On the Nature of X(4260)

We study the property of $X(4260)$ resonance by re-analyzing all experimental data available, especially the $e^+e^- \rightarrow J/\psi\,\pi^+\pi^-,\,\,\,\omega\chi_{c0}$ cross section data. The final state interactions of the $\pi\pi$, $K\bar K$ couple channel system are also taken into account. A sizable coupling between the $X(4260)$ and $\omega\chi_{c0}$ is found. The inclusion of the $\omega\chi_{c0}$ data indicates a small value of $\Gamma_{e^+e^-}=23.30\pm 3.55$eV.Comment: Refined analysis with new experimental data included. 13 page

Synergy of flocculation and flotation for microalgae harvesting using aluminium electrolysis

Microalgae are often used as feedstock for renewable biofuel production and as pollutant up-takers for wastewater treatment; however, biomass harvesting still remains a challenge in field applications. In this study, electro-flocculation using aluminium electrolysis was tested as a method to collect Chlorella vulgaris. The electrolysis products were positively charged over a wide pH range below 9.5, which gave them a flocculation potential for negatively charged microalgae. As flocculants were in-situ generated and gradually released, microalgae flocs formed in a snowballing mode, resulting in the compaction of large flocs. When higher current density was applied, microalgae could be harvested more rapidly, although there was a trade-off between a higher energy use and more residual aluminium in the culture medium. Benefits of this flocculation method are two-fold: the phosphate decrease in post-harvesting could improve nutrient removal in microalgae based wastewater treatment, while the ammonium increase may favor microalgae recovery for medium recycling

Deflection of Slow Light by Magneto-Optically Controlled Atomic Media

We present a semi-classical theory for light deflection by a coherent $\Lambda$-type three-level atomic medium in an inhomogeneous magnetic field or an inhomogeneous control laser. When the atomic energy levels (or the Rabi coupling by the control laser) are position-dependent due to the Zeeman effect by the inhomogeneous magnetic field (or the inhomogeneity of the control field profile), the spatial dependence of the refraction index of the atomic medium will result in an observable deflection of slow signal light when the electromagnetically induced transparency happens to avoid medium absorption. Our theoretical approach based on Fermat's principle in geometrical optics not only provides a consistent explanation for the most recent experiment in a straightforward way, but also predicts the new effects for the slow signal light deflection by the atomic media in an inhomogeneous off-resonant control laser field.Comment: 4 pages, 3 figure

Entangled two atoms through different couplings and the thermal noise

The entanglement of two atoms is studied when the two atoms are coupled to a single-mode thermal field with different couplings. The different couplings of two atoms are in favor of entanglement preparation: it not only makes the case of absence entanglement with same coupling appear entanglement, but also enhances the entanglement with the increasing of the relative difference of two couplings. We also show that the diversity of coupling can improved the critical temperature. If the optical cavity is leaky during the time evolution, the dissipative thermal environment is benefit to produce the entanglement.Comment: 4 pages, 4 figure

Carbon-doped ZnO: A New Class of Room Temperature Dilute Magnetic Semiconductor

We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78 $\mu_B$ per carbon. The theoretical prediction was confirmed experimentally. C-doped ZnO films deposited by pulsed laser deposition with various carbon concentrations showed ferromagnetism with Curie temperatures higher than 400 K, and the measured magnetic moment based on the content of carbide in the films ($1.5 - 3.0 \mu_B$ per carbon) is in agreement with the theoretical prediction. The magnetism is due to bonding coupling between Zn ions and doped C atoms. Results of magneto-resistance and abnormal Hall effect show that the doped films are $n$-type semiconductors with intrinsic ferromagnetism. The carbon doped ZnO could be a promising room temperature dilute magnetic semiconductor (DMS) and our work demonstrates possiblity of produing DMS with non-metal doping.Comment: REVtex source with 4 figures in eps forma

Entanglement detection via condition of quantum correlation

We develop a novel necessary condition of quantum correlation. It is utilized to construct $d$-level bipartite Bell-type inequality which is strongly resistant to noise and requires only analyses of $O(d)$ measurement outcomes compared to the previous result $O(d^{2})$. Remarkably, a connection between the arbitrary high-dimensional bipartite Bell-type inequality and entanglement witnesses is found. Through the necessary condition of quantum correlation, we propose that the witness operators to detect truly multipartite entanglement for a generalized Greenberger-Horne-Zeilinger (GHZ) state with two local measurement settings and a four-qubit singlet state with three settings. Moreover, we also propose the first robust entanglement witness to detect four-level tripartite GHZ state with only two local measurement settings