SuperView-I satellite constellation （SuperView-I for short） is the first commercial remote sensing constellation with a resolution down to 0.5 m. It＇s an important part of the national spatial information infrastru...SuperView-I satellite constellation （SuperView-I for short） is the first commercial remote sensing constellation with a resolution down to 0.5 m. It＇s an important part of the national spatial information infrastructure construction. It will play an important role for the global users providing remote sensing data, application solutions and remote sensing value-added services with its highresolution and 24-hour observation capability. At present, 4 satellites of the constellation have been successfully launched and networked on orbit. The services cover surveying and mapping, land resource surveying, urban planning, agriculture, forestry, water conservancy, geological mining, environmental monitoring, defense, disaster reduction along with other traditional industries. There are also great potential applications in Mobile Intemet, LBS, Smart city, insurance and other emerging professions. The successful operation of SuperView-I breaks the overseas monopoly for commercial high-resolution remote sensing satellite imagery in the China market. It＇s one of the major achievements in China space science and technology by actively exploring the development of commercial remote sensing markets, which is of strategic significance to the development of China remote sensing satellite business.展开更多
Interaction of the solar wind with the interstellar medium leads to the formation of the heliosphere and termination shock. This article addresses three aspects of the plasma and magnetic field on two sides of the hel...Interaction of the solar wind with the interstellar medium leads to the formation of the heliosphere and termination shock. This article addresses three aspects of the plasma and magnetic field on two sides of the heliopause： （1） The interstellar magnetic field surrounding the heliopause. In the limit of very low plasma β-ratio an analytical solution is obtained for the 3D interstellar magnetic field by means of a line dipole method. The undisturbed magnetic field in the upstream is allowed to have an arbitrary inclination angle. The solution describes the heliosphere as having a blunt-nosed geometry on the upwind side and approaching a cylindrical geometry on the downwind side. The distortion of the magnetic field can penetrate very deep into the interstellar space. （2） Interaction of the interstellar neutral hydrogen with the global solar wind. The ionization process leads to removal of interstellar neutral hydrogen in the heliosphere： on the upwind side, 90% of hydrogen depletion occurs inside 60 AU, the hydrogen density changes rapidly inside 10 AU. A hydrogen cavity forms inside -4 AU; the cavity extends on the downwind side to form a long cavity wake. Outside the cavity and cavity wake, pickup protons are produced, they cause deceleration and heating of the solar wind. The wind speed and temperature also increase steadily with heliolatitude caused by the latitudinal increase in wind speed at the inner boundary. （3） The global geometry of the termination shock. The termination shock has been treated as having a closed geometry in previous heliosphere models. This study presents a new perspective that the global termination shock may have a bow-shaped open geometry. The termination shock forms on the upwind side because the forward motion of the supersonic solar wind is blocked at the blunt-nosed heliopause. However, the heliopause likely to be open on the downwind side; the motion of the supersonic solar wind is unobstructed for shock formation. Thus, the global termination shock likely has an open geometry. On the upwind side the shock flares out and weakens from the nose to its flanks. Eventually, the shock asymptotically reduces to a Mach wave. The supersonic solar wind remains shock free in the heliotail.展开更多
Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated ...Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.展开更多
文摘SuperView-I satellite constellation （SuperView-I for short） is the first commercial remote sensing constellation with a resolution down to 0.5 m. It＇s an important part of the national spatial information infrastructure construction. It will play an important role for the global users providing remote sensing data, application solutions and remote sensing value-added services with its highresolution and 24-hour observation capability. At present, 4 satellites of the constellation have been successfully launched and networked on orbit. The services cover surveying and mapping, land resource surveying, urban planning, agriculture, forestry, water conservancy, geological mining, environmental monitoring, defense, disaster reduction along with other traditional industries. There are also great potential applications in Mobile Intemet, LBS, Smart city, insurance and other emerging professions. The successful operation of SuperView-I breaks the overseas monopoly for commercial high-resolution remote sensing satellite imagery in the China market. It＇s one of the major achievements in China space science and technology by actively exploring the development of commercial remote sensing markets, which is of strategic significance to the development of China remote sensing satellite business.
文摘Interaction of the solar wind with the interstellar medium leads to the formation of the heliosphere and termination shock. This article addresses three aspects of the plasma and magnetic field on two sides of the heliopause： （1） The interstellar magnetic field surrounding the heliopause. In the limit of very low plasma β-ratio an analytical solution is obtained for the 3D interstellar magnetic field by means of a line dipole method. The undisturbed magnetic field in the upstream is allowed to have an arbitrary inclination angle. The solution describes the heliosphere as having a blunt-nosed geometry on the upwind side and approaching a cylindrical geometry on the downwind side. The distortion of the magnetic field can penetrate very deep into the interstellar space. （2） Interaction of the interstellar neutral hydrogen with the global solar wind. The ionization process leads to removal of interstellar neutral hydrogen in the heliosphere： on the upwind side, 90% of hydrogen depletion occurs inside 60 AU, the hydrogen density changes rapidly inside 10 AU. A hydrogen cavity forms inside -4 AU; the cavity extends on the downwind side to form a long cavity wake. Outside the cavity and cavity wake, pickup protons are produced, they cause deceleration and heating of the solar wind. The wind speed and temperature also increase steadily with heliolatitude caused by the latitudinal increase in wind speed at the inner boundary. （3） The global geometry of the termination shock. The termination shock has been treated as having a closed geometry in previous heliosphere models. This study presents a new perspective that the global termination shock may have a bow-shaped open geometry. The termination shock forms on the upwind side because the forward motion of the supersonic solar wind is blocked at the blunt-nosed heliopause. However, the heliopause likely to be open on the downwind side; the motion of the supersonic solar wind is unobstructed for shock formation. Thus, the global termination shock likely has an open geometry. On the upwind side the shock flares out and weakens from the nose to its flanks. Eventually, the shock asymptotically reduces to a Mach wave. The supersonic solar wind remains shock free in the heliotail.
基金supported by the National Natural Science Foundation of China(Grant Nos.1140522311175219+4 种基金11275271 and 11435014)the National Program on Key Basic Research Project(Grant No.2013CB834405)the Knowledge Innovation Project of Chinese Academy of Sciences(Grant No.KJCX2-EW-N01)the Funds for Creative Research Groups of China(Grant No.11021504)the Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.
