1.Introduction The China Seismo-Electromagnetic Satellite (CSES), which is also called ZhangHeng-1 (ZH-1), is the first Chinese space-borne platform dedicated to geophysical field measurement andearthquake monitoring ...1.Introduction The China Seismo-Electromagnetic Satellite (CSES), which is also called ZhangHeng-1 (ZH-1), is the first Chinese space-borne platform dedicated to geophysical field measurement andearthquake monitoring by detecting variations in the electromagnetic environment of space. The CSES was launched successfully at15:51 on February 2, 2018, at China’s Jiuquan Satellite Launching Center.展开更多
Quantum technology establishes a foundation for secure communication via quantum key distribution （QKD）. In the last two decades, the rapid development of QKD makes a global quantum communication network feasible. I...Quantum technology establishes a foundation for secure communication via quantum key distribution （QKD）. In the last two decades, the rapid development of QKD makes a global quantum communication network feasible. In order to construct this network, it is economical to consider small-sized and low-cost QKD payloads, which can be assembled on satellites with different sizes, such as space stations. Here we report an experimental demonstration of space-to-ground QKD using a small-sized payload, from Tiangong-2 space lab to Nanshan ground station. The 57.9-kg payload integrates a tracking system, a QKD transmitter along with modules for synchronization, and a laser communication transmitter. In the space lab, a 50MHz vacuum＋weak decoy-state optical source is sent through a reflective telescope with an aperture of 200mm. On the ground station, a telescope with an aperture of 1200mm collects the signal photons. A stable and high-transmittance communication channel is set up with a high-precision bidirectional tracking system, a polarization compensation module, and a synchronization system. When the quantum link is successfully established, we obtain a key rate over 100bps with a communication distance up to 719km. Together with our recent development of QKD in daylight, the present demonstration paves the way towards a practical satellite-constellation-based global quantum secure network with small-sized QKD payloads.展开更多
Earth’s near space,located in the region between 20 and 100 km above sea level,is characterized by extreme conditions,such as low temperature,low atmospheric pressure,harsh radiation,and extreme dryness.These conditi...Earth’s near space,located in the region between 20 and 100 km above sea level,is characterized by extreme conditions,such as low temperature,low atmospheric pressure,harsh radiation,and extreme dryness.These conditions are analogous to those found on the surface of Mars and in the atmosphere of Venus,making Earth’s near space a unique natural laboratory for astrobiological research.To address essential astrobiological questions,teams from the Chinese Academy of Sciences(CAS)have developed a scientific balloon platform,the CAS Balloon-Borne Astrobiology Platform(CAS-BAP),to study the effects of near space environmental conditions on the biology and survival strategies of representative organisms in this terrestrial analog.Here,we describe the versatile Biological Samples Exposure Payload(BIOSEP)loaded on the CAS-BAP with respect to its structure and function.The primary function of BIOSEP is to expose appropriate biological specimens to the harsh conditions of near space and subsequently return the exposed samples to laboratories for further analysis.Four successful flight missions in near space from 2019 to 2021 have demonstrated the high reliability and efficiency of the payload in communicating between hardware and software units,recording environmental data,exposing sample containers,protecting samples from external contamination,and recovering samples.Understanding the effects of Earth’s near space conditions on biological specimens will provide valuable insights into the survival strategies of organisms in extreme environments and the search for life beyond Earth.The development of BIOSEP and associated biological exposure experiments will enhance our understanding of the potential for life on Mars and the habitability of the atmospheric regions of other planets in the solar system and beyond.展开更多
目的利用高分辨质谱仪快速筛查壮阳类保健食品中的磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE-5i),确证其中发现的新型非法添加物并建立定量检测方法。方法采用超高效液相色谱-四级杆-飞行时间质谱仪(ultra performa...目的利用高分辨质谱仪快速筛查壮阳类保健食品中的磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE-5i),确证其中发现的新型非法添加物并建立定量检测方法。方法采用超高效液相色谱-四级杆-飞行时间质谱仪(ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry,UPLC-Q-TOF/MS)对20批次保健食品中的非法添加物进行日常非靶向筛查,在2批次压片糖果中鉴别出一种新型伐地那非类似物。结合化合物的质谱裂解规律及核磁共振波谱(nuclear magnetic resonance spectrometry,NMR)对未知物结构进行确证。采用超高效液相色谱-三重四级杆质谱法(ultra performance liquid chromatography-coupled triple quadrupole mass spectrometry,UPLC-MS/MS)建立了典型食品基质中未知物的定量检测方法。结果未知物被确证为O-丙基羟基伐地那非。该物质溶剂校准和基质匹配曲线在2~100 ng/mL质量浓度范围内线性关系良好,相关系数(r2)大于0.995,检出限为0.05 mg/kg,定量限为0.10 mg/kg。在固体饮料、压片糖果、果冻基质中3个水平加标回收率为94.45%~104.16%,相对标准偏差(relative standard deviation,RSD)为0.70%~4.02%。采用该方法测得2批次阳性样品中O-丙基羟基伐地那非的含量分别为22.0 mg/kg、13.8 g/kg。结论本方法适用于食品中那非类似物的快速筛查,用于O-丙基羟基伐地那非的定量检测高效、灵敏、准确。本研究为食品基质中非法添加物的系统性确证和定量研究提供了可供借鉴的参考模型。展开更多
文摘1.Introduction The China Seismo-Electromagnetic Satellite (CSES), which is also called ZhangHeng-1 (ZH-1), is the first Chinese space-borne platform dedicated to geophysical field measurement andearthquake monitoring by detecting variations in the electromagnetic environment of space. The CSES was launched successfully at15:51 on February 2, 2018, at China’s Jiuquan Satellite Launching Center.
