Tension Leg Platform(TLP)in deepwater oil and gas field development usually consists of a hull,tendons,and top tension risers(TTRs).To maintain its top tension,each TTR is connected with a tensioner system to the hull...Tension Leg Platform(TLP)in deepwater oil and gas field development usually consists of a hull,tendons,and top tension risers(TTRs).To maintain its top tension,each TTR is connected with a tensioner system to the hull.Owing to the complicated configuration of the tensioners,the hull and TTRs form a strong coupled system.Traditionally,some simplified tensioner models are applied to analyze the TLP structures.There is a large discrepancy between their analysis results and the actual mechanism behaviors of a tensioner.It is very necessary to develop a more detailed tensioner model to consider the coupling effects between TLP and TTRs.In the present study,a fully coupled TLP hull-TTR system for hydrodynamic numerical simulation is established.A specific hydraulic pneumatic tensioner is modeled by considering 4 cylinders.The production TTR model is stacked up by specific riser joints.The simulation is also extended to analyze an array of TTRs.Different regular and irregular waves are considered.The behaviors of different cylinders are presented.The results show that it is important to consider the specific configurations of the tensioner and TTRs,which may lead to obviously different response behaviors,compared with those from a simplified model.展开更多
重型车辆具有重心高,装载量大,高宽比相对乘用车较大等特点,导致其侧翻稳定极限较低,极易发生侧翻事故。建立重型车辆侧翻预测模型,利用车辆实车试验数据离线辨识技术,辨识出3自由度车辆模型中的关键参数,然后利用改进后的车辆模型进行...重型车辆具有重心高,装载量大,高宽比相对乘用车较大等特点,导致其侧翻稳定极限较低,极易发生侧翻事故。建立重型车辆侧翻预测模型,利用车辆实车试验数据离线辨识技术,辨识出3自由度车辆模型中的关键参数,然后利用改进后的车辆模型进行在线侧翻危险预测及控制,实现车辆动态侧翻特性精确预测。在此基础上,将卡尔曼滤波技术融入到改进侧翻预测时间(Time to rollover,TTR)侧翻预警算法中,选取车辆的横向载荷转移率作为侧翻极限判据,根据当前车辆状态预测未来3 s车辆的侧翻危险程度,并实时计算TTR值,一旦TTR值满足侧翻条件,系统自动触发预警装置。利用侧翻预警系统车载试验平台,对侧翻预警控制系统进行验证。侧翻预警场地试验结果表明:所开发的重型车辆侧翻预警系统可以准确有效地进行车辆侧翻危险程度预警,达到预期的开发设计目标。展开更多
该研究通过3管型微量MPN计数法(Mini Most Probable Number,mini-MPN)建立了一种快速定量检测食源性沙门氏菌的荧光定量环介导等温扩增(Quantitative Loop-Mediated Isothermal Amplification,qLAMP)方法。依据沙门菌属ttr基因设计了qL...该研究通过3管型微量MPN计数法(Mini Most Probable Number,mini-MPN)建立了一种快速定量检测食源性沙门氏菌的荧光定量环介导等温扩增(Quantitative Loop-Mediated Isothermal Amplification,qLAMP)方法。依据沙门菌属ttr基因设计了qLAMP和荧光定量PCR(Quantitative Polymerase Chain Reaction,qPCR)引物,结合5 h BPW增菌和MPN计数法建立了mini-MPN-qLAMP沙门氏菌快速定量检测方法;使用两种人工污染样品对mini-MPN-qLAMP法进行验证,使用Bland-Altman分析比较不同检测方法检测结果的一致性。结果表明,建立的qLAMP法与qPCR法反应特异性均良好,纯培养时qLAMP法检出限为500 CFU/mL。通过Bland-Altman分析表明所建立的mini-MPN-qLAMP法在速冻乌米饭中检测结果与mini-MPN-qPCR、mini-MPN计数法、平板计数法相比均具有较高的一致性,r^(2)≥0.994,检出限为-0.44 lg MPN/mL;而在速冻鸡胸肉中该法检测结果与mini-MPN-qPCR结果一致性最佳,r^(2)=0.990,检出限为-0.64 lg MPN/mL。肉制品中腐败杂菌会影响mini-MPN计数和平板计数结果,mini-MPN-qLAMP可排除肉制品中腐败杂菌对检测结果的影响。该研究所建立的mini-MPN-qLAMP法简单易行,准确度高,可用于食品中沙门氏菌的快速定量检测。展开更多
为提高森林消防车的主动安全性能,降低抢险救灾中的事故发生率,深入研究了基于TTR的森林消防车侧翻预警系统。首先,采用基于侧翻时间(Time to Rollover,TTR)的动态侧翻预警算法,以车辆的实时侧倾角及其角速度为输入变量,以动态横向载荷...为提高森林消防车的主动安全性能,降低抢险救灾中的事故发生率,深入研究了基于TTR的森林消防车侧翻预警系统。首先,采用基于侧翻时间(Time to Rollover,TTR)的动态侧翻预警算法,以车辆的实时侧倾角及其角速度为输入变量,以动态横向载荷转移率(Lateral-Load Transfer Ratio,LTR)作为侧翻判定指标。其次,在CarSim中建立森林消防车动力学模型,在Matlab/Simulink中搭建预警算法,针对典型鱼钩转向工况进行CarSim和Matlab/Simulink的非绊倒型侧翻联合模拟仿真,得到满意仿真结果。最后,应用惯导元件MPU6050和STM32单片机自主开发了侧翻预警系统,并参考国标GB/T 6323-2014开展蛇形试验,试验表明:该侧翻预警系统得到的风险趋势符合实际情况,能辅助驾驶员判断侧翻风险。综上所述,本侧翻预警系统的研究,可有效地提高森林消防车的主动安全性。展开更多
基金The research was financially supported by the National Natural Science Foundation of China for Youth(Grant No.51609169)Guangxi Science and Technology Major Project(Grant No.Guike AA17292007)+2 种基金the National Key R&D Program of China(Grant No.2018YFC0310502)National Natural Science Foundation of China(Grant No.51779173)China Scholarship Council(CSC).
