Search

In this study, we establish a nested atmospheric inversion system with a focus on China using the Bayesian method. The global surface is separated into 43 regions based on the 22 TransCom large regions, with 13 small regions in China. Monthly CO2 concentrations from 130 GlobalView sites and 3 additional China sites are used in this system. The core component of this system is an atmospheric transport matrix, which is created using the TM5 model with a horizontal resolution of 3° x 2°. The net carbon fluxes over the 43 global land and ocean regions are inverted for the period from 2002 to 2008. The inverted global terrestrial carbon sinks mainly occur in boreal Asia, South and Southeast Asia, eastern America and southern South America. Most China areas appear to be carbon sinks, with strongest carbon sinks located in Northeast China. From 2002 to 2008, the global terrestrial carbon sink has an increasing trend, with the lowest carbon sink in 2002. The inter-annual variation (IAV) of the land sinks shows remarkable correlation with the El Nino Southern Oscillation (ENSO). The terrestrial carbon sinks in China also show an increasing trend. However, the IAV in China is not the same as that of the globe. There is relatively stronger land sink in 2002, lowest sink in 2006, and strongest sink in 2007 in China. This IAV could be reasonably explained with the IAVs of temperature and precipitation in China. The mean global and China terrestrial carbon sinks over the period 2002-2008 are -3.20 ± 0.63 and -0.28 ± 0.18PgCyr-1, respectively. Considering the carbon emissions in the form of reactive biogenic volatile organic compounds (B VOCs) and from the import of wood and food, we further estimate that China's land sink is about -0.3 lPgCyr-1. [ABSTRACT FROM AUTHOR]

Abstract  Two tropical species of North Australia, Acacia crassicarpa and Eucalyptus pellita, have similar leaf size and leaf structure but different leaf angles. A. crassicarpa with near vertical leaf angle directly reduced photon absorption and leaf temperature (T l) and had relatively high photosynthetic activity (P max) and low xanthophyll cycle activity. In contrast, E. pellita with a small leaf angle exhibited high T l, low P max, and high activity of xanthophyll cycle which was useful for the dissipation of excessive energy and reduction of photoinhibition. In the dry season, contents of soluble sugars including pinitol, sucrose, fructose, and glucose in A. crassicarpa increased whereas larger amounts of only fructose and glucose were accumulated in E. pellita. Different sugar accumulation may be involved in osmotic adjustment of leaves during water stress that makes photosynthesis more efficient. The leaf angle may be critical for developing different protective mechanisms in these two tropical tree species that ensure optimal growth in the high irradiance and drought stress environment in North Australia. [ABSTRACT FROM AUTHOR]

We present the synthesis and visible-light-induced catalytic activity of one-dimensional (1D) TiO2/V2O5 branched heterostructures. The 1D TiO2/V2O5 heterostructures were prepared by RF reactive magnetron sputtering of V2O5 onto electrospun TiO2 nanofibers. Then, the samples were annealed at 300 degC for 2 h in air ambient to form the 1D TiO2/V2O5 branched heterostructures. The photodecomposition rate of Rhodamine B (RhB) by the 1D TiO2/V2O5 branched heterostructures under visible light was much faster than that of pure TiO2 nanofibers, revealing that the visible-light-induced catalytic activity of the 1D TiO2/V2O5 branched heterostructures was greatly improved. The enhancement of the photocatalytic activity of the 1D TiO2/V2O5 branched heterostructures can be ascribed to the coupling with a small bandgap semiconductor material V2O5, where the absorption range is extended, the photogenerated electrons and holes are highly separated and the surface charge carrier transfer rate is promoted. [ABSTRACT FROM AUTHOR]