基金Supported by China Manned Space Program,Technology and Engineering Center for Space Utilization Chinese Academy of Sciences,Chinese Academy of Sciencesthe National Natural Science Foundation of China
文摘Quantum technology establishes a foundation for secure communication via quantum key distribution （QKD）. In the last two decades, the rapid development of QKD makes a global quantum communication network feasible. In order to construct this network, it is economical to consider small-sized and low-cost QKD payloads, which can be assembled on satellites with different sizes, such as space stations. Here we report an experimental demonstration of space-to-ground QKD using a small-sized payload, from Tiangong-2 space lab to Nanshan ground station. The 57.9-kg payload integrates a tracking system, a QKD transmitter along with modules for synchronization, and a laser communication transmitter. In the space lab, a 50MHz vacuum＋weak decoy-state optical source is sent through a reflective telescope with an aperture of 200mm. On the ground station, a telescope with an aperture of 1200mm collects the signal photons. A stable and high-transmittance communication channel is set up with a high-precision bidirectional tracking system, a polarization compensation module, and a synchronization system. When the quantum link is successfully established, we obtain a key rate over 100bps with a communication distance up to 719km. Together with our recent development of QKD in daylight, the present demonstration paves the way towards a practical satellite-constellation-based global quantum secure network with small-sized QKD payloads.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA17010505)
文摘Earth’s near space,located in the region between 20 and 100 km above sea level,is characterized by extreme conditions,such as low temperature,low atmospheric pressure,harsh radiation,and extreme dryness.These conditions are analogous to those found on the surface of Mars and in the atmosphere of Venus,making Earth’s near space a unique natural laboratory for astrobiological research.To address essential astrobiological questions,teams from the Chinese Academy of Sciences(CAS)have developed a scientific balloon platform,the CAS Balloon-Borne Astrobiology Platform(CAS-BAP),to study the effects of near space environmental conditions on the biology and survival strategies of representative organisms in this terrestrial analog.Here,we describe the versatile Biological Samples Exposure Payload(BIOSEP)loaded on the CAS-BAP with respect to its structure and function.The primary function of BIOSEP is to expose appropriate biological specimens to the harsh conditions of near space and subsequently return the exposed samples to laboratories for further analysis.Four successful flight missions in near space from 2019 to 2021 have demonstrated the high reliability and efficiency of the payload in communicating between hardware and software units,recording environmental data,exposing sample containers,protecting samples from external contamination,and recovering samples.Understanding the effects of Earth’s near space conditions on biological specimens will provide valuable insights into the survival strategies of organisms in extreme environments and the search for life beyond Earth.The development of BIOSEP and associated biological exposure experiments will enhance our understanding of the potential for life on Mars and the habitability of the atmospheric regions of other planets in the solar system and beyond.
文摘目的利用高分辨质谱仪快速筛查壮阳类保健食品中的磷酸二酯酶5型抑制剂(phosphodiesterase type 5 inhibitors,PDE-5i),确证其中发现的新型非法添加物并建立定量检测方法。方法采用超高效液相色谱-四级杆-飞行时间质谱仪(ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry,UPLC-Q-TOF/MS)对20批次保健食品中的非法添加物进行日常非靶向筛查,在2批次压片糖果中鉴别出一种新型伐地那非类似物。结合化合物的质谱裂解规律及核磁共振波谱(nuclear magnetic resonance spectrometry,NMR)对未知物结构进行确证。采用超高效液相色谱-三重四级杆质谱法(ultra performance liquid chromatography-coupled triple quadrupole mass spectrometry,UPLC-MS/MS)建立了典型食品基质中未知物的定量检测方法。结果未知物被确证为O-丙基羟基伐地那非。该物质溶剂校准和基质匹配曲线在2~100 ng/mL质量浓度范围内线性关系良好,相关系数(r2)大于0.995,检出限为0.05 mg/kg,定量限为0.10 mg/kg。在固体饮料、压片糖果、果冻基质中3个水平加标回收率为94.45%~104.16%,相对标准偏差(relative standard deviation,RSD)为0.70%~4.02%。采用该方法测得2批次阳性样品中O-丙基羟基伐地那非的含量分别为22.0 mg/kg、13.8 g/kg。结论本方法适用于食品中那非类似物的快速筛查,用于O-丙基羟基伐地那非的定量检测高效、灵敏、准确。本研究为食品基质中非法添加物的系统性确证和定量研究提供了可供借鉴的参考模型。
