One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object...One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.展开更多
针对C/S(Client/Server)架构下的OPC(OLE for Process Control)实时监控系统在互联网应用中的局限,采用ASP.NET和Comet技术,提出了一种B/S(Browser/Server)架构下OPC实时监控系统的设计和实现。该方案只需在客户端安装支持Ajax技术的浏...针对C/S(Client/Server)架构下的OPC(OLE for Process Control)实时监控系统在互联网应用中的局限,采用ASP.NET和Comet技术,提出了一种B/S(Browser/Server)架构下OPC实时监控系统的设计和实现。该方案只需在客户端安装支持Ajax技术的浏览器即可正常工作,通过与采用其他技术实现此系统的方案的对比研究,发现该方案具有较好的易用性、跨平台性。对OPC-DA(OPC-Data Access)连接组件进行了改进和封装,使其更加符合实际应用的需要。模拟实验结果表明,采用Comet技术的方案在保证较好的实时性的同时,服务器的开销也较小,是一种满足Web应用实时性需求的可行方案。展开更多
基金Supported by the National Natural Science Foundation of China(42474239,41204128)China National Space Administration(Pre-research project on Civil Aerospace Technologies No.D010301)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA17010303)。
文摘One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.
文摘针对C/S(Client/Server)架构下的OPC(OLE for Process Control)实时监控系统在互联网应用中的局限,采用ASP.NET和Comet技术,提出了一种B/S(Browser/Server)架构下OPC实时监控系统的设计和实现。该方案只需在客户端安装支持Ajax技术的浏览器即可正常工作,通过与采用其他技术实现此系统的方案的对比研究,发现该方案具有较好的易用性、跨平台性。对OPC-DA(OPC-Data Access)连接组件进行了改进和封装,使其更加符合实际应用的需要。模拟实验结果表明,采用Comet技术的方案在保证较好的实时性的同时,服务器的开销也较小,是一种满足Web应用实时性需求的可行方案。
