The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the eng...The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the engine performance and influence exhaust gas emissions.In this study,the intake valve deposits (IVD) and combustion chamber deposits (CCD) produced from combustion of fuel containing 21 v%—42 v% of aromatics and 8 v%—31 v% of olefins have been studied using Ford engine tests,and the characteristics of deposits were studied by IR spectroscopy,TGA and elemental analysis instrument.The test results have shown that deposit formation depends on the fuel composition,especially the aromatic content in the fuel.It is also observed that there are differences in the values of IVD and CCD measured by IR spectrometry and elemental analyses.展开更多
To date many monitoring techniques have been used to determine the efficacy of surgical correction of mitral valve disease. The most common non-invasive method in use is echocardiography which can assess the myocardia...To date many monitoring techniques have been used to determine the efficacy of surgical correction of mitral valve disease. The most common non-invasive method in use is echocardiography which can assess the myocardial and mitral valve function changes after mitral valve replacement procedures. In this study, we investigated the five-year follow-up echocardiographic results of 143 patients undergoing mitral valve replacement with preservation of subvalvular apparatus to analyze the recovery of myocardial and mitral valve functions.展开更多
A piezoelectric pump with flexible valve has been developed to pump high viscosity cooling liquid in the nanosats thermal control system. The structure of the flexible valve is designed according to the characteristic...A piezoelectric pump with flexible valve has been developed to pump high viscosity cooling liquid in the nanosats thermal control system. The structure of the flexible valve is designed according to the characteristics of the human aortic shape with the aim to simulate the bionic pumping function of the human heart. Dynamic stress-strain features of the flexible valve are analyzed by the finite element method,and the results show that the proposed flexible valve is suitable and functional for the piezoelectric pump. Then the cylinder and diffuser/nozzle piezoelectric pumps based on flexible valves have been developed and fabricated. Experimental results of the output performance indicate that the maximum flow rate of the cylinder piezoelectric pump with flexible valve is 15.38 mL/min,170.77% higher than the diffuser/nozzle piezoelectric pump with flexible valve. The ability of the cylinder piezoelectric pump with flexible valve for transmitting high viscosity liquid has been validated. The piezoelectric pump with flexible valve has potential applications in the nanosats thermal control system.展开更多
The concept and structure of serial-connection multi-chamber (SCMC) micropumps with cantilever valves is introduced. The SCMC micropump, which can be manufactured using conventional production techniques and materials...The concept and structure of serial-connection multi-chamber (SCMC) micropumps with cantilever valves is introduced. The SCMC micropump, which can be manufactured using conventional production techniques and materials, has a multi-layer circular planar structure. The border-upon piezoelectric actuators of a SCMC micropump work in anti-phase, as a result the pumping performance is similar to that of several single-chamber pumps running in series. The theoretical analysis shows that the pumping performance of a SCMC micropump depends not only on the characteristic and geometrical parameters of the piezoelectric actuators, but also on the number of pump chambers. Both flowrate and pressure of a SCMC pump can be enhanced to a certain extent. Four piezoelectric micropumps with different chambers were fabricated and tested. The testing results show that the enhancing extents of the flowrate and pressure of a SCMC piezoelectric micropump are different. The maximum flowrate and pressure of the four-chamber pump achieved are 2.5 times and 3.6 times those of the single-chamber pump achieved.展开更多
基金the PetroChina Corporation Research and Development Project (06-03B-01-01) for financial support
文摘The cleanliness of gasoline is related to its components and properties.All commercial gasoline builds up deposits on the engine's injector,intake valve and combustion chamber,which can significantly lower the engine performance and influence exhaust gas emissions.In this study,the intake valve deposits (IVD) and combustion chamber deposits (CCD) produced from combustion of fuel containing 21 v%—42 v% of aromatics and 8 v%—31 v% of olefins have been studied using Ford engine tests,and the characteristics of deposits were studied by IR spectroscopy,TGA and elemental analysis instrument.The test results have shown that deposit formation depends on the fuel composition,especially the aromatic content in the fuel.It is also observed that there are differences in the values of IVD and CCD measured by IR spectrometry and elemental analyses.
文摘To date many monitoring techniques have been used to determine the efficacy of surgical correction of mitral valve disease. The most common non-invasive method in use is echocardiography which can assess the myocardial and mitral valve function changes after mitral valve replacement procedures. In this study, we investigated the five-year follow-up echocardiographic results of 143 patients undergoing mitral valve replacement with preservation of subvalvular apparatus to analyze the recovery of myocardial and mitral valve functions.
基金supported by the National Natural Science Foundation of China (Nos. 51605200,61973207)the Natural Science Foundation of Shanghai(No.19ZR1474000)+1 种基金the Senior Talent Start-up Foundation of Jiangsu University(No.14JDG145)the Foundation of State Key Laboratory of Mechanics and Control of Mechanical Structures of Nanjing University of Aeronautics and Astronautics(No.MCMS-E-0320G01)。
文摘A piezoelectric pump with flexible valve has been developed to pump high viscosity cooling liquid in the nanosats thermal control system. The structure of the flexible valve is designed according to the characteristics of the human aortic shape with the aim to simulate the bionic pumping function of the human heart. Dynamic stress-strain features of the flexible valve are analyzed by the finite element method,and the results show that the proposed flexible valve is suitable and functional for the piezoelectric pump. Then the cylinder and diffuser/nozzle piezoelectric pumps based on flexible valves have been developed and fabricated. Experimental results of the output performance indicate that the maximum flow rate of the cylinder piezoelectric pump with flexible valve is 15.38 mL/min,170.77% higher than the diffuser/nozzle piezoelectric pump with flexible valve. The ability of the cylinder piezoelectric pump with flexible valve for transmitting high viscosity liquid has been validated. The piezoelectric pump with flexible valve has potential applications in the nanosats thermal control system.
文摘The concept and structure of serial-connection multi-chamber (SCMC) micropumps with cantilever valves is introduced. The SCMC micropump, which can be manufactured using conventional production techniques and materials, has a multi-layer circular planar structure. The border-upon piezoelectric actuators of a SCMC micropump work in anti-phase, as a result the pumping performance is similar to that of several single-chamber pumps running in series. The theoretical analysis shows that the pumping performance of a SCMC micropump depends not only on the characteristic and geometrical parameters of the piezoelectric actuators, but also on the number of pump chambers. Both flowrate and pressure of a SCMC pump can be enhanced to a certain extent. Four piezoelectric micropumps with different chambers were fabricated and tested. The testing results show that the enhancing extents of the flowrate and pressure of a SCMC piezoelectric micropump are different. The maximum flowrate and pressure of the four-chamber pump achieved are 2.5 times and 3.6 times those of the single-chamber pump achieved.
