The position deviation of the underwater manipulator generated by vortex-induced vibration(VIV)in the shear flow increases relative to that in the uniform flow.Thus,this study established an experimental platform to i...The position deviation of the underwater manipulator generated by vortex-induced vibration(VIV)in the shear flow increases relative to that in the uniform flow.Thus,this study established an experimental platform to investigate the vibration characteristics of the underwater manipulator under shear flow.The vibration response along the manipulator was obtained and compared with that in the uniform flow.Results indicated that the velocity,test height,and flow field were the main factors affecting the VIV of the underwater manipulator.With the increase in the reduced velocity(U_(r)),the dimensionless amplitudes increased rapidly in the in-line(IL)direction with a maximum of 0.13D.The vibration responses in the cross-flow(CF)and IL directions were concentrated at positions 2,3 and positions 1,2,with peak values of 0.46 and 0.54 mm under U_(r)=1.54,respectively.In addition,the vibration frequency increased with the reduction of velocity.The dimensionless dominant frequency in the CF and IL directions varied from 0.39-0.80 and 0.35-0.64,respectively.Moreover,the ratio of the CF and IL directions was close to 1 at a lower U_(r).The standard deviation of displacement initially increased and then decreased as the height of the test location increased.The single peak value of the standard deviation showed that VIV presented a single mode.Compared with the uniform flow,the maximum and average values of VIV displacement increased by 104%and 110%under the shear flow,respectively.展开更多
目的比较中国住院患者采用乙型和丙型肝炎核酸筛查、免疫学筛查和无筛查策略时不同支付意愿(WTP)下的成本效果,探索最优策略。方法以核酸筛查、免疫学筛查和无筛查为研究策略,2021年我国国内生产总值(GDP)80976元为WTP阈值,构建马尔可...目的比较中国住院患者采用乙型和丙型肝炎核酸筛查、免疫学筛查和无筛查策略时不同支付意愿(WTP)下的成本效果,探索最优策略。方法以核酸筛查、免疫学筛查和无筛查为研究策略,2021年我国国内生产总值(GDP)80976元为WTP阈值,构建马尔可夫模型。引入住院患者乙型和丙型肝炎诊断治疗相关参数后,采用TreeAge Pro 2021软件创建以10万例住院患者作为模拟队列的决策树模型,计算不同筛查策略的总成本、总效果、增量成本效果比和平均成本效果比,进行成本效果比较和评估。采用单因素和概率敏感性分析用于评估参数不确定性对最终结果的影响。结果相对无筛查策略,对队列患者乙型肝炎免疫学筛查策略增量总成本为11049536元,增量成本效果比为24762元/质量调整寿命年(QALY),而核酸筛查获得增量总成本19208059元,增量成本效果比为29873元/QALY;核酸与免疫学筛查比较增量成本效果比为45834元/QALY。相对无筛查策略,丙型肝炎免疫学筛查策略增量成本效果比为5731元/QALY,核酸筛查策略增量成本效果比为8722元/QALY,核酸筛查与免疫学筛查的增量效果比为45591元/QALY。概率敏感性分析结果显示,当核酸检测费用超过214.53元时,在1倍GDP的WTP值下进行乙型肝炎核酸筛查不具有成本效果。当核酸检测费用超过132.18元时,在1倍GDP的WTP值下进行丙型肝炎筛查不具有成本效果。结论核酸筛查策略能获得更多的成本效果。与对住院患者乙型和丙型肝炎无筛查策略比较,无论是核酸筛查还是免疫学筛查策略均具有成本效果。展开更多
基金Supported by the National Natural Science Foundation of China(No.51905211)the“20 Regulations for New Universities”of Jinan(No.202228116).
文摘The position deviation of the underwater manipulator generated by vortex-induced vibration(VIV)in the shear flow increases relative to that in the uniform flow.Thus,this study established an experimental platform to investigate the vibration characteristics of the underwater manipulator under shear flow.The vibration response along the manipulator was obtained and compared with that in the uniform flow.Results indicated that the velocity,test height,and flow field were the main factors affecting the VIV of the underwater manipulator.With the increase in the reduced velocity(U_(r)),the dimensionless amplitudes increased rapidly in the in-line(IL)direction with a maximum of 0.13D.The vibration responses in the cross-flow(CF)and IL directions were concentrated at positions 2,3 and positions 1,2,with peak values of 0.46 and 0.54 mm under U_(r)=1.54,respectively.In addition,the vibration frequency increased with the reduction of velocity.The dimensionless dominant frequency in the CF and IL directions varied from 0.39-0.80 and 0.35-0.64,respectively.Moreover,the ratio of the CF and IL directions was close to 1 at a lower U_(r).The standard deviation of displacement initially increased and then decreased as the height of the test location increased.The single peak value of the standard deviation showed that VIV presented a single mode.Compared with the uniform flow,the maximum and average values of VIV displacement increased by 104%and 110%under the shear flow,respectively.
文摘目的比较中国住院患者采用乙型和丙型肝炎核酸筛查、免疫学筛查和无筛查策略时不同支付意愿(WTP)下的成本效果,探索最优策略。方法以核酸筛查、免疫学筛查和无筛查为研究策略,2021年我国国内生产总值(GDP)80976元为WTP阈值,构建马尔可夫模型。引入住院患者乙型和丙型肝炎诊断治疗相关参数后,采用TreeAge Pro 2021软件创建以10万例住院患者作为模拟队列的决策树模型,计算不同筛查策略的总成本、总效果、增量成本效果比和平均成本效果比,进行成本效果比较和评估。采用单因素和概率敏感性分析用于评估参数不确定性对最终结果的影响。结果相对无筛查策略,对队列患者乙型肝炎免疫学筛查策略增量总成本为11049536元,增量成本效果比为24762元/质量调整寿命年(QALY),而核酸筛查获得增量总成本19208059元,增量成本效果比为29873元/QALY;核酸与免疫学筛查比较增量成本效果比为45834元/QALY。相对无筛查策略,丙型肝炎免疫学筛查策略增量成本效果比为5731元/QALY,核酸筛查策略增量成本效果比为8722元/QALY,核酸筛查与免疫学筛查的增量效果比为45591元/QALY。概率敏感性分析结果显示,当核酸检测费用超过214.53元时,在1倍GDP的WTP值下进行乙型肝炎核酸筛查不具有成本效果。当核酸检测费用超过132.18元时,在1倍GDP的WTP值下进行丙型肝炎筛查不具有成本效果。结论核酸筛查策略能获得更多的成本效果。与对住院患者乙型和丙型肝炎无筛查策略比较,无论是核酸筛查还是免疫学筛查策略均具有成本效果。
