Effects of Specimen Shape and Size on Water Loss and Drying Shrinkage of Cement-based Materials

The effects of specimen size and shape on development of water loss and shrinkage of mortar and concrete respectively were investigated. The experimental results showed that the effects of specimen size and shape on water loss ratio were consistent with those on drying shrinkage strain. It is also indicated that drying shrinkage strain has obvious linear correlation with water loss ratios independent of specimen size and shape. The effects of specimen size and shape on the water loss ratio were embodied in established model of averaged relative humidity improved by considering effects of sequential hydration and calculated by finite difference method. Furthermore, the effects of specimen size and shape on drying shrinkage strain of concrete were experimentally deduced and applied to modify criterion EB-FIP1990. The comparison between experimental and calculated results shows that the modified EB-FIP1990 can be adopted to predict drying shrinkage strain of concrete with reasonable accuracy.

Morphology effect of zirconia support on the catalytic performance of supported Ni catalysts for dry reforming of methane

An immature pinecone shaped hierarchically structured zirconia （ZrO2-ipch） and a cobblestone-like zirconia nanoparticulate （ZrO2-cs）, both with the monoclinic phase （m-phase）, were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane （DRM） with CO2. ZrO2-ipch is a much better support than ZrO2-cs and the traditional ZrO2 irregular particles made by a simple precipitation method （ZrO2-ip）. The supported Ni catalyst on ZrO2-ipch （Ni/ZrO2-ipch） exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO2-cs （Ni/ZrO2-cs） and ZrO2-ip （Ni/ZrO2-ip）. Ni/ZrO2-ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N2 adsorption measurement （BET）, TEM, H2-TPR, CO chemisorption, CO2-TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO2-ipch to Ni/ZrO2-cs or Ni/ZrO2-ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mo- bility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO2-ipch support. Ni/ZrO2-ipch exhibited better stability for the DRM reaction than Ni/ZrO2-ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO2-ipch for the DRM reaction in comparison with Ni/ZrOz-ip orignated from the coke-removalabitity of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO2-TPD analysis, and the stabilized Ni on the Ni/ZrO2-ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO2-ipch sup- port. The superior catalytic performance and coking resistance of the Ni/ZrO2-ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction.

Study on the Dry Island Effect in Xiamen City

Using relative humidity data from two meteorological stations in Xiamen and absolute humidity calculated from temperature and water vapor,the annual,seasonal and monthly change characteristic of relative humidity and absolute humidity were comprehensive analyzed.Then the dry island effect of Xiamen city was studied.The result demonstrated that because of unique geographical features,the air humidity showed different change rules between urban and suburb.There was no obvious dry island effect in urban and suburb at last century.The change trend of average air humidity was unapparent before 90th of last century.From early 90th of last century,the air humidity in suburb began to decrease obviously.There was dry mutation for these two stations in 1993 and 2004 respectively.From the beginning of early of this century,both areas became dry obviously.The seasonal average relative humidity of Tongan station decreased each season,but what in Xiamen station changed unapparent.The seasonal average absolute humidity of Tongan station decreased apparently in spring and summer,but what did not change obviously in autumn and winter.The seasonal average absolute humidity of Xiamen station decreased apparently in summer,but what did not change apparently in other seasons.As respect from climate change of air humidity of each time,it decreased obviously at all four times at Tongan station.Relative humidity diminished most apparently at 8 and 20 o'clock.Absolute humidity diminished most apparently at 14 o'clock.For Xiamen station,relative humidity diminished most apparently at 14 o'clock.Absolute humidity diminished most apparently at 2 and 20 o'clock.

Establishment of ANEDr model for evaluating absorbed-nitrogen effects on wheat dry matter production

Applying mathematic models to evaluate absorbed-N effects on dry matter production at different developmental stages would help determine proper nitrogen management according to crop demands and yield target. Two field trials were carried out for establishing absorbed-N effects on dry matter production（ANEDr） model, using uniform design in 2010–2011and 2012–2013 winter wheat growing seasons in Hebei Province, China. Another field trial was carried out in 2010–2011for model validation. Dry matter and N concentration in leaf and non-leaf organs were measured at setting, jointing, anthesis, and maturity. Theory of best linear unbiased prediction（BLUP） was applied to analyse the N effects of leaf and non-leaf organs on dry matter production. Within ANEDr model, four N-affected phases at each stage were concerned,leaf absorbed-N effect before this stage, non-leaf organ absorbed-N effect before this stage,leaf absorbed-N effect at this stage, and non-leaf organ absorbed-N effect at this stage. In addition, developmental processes, genotype characters and temperature were three factors that determine each N effect. It was demonstrated that ANEDr model can precisely quantify absorbed-N effects on dry matter production with high correlation coefficient（r=0.95）. Comparing with other models, ANEDr model considered both leaf and non-leaf organs according to developmental processes of winter wheat, showed higher flexibility and simplicity, thus could be applied to different environments, cultivars and crops after parameter adjustment.

The heterotic effects on dry matter production and grain yield formation in hybrid rice

We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar