High-throughput deformation potential and electrical transport calculations

The deformation potential plays an important role in electrical transport properties, but in the context of high-throughputsearches requires a consistent and readily computable reference level. Here, we design a high-throughput method forcalculating the deformation potential for semiconductors in the MatHub-3d database. The deformation potential is obtainedfrom the volume-dependent band edge (valence band maximum and conduction band minimum) variations with respect tothe reference level. In order to adapt the calculation of reference level to a high-throughput manner, the average value of thefirst valence electron energy band associated with each compound is used as the reference level. Deformation potentials for11,993 materials are calculated using the above-mentioned method. By considering the calculated deformation potentials,electronic structures, and bulk moduli, 9957 compounds with converged electrical transport properties are obtained. 332promising p-type thermoelectric materials, and 321 n-type entries are then proposed. Among them, 156 compounds arescreened to having both potentially good n- and p-type thermoelectric transport properties. The band structures and chemicalbonding information for several typical compounds are further presented to reveal favorable band and bonding features forthermoelectrics.

Promotion mechanism of self-transmissible degradative plasmid transfer in maize rhizosphere and its application in naphthalene degradation in soil

Rhizospheres can promote self-transmissible plasmid transfer,however,the corresponding mechanism has not received much attention.Plant-microbe remediation is an effective way to promote pollutant biodegradation;however,some pollutants,such as naphthalene,are harmful to plants and result in inefficient plant-microbe remediation.In this study,trans-fer of a TOL-like plasmid,a self-transmissible plasmid loaded with genetic determinants for pollutant degradation,among different bacteria was examined in bulk and rhizosphere soils as well as addition of maize root exudate and its artificial root exudate(ARE).The results showed that the numbers of transconjugants and recipients as well as bacterial metabolic activities,such as xylE mRNA expression levels and catechol 2,3-dioxygenase(C23O)activ-ities of bacteria,remained high in rhizosphere soils,when compared with bulk soils.The number of transconjugants and bacterial metabolic activities increased with the increasing exudate and ARE concentrations,whereas the populations of donor and recipient bacteria were substantially unaltered at all concentrations.All the experiments consistently showed that a certain number of bacteria is required for self-transmissible plasmid transfer,and that the increased plasmid transfer might predominantly be owing to bacterial metabolic activ-ity stimulated by root exudates and ARE.Furthermore,ARE addition increased naphthalene degradation by transconjugants in both culture medium and soil.Thus,the combined action of a wide variety of components in ARE might contribute to the increased plasmid transfer and naphthalene degradation.These findings suggest that ARE could be an effectively al-ternative for plant-microbe remediation of pollutants in environments where plants cannot survive.

High-throughput screening of room temperature active Peltier cooling materials in Heusler compounds

Active Peltier cooling enables Peltier heat transfer in addition to the traditional Fourier thermal conductance,which is useful in some special applications,such as the microthermostats.From the material wise,however,the study on the active Peltier cooling materials is rare.We carried out a high-throughput workflow to screen out 5 room-temperature active Peltier cooling materials,GaSbLi_(2),HgPbCa_(2),SnTiRu_(2),GeYbLi_(2),and GeTiFe_(2),from 2958 Heusler materials.All the five materials are semimetals or very narrow band gap systems with high electrical conductivity.Some of these materials have relatively large Seebeck coefficients due to the band asymmetry.Their effective thermal conductivityκ_(eff)s,which are the summation of active Peltier thermal conductivity and passive thermal conductivity,are all greater than Cu at the room temperature andΔT=1 K.The present work gives a possible way to search active cooling Peltier materials for the applications of precise temperature control.