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The elemental interdiffusion between the bond-coat in the thermal barrier coatings (TBCs) system and the superalloy substrate has emerged as a critical factor affecting the service life of the TBCs-coated turbine blades in aero-engines. To address this issue, a NiCrAlY bond-coat with low Al content and high Y content was designed and sprayed on the superalloy using high velocity oxygen fuel method. The performance of the as-deposited coating was assessed through isothermal oxidation test at 1000 °C for durations ranging from 10 to 1000 h. The results revealed the precipitation of c-Y2O3 particles at the grain boundaries of the as-deposited coating. These particles appeared to impede the diffusion of coating elements, resulting in improved oxidation resistance. The oxidation mechanism of the as-deposited coating on the flat region was divided into two stages: the preferential oxidation of Al and the formation of spinel; the inward growth of alumina along with outward growth of spinel. In the concave area, the oxidation mechanism was characterized by a rapid thickening of the spinel phase and NiO, attributed to the thinner coating and special Ni diffusion method. Semi-molten particles formed an overlaying structure after oxidation as the elements diffused in surrounding areas, with only the Ni element remaining inside it. The designed low Al content NiCrAlY coating exhibits excellent oxidation resistance at 1000 °C. [ABSTRACT FROM AUTHOR]

The study is about the size distribution and health risks of polycyclic aromatic hydrocarbons (PAHs) in indoor environment of Xuanwei, Southwest China particle samples were collected by Anderson 8-stage impactor which was used to gather particle samples to nine size ranges. Size-segregated samples were collected in indoor from a rural village in Xuanwei during the non-heating and heating seasons. The results showed that the total concentrations of the indoor particulate matter (PM) were 757 ± 60 and 990 ± 78 μg/m3 in non-heating and heating seasons, respectively. The total concentration of indoor PAHs reached to 8.42 ± 0.53 μg/m3 in the heating season, which was considerably greater than the concentration in the non-heating season (2.85 ± 1.72 μg/m3). The size distribution of PAHs showed that PAHs were mainly enriched in PMs with the diameter <1.1 μm. The diagnostic ratios (DR) and principal component analysis (PCA) showed that coal and wood for residential heating and cooking were the main sources of indoor PAHs. The results of the health risk showed that the total deposition concentration (DC) in the alveolar region (AR) was 0.25 and 0.68 μg/m3 in the non-heating and heating seasons respectively. Throughout the entire sampling periods, the lifetime cancer risk (R) based on DC of children and adults varied between 3.53 ×10−5 to 1.79 ×10−4. During the heating season, the potential cancer risk of PAHs in adults was significant, exceeding 10−4, with a rate of 96%. [ABSTRACT FROM AUTHOR]

We sequenced and analyzed the complete chloroplast genomes of Lilium amoenum, Lilium souliei, and Nomocharis forrestii in detail, including the first sequence and structural comparison of Nomocharis forrestii. We found that the lengths and nucleotide composition of the three chloroplast genes showed little variation. The chloroplast genomes of the three Lilium species contain 87 protein coding genes (PCGs), 38 tRNAs, and 8 rRNA genes. The only difference is that Nomocharis forrestii had an additional infA pseudogene. In the sequence analysis of the Lilium chloroplast genomes, 216 SSRs, 143 pairs of long repeats, 571 SNPs, and 202 indels were detected. In addition, we identified seven hypervariable regions that can be used as potential molecular markers and DNA barcodes of Lilium through complete sequence alignment. The phylogenetic tree was constructed from the three chloroplast genome sequences of Lilium obtained here and 40 chloroplast genome sequences from the NCBI database (including 35 Lilium species, 4 Fritillaria species, and one species of Smilax). The analysis showed that the species clustering of the genus Lilium essentially conformed to the classical morphological classification system of Comber, but differences in the classification of individual species remained. In our report, we support the reclassification of Lilium henryi and Lilium rosthorniiy in the genus Lilium. In general, this study not only provides genome data for three Lilium species, but also provides a comparative analysis of the Lilium chloroplast genomes. These advances will help to identify Lilium species, clarify the phylogenetic analysis of the Lilium genus, and help to solve and improve the disputes and deficiencies in the traditional morphological classification. [ABSTRACT FROM AUTHOR]

Key message: Populus tomentosadevelopeda deep root system, wide-spreading and dense lateral roots, and structural roots exploring both deep and shallow soil resources to adapt to intense seasonal groundwater table fluctuation.Abstract: To elucidate the root-system characteristics of P. tomentosa adapting to seasonal fluctuation in the groundwater table, coarse-root architecture and fine-root morphology were investigated in a P. tomentosa plantation under groundwater table fluctuation with an average annual amplitude of 363 cm. Three stands of different ages and planting densities were selected for root sampling, comprising 34 structural roots for assessment of root architecture, ten stumps for measurement of rooting depth and spread distance, and 2106 soil blocks (to 150 cm depth) for analysis of fine-root distribution. The average rooting depth of these stands was 200 cm (maximum root depth 270 cm), indicating that P. tomentosa can be phreatophytic. In 4- and 7-year-old stands, the average lateral root spread distances were 437 and 535 cm, respectively. About 23% of the root area density was distributed in the top-most 20 cm soil, which might help P. tomentosa to intercept rainwater efficiently and absorb shallow soil water resources when the uptake function of deep roots was inhibited by flooding. Some horizontal, inclined, and vertical structural roots were capable of exploring both deep and shallow soil layers. In conclusion, a deep root system, wide-spreading and dense lateral roots in shallow soil layers, and development of some structural roots exploring both deep and shallow soil resources may be the three coordinate rooting adaption strategies that permit P. tomentosa to thrive in sites subject to large fluctuation in the groundwater table. [ABSTRACT FROM AUTHOR]