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Strata movement of solid backfill mining is distinctly different from that of traditional caving mining. In order to calculate strata movement accurately after solid materials being backfilled into gob, based on the strata movement characteristics of dense solid backfill mining, a mechanical model of backfill body-main roof for dense solid backfill mining was established using the theory of thin plate on elastic foundation. A stress equation and a deflection equation of main roof were derived, and a critical condition of roof breakage was given. Then the elastic foundation coefficient was analyzed to be the key factor influencing roof movement and deformation according to the stress equation and the deflection equation. In addition, the relationship between the maximal value of main roof subsidence, stress and the elastic foundation coefficient were obtained combined with specific parameters. The practical application at the 15-13080 panel of the No. 12 Coal Mine in Pingdingshan shows that the measured maximal value of roof subsidence is 347 mm which corresponds to the theoretical one. [ABSTRACT FROM AUTHOR]

For roof gap of backfilling-coal mining hydraulic support significantly affecting compression ratio and backfilling operation efficiency, authors revealed its existence mechanism, which were structural interference leading to theory roof gap and site operation leading to actual roof gap. According to these two mechanisms, authors analyzed two design theories of reasonable roof gap from structure optimization and different compression ratio requirement respectively, proposed the sensible design standard that the designed roof gap must meet this two theories at the same time, i. e., the accumulated quantity by backfill operation strictly controlled by roof gap should be no less than the quantity required by different compression ratio (namely Vzjρ1 ≥ V zρ2). With machinery automation simulation software Pro/E 5. 0, simulated and analyzed the change law between mining height and roof gap value for dimensions given hydraulic support, based on simulation curve, divided compaction ratio assurance area for this hydraulic support, judged its design and pros and cons of mechanism optimization. Eventually formed a judgment method and inspection standard for reasonableness design of hydraulic support based on index of roof gap. [ABSTRACT FROM AUTHOR]

To explore the effects of small watersheds with different ecological managements on soil properties, the spatial differences of soil organic matter (SOM), bulk density (BD), and clay content (CC) in the four facets, including slope aspect, slope position, zone, and soil layer, were analyzed between Yangjiagou (YJG, artificial Robinia pseudoacacia forest watershed) and Dongzhuanggou (DZG, closed grassland watershed). The results showed that SOM, BD and CC were 12.78 g·kg -1 , 1.24 g·cm -3 , 19.2% for YJG and 11.13 g·kg -1 , 1.21 g·cm -3 , 18.2% for DZG, respectively. The values for YJG were slightly higher than those for DZG, but the difference was insignificant. All indices in the east slope were bigger than those in the west slope. Across different slope positions, the variation of BD was small, SOM and CC showed increasing trends from top to bottom. BD and CC declined downward the watershed, whereas SOM changed in an opposite trend. From the soil surface down to 60 cm soil depth, BD and CC increased and SOM decreased. The spatial sensitivity followed CC > SOM > BD, and the effects of the spatial factors can be ordered as soil layer > zone > slope aspect > slope position. There were significant differences in CC of the upper reaches, BD and CC of the middle reaches between the two basins. The sensitivity of each index to slope position, zone and soil layer in YJG was lower than that in DZG.

Objective: To study the association between the single nucleotide polymorphisms (SNPs) in FXYD6 gene and schizophrenia in a family-trios population., Methods: Six SNPs (rs10790212, rs11544201, rs555577, rs1815774, rs4938446 and rs497768) in the FXYD6 gene were genotyped by allele-specific PCR method in 101 nuclear families, and transmission disequilibrium test (TDT) was performed., Results: SNPs rs10790212 and rs11544201 showed significant association with schizophrenia (P<0.05). Furthermore, significant association of schizophrenia with the haplotype rs10790212-rs11544201 was found (P<0.05)., Conclusion: FXYD6 gene might play an important role in schizophrenia susceptibility and functional analysis of FXYD6 are needed.