We propose a Very Long Baseline Interferometry(VLBI)precision evaluation method for probe delay measurement,so as to investigate the error contributions from different components in the Chinese VLBI Network(CVN).This ...We propose a Very Long Baseline Interferometry(VLBI)precision evaluation method for probe delay measurement,so as to investigate the error contributions from different components in the Chinese VLBI Network(CVN).This method takes the idea of traditional closure delay analysis for distant radio sources.It focuses on the VLBI closure delay only and therefore excludes the influence of probe orbit determination,which makes it very suitable to evaluate the capability of VLBI probe delay measurement.In this paper,we first introduce the principles of closure delay analysis.Then the statistical results of typical CE5(Chinese Chang’e 5 lunar exploration mission)and HX1(Chinese Mars exploration mission)observations are presented,including the comparison of the closure delay precisions between CE5 and HX1 for four closed baseline triangles in CVN.According to the result,we realize that the precision discrepancy between CE5 and HX1 in the closure delay analysis is less than that of residual delay after orbit determination,which reflects the precision level of the VLBI delay measurement.展开更多
The core-shell gold nanoparticle film is fabricated by using nanolithography and self-assembly monolayer technology. The film exhibits unique optical properties and has strong surface enhanced Raman scattering （SERS...The core-shell gold nanoparticle film is fabricated by using nanolithography and self-assembly monolayer technology. The film exhibits unique optical properties and has strong surface enhanced Raman scattering （SERS） activity. The relationship between nanostructure and surface electrical field is studied by employing pyridine as the SERS probe. It is found that particle size and inter-particle space are important factors. The enhancement ratio is measured to be more than 10^4.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11973011,11573057,11903067,U1938114 and U1831137)National Science and Technology Basic Conditions Platform Project“National Basic Science Data Sharing Service Platform”(Grant No.DKA201712-02-09)Key Technical Talents of Chinese Academy of Sciences,Shanghai Outstanding Academic Leaders Plan,Lunar Exploration Project and Key Cultivation Projects of Shanghai Astronomical Observatory。
文摘We propose a Very Long Baseline Interferometry(VLBI)precision evaluation method for probe delay measurement,so as to investigate the error contributions from different components in the Chinese VLBI Network(CVN).This method takes the idea of traditional closure delay analysis for distant radio sources.It focuses on the VLBI closure delay only and therefore excludes the influence of probe orbit determination,which makes it very suitable to evaluate the capability of VLBI probe delay measurement.In this paper,we first introduce the principles of closure delay analysis.Then the statistical results of typical CE5(Chinese Chang’e 5 lunar exploration mission)and HX1(Chinese Mars exploration mission)observations are presented,including the comparison of the closure delay precisions between CE5 and HX1 for four closed baseline triangles in CVN.According to the result,we realize that the precision discrepancy between CE5 and HX1 in the closure delay analysis is less than that of residual delay after orbit determination,which reflects the precision level of the VLBI delay measurement.
基金supported by the National Natural Science Foundation of China for Young Researcher (No. 60508003)the Applied Basic Research Program of Tianjin, China (No. 06YFJMJC07100).
文摘The core-shell gold nanoparticle film is fabricated by using nanolithography and self-assembly monolayer technology. The film exhibits unique optical properties and has strong surface enhanced Raman scattering （SERS） activity. The relationship between nanostructure and surface electrical field is studied by employing pyridine as the SERS probe. It is found that particle size and inter-particle space are important factors. The enhancement ratio is measured to be more than 10^4.
