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In this paper, phytoplankton investigation and environmental assessment for the dredged areas in Caohai section of Dianchi Lake in Kunming City were reported. After microscopic identification and counting of 7 water samples (one of them is control plot), the water environment was evaluated by the phytoplankton species and quantity which were assessed by the biological diversity index, including Maglarf, Shanon-Wiener, Simpson diversity index, Pielou index and Berger-Parker dominance index. The results showed that there were mainly 21 species of algae, and among them, Microcystis spp., Melosira spp., Oscillatoria spp.et al., were the dominant species. So the water was assessed as eutrophication, polluted water band B. Based on the diversity index analysis, the dredged area sampling sites were relatively higher than the un-dredged areas in biodiversity of phytoplankton. Summarily, the water quality after dredging had been improved. Phytoplankton biodiversity indicators should be the important water environmental assessment method. [ABSTRACT FROM PUBLISHER]

Intense high frequency laser field induced electronic and optical properties of heavy hole exciton in the InAs0.8P0.2/InP quantum wire is studied taking into account the geometrical confinement effect. Laser field related exciton binding energies and the optical band gap in the InAs0.8P0.2/InP quantum well wire are investigated. The optical gain, for the interband optical transition, as a function of photon energy, in the InAs0.8P0.2/InP quantum wire, is obtained in the presence of intense laser field. The compact density matrix method is employed to obtain the optical gain. The obtained optical gain in group III-V narrow quantum wire can be applied for achieving the preferred telecommunication wavelength. [ABSTRACT FROM AUTHOR]

Passive mode-locking of a Ti:sapphire laser employing monolayer graphene as saturable absorber was demonstrated for the first time. The large-area, high-quality monolayer graphene was fabricated by chemical vapor deposition method. Without any additional treatment, monolayer graphene shows ultrafast recovery time and nonlinear absorption properties appropriate for the bulk laser mode-locking near 800 nm. The graphene mode-locked Ti:sapphire laser delivers 63-fs pulses with a maximum output power of 480 mW. [ABSTRACT FROM PUBLISHER]