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Study on the migration characteristics of Cu2+ ions of backfill gangue in subsided area

100%

Li J. , Huang Y. , Yang D. , Kong G.

nr 1

Even though solid backfill mining can address some environmental issues of coal mining (like surface subsidence and gangue storage), on the other hand the long exposure of gangue to rain or other surficial water will also result in the leaching of heavy metal ions, which in turn will pose the threat of potential pollution to groundwater. In response to resolving the above-mentioned problem, this paper simulated the concentration distribution and migration principle of Cu²⁺ in various soils by applying COMSOL Multiphysics software, and the results show that the diffusion distance of Cu²⁺ in different soils are ranked as clay, silty clay, loess, and sandy soil. In addition, the concentration will decrease with the increase of depth and the Darcy velocity contours of Cu²⁺ distribute radially and symmetrically in the transverse direction. The velocity gradient of Darcy velocity in different soils is clay soil > Silty clay soil > loess > sandy soil.

Nutrient resorption and use efficiency at different canopy heights of Alpine tree species Abies georgei var. smithii (Viguie et Gaussen) Cheng, Tibetan Plateau

100%

Li M. , Liu D. , Kong G.

tom Vol. 57, nr 1

63-72

Nutrients may be mobilized from senescing leaves and transported to other plant tissues, enabling plants to conserve them and reuse. Nitrogen and phosphorus are two dominant nutrients related to photosynthetic capacity and limiting plant growth. In this study, we examined the effect of canopy height on nutrient use by analyzing N and P concentrations of green and senescent leaves collected from different canopy heights of Abies georgei var. smithii (Viguie et Gaussen) Cheng growing at the alpine timberline in Sergyemla Mt.(4 350 m a.s.l), southeastern Tibetan Plateau. The results showed that N and P concentrations per unit needle mass decreased significantly with needle age, but no significant difference was found among upper, middle and lower canopy. However, area-based N and P concentrations increased with the height of canopy. The leaf level nutrient resorption and use efficiency varied in the order: upper canopy> middle canopy >lower canopy for both N and P. The higher nutrient resorption efficiency had significant relationship with leaf level nutrient use efficiency, that is, higher leaf level nutrient use efficiency was partly due to the high resorption from senescent needles. Additionally, the higher nutrient resorption was related to high current nutrient concentration. Vertical variations of leaf level nutrient use efficiency in this study reflected the strategy of alpine trees to respond to imbalance between light availability and soil nutrients.

A computationally constructed ceRNA interaction network based on a comparison of the SHEE and SHEEC cell lines

63%

Sun J. , Yan J. , Yuan X. , Yang R. , Dan T. , Wang X. , Kong G. , Gao S.

tom 21