文摘Tension Leg Platform(TLP)in deepwater oil and gas field development usually consists of a hull,tendons,and top tension risers(TTRs).To maintain its top tension,each TTR is connected with a tensioner system to the hull.Owing to the complicated configuration of the tensioners,the hull and TTRs form a strong coupled system.Traditionally,some simplified tensioner models are applied to analyze the TLP structures.There is a large discrepancy between their analysis results and the actual mechanism behaviors of a tensioner.It is very necessary to develop a more detailed tensioner model to consider the coupling effects between TLP and TTRs.In the present study,a fully coupled TLP hull-TTR system for hydrodynamic numerical simulation is established.A specific hydraulic pneumatic tensioner is modeled by considering 4 cylinders.The production TTR model is stacked up by specific riser joints.The simulation is also extended to analyze an array of TTRs.Different regular and irregular waves are considered.The behaviors of different cylinders are presented.The results show that it is important to consider the specific configurations of the tensioner and TTRs,which may lead to obviously different response behaviors,compared with those from a simplified model.
文摘重型车辆具有重心高,装载量大,高宽比相对乘用车较大等特点,导致其侧翻稳定极限较低,极易发生侧翻事故。建立重型车辆侧翻预测模型,利用车辆实车试验数据离线辨识技术,辨识出3自由度车辆模型中的关键参数,然后利用改进后的车辆模型进行在线侧翻危险预测及控制,实现车辆动态侧翻特性精确预测。在此基础上,将卡尔曼滤波技术融入到改进侧翻预测时间(Time to rollover,TTR)侧翻预警算法中,选取车辆的横向载荷转移率作为侧翻极限判据,根据当前车辆状态预测未来3 s车辆的侧翻危险程度,并实时计算TTR值,一旦TTR值满足侧翻条件,系统自动触发预警装置。利用侧翻预警系统车载试验平台,对侧翻预警控制系统进行验证。侧翻预警场地试验结果表明:所开发的重型车辆侧翻预警系统可以准确有效地进行车辆侧翻危险程度预警,达到预期的开发设计目标。
文摘该研究通过3管型微量MPN计数法(Mini Most Probable Number,mini-MPN)建立了一种快速定量检测食源性沙门氏菌的荧光定量环介导等温扩增(Quantitative Loop-Mediated Isothermal Amplification,qLAMP)方法。依据沙门菌属ttr基因设计了qLAMP和荧光定量PCR(Quantitative Polymerase Chain Reaction,qPCR)引物,结合5 h BPW增菌和MPN计数法建立了mini-MPN-qLAMP沙门氏菌快速定量检测方法;使用两种人工污染样品对mini-MPN-qLAMP法进行验证,使用Bland-Altman分析比较不同检测方法检测结果的一致性。结果表明,建立的qLAMP法与qPCR法反应特异性均良好,纯培养时qLAMP法检出限为500 CFU/mL。通过Bland-Altman分析表明所建立的mini-MPN-qLAMP法在速冻乌米饭中检测结果与mini-MPN-qPCR、mini-MPN计数法、平板计数法相比均具有较高的一致性,r^(2)≥0.994,检出限为-0.44 lg MPN/mL;而在速冻鸡胸肉中该法检测结果与mini-MPN-qPCR结果一致性最佳,r^(2)=0.990,检出限为-0.64 lg MPN/mL。肉制品中腐败杂菌会影响mini-MPN计数和平板计数结果,mini-MPN-qLAMP可排除肉制品中腐败杂菌对检测结果的影响。该研究所建立的mini-MPN-qLAMP法简单易行,准确度高,可用于食品中沙门氏菌的快速定量检测。
文摘为提高森林消防车的主动安全性能,降低抢险救灾中的事故发生率,深入研究了基于TTR的森林消防车侧翻预警系统。首先,采用基于侧翻时间(Time to Rollover,TTR)的动态侧翻预警算法,以车辆的实时侧倾角及其角速度为输入变量,以动态横向载荷转移率(Lateral-Load Transfer Ratio,LTR)作为侧翻判定指标。其次,在CarSim中建立森林消防车动力学模型,在Matlab/Simulink中搭建预警算法,针对典型鱼钩转向工况进行CarSim和Matlab/Simulink的非绊倒型侧翻联合模拟仿真,得到满意仿真结果。最后,应用惯导元件MPU6050和STM32单片机自主开发了侧翻预警系统,并参考国标GB/T 6323-2014开展蛇形试验,试验表明:该侧翻预警系统得到的风险趋势符合实际情况,能辅助驾驶员判断侧翻风险。综上所述,本侧翻预警系统的研究,可有效地提高森林消防车的主动安全性。
