The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then th...The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.展开更多
目的探讨老年科病房移动式多点护理区域的建立与管理改革实施成效。方法在老年科责任护士工作区域,建立由移动电脑、掌上电脑(personal digital assistant,PDA)、多功能治疗车等构建的多个护理区域,责任护士实行区域工作制。对比实施前...目的探讨老年科病房移动式多点护理区域的建立与管理改革实施成效。方法在老年科责任护士工作区域,建立由移动电脑、掌上电脑(personal digital assistant,PDA)、多功能治疗车等构建的多个护理区域,责任护士实行区域工作制。对比实施前后的护理工作效率、工作质量和满意度。结果实施前后,护理工作效率和满意度比较,差异均具有统计学意义(P<0.05);实施后,患者的呼叫铃声次数明显下降,护士应答呼叫铃声平均时间明显缩短;医生、患者及护士对护理工作满意度明显提高。结论在老年科病房设立移动式多点护理区域,能显著提高护士工作效率及护理质量,提升医、护、患三方满意度。展开更多
基金Project (No. 2006C11148) supported by the ScienceTechnology Project of Zhejiang Province, China
文摘The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.
文摘目的探讨老年科病房移动式多点护理区域的建立与管理改革实施成效。方法在老年科责任护士工作区域,建立由移动电脑、掌上电脑(personal digital assistant,PDA)、多功能治疗车等构建的多个护理区域,责任护士实行区域工作制。对比实施前后的护理工作效率、工作质量和满意度。结果实施前后,护理工作效率和满意度比较,差异均具有统计学意义(P<0.05);实施后,患者的呼叫铃声次数明显下降,护士应答呼叫铃声平均时间明显缩短;医生、患者及护士对护理工作满意度明显提高。结论在老年科病房设立移动式多点护理区域,能显著提高护士工作效率及护理质量,提升医、护、患三方满意度。