Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direc...Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direct simulation Monte Carlo method is used to model momentum and charge exchange （CEX） collisions. The software is based on unstructured grids which make it easy to handle with complex geometry. The results of chamber simulation are compared with experimental data in ion current density and number density, which show good agreements. The maximum difference of current density along the thruster centerline is less than 9.30%. The interaction effects of plumes when multiple thrusters are operating in vacuum are predicted. Distributions of single charged xenon ions are significantly different in the near-field plume flow, however, merge into one in the far downstream region. Moreover, the interaction effect on the spatial distribution of CEX xenon ions is displayed as well.展开更多
Fluorescent aptasensor was developed for acrylamide(AAm)detection by utilizing the adsorption effect of Au nanoparticles(AuNPs)and fluorescence properties of SYBR Green I(SGI)towards double-stranded DNA(dsDNA).Compare...Fluorescent aptasensor was developed for acrylamide(AAm)detection by utilizing the adsorption effect of Au nanoparticles(AuNPs)and fluorescence properties of SYBR Green I(SGI)towards double-stranded DNA(dsDNA).Compared to the binding of aptamer with AAm,the higher affinity of aptamer with cDNA may facilitate a structure switching from the aptamer/AAm complex to aptamer/cDNA dsDNA.The free aptamers were adsorbed onto AuNPs and separated by centrifugation.Subsequently,SGI was introduced as a fluorescent reporter for quantitative detection.Compared to conventional AuNPs-based colorimetric detection,the sensitivity of this strategy was improved by 3.18-fold in the range of 0.005–50 mg/L with a low detection limit of 4.68μg/L.The method has been successfully applied to analyze fried twists and biscuits.Notably,it is a low-cost and general method that provides guidance for the development of rapid screening technology in the field.展开更多
文摘Ion thruster plumes from a multi-thruster array of different working configurations are simulated by a hybrid fluid-particle software. The particle in cell method is employed to model the transports of ions. The direct simulation Monte Carlo method is used to model momentum and charge exchange （CEX） collisions. The software is based on unstructured grids which make it easy to handle with complex geometry. The results of chamber simulation are compared with experimental data in ion current density and number density, which show good agreements. The maximum difference of current density along the thruster centerline is less than 9.30%. The interaction effects of plumes when multiple thrusters are operating in vacuum are predicted. Distributions of single charged xenon ions are significantly different in the near-field plume flow, however, merge into one in the far downstream region. Moreover, the interaction effect on the spatial distribution of CEX xenon ions is displayed as well.
基金supported by Science and Technology Development Program of Jilin Province,China(No.20210509024RQ)On-budget Capital Construction Fund of Jilin Province Development and Reform Commission,China(2023C014)+1 种基金Graduate Innovation Fund of Jilin University,China(No.2022051)College Students'Innovative Entrepreneurial Training Plan Program of Jilin University,China(S202210183292).
文摘Fluorescent aptasensor was developed for acrylamide(AAm)detection by utilizing the adsorption effect of Au nanoparticles(AuNPs)and fluorescence properties of SYBR Green I(SGI)towards double-stranded DNA(dsDNA).Compared to the binding of aptamer with AAm,the higher affinity of aptamer with cDNA may facilitate a structure switching from the aptamer/AAm complex to aptamer/cDNA dsDNA.The free aptamers were adsorbed onto AuNPs and separated by centrifugation.Subsequently,SGI was introduced as a fluorescent reporter for quantitative detection.Compared to conventional AuNPs-based colorimetric detection,the sensitivity of this strategy was improved by 3.18-fold in the range of 0.005–50 mg/L with a low detection limit of 4.68μg/L.The method has been successfully applied to analyze fried twists and biscuits.Notably,it is a low-cost and general method that provides guidance for the development of rapid screening technology in the field.
