The authors report the synthesis of Mg-based metallic glass composite reinforced with Nb particles which are simply added during melting process. The ductile Nb particles effectively impede shear band propagation and upon yielding, deformed Nb particles distribute the load uniformly to the surrounding glassy matrix to promote the initiation and branching of abundant secondary shear bands. In contrast to the previous Mg-based metallic glass composites which fracture with very little plasticity, the composite shows great resistance to crack growth. The high strength of 900MPa and large plasticity of 12.1±2% have made it comparable to excellent Zr- or Ti-based metallic glass composite.

No abstract

In this paper we present an estimate of net ecosystem CO 2 exchange over China for the years 2001-2010 using the CarbonTracker Data Assimilation System for CO 2 (CTDAS). Additional Chinese and Asian CO 2 observations are used in CTDAS to improve our estimate. We found that the combined terrestrial ecosystems in China absorbed about À0.33 Pg C yr À1 during 2001-2010. The uncertainty on Chinese terrestrial carbon exchange estimates as derived from a set of sensitivity experiments suggests a range of À0.29 to À0.64 Pg C yr À1 . This total Chinese terrestrial CO 2 sink is attributed to the three major biomes (forests, croplands, and grass/shrublands) with estimated CO 2 fluxes of À0.12 Pg C yr À1 (range from À0.09 to À0.19 Pg C yr À1 ), À0.12 Pg C yr À1 (range from À0.09 to À0.26 Pg C yr À1 ), and À0.09 Pg C yr À1 (range from À0.09 to À0.17 Pg C yr À1 ), respectively. The peak-to-peak amplitude of interannual variability of the Chinese terrestrial ecosystem carbon flux is 0.21 Pg C yr À1 (~64% of mean annual average), with the smallest CO 2 sink (À0.19 Pg C yr À1 ) in 2003 and the largest CO 2 sink (À0.40 Pg C yr À1 ) in 2007. We stress that our estimate of terrestrial ecosystem CO 2 uptake based on inverse modeling strongly depends on a limited number of atmospheric CO 2 observations used. More observations in China specifically and in Asia in general are needed to improve the accuracy of terrestrial carbon budgeting for this region.