Characteristics of a pre-combustion plasma jet igniter

Plasma ignition technology has delivered good performance in the aerospace industry. In this study, a pre-combustion plasma jet igniter was designed, and its characteristics were examined from three aspects: the morphology, temperature, and discharge characteristics and process of ignition. Images of the OH distribution were obtained by using an OH Planar Laser-Induced Fluorescence(OH-PLIF) experimental system. Results have shown that the proposed plasma jet had a higher OH concentration, longer length, and larger area than those of a traditional igniter. The stability of discharge of the igniter was improved as the equivalence ratio φ was increased, and reducing gas flow reduced the pulsation of the plasma jet. When the input current was increased from 15A to 35 A, the highest average temperature increased from 5127 K to 7987 K. An increase in the equivalence ratio reduced the region of arc ionization, but expanded the regions of the core combustion reaction and the outer flame. Herein, this study has obtained a deep understanding of the jet and ignition law and developed a new idea for the application of plasma in the ignition field.A pre-combustion plasma jet igniter can significantly improve the efficiency of ignition and shorten the ignition process compared with a traditional igniter.

Deterministic processes dominate microbial community assembly in artificially bred Schizothorax wangchiachii juveniles after being released into wild

Fish artificial breeding and release is an important method to restore wild populations of endemic fish species around the world.Schizothorax wangchiachii(SW)is an endemic fish in the upper Yangtze River and is one of the most important species for the artificial breeding and release program implemented in the Yalong River drainage system in China.It is unclear how artificially bred SW adapts to the changeable wild environment post-release,after being in a controlled and very different artificial environment.Thus,the gut samples were collected and analyzed for food composition and microbial 16S rRNA in artificially bred SW juveniles at day 0(before release),5,10,15,20,25,and 30 after release to the lower reaches of the Yalong River.The results indicated that SW began to ingest periphytic algae from the natural habitat before day 5,and this feeding habit is gradually stabilized at day 15.Prior to release,Fusobacteria are the dominant bacteria in the gut microbiota of SW,while Proteobacteria and Cyanobacteria generally are the dominant bacteria after release.The results of microbial assembly mechanisms illustrated that deterministic processes played a more prominent role than stochastic processes in the gut microbial community of artificially bred SW juveniles after releasing into the wild.Overall,the present study integrates the macroscopic and microscopic methods to provide an insight into the food and gut microbial reorganization in the released SW.This study will be an important research direction to explore the ecological adaptability of artificially bred fish after releasing into the wild.