| 1 | Identifying the turbulent flow developing inside and around the bottom trawl by Electromagnetic Current Velocity Meter approach in the flume tank显示文摘The Knowledge of turbulent flow developing inside and around the bottom trawl net is of great importance not only for improving the hydrodynamic performance of the gear but also for the selectivity via the fish response,such as the herding response or escape behavior.The 3-D Electromagnetic Current Velocity Meter(ECVM)measurements were performed to investigate the effect of turbulent flow on the bottom trawl net performance and to analyze the turbulence intensity and velocity ratio inside and around different parts of the trawl net.Proper orthogonal decomposition(POD)method was applied in order to extract the phase averaged mean velocity field of turbulent flow from each available ECVM instantaneous velocity.The results demonstrated the existence of turbulence flow,consisting of turbulent boundary layer flow and the turbulence due to the trawl wake developing all inside and around the bottom trawl net.Increasing input streamwise velocity results in faster trawl movement and a significant turbulent flow.The maximum turbulence intensity inside and around trawl wing,square part,first belly,second belly,third belly,cod-end is 0.95%,1.34%,3.40%,4.10%,4.25%and 3.80%,respectively.It was found that the mean velocity field in a turbulent flow inside and around trawl net cod-end recovered on the average was~77.58%of the input streamwise velocity.It is~12.92%,~13.07%,~11.40%,~13.00%and~0.45%less than that inside and around trawl wing,square part,first belly,second belly,and third belly of the bottom trawl net,respectively.The turbulent flow behavior depends strongly on the structure oscillation,input streamwise velocity and,porosity of the net structure.It is necessary to take into account the velocity reduction inside and around a different part of the trawl net to improve the entire drag force determination,cod-end design,and further selectivity control of the fishing gear. | Nyatchouba Nsangue Bruno Thierry Hao Tang Liu-xiong Xu Fuxiang Hu Xinxing You Micah Adekunle David Njomoue Pandong Achille | 2021 | Journal of Hydrodynamics2021，33，3： | 1 |
| 2 | Probing surface structure on two-dimensional metal-organic layers to understand suppressed interlayer packing显示文摘Two-dimensional metal-organic layers(MOLs)from alternatively connected benzene-tribenzoate ligands and Zr6(μ3-O)_(4)(μ3-OH)_(4) or Hf6(μ3-O)_(4)(μ3-OH)_(4) secondary building units can be prepared in gram scale via solvothermal synthesis.However,the reason why the monolayers did not pack to form thick crystals is unknown.Here we investigated the surface structure of the MOLs by a combination of sum-frequency generation spectroscopy,nanoscale infrared microscopy,atomic force microscopy,aberration-corrected transmission electron microscopy,and compositional analysis.We found a partial coverage of the monolayer surface by dangling tricarboxylate ligands,which prevent packing of the monolayers.This finding illustrates low-density surface modification as a strategy to prepare new two-dimensional materials with a high percentage of exposed surface. | Peican Chen Yi Liu Xuefu Hu Xiaolin Liu En-Ming You Xudong Qian Jiawei Chen Liangping Xiao Lingyun Cao Xinxing Peng Zhongming Zeng Yibing Jiang Song-Yuan Ding Honggang Liao Zhaohui Wang Da Zhou Cheng Wang | 2020 | Nano Research2020，13，11： | 0 |
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