Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components...Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components, anchor and so on is modeled by applying multi-body dynamics method. The motion equations are developed in discrete node description and fully Cartesian coordinates. Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board. The trajectories and velocities of different nodes without current and with current in buoy system are obtained. The transient tension force of each part of the cable is analyzed in the process of deployment. Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration. This work is helpful for design and deployment planning of buoy system.展开更多
The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. Ho...The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.展开更多
目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸...目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸、穿心莲内酯、脱水穿心莲内酯、穿心莲新酯、去氧穿心莲内酯、脱水穿心莲内酯琥珀酸半酯、亚硫酸氢钠穿心莲内脂的相对校正因子,利用相对校正因子来计算各成分的含量,同时将QAMS法计算结果和外标法实测值进行比较。结果 相对校正因子重现性良好,使用QAMS法与外标法所测得的结果无明显的差异。结论 QAMS法适用于穿心莲中9种成分的同时测定,以保证质量的可靠性。展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51175484)the Science Foundation of Shandong Province (Grant No. ZR2010EM052)
文摘Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components, anchor and so on is modeled by applying multi-body dynamics method. The motion equations are developed in discrete node description and fully Cartesian coordinates. Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board. The trajectories and velocities of different nodes without current and with current in buoy system are obtained. The transient tension force of each part of the cable is analyzed in the process of deployment. Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration. This work is helpful for design and deployment planning of buoy system.
基金supported by National Natural Science Foundation of China (Grant Nos. 51175032, U1134201)National Basic Research Program of China (973 Program, Grant No. 2011CD711104)
文摘The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.
文摘为提高6轴机器人的运动学绝对定位精度,提出了一种闭环校准方法.首先,通过视觉位姿测量方法,建立多点位姿约束;其次,利用差分方法构建辨识方程;最后,采用加权最小二乘法对机器人运动学参数进行辨识.测量设备为安装在机器人末端的相机,其与固定的高精度标定板配合使用,以实现多点位姿约束.根据工业应用中的逆解参数约束条件和手眼系统的运动学耦合关系,确定了包含14个参数的最小校准参数集.基于此参数集,应用加权最小二乘法进行参数辨识,从而完成了机器人的运动学参数校准.采用该方法对华数HSR-JR605机器人进行校准后,机器人末端绕点运动的平均距离误差显著降低,从2.77 mm降低到0.42 mm.
文摘目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸、穿心莲内酯、脱水穿心莲内酯、穿心莲新酯、去氧穿心莲内酯、脱水穿心莲内酯琥珀酸半酯、亚硫酸氢钠穿心莲内脂的相对校正因子,利用相对校正因子来计算各成分的含量,同时将QAMS法计算结果和外标法实测值进行比较。结果 相对校正因子重现性良好,使用QAMS法与外标法所测得的结果无明显的差异。结论 QAMS法适用于穿心莲中9种成分的同时测定,以保证质量的可靠性。
