Modification mechanism of Te and morphology evolution of primary MgSi in an Al-20MgSi alloy.

In the present work, the modification effect of Te and the corresponding growth process of MgSi were clarified. With 0.5 wt% Te addition, the dendritic primary MgSi transformed to polygons, accompanied by a reduction in size from over ∼165 μm-∼18 μm.

Distribution of soil available nutrients and their response to environmental factors based on path analysis model in arid and semi-arid area of northwest China.

The study on the distribution of soil available nutrients and their response to the natural environment can provide valuable data and theoretical guidance for supporting human agricultural activities, especially in arid and semi-arid area where the ecological environment is extremely fragile. Based on the soil sampling and survey data set, this study established the path analysis model of SANs (soil available nutrients, including ammonium nitrogen (AN), available phosphorus (AP) and available potassium (AK)) with topography, climate and vegetation in order to explore how environmental factors interact to affect the content of SANs. Then, we combined Pearson correlation analysis and statistical analysis to explore the distribution of SANs under different environmental conditions and the response of vegetation growth to climate changes, in order to further reveal the availability of soil nutrients.

Heavy metal pollution levels, source apportionment and risk assessment in dust storms in key cities in Northwest China.

In this study, the potential hazards of heavy metals in dust storms were investigated by collecting dust storm samples, measuring their heavy metal concentrations, and using index evaluation, spatial analysis, positive matrix factorization (PMF) model and risk assessment model. Heavy metals in dust storms were contaminated by anthropogenic sources leading to their concentrations being higher than the background values. The enrichment factors and geoaccumulation indices showed that the heavy metals came from both natural and anthropogenic sources, Cu, Ni, Zn and Pb are strongly influenced by anthropogenic sources.

Predicting the spatial pollution of soil heavy metals by using the distance determination coefficient method.

Identifying the spatial distribution of heavy metal concentrations is a prerequisite for soil contamination assessment and control. In this study, soil surface samples (0-20 cm) were collected in Wuwei, China, and heavy metal concentrations were determined. The LUR (land use regression) model was used to simulate the spatial distribution of seven heavy metal concentrations in the study area, considering various factors, and the results were compared with ordinary kriging (OK) interpolation.

Three new species of from tropical Asia support an amphi-Pacific disjunct distribution in the genus.

is reported for the first time from tropical regions in China, thus expanding its known native geographic range from the Neotropics to tropical Asia. Phylogenetic evidence from four nuclear loci supports the monophyly of and a close evolutionary relationship with the nonmonophyletic genera and in the Agaricaceae. Detailed morphological descriptions are provided for three newly described species from China: , and .