Through using both Cr^4+:YAG and GaAs saturable absorbers, a diode-pttmped double passively Q-switched Nd:GdVO4 laser is realized and compared with a single passively Q-switched laser. This laser can generate symme...Through using both Cr^4+:YAG and GaAs saturable absorbers, a diode-pttmped double passively Q-switched Nd:GdVO4 laser is realized and compared with a single passively Q-switched laser. This laser can generate symmetric pulse temporal profiles and shorter pulses. A laser pulse width of 17 ns has been achieved with the incident pump power of 8.5 W.展开更多
Hydrostatic slipper was often used in friction bearing design, allowing improvement of the latter's dynamic behavior. The influence of thermal effect on hydrostatic slipper bearing capacity of axial piston pump wa...Hydrostatic slipper was often used in friction bearing design, allowing improvement of the latter's dynamic behavior. The influence of thermal effect on hydrostatic slipper bearing capacity of axial piston pump was investigated. A set of lumped parameter mathematical models were developed based on energy conservation law of slipper/ swash plate pair. The results show that thermal equilibrium clearance due to solid thermal deformation periodically changes with shaft rotational angle. The slipper bearing capacity increases dramatically with decreasing thermal equilibrium clearance. In order to improve the slipper bearing capacity, length-to-diameter ratio of fixed damper varies from 3.5 to 8.75 and radius ratio of slipper varies from 1.5 to 2.0. In addition, the higher slipper thermal conductivity is useful to improve slipper bearing capability, but the thermal equilibrium clearance is not compromised.展开更多
Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2...Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2-based in the HTHP in different running conditions.The results demonstrated the feasibility and reliability of M1 and M2 as new high-temperature refrigerants.Additionally,the exploration and analyses of the support vector machine(SVM)and back propagation(BP)neural network models were made to find a practical way to predict the performance of HTHP system.The results showed that SVM-Linear,SVM-RBF and BP models shared the similar ability to predict the heat capacity and power input with high accuracy.SVM-RBF demonstrated better stability for coefficient of performance prediction.Finally,the proposed SVM model was used to assess the potential of the M1 and M2.The results indicated that the HTHP system using M1 could produce heat at the temperature of 130°C with good performance.展开更多
This paper shows the blood flow control (FwC) performance to adjust rotational speed of an ICBP (implantable centrifugal blood pump) in order to provide an adequate flow to left ventricle in different patient cond...This paper shows the blood flow control (FwC) performance to adjust rotational speed of an ICBP (implantable centrifugal blood pump) in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD (left ventricular assist device) with ceramic bearings developed for long term circulatory assistance. FwC uses PI (proportional-integral) control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS (hybrid cardiovascular simulator) as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease: ejection fraction (10-25%) and heart rate (50-110 bpm). FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.展开更多
基金Natural Science Foundation of Shandong Province(Y2007G01).
文摘Through using both Cr^4+:YAG and GaAs saturable absorbers, a diode-pttmped double passively Q-switched Nd:GdVO4 laser is realized and compared with a single passively Q-switched laser. This laser can generate symmetric pulse temporal profiles and shorter pulses. A laser pulse width of 17 ns has been achieved with the incident pump power of 8.5 W.
基金Projects(51475332,51275356)supported by the National Natural Science Foundation of China
文摘Hydrostatic slipper was often used in friction bearing design, allowing improvement of the latter's dynamic behavior. The influence of thermal effect on hydrostatic slipper bearing capacity of axial piston pump was investigated. A set of lumped parameter mathematical models were developed based on energy conservation law of slipper/ swash plate pair. The results show that thermal equilibrium clearance due to solid thermal deformation periodically changes with shaft rotational angle. The slipper bearing capacity increases dramatically with decreasing thermal equilibrium clearance. In order to improve the slipper bearing capacity, length-to-diameter ratio of fixed damper varies from 3.5 to 8.75 and radius ratio of slipper varies from 1.5 to 2.0. In addition, the higher slipper thermal conductivity is useful to improve slipper bearing capability, but the thermal equilibrium clearance is not compromised.
基金Project (2015CB251403) supported by the National Key Basic Research Program of China(973)
文摘Two new binary near-azeotropic mixtures named M1 and M2 were developed as the refrigerants of the high-temperature heat pump(HTHP).The experimental research was used to analyze and compare the performance of M1 and M2-based in the HTHP in different running conditions.The results demonstrated the feasibility and reliability of M1 and M2 as new high-temperature refrigerants.Additionally,the exploration and analyses of the support vector machine(SVM)and back propagation(BP)neural network models were made to find a practical way to predict the performance of HTHP system.The results showed that SVM-Linear,SVM-RBF and BP models shared the similar ability to predict the heat capacity and power input with high accuracy.SVM-RBF demonstrated better stability for coefficient of performance prediction.Finally,the proposed SVM model was used to assess the potential of the M1 and M2.The results indicated that the HTHP system using M1 could produce heat at the temperature of 130°C with good performance.
文摘This paper shows the blood flow control (FwC) performance to adjust rotational speed of an ICBP (implantable centrifugal blood pump) in order to provide an adequate flow to left ventricle in different patient conditions. ICBP is a totally implantable LVAD (left ventricular assist device) with ceramic bearings developed for long term circulatory assistance. FwC uses PI (proportional-integral) control to adjust rotational speed in order to provide blood flow. FwC does not use sensor for feedback, as there is an estimation system to provide blood flow measurement. Control strategy has being studied in a HCS (hybrid cardiovascular simulator) as a tool that allows the physical connection of ICBP during evaluation. In addition, HCS allows changes of some cardiovascular parameters in order to simulate specific heart disease: ejection fraction (10-25%) and heart rate (50-110 bpm). FwC was able to adjust blood flow with steady error less than 2%. Results demonstrated that FwC is adequate to LVAD control irL different left ventricle failure conditions.