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The effects of different CO2 gas blowing temperatures on the strength and gel structure of sodium silicate binder system were studied. Through the experimental study, it is found that the increase in blowing gas temperature has a significant effect on the bond strength of CO2-hardened Na2SiO3 sodium glass sand mold. The blowing gas temperature of CO2 is closely related to the diffusion coefficient of CO2 at different temperatures. By thermogravimetric analysis of the sample weight change from room temperature to 80 °C combined with SEM results, the primary reason for the increase in tensile strength of sand mold was the acceleration of binder gel rate due to the increase in temperature. Through SEM observation, it was found that the adhesive gel obtained at appropriate temperature was denser and the bond bridge was stronger. The above results show that the increase in tensile strength of sand mold is due to the formation of more uniform, non-lamellar crystals by silicic acid gel at the appropriate temperature, and the acceleration of water loss in the hardening process of sand mold, which enhances the strength of the binder. But too high temperature will lead to violent reaction, dendritic crystal to lamellar crystal transformation, and tensile strength gradually decreased. Finally, based on molecular dynamics simulation, it was found that the diffusion coefficient of CO2 in sodium silicate binder system was greatly affected by different blowing temperature, which confirmed the effect of temperature on gel quality. This study provides an important theoretical basis for improving the casting process of CO2-hardened Na2SiO3 sand. [ABSTRACT FROM AUTHOR]

Age-related hearing loss is a complex disease caused by a combination of genetic and environmental factors, and a study have conducted animal experiments to explore the association between BCL11B heterozygosity and age-related hearing loss. The present study used established genetic models to examine the association between BCL11B gene polymorphisms and age-related hearing loss. A total of 410 older adults from two communities in Qingdao, China, participated in this study. The case group comprised individuals aged ≥ 60 years with age-related hearing loss, and the control group comprised individuals without age-related hearing loss from the same communities. The groups were matched 1:1 for age and sex. The individual characteristics of the participants were analyzed descriptively using the Mann–Whitney U test and the chi-square test. To explore the association between BCL11B gene polymorphisms and age-related hearing loss, conditional logistic regression was performed to construct genetic models for two single-nucleotide-polymorphisms (SNPs) of BCL11B, and haplotype analysis was conducted to construct their haplotype domains. Two SNP sites of the BCL11B gene, four genetic models of rs1152781 (additive, dominant, recessive, and codominant), and five genetic models of rs1152783 (additive, dominant, recessive, codominant, and over dominant) were significantly associated with age-related hearing loss in the models both unadjusted and adjusted for all covariates (P < 0.05). Additionally, a linkage disequilibrium between rs1152781 and rs1152783 was revealed through haplotype analysis. Our study revealed that BCL11B gene polymorphisms were significantly associated with age-related hearing loss. [ABSTRACT FROM AUTHOR]

The Carboniferous-Permian strata in Henan Province are a set of coal-bearing series of transitional marine-continental facies，of which the mudstones have potentials for shale gas exploration.The mudstones are characterized by a variable thickness of the individual effective mudstone layer and a huge accumulative thickness.In this paper，we utilized the outcrop and borehole core data and investigated the accumulation conditions and the reservoir characteristics of the shale gas in the Carboniferous and Permian coal-bearing strata of Henan Province.The total organic carbon(TOC)，organic matter types，thermal evolution degree，contents of brittle minerals and clay minerals，and pore morphological types of the mudstones were determined by the TOC analyzer，microscopic identification of kerogen，reflectance measurement of vitrinite，X-ray diffraction(XRD)，low temperature nitrogen gas adsorption，respectively.The results showed that the abundance of organic matters of the mudstones was relatively high，with the TOC contents in the mudstones of the Taiyuan，Shanxi and Xiashihezi Formations being 0.95% ～8.04%，0.78% ～9.41%and 0.2% ～ 2.13%，respectively.The types of organic matter were dominated by typeⅢ，followed by typeⅡ2.The thermal evolution degree ranged from mature to over-mature stage which was favorable for the formation of dry gas.The maturity of the mudstones had a zoned distribution，with the highest maturity being distributed along the Jiaozuo-Zhoukou belt and the lower maturity being distributed towards the south and north from this belt.The XRD analysis showed that the clay minerals of the mudstones could account for 62.0%while the brittle minerals only accounted for 34.1%，indicating that the mudstones had a higher gas adsorption capacity but were difficult for hydraulic fracturing.The clay minerals were mainly composed of 57.1%of illite/smectite mixed layer and 23.5%of kaolinite，which were beneficial to the formation of pore space.The porosity of the mudstones ranged from 1.0%to 4.5%，and the permeability varied between 0.003 and 0.032 mD.The experiment of low temperature nitrogen gas adsorption revealed that the morphological types of the pores included the parallel plate-slit pores and the inclined plate-slit pores.The meso-pores provided the vast majority of specific surface area and total pore volume.The gas contents could reach 1.0 ～3.0 m3/t which is suitable for the condition of shale gas reservoir.It was concluded that the siliciclastic member in the middle Taiyuan Formation(H1)and the basal part of the Shanxi Formation(H2)have a higher hydrocarbon potential.The major favorable exploration areas are those having a good preservation condition or a less serious influence from the regional thermal events.