Effect of the Interfacial Transition Zone on Basic Mechanical Properties of a Solid Composite Propellant

The evaluation of basic mechanical properties are shown to be of importance for the solid composite propellant development and application. The numerical analysis approach termed the three-phase Voronoi cell finite element method, was proposed to evaluate of the interfacial transition zone effect. Numerical results showed that the performance of the effective modulus could be essentially enhanced by increasing the zone thickness. The module of the composite with the inhomogeneous zone was higher than that of the composite with the homogeneous one. The effect of different zones on volume fractions and matrix moduli was also calculated. The Voronoi method can also be helpful for analyzing the characteristic properties of other three-phase composites.Определение основных механических характеристик играет важную роль в разработке и применении композитного твердого ракетного топлива. Предложен численный метод, получивший название “трехфазный метод конечных элементов ячейки Вороного”, для оценки влияния зоны межфазного перехода. Численные результаты показывают, что эффективный модуль можно улучшить, увеличив толщину зоны межфазного перехода. Модуль композита с неоднородной зоной межфазного перехода выше такового с однородной зоной межфазного перехода. Рассчитано влияние различных зон межфазного перехода на объемные доли и модули матрицы. Для анализа характеристических свойств других трехфазных композитов также можно использовать трехфазный метод конечных элементов ячейки Вороного

The open-charm radiative and pionic decays of molecular charmonium Y(4274)

In this work, we investigate the decay widths and the line shapes of the open-charm radiative and pionic decays of Y(4274) with the $D_s\bar{D}_{s0}(2317)$ molecular charmonium assignment. Our calculation indicates that the decay widths of $Y(4274)\to D^{+}_{s}D^{*-}_{s}\gamma$ and $Y(4274)\to D^+_{s}D^-_{s}\pi^0$ can reach up to 0.05 keV and 0.75 keV, respectively. In addition, the result of the line shape of the photon spectrum of $Y(4274)\to D_s^+ {D}_s^{*-} \gamma$ shows that there exists a very sharp peak near the large end point of photon energy. The line shape of the pion spectrum of $Y(4274)\to D_s^+ {D}_s^{*-} \pi^0$ is similar to that of the pion spectrum of $Y(4274)\to D_s^+ {D}_s^{*-} \gamma$, where we also find a very sharp peak near the large end point of pion energy. According to our calculation, we suggest further experiments to carry out the search for the open-charm radiative and pionic decays of Y(4274).Comment: 7 pages, 6 figures, 1 table. Published versio

On the energy functional on Finsler manifolds and applications to stationary spacetimes

In this paper we first study some global properties of the energy functional on a non-reversible Finsler manifold. In particular we present a fully detailed proof of the Palais--Smale condition under the completeness of the Finsler metric. Moreover we define a Finsler metric of Randers type, which we call Fermat metric, associated to a conformally standard stationary spacetime. We shall study the influence of the Fermat metric on the causal properties of the spacetime, mainly the global hyperbolicity. Moreover we study the relations between the energy functional of the Fermat metric and the Fermat principle for the light rays in the spacetime. This allows us to obtain existence and multiplicity results for light rays, using the Finsler theory. Finally the case of timelike geodesics with fixed energy is considered.Comment: 23 pages, AMSLaTeX. v4 matches the published versio

Knockout of p75 neurotrophin receptor attenuates the hyperphosphorylation of Tau in pR5 mouse model

p75 neurotrophin receptor (p75NTR) has been implicated in Alzheimer's disease (AD). However, whether p75NTR is involved in Tau hyperphosphorylation, one of the pathologies observed in AD, remains unclear. In our previous study, the extracellular domain of p75NTR blocked amyloid beta (Aβ) toxicity and attenuated Aβ-induced Tau hyperphosphorylation. Here we show that, in the absence of Aβ, p75NTR regulates Tau phosphorylation in the transgenic mice with the P301L human Tau mutation (pR5). The knockout of p75NTR in pR5 mice attenuated the phosphorylation of human Tau. In addition, the elevated activity of kinases responsible for Tau phosphorylation including glycogen synthase kinase 3 beta; cyclin-dependent-kinase 5; and Rho-associated protein kinase was also inhibited when p75NTR is knocked out in pR5 mice at 9 months of age. The increased caspase-3 activity observed in pR5 mice was also abolished in the absence of p75NTR. Our study also showed that p75NTR is required for Aβ- and pro-brain derived neurotrophin factor (proBDNF)-induced Tau phosphorylation, in vitro. Overall, our data indicate that p75NTR is required for Tau phosphorylation, a key event in the formation of neurofibrillary tangles, another hallmark of AD. Thus, targeting p75NTR could reduce or prevent the pathologic hyperphosphorylation of Tau.Noralyn B. Mañucat-Tan, Lin-Lin Shen, Larisa Bobrovskaya, Mohammed Al-hawwas, Fiona H. Zhou, Yan-Jiang Wang, Xin-Fu Zho

