目的建立基于Turboflow在线净化结合超高效液相色谱-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-electrostatic field orbital high resolution mass spectrometry,UPLC-Q Exactive MS)测定水产品中4种地西泮...目的建立基于Turboflow在线净化结合超高效液相色谱-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-electrostatic field orbital high resolution mass spectrometry,UPLC-Q Exactive MS)测定水产品中4种地西泮及代谢物和6种丁香酚类化合物的方法。方法采用Turboflow在线净化,Accucore^(TM) aQ C_(18)柱(100 mm×2.1 mm,2.6μm)分离,以水-乙腈为流动相梯度洗脱,全扫描+自动触发二级质谱的正离子扫描监测模式,外标法定量。结果地西泮及代谢物和丁香酚类化合物在1.0~100.0μg/L范围内线性良好,化合物的相关系数(r^(2))均大于0.995;在水产品中的定量限分别为0.5μg/kg、2.0μg/kg;加标回收率为75.3%~110.0%,相对标准偏差小于10%。结论该方法操作简便、灵敏度高、检出限低,适用于水产品中地西泮及丁香酚类化合物的测定。通过调查发现,运输环节中水产品中检出地西泮和丁香酚类化合物,亟需对水产品中镇静剂或麻醉剂残留情况开展风险监测,加强监管以保障水产品质量安全。展开更多
This study investigates the effect of the initial tropical cyclone(TC)vortex structure on the intensity change during the eyewall replacement cycle(ERC)of TCs based on two idealized simulations using the Weather Resea...This study investigates the effect of the initial tropical cyclone(TC)vortex structure on the intensity change during the eyewall replacement cycle(ERC)of TCs based on two idealized simulations using the Weather Research and Forecasting(WRF)model.Results show that an initially smaller TC with weaker outer winds experienced a much more drastic intensity change during the ERC than an initially larger TC with stronger outer winds.It is found that an initially larger TC vortex with stronger outer winds favored the development of more active spiral rainbands outside the outer eyewall,which slowed down the contraction and intensification of the outer eyewall and thus prolonged the duration of the concentric eyewall and slow intensity evolution.In contrast,the initially smaller TC with weaker outer winds corresponded to higher inertial stability in the inner core and weaker inertial stability but stronger filamentation outside the outer eyewall.These led to stronger boundary layer inflow,stronger updraft and convection in the outer eyewall,and suppressed convective activity outside the outer eyewall.These resulted in the rapid weakening during the formation of the outer eyewall,followed by a rapid re-intensification of the TC during the ERC.Our study demonstrates that accurate initialization of the TC structure in numerical models is crucial for predicting changes in TC intensity during the ERC.Additionally,monitoring the activity of spiral rainbands outside the outer eyewall can help to improve short-term intensity forecasts for TCs experiencing ERCs.展开更多
针对推力状态控制时执行机构传感器发生故障影响发动机安全运行的问题,提出了一种非相似容错控制计划。该方法将燃油闭环/喷管开环和喷管闭环/燃油开环两种控制计划互为备份,并结合一种惯性切换逻辑,在执行机构传感器发生故障时切换控...针对推力状态控制时执行机构传感器发生故障影响发动机安全运行的问题,提出了一种非相似容错控制计划。该方法将燃油闭环/喷管开环和喷管闭环/燃油开环两种控制计划互为备份,并结合一种惯性切换逻辑,在执行机构传感器发生故障时切换控制计划以保障发动机的安全运行。面向串联式TBCC(Turbine Based Combined Cycle)发动机的冲压模态开展了仿真验证,结果表明,该容错控制计划能够实现发动机全包线范围内的推力状态容错控制,并且在传感器发生故障时能够平稳切换,推力波动小于1%,增强了控制系统的容错性。展开更多
文摘目的建立基于Turboflow在线净化结合超高效液相色谱-静电场轨道阱高分辨质谱法(ultra performance liquid chromatography-electrostatic field orbital high resolution mass spectrometry,UPLC-Q Exactive MS)测定水产品中4种地西泮及代谢物和6种丁香酚类化合物的方法。方法采用Turboflow在线净化,Accucore^(TM) aQ C_(18)柱(100 mm×2.1 mm,2.6μm)分离,以水-乙腈为流动相梯度洗脱,全扫描+自动触发二级质谱的正离子扫描监测模式,外标法定量。结果地西泮及代谢物和丁香酚类化合物在1.0~100.0μg/L范围内线性良好,化合物的相关系数(r^(2))均大于0.995;在水产品中的定量限分别为0.5μg/kg、2.0μg/kg;加标回收率为75.3%~110.0%,相对标准偏差小于10%。结论该方法操作简便、灵敏度高、检出限低,适用于水产品中地西泮及丁香酚类化合物的测定。通过调查发现,运输环节中水产品中检出地西泮和丁香酚类化合物,亟需对水产品中镇静剂或麻醉剂残留情况开展风险监测,加强监管以保障水产品质量安全。
基金National Key R&D Program of China (2022YFC3004200)National Natural Science Foundation of China (42305007,41730960,41875057)National Science Foundation (AGS-1834300)。
文摘This study investigates the effect of the initial tropical cyclone(TC)vortex structure on the intensity change during the eyewall replacement cycle(ERC)of TCs based on two idealized simulations using the Weather Research and Forecasting(WRF)model.Results show that an initially smaller TC with weaker outer winds experienced a much more drastic intensity change during the ERC than an initially larger TC with stronger outer winds.It is found that an initially larger TC vortex with stronger outer winds favored the development of more active spiral rainbands outside the outer eyewall,which slowed down the contraction and intensification of the outer eyewall and thus prolonged the duration of the concentric eyewall and slow intensity evolution.In contrast,the initially smaller TC with weaker outer winds corresponded to higher inertial stability in the inner core and weaker inertial stability but stronger filamentation outside the outer eyewall.These led to stronger boundary layer inflow,stronger updraft and convection in the outer eyewall,and suppressed convective activity outside the outer eyewall.These resulted in the rapid weakening during the formation of the outer eyewall,followed by a rapid re-intensification of the TC during the ERC.Our study demonstrates that accurate initialization of the TC structure in numerical models is crucial for predicting changes in TC intensity during the ERC.Additionally,monitoring the activity of spiral rainbands outside the outer eyewall can help to improve short-term intensity forecasts for TCs experiencing ERCs.
文摘针对推力状态控制时执行机构传感器发生故障影响发动机安全运行的问题,提出了一种非相似容错控制计划。该方法将燃油闭环/喷管开环和喷管闭环/燃油开环两种控制计划互为备份,并结合一种惯性切换逻辑,在执行机构传感器发生故障时切换控制计划以保障发动机的安全运行。面向串联式TBCC(Turbine Based Combined Cycle)发动机的冲压模态开展了仿真验证,结果表明,该容错控制计划能够实现发动机全包线范围内的推力状态容错控制,并且在传感器发生故障时能够平稳切换,推力波动小于1%,增强了控制系统的容错性。
