Radio Polarization of BL Lacertae objects

In this paper, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio frequencies, we studied the polarization properties for 47 BL Lacertae objects(38 radio selected BL Lacertae objects, 7 X-ray selected BL Lacertae, and two inter-middle objects (Mkn 421 and Mkn 501), and found that (1) The polarizations at higher radio frequency is higher than those at lower frequency, (2) The variability of polarization at higher radio frequency is higher than those at lower frequency, (3) The polarization is correlated with the radio spectral index, and (4) The polarization is correlated with core-dominance parameter for those objects with known core-dominance parameters suggesting that the relativistic beaming could explain the polarization characteristic of BL Lacs.Comment: 5 pages, 3 figures, 1 table. PASJ, in pres

Investigating Ds+→π0ℓ+νℓD_s^+ \to \pi^0 \ell^+ \nu_\ell decay process within QCD sum rule approach

In this paper, the semileptonic decays $D_s^+ \to \pi^0\ell^+ \nu_\ell$ with $\ell=(e,\mu)$ are investigated by using the light-cone sum rule approach. Firstly, the neutral meson mixing scheme between $\pi^0$, $\eta$, $\eta^\prime$ and pseudoscalar gluonium $G$ is discussed in a unified way, which leads to the direct connection between two different channels for $D_s^+\to \pi^0\ell^+\nu_\ell$ and $D_s^+ \to \eta\ell^+\nu_\ell$ by the $\pi^0-\eta$ mixing angle. Then we calculated the $D_s\to \pi^0$ transition form factors (TFFs) within QCD light-cone sum rule approach up to next-to-leading order correction. At the large recoil point, we have $f_+^{D_s^+\pi^0}(0)=0.0113_{-0.0019}^{+0.0024}$ and $f_-^{D_s^+\pi^0}(0)=0.0020_{-0.0009}^{+0.0008}$. Furthermore, the TFFs are extrapolated to the whole physical $q^2$-region by using the simplified $z(q^2)$-series expansion. The behaviors of TFFs and related three angular coefficient functions $a_{\theta_\ell}(q^2)$, $b_{\theta_\ell}(q^2)$ and $c_{\theta_\ell}(q^2)$ are given. The differential decay widths for $D_s^+ \to \pi^0\ell^+ \nu_\ell$ with respect to $q^2$ and $\cos\theta_\ell$ are displayed, and also lead to the branching fractions ${\cal B}(D_s^+\to \pi ^0e^+\nu_e) =2.60_{-0.51}^{+0.57}\times 10^{-5}$ and ${\cal B}(D_s^+\to \pi ^0\mu^+\nu _\mu )= 2.58_{-0.51}^{+0.56}\times 10^{-5}$. These results show well agreement with the recent BESIII measurements and theoretical predictions. Then the differential distributions and integrated predictions for three angular observables, {\it i.e.} forward-backward asymmetries, $q^2$-differential flat terms and lepton polarization asymmetry are given separately. Lastly, we estimate the ratio for different decay channels ${\cal R}_{\pi ^0/\eta}^{\ell}=1.108_{-0.071}^{+0.039}\times 10^{-3}$.Comment: 10 pages, 5 figure

Biomechanics Characteristics of New Type Artificial Hip Joint

The structure, geometrical shape and material are the three main parts of the prostheses. This research focuses on the geometrical shape analysis. The geometrical shape of human natural femoral head is similar to the ellipse, but, the artificial femoral head is rotundity shape. There is difference between ellipse and rotundity femoral head. Two models are developed and analyzed in this paper under same conditions used Finite element analysis method. Based on the calculation results, it is shown that the ellipse shape femoral head have the similar characteristics to the natural joint than rotundity model. The ellipse has the more lowness stress distribution area and more small distortion magnitude than rotundity shape artificial femoral head. It should have the more kind effect replace rotundity femoral head with ellipse shape artificial formal head. Keywords: hip joint; prosthesis design; finite element analysis; biomechanic

Studies on some active components and antimicrobial activities of the fermentation broth of endophytic fungi DZY16 Isolated from Eucommia ulmoides Oliv.

Research into plant-derived endophytic fungi has grown in recent decades. Endophytic fungi still have enormous potential to inspire and influence modern agriculture. In this study, the endophytic fungi DZY16 isolated from Eucommia ulmoides Oliv. was tested for its bioactive components and antimicrobial activities using phenol-sulfuric acid method, high performance liquid chromatography method and growth inhibition measurements. The results show that variation trend of extracellular polysaccharide content at different growth stages of the strain DZY16 and the maximum content of extracellular polysaccharide was 2.02 g/L at the sixth day. Moreover, the fermentation broth of the DZY16 contained guanosine, uridine and adenosine; the contents were 1.54 mg/g, 1.07 mg/g and 1.36 mg/g respectively. On the other hand, the strongest antimicrobial activity was exhibited by the acetylacetate extract of strain DZY16 against Rhizoctonia solani and Gibberella zeae, showing 59.84 and 70.86% respectively. The strain DZY16 was identified by internal transcribed spacer (ITS) sequence as belonging to Nigrospora. The results indicate that the endophytic fungi DZY16 of the plant E. ulmoides Oliv. is a promising source of novel bioactive compounds.Keywords: Eucommia ulmoides Oliv., endophytic fungi, extracellular polysaccharide, nucleotides, antimicrobial activityAfrican Journal of Biotechnology Vol. 12(15), pp. 1862-186

Comparison of the quality of life for spectacle wearers and contact lens wearers before and after refractive surgery

AIM: To compare the difference of the quality of life(QOL)of spectacle wearers or contact lens wearers before and after refractive surgery by the quality of life impact of refractive correction(QIRC). METHODS:Totally 72 cases were enrolled in the investigation with 50 spectacle wearers and 22 contact lens wearers. The QOL of them were surveyed by Chinese QIRC before surgery and 3 months later after surgery. RESULTS: 1. The QOL scores(42.29±4.90 in post-operation vs 39.30±5.16 in pre-operation)and satisfaction scores(86.51±9.14 in post-operation vs 71.58±13.24 in pre-operation)of spectacle wearers were higher after surgery more than before, and the difference was statistically significant(P<0.01). The vision and physical functioning(P<0.05), driving and activity in night