model drug had a high encapsulation efficiency and loading capacity and the release of insulin was increased at higher glucose levels. Furthermore, the nanoparticles showed a low-toxicity in cell and animal studies and they were effective at decreasing blood glucose levels of mice over 96 h. These p(AAPBA-b-OVZG) nanoparticles show promise for applications in diabetes treatment using insulin or other hypoglycemic proteins

A proposal on the search for the hybrid with IG(JPC)=1−(1−+)I^G(J^{PC})=1^-(1^{-+}) in the process J/ψ→ρωππJ/\psi\to\rho\omega\pi\pi at upgraded BEPC/BES

The moment expressions for the boson resonances X with spin-parity 0++, 1-+, 1++, and 2++ possibly produced in the process $J/\psi\to\rho X$, $X\to b_1(1235)\pi$, $b_1\to \omega \pi$ are given in terms of the generalized moment analysis method. The 1-+ resonance can be distinguished from other resonances by means of these moments except for some rather special cases. The suggestion that the search for the 1-+ hybrid can be performed in the above decay channel at upgraded BEPC/BES is presented.Comment: Latex 13 pages, no figur

On the mass relation of a meson nonet

It is pointed out that the omission of the effects of the transition between quarkonia or the assumption that the transition between quarkonia is flavor-independent would result in the inconsistent results for the pseudoscalar meson nonet. It is emphasized that the mass relation of the non-ideal mixing meson nonets should incorporate the effects of the flavor-dependent transition between quarkonia. The new mass relations of a meson nonet are presented.Comment: Latex, 10 pages, to appear in Mod. Phys. Lett.

Thermal-Mechanical Properties of Polyurethane-Clay Shape Memory Polymer Nanocomposites

Shape memory nanocomposites of polyurethane (PU)-clay were fabricated by melt mixing of PU and nano-clay. Based on nano-indentation and microhardness tests, the strength of the nanocomposites increased dramatically as a function of clay content, which is attributed to the enhanced nanoclay–polymer interactions. Thermal mechanical experiments demonstrated good mechanical and shape memory effects of the nanocomposites. Full shape memory recovery was displayed by both the pure PU and PU-clay nanocomposites.

Effects of Flavor-dependent qqˉq\bar{q} Annihilation on the Mixing Angle of the Isoscalar Octet-Singlet and Schwinger's Nonet Mass Formula

By incorporating the flavor-dependent quark-antiquark annihilation amplitude into the mass-squared matrix describing the mixing of the isoscalar states of a meson nonet, the new version of Schwinger's nonet mass formula which holds with a high accuracy for the $0^{-+}$, $1^{--}$, $2^{++}$, $2^{-+}$ and $3^{--}$ nonets is derived and the mixing angle of isoscalar octet-singlet for these nonets is obtained. In particular, the mixing angle of isoscalar octet-singlet for pseudoscalar nonet is determined to take the value of $-12.92^\circ$, which is in agreement with the value of $-13^\circ\sim-17^\circ$ deduced from a rather exhaustive and up-to-date analysis of data. It is also pointed out that the omission of the flavor-dependent $q\bar{q}$ annihilation effect might be a factor resulting in the invalidity of Schwinger's original nonet mass formula for pseudoscalar nonet.Comment: Latex, 7 page

Study of Ionic Conductivity Profiles of the Air Cathode of a PEMFC by AC Impedance Spectroscopy

A characterization of the ionic conduction of the active layer of a polymer electrolyte membrane fuel cell (PEMFC) cathode by ac impedance measurement at open-circuit potential conditions was conducted. Porous electrode theory was used to derive a compact equation, ∂2Φ̑2/∂y2+∂lnf(y)/∂y×∂Φ̑2/∂y−R/f(y)(1+jΩ)Φ̑2=0, to solve for the impedance response of a cathode at open-circuit potential conditions. This equation includes a parameter R, the ratio of an ionic resistance (evaluated at the active layer/membrane interface), to the total charge-transfer resistance of the active layer. The influence of an assumed ionic conductivity distribution profile f(y) on the error in the estimation of total double-layer capacitance of the active layer from the −1/(ZImω) vs. ZRe plot was also investigated in this work. The increase of ionic conductivity in the active layer of an air cathode with an increase in the ionomer loading was revealed from both impedance data and surface area measurements. A nonlinear parameter estimation method was used to extract the ionic resistance from the high-frequency region of the impedance data at open-circuit potential conditions. The assumed ionic conductivity distribution profile in the active layer was found to vary with ionomer loadings