In order to meet the demand of CubeSats for low power and high-performance micro-propulsion system,a porous ionic liquid electrospray thruster prototype is developed in this study.1010 conical emitter arrays are fabri...In order to meet the demand of CubeSats for low power and high-performance micro-propulsion system,a porous ionic liquid electrospray thruster prototype is developed in this study.1010 conical emitter arrays are fabricated on an area of 3.24 cm^(2) by computer numerical control machining technology.The propellant is 1-ethyl-3-methylimidazolium tetrafluoroborate.The over-all dimension of the assembled prototype is 3 cm×3 cm×1 cm,with a total weight of about 15 g(with propellant).The performance of this prototype is tested under vacuum.The results show that it can work in the voltage range of±2.0 kV to±3.0 kV,and the maximum emission current and input power are about 355 lA and 1.12 W.Time of Flight(TOF)mass spectrometry results show that cationic monomers and dimers dominate the beam in positive mode,while a higher proportion of higher-order solvated ion clusters in negative mode.The maximum specific impulse is 2992 s in positive mode and 849 s in negative mode.The thrust is measured in two methods:one is calculated by TOF results and the other is directly measured by high-precision torsional thrust stand.The thrust(T)obtained by these two methods conforms to a certain scaling law with respect to the emis-sion current(I_(em))and the applied voltage(V_(app)),following the scale of T-Iem_(Vapp)^(0.5),and the thrust range is from 2.1 lN to 42.6 lN.Many thruster performance parameters are significantly different in positive and negative modes.We speculate that due to the higher solvation energy of the anion,more solvated ion clusters are formed rather than pure ions under the same electric field.It may help to improve thruster performance if porous materials with smaller pore sizes are used as reservoirs.Although there are still many problems,most of the performance parameters of ILET-3 are good,which can theoretically meet the requirements of CubeSats for micro-propulsion system.展开更多
On May 28, the 120-ton thrust liquid-oxygen/kerosene engine developed by the Academy of Aerospace Liquid Propulsion Technology (AALPT) passed the acceptance test organized by China National Space Administration (CNSA)...On May 28, the 120-ton thrust liquid-oxygen/kerosene engine developed by the Academy of Aerospace Liquid Propulsion Technology (AALPT) passed the acceptance test organized by China National Space Administration (CNSA). The 120-ton thrust liquid-oxygen/kerosene engine is a non-pollution, non-toxic, high performance and reliable basic pro-展开更多
Background:Jaw thrust has been proven as a useful test determining adequate depth of anesthesia for successful insertion of supraglottic airway device(SAD)in normal adults and children receiving intra-venous or inhala...Background:Jaw thrust has been proven as a useful test determining adequate depth of anesthesia for successful insertion of supraglottic airway device(SAD)in normal adults and children receiving intra-venous or inhalational anesthesia induction.This prospective observational study aimed to determine the feasibility and validity of this test when using as an indicator assessing adequate depth of anesthesia for successful insertion of SAD in spontaneously breathing morbidly obese patients receiving sevoflurane inhalational induction.Methods:Thirty morbidly obese patients with a body mass index 40 to 73 kg/m2 undergoing bariatric surgery in Beijing Friendship Hospital from October 2018 to January 2019 were included in this study.After adequate pre-oxygenation,5%sevoflurane was inhaled and inhalational concentration of sevoflurane was increased by 1%every 2 min.After motor responses to jaw thrust disappeared,a SAD was inserted and insertion conditions were graded.The anatomic position of SAD was assessed using a fiberoptic bronchoscope.Results:The SAD was successfully inserted at the first attempt in all patients.Insertion conditions of SAD were excellent in nine patients(30%)and good in 21 patients(70%),respectively.The fiberoptic views of SAD position were adequate in 28 patients(93%).Conclusions:Jaw thrust test is a reliable indicator determining adequate anesthesia depth of sevoflurane inhalational induction for successful insertion of SAD in spontaneously breathing morbidly obese patients.展开更多
基金supported by the National Key R&D Program of China(No.2020YFC2201103).
文摘In order to meet the demand of CubeSats for low power and high-performance micro-propulsion system,a porous ionic liquid electrospray thruster prototype is developed in this study.1010 conical emitter arrays are fabricated on an area of 3.24 cm^(2) by computer numerical control machining technology.The propellant is 1-ethyl-3-methylimidazolium tetrafluoroborate.The over-all dimension of the assembled prototype is 3 cm×3 cm×1 cm,with a total weight of about 15 g(with propellant).The performance of this prototype is tested under vacuum.The results show that it can work in the voltage range of±2.0 kV to±3.0 kV,and the maximum emission current and input power are about 355 lA and 1.12 W.Time of Flight(TOF)mass spectrometry results show that cationic monomers and dimers dominate the beam in positive mode,while a higher proportion of higher-order solvated ion clusters in negative mode.The maximum specific impulse is 2992 s in positive mode and 849 s in negative mode.The thrust is measured in two methods:one is calculated by TOF results and the other is directly measured by high-precision torsional thrust stand.The thrust(T)obtained by these two methods conforms to a certain scaling law with respect to the emis-sion current(I_(em))and the applied voltage(V_(app)),following the scale of T-Iem_(Vapp)^(0.5),and the thrust range is from 2.1 lN to 42.6 lN.Many thruster performance parameters are significantly different in positive and negative modes.We speculate that due to the higher solvation energy of the anion,more solvated ion clusters are formed rather than pure ions under the same electric field.It may help to improve thruster performance if porous materials with smaller pore sizes are used as reservoirs.Although there are still many problems,most of the performance parameters of ILET-3 are good,which can theoretically meet the requirements of CubeSats for micro-propulsion system.
文摘On May 28, the 120-ton thrust liquid-oxygen/kerosene engine developed by the Academy of Aerospace Liquid Propulsion Technology (AALPT) passed the acceptance test organized by China National Space Administration (CNSA). The 120-ton thrust liquid-oxygen/kerosene engine is a non-pollution, non-toxic, high performance and reliable basic pro-
文摘Background:Jaw thrust has been proven as a useful test determining adequate depth of anesthesia for successful insertion of supraglottic airway device(SAD)in normal adults and children receiving intra-venous or inhalational anesthesia induction.This prospective observational study aimed to determine the feasibility and validity of this test when using as an indicator assessing adequate depth of anesthesia for successful insertion of SAD in spontaneously breathing morbidly obese patients receiving sevoflurane inhalational induction.Methods:Thirty morbidly obese patients with a body mass index 40 to 73 kg/m2 undergoing bariatric surgery in Beijing Friendship Hospital from October 2018 to January 2019 were included in this study.After adequate pre-oxygenation,5%sevoflurane was inhaled and inhalational concentration of sevoflurane was increased by 1%every 2 min.After motor responses to jaw thrust disappeared,a SAD was inserted and insertion conditions were graded.The anatomic position of SAD was assessed using a fiberoptic bronchoscope.Results:The SAD was successfully inserted at the first attempt in all patients.Insertion conditions of SAD were excellent in nine patients(30%)and good in 21 patients(70%),respectively.The fiberoptic views of SAD position were adequate in 28 patients(93%).Conclusions:Jaw thrust test is a reliable indicator determining adequate anesthesia depth of sevoflurane inhalational induction for successful insertion of SAD in spontaneously breathing morbidly obese patients.
