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
【目的】建立一种猪A群轮状病毒(porcine rotavirus group A, PoRV A)快速检测方法,用于PoRV检测和流行病学调查。【方法】参考GenBank中猪A群轮状病毒(PoRVA)VP6基因序列(登录号MT025937.1、OP978242.1、PP566178.1)设计特异性引物和探...【目的】建立一种猪A群轮状病毒(porcine rotavirus group A, PoRV A)快速检测方法,用于PoRV检测和流行病学调查。【方法】参考GenBank中猪A群轮状病毒(PoRVA)VP6基因序列(登录号MT025937.1、OP978242.1、PP566178.1)设计特异性引物和探针,优化反应体系中引物和探针的浓度,建立Taq Man RT-qPCR检测方法,并通过特异性、灵敏性和重复性的结果以及临床应用对该方法进行评价。【结果】该方法可特异性扩增PoRV核酸,最低检出限度为27.0 copies·μL^(-1),灵敏度高于普通RT-PCR 100倍;与猪流行性腹泻病毒(porcine epidemicdiarrheavirus,PEDV)、猪德尔塔冠状病毒(porcinedeltacoronavirus,PDCoV)、猪传染性胃肠炎病毒(transmissible gastroenteritis of swine, TGEV)核酸均无交叉反应;组内和组间变异系数均小于1.10%,重复性好。151份疑似PoRV的临床样品使用RT-qPCR进行检测,结果显示检出率为42.38%(64/151),优于常规RT-PCR的检出率(33.11%,50/151)。【结论】本研究基于猪A群轮状病毒VP6基因,建立了适用于PoRV A检测及其流行病学调查的Taq Man实时荧光定量PCR检测方法,具有灵敏度高、特异性强、重复性好等优势,为猪轮状病毒检测和流行病学调查提供了技术手段。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【目的】建立一种猪A群轮状病毒(porcine rotavirus group A, PoRV A)快速检测方法,用于PoRV检测和流行病学调查。【方法】参考GenBank中猪A群轮状病毒(PoRVA)VP6基因序列(登录号MT025937.1、OP978242.1、PP566178.1)设计特异性引物和探针,优化反应体系中引物和探针的浓度,建立Taq Man RT-qPCR检测方法,并通过特异性、灵敏性和重复性的结果以及临床应用对该方法进行评价。【结果】该方法可特异性扩增PoRV核酸,最低检出限度为27.0 copies·μL^(-1),灵敏度高于普通RT-PCR 100倍;与猪流行性腹泻病毒(porcine epidemicdiarrheavirus,PEDV)、猪德尔塔冠状病毒(porcinedeltacoronavirus,PDCoV)、猪传染性胃肠炎病毒(transmissible gastroenteritis of swine, TGEV)核酸均无交叉反应;组内和组间变异系数均小于1.10%,重复性好。151份疑似PoRV的临床样品使用RT-qPCR进行检测,结果显示检出率为42.38%(64/151),优于常规RT-PCR的检出率(33.11%,50/151)。【结论】本研究基于猪A群轮状病毒VP6基因,建立了适用于PoRV A检测及其流行病学调查的Taq Man实时荧光定量PCR检测方法,具有灵敏度高、特异性强、重复性好等优势,为猪轮状病毒检测和流行病学调查提供了技术手段。
