新冠肺炎疫情防控后强化卫生监督体系建设有关问题的思考

突如其来的新冠肺炎疫情在充分展示中国治理体系制度优势的同时,也暴露出我国在重大疫情防控体制机制、公共卫生应急管理体系等方面存在的明显短板和不足。尽管应对传染病疫情等突发公共卫生事件,我国相关法律规制基本齐备,但实际上,从野生动物的管控,到新冠肺炎的发现、报告、应对和处置,很少有按照相关法律法规有条不紊的举措。公共卫生领域的法律规制刚性约束不强,执法力量薄弱,导致法律无法有效规范各方行为。因此,着力提高法律规制的针对性、合理性和可操作性,尤其是约束性,加强健康相关领域的执法监督与行政督察,逐步补齐公共卫生体系中卫生健康执法监督的短板,是依法推进疫情防治和突发公共卫生事件处置的必由之路。本文就公共卫生体系建设发展及不平衡问题、强化卫生监督体系建设的重要意义、当前卫生监督体系建设面临的困难和挑战等方面问题进行思考和分析,对新冠肺炎疫情之后强化卫生监督体系建设提出发展建议。

Investigation on Effects of Vertical Degree of Freedom on Gap Resonance Between Two Side-by-Side Boxes Under Wave Actions

The possible wave resonance in the narrow gap formed by the parallel arrangement of ships will lead to the sharp increase of wave loads and the rapid growth of motion response.The fluid resonance inside a narrow gap between two side-by-side boxes is investigated numerically based on an open-source CFD package,OpenFOAM.The upstream box remains fixed,while the downstream box is allowed to heave freely under wave actions.This work aims to examine the influence of the motion of the downstream box on the fluid resonant behaviors inside the gap.The hydrodynamic behaviors considered include the wave height inside the gap,the heave displacement,and the reflection,transmission,and energy loss coefficients.Gao et al.(2021)reported the influence of the motion of the upstream box on gap resonant behaviors.For comparative study,some results of Gao et al.(2021)are also presented in this work.It is found that the heave motion of any box in the two-box system leads to a smaller resonant wave height amplification and a larger fluid resonance frequency.The frequency at which the maximum heave displacement of the downstream box occurs is less than the fluid resonant frequency.The heave motion of any box in the two-box system results in a larger reflection coefficient and a smaller energy loss coefficient.

基于两相流理论的稀疏和致密颗粒流统一模型

统一描述不同浓度的固、液两相流动具有重要意义。该文充分考虑不同流态下颗粒体的本构关系、颗粒体与流体的相间作用以及流体紊动影响,应用两相流模型对统一描述稀疏和致密颗粒流问题进行了探索。经与实验结果比较,该两相流模型对不同粒径的稀疏和致密颗粒体的运动过程均能准确刻画。模拟结果表明,不同粒径稀疏颗粒体与流体的相间作用差异较大,其中细颗粒体受到的沉积作用更弱,更容易在周围流体中保持悬浮状态,因而前端运动距离更长。流体紊动粘性对涡旋结构的发展有较大的影响,考虑紊动时流体倾向于向前运动,进而促进了稀疏颗粒体的发展。致密颗粒体堆积表面附近受到的流体拖曳力较大,其在较长时间内促进了细颗粒体的向外发展,对粗颗粒体的运动则主要起到了阻碍作用。致密细颗粒体中的流体动压作用更为明显,流体正压促进了初始颗粒体前端的发展,流体负压则影响着颗粒体堆积形态的塑造。