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In this paper, air preheater is used the research object and its heat transfer law is studied by experiment and numerical simulation. The experimental data showed that with the increases of inlet air velocity, the comprehensive heat transfer coefficient and heat transfer efficiency increase, but the temperature efficiency decreases and the resistance loss on the air side increases. The numerical simulation results showed that the larger the diameter of the tube, the better the heat transfer effect. When horizontal spacing in the range of 290 - 305 mm and longitudinal spacing is 70 - 90 mm, the heat transfer effect is best. The optimized heat exchanger structure is that diameter is 60 mm, horizontal spacing is 300 mm, longitudinal spacing is 90 mm. As the inlet air flow rate increases, the heat transfer efficiency increases, but the temperature efficiency decreases and the resistance loss on the air side increases. [ABSTRACT FROM AUTHOR]

Hot metal pretreatment desulfurization is an important way in metallurgical industry, and Mg as a desulfurizer is widely used in the steel industry. In this paper, magnesite based desulfurizer that the ratio is 63 % MgF2, 12 % CaF2, 18 % NaF and 7 % MgO is used and at the molten iron temperature, magnesite based desulfurizer molten salt system is electrolyzed and the counter electromotive force and cell voltage is measured. The results of X-ray diffration(XRD) analysis of the desulfurization reaction products show that the counter electromotive force and the cell voltage of the magnesite desulfurizer is linear with current; MgO is electrolyzed and generated Mg, but other substances are not electrolyzed; The generated Mg is successfully desulfurized. All those indicated that it is feasible for magnesite based desulfurizer electrolytic desulfurization at the temperature of molten iron. [ABSTRACT FROM AUTHOR]

In the hot metal pretreatment conditions, the direct current electric field is applied to study the new desulfurizer of magnesite to achieve the goal of in situ desulfurization instead of metal magnesium. A total of three desulfurizers were selected and the melting point, viscosity, primary crystal temperature, density and conductivity were measured and analyzed. The results can be shown that 18 %NaF-63 %MgF2-12 %CaF2-7 %MgO is the study of the latest desulfurization agent. [ABSTRACT FROM AUTHOR]

Transcription factor forkhead box L2 (FOXL2) and growth differentiation factor-9 (GDF9) genes have critical roles in the regulation of hen ovarian development. In the present study, these genes were explored as possible molecular markers associated with BW, hen-housed egg production, and egg weight in Chinese Dagu hens. Samples were analyzed using the PCR–single strand conformation polymorphism (PCR-SSCP) technique followed by sequencing analysis, and two novel single nucleotide polymorphisms (SNPs) were identified within these candidate genes. Among them, an A/G transition at base position 238 in the coding region of the FOXL2 gene and a G/T transversion at base position 1609 in exon 2 of the GDF9 gene were found to be polymorphic and named SNPs A238G and G1609T, respectively. The SNP A238G (FOXL2) leads to a nonsynonymous substitution (isoleucine77-to-valine), and when the 360 Dagu hen samples were divided into genotypes AA and AB, allele A was found to be present at a higher frequency. Furthermore, the AA genotype correlated with significantly higher hen-housed egg production at 30, 43, 57, and 66 wk of age and with a higher egg weight at 43 wk (P < 0.05). For the SNP G1609T (GDF9), the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher hen-housed egg production and a higher egg weight (P < 0.05). Moreover, four haplotypes were reconstructed based on these two SNPs, with the AATC haplotype found to be correlated with the highest hen-housed egg production at 30 to 66 wk of age and with higher egg weights at 43 wk (P < 0.05). Collectively, the two SNPs identified in this study might be used as possible genetic molecular markers to aid in the improvement of egg production traits in chicken breeding. [ABSTRACT FROM AUTHOR]