Simultaneously optimizing electrical and thermal transport properties of bulk thermoelectric materials remains a key challenge due to the conflicting combination of material traits. Here, we have explored the electrical and thermal transport features of In-filled CoSb₃ through X-ray absorption fine structure, X-ray photoemission spectra, transport measurement and theoretical calculation. The results provide evidence of three types of coexisting multi-localization transport behaviours in the material; these are heat-carrying phonon-localized resonant scattering, accelerated electron movement and increase in density of states near the Fermi level. The 5p-orbital hybridization between In and Sb is discovered in the In-filled CoSb₃ compound, which results in a charge transfer from Sb to In and the enhancement of p–d orbital hybridization between Co and Sb. Our work demonstrates that the electrical and thermal properties of filled skutterudite bulk thermoelectric materials can be simultaneously optimized through the three types of coexisting multi-localization transport behaviours in an independent way.

The aggregate segregation during construction has a significant impact on the performance of asphalt pavement; however, the segregation evaluation parameters selected by different researchers varied a lot. Also, standard criteria for the impaction of segregation on the performance are still lacking. Therefore, this research proposed a set of segregation evaluation indexes that divided the gradation types into five levels, from coarse-severe to fine-severe gradation. The impact of various segregation levels on the volumetrics, mechanical performance, and road performance of the pavement were evaluated. The mechanical test results indicated that, given the change in the segregation degree from coarse to fine, the Marshall stability and immersive residual stability of the asphalt mixture obviously increased, and the dynamic stability and low temperature failure strain of the heavy segregation gradation obviously decreased. The result also indicated that the rutting resistance first increased first and then decreased because of the cohesion reduction when the gradation was changing from fine to coarse. The result found that the proposed evaluation index can reasonably characterize the degree of aggregate segregation.

To promote the resource utilization of steel slag and improve the production process of steel slag in steelmaking plants, this research studied the characteristics of three different processed steel slags from four steelmaking plants. The physical and mechanical characteristics and volume stability of steel slags were analyzed through density, water absorption, and expansion tests. The main mineral phases, morphological characteristics, and thermal stability of the original steel slag and the steel slag after the expansion test are analyzed with X-ray diffractometer (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TG) tests. The results show that the composition of steel slag produced by different processes is similar. The main active substances of other processed steel slags are dicalcium silicate (C₂S), tricalcium silicate (C₃S), CaO, and MgO. After the expansion test, the main chemical products of steel slag are CaCO₃, MgCO₃, and calcium silicate hydrate (C-S-H). Noticeable mineral crystals appeared on the surface of the steel slag after the expansion test, presenting tetrahedral or cigar-like protrusions. The drum slag had the highest density and water stability. The drum slag had the lowest porosity and the densest microstructure surface, compared with steel slags that other methods produce. The thermal stability of steel slag treated by the hot splashing method was relatively higher than that of steel slag treated by the other two methods.