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A quantum confinement model for nanocrystals developed is extended to study for the optical gap shifts in core/shell quantum dots and nanowires. The chemical bond properties and gap shifts in the InP/ZnS, CdSe/CdS, CdSe/ZnS, and CdTe/ZnS core/shell quantum dots are calculated in detail. The calculated band gaps are in excellent agreement with experimental values. The effects of structural taping and twinning on quantum confinement of InP and Si nanowires are elucidated. It is found theoretically that a competition between the positive Kubo energy-gap shift and the negative surface energy shift plays the crucial role in the optical gaps of these nanosystems.

The microbial community compositions of a chemostat enriched in a thermophilic (55 °C) mixed culture fermentation (MCF) for hydrogen production under different operational conditions were revealed in this work by integrating denaturing gradient gel electrophoresis (DGGE), Illumina Miseq high-throughput sequencing, and 16S rRNA clone library sequencing. The results showed that the community structure of the enriched cultures was relatively simple. Clones close to the genera of Thermoanaerobacter and/or Bacillus mainly dominated the bacteria. And homoacetogens and archaea were washed out and not detected even by Illumina Miseq high-throughput sequencing which supported the benefit for hydrogen production. On the other hand, the results revealed that the metabolic shift was clearly associated with the change of dominated bacterial groups. The effects of hydrogen partial pressure (PH2) and pH from 4.0 to 5.5 on the microbial compositions were not notable and Thermoanaerobacter was dominant, thus, the metabolites were also not changed. While Bacillus, Thermoanaerobacter and Propionispora hippei dominated the bacteria communities at neutral pH, or Bacillus and Thermoanaerobacter dominated at high influent glucose concentrations, consequently the main metabolites shifted to acetate, ethanol, propionate, or lactate. Thereby, the effect of microbial composition on the metabolite distribution and shift shall be considered when modeling thermophilic MCF in the future.

Heteronuclear dual‐site catalysts (HDACs), inspired from single‐atom catalyst, have been proposed as advanced alternatives of noble metal catalyst, especially toward nitrogen reduction reaction (NRR). However, the search for favorable candidates with both promising NH3 yield and noble Faradaic efficiency is still challenging, due to limited experimentally available bi‐metal pairs and lack of thorough understanding of the design criteria. Herein, by theoretical screening of a family of M/Fe combinations (M = Sc, Ti, V, Cr, Mn, Co, and Ni), atomically dispersed binary V/Fe architecture anchored on nitrogen‐doped carbon matrix (VFe/NC) is proposed with a small limiting potential (0.39 V) and high selectivity over the hydrogen evolution reaction (HER). Owing to a perfect matching with N2 antibonding state, V 3dz2 orbitals, “push” electrons into adsorbed N2 antibonding stats and simultaneously Fe 3dyz “pull” extra electrons back. Benefiting from the synergistic effect from the dual‐active sites, an outstanding NH3 yield of 73.44 μg h−1 mgcat−1 (8070.32 μg h−1 mgVFe−1) and an excellent Faradaic efficiency of 43% are achieved, overwhelming literature‐reported atomic‐level catalysts. This study promotes the development of HDACs that are capable of high yield rate accompanied with high Faradaic efficiency.

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