Medically, electrical impedance tomography （EIT） is a relatively inexpensive, safe, non-invasive and portable technique compared with computerized tomography （CT） and magnetic resonance imaging （MRI）. In this pa...Medically, electrical impedance tomography （EIT） is a relatively inexpensive, safe, non-invasive and portable technique compared with computerized tomography （CT） and magnetic resonance imaging （MRI）. In this paper, EIT_TJU_ II system is developed including both the data collection system and image reconstruction algo- rithm. The testing approach of the system performance, including spatial resolution and sensitivity, is described through brine tank experiments. The images of the thorax physical model verify that the system can reconstruct the interior resistivity distribution. Finally, the lung ventilation functional monitoring in vivo is realized by EIT, and the visualized images indicate that the configuration and performance of EIT_TJU_ II system are feasible and EIT is a promising technique in clinical monitoring application.展开更多
The ultrafast dissociation dynamics of NO2 molecules was investigated by femtosecond laser pump-probe mass spectra and ion images.The results show that the kinetic energy release of NO+ions has two components,0.05 eV ...The ultrafast dissociation dynamics of NO2 molecules was investigated by femtosecond laser pump-probe mass spectra and ion images.The results show that the kinetic energy release of NO+ions has two components,0.05 eV and 0.25 eV,and the possible dissociation channels have been assigned.The channel resolved transient measurement of NO^+provides a method to disentangle the contribution of ultrafast dissociation pathways,and the transient curves of NO^+ions at different kinetic energy release are fitted by a biexponential function.The fast component with a decay time of 0.25 ps is generated from the evolution of Rydberg states.The slow component is generated from two competitive channels,one of the channel is absorbing one 400nm photon to the excited state A^2B2,which has a decay time of 30.0ps,and the other slow channel is absorbing three 400nm photons to valence type Rydberg states which have a decay time less than 7.2ps.The channel and time resolved experiment present the potential of sorting out the complex ultrafast dissociation dynamics of molecules.展开更多
Light-emitting electrochemical cells(LECs) are organic photonic devices based on a mixed electronic and ionic conductor.The active layer of a polymer-based LEC consists of a luminescent polymer,an ion-solvating/transp...Light-emitting electrochemical cells(LECs) are organic photonic devices based on a mixed electronic and ionic conductor.The active layer of a polymer-based LEC consists of a luminescent polymer,an ion-solvating/transport polymer,and a compatible salt.The LEC p-n or p-i-n junction is ultimately responsible for the LEC performance.The LEC junction,however,is still poorly understood due to the difficulties of characterizing a dynamic-junction LEC.In this paper,we present an experimental and modeling study of the LEC junction using scanning optical imaging techniques.Planar LECs with an interelectrode spacing of 560μm have been fabricated,activated,frozen and scanned using a focused laser beam.The optical-beam-induced-current(OBIC)and photoluminescence(PL) data have been recorded as a function of beam location.The OBIC profile has been simulated in COMSOL that allowed for the determination of the doping concentration and the depletion width of the LEC junction.展开更多
基金Supported by National Natural Science Foundation of China (No.60820106002, No.60532020)Tianjin Natural Science Foundation (No.08JCYBJC03500).
文摘Medically, electrical impedance tomography （EIT） is a relatively inexpensive, safe, non-invasive and portable technique compared with computerized tomography （CT） and magnetic resonance imaging （MRI）. In this paper, EIT_TJU_ II system is developed including both the data collection system and image reconstruction algo- rithm. The testing approach of the system performance, including spatial resolution and sensitivity, is described through brine tank experiments. The images of the thorax physical model verify that the system can reconstruct the interior resistivity distribution. Finally, the lung ventilation functional monitoring in vivo is realized by EIT, and the visualized images indicate that the configuration and performance of EIT_TJU_ II system are feasible and EIT is a promising technique in clinical monitoring application.
基金supported by the National Natural Science Foundation of China(No.11704148,No.11847039,No.11534004)
文摘The ultrafast dissociation dynamics of NO2 molecules was investigated by femtosecond laser pump-probe mass spectra and ion images.The results show that the kinetic energy release of NO+ions has two components,0.05 eV and 0.25 eV,and the possible dissociation channels have been assigned.The channel resolved transient measurement of NO^+provides a method to disentangle the contribution of ultrafast dissociation pathways,and the transient curves of NO^+ions at different kinetic energy release are fitted by a biexponential function.The fast component with a decay time of 0.25 ps is generated from the evolution of Rydberg states.The slow component is generated from two competitive channels,one of the channel is absorbing one 400nm photon to the excited state A^2B2,which has a decay time of 30.0ps,and the other slow channel is absorbing three 400nm photons to valence type Rydberg states which have a decay time less than 7.2ps.The channel and time resolved experiment present the potential of sorting out the complex ultrafast dissociation dynamics of molecules.
基金supported by the Natural Sciences and Engineering Research Council of Canada.Faleh AlTal is supported by an Ontario Trillium Fellowship
文摘Light-emitting electrochemical cells(LECs) are organic photonic devices based on a mixed electronic and ionic conductor.The active layer of a polymer-based LEC consists of a luminescent polymer,an ion-solvating/transport polymer,and a compatible salt.The LEC p-n or p-i-n junction is ultimately responsible for the LEC performance.The LEC junction,however,is still poorly understood due to the difficulties of characterizing a dynamic-junction LEC.In this paper,we present an experimental and modeling study of the LEC junction using scanning optical imaging techniques.Planar LECs with an interelectrode spacing of 560μm have been fabricated,activated,frozen and scanned using a focused laser beam.The optical-beam-induced-current(OBIC)and photoluminescence(PL) data have been recorded as a function of beam location.The OBIC profile has been simulated in COMSOL that allowed for the determination of the doping concentration and the depletion width of the LEC junction.
