Xiangxiang Fan

In this work, ZIF-8-derived Co₃O₄@ZnO microspheres were prepared by a liquid-phase concentration-controlled nucleation strategy. The results of the material characterization showed that Co₃O₄@ZnO microspheres were obtained, and the surface structure could be controlled with the concentration of the ligand. Compared with pure Co₃O₄ microspheres, the operating temperature of optimized Co₃O₄@ZnO microspheres increased by 90 °C after the gas-sensing test. The response to 50 ppm acetone of Co₃O₄@ZnO microspheres was 4.5 times higher than that of pure Co₃O₄, and the detection limit reached 0.5 ppm. Meanwhile, Co₃O₄@ZnO microspheres showed a shorter response-recovery time and better selectivity. The enhanced-sensing mechanism of the ZIF-8-derived Co₃O₄@ZnO microspheres was also analyzed.

With the synergistic effect of Pr and Zn, the material of Co ₃ O ₄ mixed with Pr/Zn exhibits improved properties of anti-humidity and acetone sensitivity.

The In₂O₃–NiO nanofiber with p–n heterojunctions exhibited an enhanced acetone sensing performance, and the detection limit reached 10 ppb.

The Low-Efficiency Adaptive Clustering Hierarchical (LEACH) protocol, a hierarchical routing protocol, has the advantage of simple implementation and can effectively balance network loads. However, to date there has been a lack of consideration for its use in heterogeneous energy network environments. To solve this problem, the Energy-Coverage Ratio Clustering Protocol (E-CRCP) is proposed, which is based on reducing the energy consumption of the system and utilizing the regional coverage ratio. First, the energy model is designed. The optimal number of clusters is determined based on the principle of “minimum energy consumption”, and the cluster head selection is based on the principle of “regional coverage maximization”. In order to balance the network load as much as possible, in the next iteration of cluster head selection, the cluster head with the lowest residual energy and the highest energy consumption is replaced to prolong the network’s life. Our simulated results demonstrate that the proposed method has some advantages in terms of longer network life, load balancing, and overall energy consumption in the environment of a heterogeneous energy wireless sensor network.

In this work, a sensor based on electrospinning SnO₂-ZnO composite nanofibers with different parameters were prepared. For detecting of NO₂ at room-temperature, the ultraviolet light was used to enhance the gas sensing properties. The influence of Sn salt on the resistance, grain size and response to NO₂ was investigated. The results showed that the grain size was inhibited, the resistance was increased and the response to NO₂ was enhanced with the addition of Sn salt. The fibers with Sn salt mass ratio of 10% exhibited greatest sensitivity to NO₂ and good stability in cycle test. At last, a mechanism about UV-enhanced gas sensing properties of SnO₂-ZnO nanofibers was discussed.