Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and...Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.展开更多
Based on the dielectric continuum model and Loudon＇s uniaxial crystal model, the properties of the quasi. confined （QC） optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wur...Based on the dielectric continuum model and Loudon＇s uniaxial crystal model, the properties of the quasi. confined （QC） optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wurtzite quantum well （QW） are deduced via the method of electrostatic .potential expanding. The present theoretical scheme can naturally reduce to the results in symmetric wurtzite QW once a set of symmetric structural parameters are chosen. Numerical calculations on an asymmetric AlN/GaN/AIo,15 Gao.85N Wurtzite Q W are performed. A detailed comparison with the symmetric wurtzite QW was also performed. The results show that the structural asymmetry of wurtzite QW changes greatly the dispersion frequencies and the electrostatic potential distributions of the QC optical phonon modes.展开更多
基金supported by the National Key Basic Research Program of China (973 Program) (No.2005CB422005)the National Natural Science Foundation of China (No.30700108)the Forestry Commonweal Program of China(No.200804005).
文摘Relationships between carbon (C) production and nitrogen (N) mineralization were investigated in two alpine wetland soils of the Tibetan Plateau using laboratory incubation under different temperatures (5, 15, 25, and 35 ℃) and water saturation (noninundation and inundation). A significant positive relationship was found between CO2 production and N mineralization under increasing temperatures from 5 to 35 ℃ with the same water saturation condition in the marsh soil (r2 > 0.49, P < 0.0001) and the peat soil (r2 > 0.38, P < 0.002), and a negative relationship with water saturation increasing at the same temperature, especially 25 and 35 ℃, in the marsh soil (r2 > 0.70, P < 0.009) and the peat soil (r2 > 0.61, P < 0.013). In conclusion, temperatures and water saturation could regulate the relationship between CO2 production and net N mineralization in the Tibetan alpine marsh and peat soils.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 60276004 and 6939007,3, the Scientilic Research Foundation for the Returned 0overseas Chinese Scholars State Education Ministry of China
文摘Based on the dielectric continuum model and Loudon＇s uniaxial crystal model, the properties of the quasi. confined （QC） optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wurtzite quantum well （QW） are deduced via the method of electrostatic .potential expanding. The present theoretical scheme can naturally reduce to the results in symmetric wurtzite QW once a set of symmetric structural parameters are chosen. Numerical calculations on an asymmetric AlN/GaN/AIo,15 Gao.85N Wurtzite Q W are performed. A detailed comparison with the symmetric wurtzite QW was also performed. The results show that the structural asymmetry of wurtzite QW changes greatly the dispersion frequencies and the electrostatic potential distributions of the QC optical phonon modes.
