Generation of frequency multiplexed entangled single photons assisted by the entanglement

We present a scheme to generate the frequency multiplexed entangled (FME) single photons based on the entanglement between two species atomic mixture ensemble. The write and reads fields driven according to a certain timing sequence, the generation of FME single photons can be repeated until success is achieved. The source might have significant applications in wavelength division multiplexing quantum key distribution.Comment: 4 pages, 4 figures, submitted to PR

Giant mesoscopic spin Hall effect on surface of topological insulator

We study mesoscopic spin Hall effect on the surface of topological insulator with a step-function potential. The giant spin polarization induced by a transverse electric current is derived analytically by using McMillan method in the ballistic transport limit, which oscillates across the potential boundary with no confinement from the potential barrier due to the Klein paradox, and should be observable in spin resolved scanning tunneling microscope.Comment: 5 pages, 3 figure

The contributions of qqqqqˉqqqq\bar{q} components to the axial charges of proton and its resonances

We calculate the axial charges of the proton and its resonances in the framework of the constituent quark model, which is extended to include the $qqqq\bar{q}$ components. If 20% admixtures of the $qqqq\bar{q}$ components in the proton are assumed, the theoretical value for the axial charge in our model is in good agreement with the empirical value, which can not be well reproduced in the traditional constituent quark model even though the $SU(6) \bigotimes O(3)$ symmetry breaking or relativistic effect is taken into account. We also predict an unity axial charge for $N^{*}(1440)$ with 30% $qqqq\bar{q}$ components constrained by the strong and electromagnetic decays.Comment: 4 pages, 4 table

Invisible gatekeeper? Director & officer insurance in corporate governance: an empirical legal study of Taiwan

After the problems experienced by Enron, WorldCom and other companies in various financial crises, the monitoring function of Directors’ and officers’ (D&O) insurance has been discussed more frequently. Given this tendency, discussions of this issue have become more popular in Taiwan. This research analyzes the role of D&O insurance in corporate governance in Taiwan. The monitoring hypothesis suggests that firms with weak corporate governance have a greater incentive to purchase D&O insurance. D&O insurance and other monitoring mechanisms are substitutes for each other. Firms which have better corporate governance have less demand for D&O insurance. Information about insured firms’ corporate governance can be conveyed by D&O insurance. In contrast, this study proposes an alternative hypothesis to the monitoring hypothesis. It argues that D&O insurance has a positive signal effect to the market. Accordingly, the signal effect is an important consideration in D&O insurance purchases. This research empirically analyzes the purchase of D&O insurance of around 4,000 listed firms in Taiwan from 2008 to 2010. A variety of econometric and statistical methods are applied. Empirical evidence shows that the monitoring function of D&O insurance is rejected and the signal effect of D&O insurance is supported. The positive signal effect of D&O insurance is a more important consideration than the monitoring function or indemnification for insured firms. This study also finds that there is no evidence supporting the existences of moral hazard and adverse selection. Thus, the findings regarding the rejection of the monitoring hypothesis and support for the signal hypothesis will not be affected. In conclusion, this dissertation analyzes the association among D&O insurance and corporate governance by comparative law and empirical methods. It concludes that the D&O insurance may signal the information of insured firms’ corporate governance, but the mandatory insurance rule is not recommended

Hydrogen production by mixed culture of several facultative bacteria and anaerobic bacteria

AbstractThe characteristic of hydrogen production by facultative anaerobic bacteria, obligate anaerobic bacteria and their mixed culture was studied by the batch culture method. The results showed that, due to the synergistic effect between facultative bacteria and anaerobic bacteria, the ability of hydrogen production in the mixed culture was much better than that in the pure culture. Especially, the culture Scheme No.7 mixed up with three strains (Bacterium. E: Bacterium. B: Bacterium. P = 1:1:1) not only had the best hydrogen production capacity (1.885 mol H2/mol glucose) and maximum average hydrogen production rate (212.2 mL/(L·h)), but also had stable hydrogen production under continuous culture conditions, which was 1.968 mol H2/mol glucose