Partial wave analysis of J/\psi \to \gamma \phi \phi

Using $5.8 \times 10^7 J/\psi$ events collected in the BESII detector, the radiative decay $J/\psi \to \gamma \phi \phi \to \gamma K^+ K^- K^0_S K^0_L$ is studied. The $\phi\phi$ invariant mass distribution exhibits a near-threshold enhancement that peaks around 2.24 GeV/$c^{2}$. A partial wave analysis shows that the structure is dominated by a $0^{-+}$ state ($\eta(2225)$) with a mass of $2.24^{+0.03}_{-0.02}{}^{+0.03}_{-0.02}$ GeV/$c^{2}$ and a width of $0.19 \pm 0.03^{+0.06}_{-0.04}$ GeV/$c^{2}$. The product branching fraction is: $Br(J/\psi \to \gamma \eta(2225))\cdot Br(\eta(2225)\to \phi\phi) = (4.4 \pm 0.4 \pm 0.8)\times 10^{-4}$.Comment: 11 pages, 4 figures. corrected proof for journa

Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-

We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi --> D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7 J/Psi events collected with the BESII detector at the BEPC. No excess of signal above background is observed, and 90% confidence level upper limits on the branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi --> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure

Measurements of psi(2S) decays to octet baryon-antibaryon pairs

With a sample of 14 million psi(2S) events collected by the BESII detector at the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their branching ratios are determined to be (3.36+-0.09+-0.24)*10E-4, (3.39+-0.20+-0.32)*10E-4, (2.35+-0.36+-0.32)*10E-4, (3.03+-0.40+-0.32)*10E-4, respectively. In the decay psi(2S)->p p-bar, the angular distribution parameter alpha is determined to be 0.82+-0.17+-0.04.Comment: 8 pages, 8 figure

Measurements of the observed cross sections for e+e−→e^+e^-\to exclusive light hadrons containing π0π0\pi^0\pi^0 at s=3.773\sqrt s= 3.773, 3.650 and 3.6648 GeV

By analyzing the data sets of 17.3, 6.5 and 1.0 pb$^{-1}$ taken, respectively, at $\sqrt s= 3.773$, 3.650 and 3.6648 GeV with the BES-II detector at the BEPC collider, we measure the observed cross sections for $e^+e^-\to \pi^+\pi^-\pi^0\pi^0$, $K^+K^-\pi^0\pi^0$, $2(\pi^+\pi^-\pi^0)$, $K^+K^-\pi^+\pi^-\pi^0\pi^0$ and $3(\pi^+\pi^-)\pi^0\pi^0$ at the three energy points. Based on these cross sections we set the upper limits on the observed cross sections and the branching fractions for $\psi(3770)$ decay into these final states at 90% C.L..Comment: 7 pages, 2 figure

Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays

By analyzing about 33 $\rm pb^{-1}$ data sample collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we directly measure the branching fractions for the neutral and charged $D$ inclusive semimuonic decays to be $BF(D^0 \to \mu^+ X) =(6.8\pm 1.5\pm 0.7)$ and $BF(D^+ \to \mu^+ X) =(17.6 \pm 2.7 \pm 1.8)$, and determine the ratio of the two branching fractions to be $\frac{BF(D^+ \to \mu^+ X)}{BF(D^0 \to \mu^+ X)}=2.59\pm 0.70 \pm 0.25$

Measurements of the observed cross sections for exclusive light hadron production in e^+e^- annihilation at \sqrt{s}= 3.773 and 3.650 GeV

By analyzing the data sets of 17.3 pb$^{-1}$ taken at $\sqrt{s}=3.773$ GeV and 6.5 pb$^{-1}$ taken at $\sqrt{s}=3.650$ GeV with the BESII detector at the BEPC collider, we have measured the observed cross sections for 12 exclusive light hadron final states produced in $e^+e^-$ annihilation at the two energy points. We have also set the upper limits on the observed cross sections and the branching fractions for $\psi(3770)$ decay to these final states at 90% C.L.Comment: 8 pages, 5 figur