EXPERIMENTS ON AQUATIC ECOSYSTEM REGIME SHIFT IN ENCLOSURES NEAR LAKE DIANCHI, CHINA

To discover how a lake converts from a turbid state to clean state, and what drives this process, we constructed controlled enclosure ecosystems and used the ecological remediation method to force ecosystems to convert from the turbid state to the clean state. Our results show that the driving forces include temperature., macrophyte, silver carp and mussel, which form a combined force to drive the controlled ecosystem to switch. There is a threshold existing in treated enclosure ecosystem during the conversion from turbid to clean state. When TP <0.09 mg.L-1, Chl-a <0.036 mg.L-1, transparency >62 cm, TN <2.15 mg.L-1, CODMn <13.7 mg.L-1, tubidity <10, and the number of algal cells <10(6) cells.L-1, the treated ecosystem changes sharply from turbid to clean state. The conversion process can be divided into three phases: turbid state, clean-turbid transitional state as well as clean state, and described with the power function Y = a*X-b (where Y is water parameter, X is time, a and b are constants), which indicates that the shift in the enclosure ecosystem from turbid to clean state is discontinuous.

Single-photon source in strong photon-atom interaction regime in quasiperiodic photonic crystals

The antibunching properties of the fluorescence from a two-level ideal system in a 12-fold quasiperiodic photonic crystal are investigated based on the calculated local density of states. We found that the antibunching phenomenon of the fluorescence from two-level ideal systems could be significantly changed by varying their positions, i.e., perfect antibunching and antibunching with damped Rabi oscillation phenomenon occurred in different positions and at different frequencies in photonic crystals as a result of the large differences in the local density of states. This study revealed that the multi-level coherence of fluorescence from a two-level ideal system could be manipulated by controlling the position of the two-level ideal system in photonic crystals and the emission frequency in the photonic band structure. Copyright (C) EPLA, 2008

yet another meta-language for programming language processing

The formal specification language LFC was designed to support formal specification acquisition. However, it is yet suited to be used as a meta-language for specifying programming language processing. This paper introduces LFC as a meta-language, and compares it with ASF+SDF, an algebraic specification formalism that can also be used to programming languages.

Microstructure of the silicon film prepared near the phase transition regime from amorphous to nanocrystalline

A kind of hydrogenated diphasic silicon films has been prepared by a new regime of plasma enhanced chemical vapor deposition (PECVD) near the phase transition regime from amorphous to nanocrystalline. The microstructural properties of the films have been investigated by the micro-Raman and Fourier transformed Infrared (FT-IR) spectra and atom force microscopy (AFM). The obtained Raman spectra show not only the existence of nanoscaled crystallites, but also a notable improvement in the medium-range order of the diphasic films. For the FT-IR spectra of this kind of films, it notes that there is a blueshift in the Si-H stretching mode and a redshift in the Si-H wagging mode in respect to that of typical amorphous silicon film. We discussed the reasons responsible for these phenomena by means of the phase transition, which lead to the formation of a diatomic hydrogen complex, H-2* and their congeries.