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The article discusses the discovery of a new CRISPR-Cas system called Cas12j-SF05, which belongs to the hypercompact type V Cas12j subfamily. The researchers identified this system from an environmental metagenome and found that it has high gene editing efficiency in both mammalian cells and monocot plants. They also investigated the molecular mechanisms of Cas12j-SF05's recognition and cleavage of its target DNA. The findings suggest that Cas12j-SF05 has great potential as a gene editing tool in biotechnological and agricultural applications. [Extracted from the article]

Unsatisfied electrode bonding in half-Heusler devices renders thermal damage and large efficiency loss, which limits their practical service at high temperatures. Here, we develop a thermodynamic strategy to screen barrier layer elements. Theoretically, we found that the interface between VIIB elements and half-Heuslers possesses near-zero interfacial reaction energy and large atomic diffusion barrier. Experimentally, such an interphase proves to be the atomic direct bonding and has high thermal stability at 1073 K, leading to ideal ohmic contact. Such thermally inert and ohmic contact interface enable modules stably to work at elevated temperature up to 1100 K, which releases the peak performance of half-Heuslers and in turn boosts the energy conversion efficiencies to the records of 11.1% and 13.3% for half-Heusler single-stage and half-Heusler/Bi2Te3 segmented modules. This design strategy provides a feasible solution for the high-temperature half-Heusler generators and gives enlightenment for other package interconnection design of electronic devices. Unsatisfied electrode bonding in half-Heusler devices limits their practical service at high temperatures. Here, the authors develop a direct bonding interface to ideal ohmic contact and thermally inert and ohmic contact, leading to high deficiency. [ABSTRACT FROM AUTHOR]

Although the CoSb3-based skutterudite thermoelectric devices have been highly expected for wide uses such as waste heat recovery and space power supply, the limited long-term service stability majorly determined by the degradation of electrode interface obstructs its applications. Here, we built up an effective criterion for screening barrier layer based on the combination of negative interfacial reaction energy and high activation energy barrier of Sb migration through the formed interfacial reaction layer. Accordingly, we predicted niobium as a promising barrier layer. The experimental results show the skutterudite/Nb joint has the slowest interfacial reaction layer growth rate and smallest interfacial electrical resistivity. The fabricated 8-pair skutterudite module using Nb as barrier layer achieves a recorded conversion efficiency of 10.2% at hot-side temperature of 872 K and shows excellent stability during long-time aging. This simple criterion provides an effective guidance on screening barrier layer with bonding-blocking-conducting synergetic functions for thermoelectric device integration. Long-term service stability of thermoelectric devices is one of the major obstacles for their application. Here, the authors combine interfacial reaction energy and Sb migration activation energy barrier as a criterion to determine the interfacial reliability for skutterudite thermoelectric devices. [ABSTRACT FROM AUTHOR]

The structural stability of filled p-type skutterudites RETMSb ( RE = rare earth; TM = Fe, Ru) was studied via ab initio calculations. Most of the RE metals (La-Ho and Yb) could be filled into the cages (voids) of FeSb to form stable filled skutterudites. However, only a few RE metals (La-Nd and Eu) could be stably filled into the cage of RuSb-based skutterudites. Systematic analysis of bonding energy showed that the structural stability could be attributed to ionic radius and effective charge state differences of the RE fillers. Resonant rattling frequencies of the fillers in both FeSb- and RuSb-based skutterudites were also studied. [ABSTRACT FROM AUTHOR]

Heavy rare earth element Dy-filled skutterudites (DyFeCoSb) have been synthesized by a melting-quenching-annealing method and sintered by the spark plasma sintering technique. Our results suggest that single-phased DyFeCoSb compounds could be obtained when the Fe content is less than 1.5. The maximum filling fraction of Dy in skutterudites increases with increasing Fe content. We also found significant lattice expansion induced by Fe substitution at Co sites and Dy filling in the voids. The electrical conductivity, Seebeck coefficient, and thermal conductivity have been measured in the temperature range from 300 K to 800 K. The low-temperature Hall coefficient and carrier mobility are reported in the temperature range from 2.5 K to 300 K. The power factor for DyFeCoSb increases with increasing Fe content. A significant reduction in lattice thermal conductivity is observed in heavy rare earth element Dy-filled skutterudites due to the low localized vibrational frequency of Dy that effectively scatters low-frequency lattice phonons. The sample with composition DyFeCoSb has lattice thermal conductivity as low as 1.05 W m K at room temperature. The thermoelectric figure of merit ( ZT) reaches a maximum value of 0.67 at 750 K. [ABSTRACT FROM AUTHOR]

Previous reports about the thermal conductivities of VO showed various temperature dependences across metal-insulator transition (MIT) temperature. In this work, polycrystalline VO samples were fabricated by spark plasma sintering of VO powder. Temperature dependences of their thermal conductivities were investigated using laser flash technique, and the thermal conductivity showed a significant decrease trend from metal-phase to insulator phase. Electrical transport properties were investigated to confirm both carrier and lattice contribution to the thermal conductivity. It is found that the lattice thermal conductivity decreased significantly across MIT point, which may be caused by soft phonon mode in metal phase of VO. [ABSTRACT FROM AUTHOR]