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Over time, the relative effects of elevated [CO 2 ] on the aboveground photosynthesis, growth and development of rice (Oryza sativa L.) are likely to be changed with increasing duration of CO 2 exposure, but the resultant effects on rice belowground responses remain to be evaluated. To investigate the impacts of elevated [CO 2 ] on seasonal changes in root growth, morphology and physiology of rice, a free-air CO 2 enrichment (FACE) experiment was performed at Wuxi, Jiangsu, China, in 2002-2003. A japonica cultivar with large panicle was exposed to two [CO 2 ] (ambient [CO 2 ], 370 lmol mol À1 ; elevated [CO 2 ], 570 lmol mol À1 ) at three levels of nitrogen (N): low (LN, 15 g N m À2 ), medium (MN, 25 g N m À2 ) and high N (HN, 35 g N m À2 ). Elevated [CO 2 ] increased cumulative root volume, root dry weight, adventitious root length and adventitious root number at all developmental stages by 25-71%, which was mainly associated with increased root growth rate during early growth period (EGP) and lower rate of root senescence during late growth period (LGP), while a slight inhibition of root growth rate occurred during middle growth period (MGP). For individual adventitious roots, elevated [CO 2 ] increased average length, volume, diameter and dry weight early in the season, but the effects gradually disappeared in subsequent stages. Total surface area and active adsorption area per unit root dry weight reached their maxima 10 days earlier in FACE vs. ambient plants, but both of them together with root oxidation ability per unit root dry weight declined with elevated [CO 2 ] during MGP and LGP, the decline being larger during MGP than LGP. The CO 2 -induced decreases in specific root activities during MGP and LGP were associated with a larger amount of root accumulation during EGP and lower N concentration and higher C/N ratio in roots during MGP and LGP in FACE vs. ambient plants. The results suggest that most of the CO 2 -induced increases in shoot growth of rice are similarly associated with increased root growth.

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The microstructures of pure Cu processed by equal channel angular pressing (ECAP) from 4 to 24 passes were investigated. It was found that the microstructures of Cu samples with a small number of ECAP passes (4-8) were not inhomogeneous and the fraction of high-angle grain boundary (HAGB) was low (25~43%). While for the samples with many number of ECAP passes (12-24), the grains became more equiaxed-like and the GB misorientations exhibited double-peak distribution with high fraction (51~64%) of HAGB. It was dislocation cells formed in large grains of the few-pass samples, but subgrains in the many-pass samples. These characterizations suggested that ultrafine-grained (UFG) microstructures in the few-pass samples were not fully accomplished, while it was obtained after many passes (>12). It is believed that dynamic recovery during processing for many passes was attributed to the formation of UFG microstructures.

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In the paper, the effects of the foaming temperature and holding time on the quality of the foam glass were investigated by means of the different foaming technology. The results indicated that lots of the defects, such as the non-uniform size of the bubbles, big hole and the pit at the bottom, were caused by the high foaming temperature. The fine pore structure was formed by the low temperature. The molding and properties of the foaming glass was affected by the length of the heat preservation time. The rate of acceptability and the mechanical property of the foam glass can be effectively improved by the optimized foaming technology.