Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulti...Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.展开更多
Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify ig...Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify igneous rock bodies.Aimed at the characteristics of gravity and magnetic fields in the South China Sea,several potential field processing methods are preferentially selected.Reduction to the pole by variable inclinations in the area of low magnetic latitudes is used to perform reduction processing on magnetic anomalies.The preferential continuation method is used to separate gravity and magnetic anomalies and extract the gravity and magnetic anomaly information of igneous rocks in the shallow part of the South China Sea.The 3D spatial equivalent distribution of igneous rocks in South China Sea is illustrated by the 3 D correlation imaging of magnetic anomalies.Since the local anomaly boundaries are highlighted gravity and magnetic gradients,the distribution characters of different igneous rocks are roughly outlined by gravity and magnetic correlation analysis weighted by gradient.The results show the distribution of igneous rocks is controlled and influenced by deep crustal structure and faulting.展开更多
The Moon has been divided into three terranes:Procellarum KREEP Terrane(PKT),Feldspathic Highland Terrane(FHT),and South Pole-Aitken Terrane(SPAT),using globally measured Th and FeO.Many lunar evolu-tion models have p...The Moon has been divided into three terranes:Procellarum KREEP Terrane(PKT),Feldspathic Highland Terrane(FHT),and South Pole-Aitken Terrane(SPAT),using globally measured Th and FeO.Many lunar evolu-tion models have predicted that a lunar magma ocean will produce a residual layer enriched in incompatible elements such as K,REE,and P(i.e.,KREEP)in the late age of crys-tallization;and that the distribution of thorium can be used as a proxy for determining the global distribution of KREEP.The thorium distribution in these three terranes is inhomo-geneous.The highest concentration of thorium is in PKT,the medium concentration of thorium is in SPAT,and almost none in FHT.Then what is the specific distribution in each of the terrane and what enlightenment can it tell us?Here we present and describe the detailed thorium distribution in PKT,SPAT,and FHT and provide some information for the origin of asymmetries on the lunar surface.展开更多
The particular challenges of modeling control systems for the middle route of the south-to-north water transfer project are illustrated.Open channel dynamics are approximated by well-known Saint-Venant nonlinear parti...The particular challenges of modeling control systems for the middle route of the south-to-north water transfer project are illustrated.Open channel dynamics are approximated by well-known Saint-Venant nonlinear partial differential equations.For better control purpose,the finite difference method is used to discretize the Saint-Venant equations to form the state space model of channel system.To avoid calculation divergence and improve control stability,balanced model reduction together with poles placement procedure is proposed to develop the control scheme.The entire process to obtain this scheme is described in this paper,important application issue is considered as well.Experimental results show the adopted techniques are properly used in the control scheme design,and the system is able to drive the discharge to the demanded set point or maintain it around a reasonable range even if comes across big withdrawals.展开更多
The anomalous change of two polar sea ice and tropical ocean SST is a very important index for global climate monitoring and prediction. In this paper, wave resonance principle is used to calculate month by month runn...The anomalous change of two polar sea ice and tropical ocean SST is a very important index for global climate monitoring and prediction. In this paper, wave resonance principle is used to calculate month by month running crosscouple correlation coefficient time series between sea ices in different sea areas of the two poles, as well as between themand five elements of El Nino event, to analyze their variation features. and to find out their resonance periods. The reso nance period of two waves is just the strongest interaction period.borne results are as follows: 1. The Arctic sea ice to the Pacific-side (NP11) and Atlantic-side (NP12 ) shows a mu tual strong positive-negative feedback impact with the Antarctic Ross Sea ice (SP12) in equal intensity. 2. Both NP11 andNP12 give a strong positive and negative feedback to the Antarctic Wedded Sea ice (SP13) while it is rather weak in con verse status. It means that the Arctic sea ice plays a leading and controlling role on the Wedded Sea ice. 3. SST of Nino4 area in the central equatorial Pacific has a best resonance period with SP12 in a cycle period of 132 months. It closely re lates to quasi-11-year oscillation period of both. SST of Nino 4 area also has a resonance period with SP13 in a cycle of 61months. There also exist strong interaction periods between the Antarctic sea ice and other elements of El Nino event butweaker than SST of Nino 4 area.展开更多
China has carried out four unmanned missions to the Moon since it launched Chang’E-1,the first lunar orbiter in 2007.With the implementation of the Chang’E-5 mission this year,the three phases of the lunar explorati...China has carried out four unmanned missions to the Moon since it launched Chang’E-1,the first lunar orbiter in 2007.With the implementation of the Chang’E-5 mission this year,the three phases of the lunar exploration program,namely orbiting,landing and returning,have been completed.In the plan of follow-up unmanned lunar exploration missions,it is planned to establish an experimental lunar research station at the lunar south pole by 2030 through the implementation of several missions,laying a foundation for the establishment of practical lunar research station in the future.China successfully launched its first Mars probe on 23 July 2020,followed in future by an asteroid mission,second Mars mission,and a mission to explore Jupiter and its moons.展开更多
[ Objective] The research aimed to contrast and analyze meteorological factors between Zhongshan station of the South Pole and Chi- nese inland. [ Method ] Based on meteorological observation data at Zhongshan station...[ Objective] The research aimed to contrast and analyze meteorological factors between Zhongshan station of the South Pole and Chi- nese inland. [ Method ] Based on meteorological observation data at Zhongshan station of the South Pole since established, contrast and analysis were taken on the atmospheric temperature, relative humidity and atmospheric pressure with that at Shanghe station of Chinese inland, to find out variation laws of the each meteorological factor in the two stations, and to analyze different change relations among factors. [ Result] Although geo- graphic positions of the two stations were different, and they were respectively in south and north hemispheres, each meteorological factor at the two stations had same change rules. Interannual anomaly relationship of the meteorological factor had certain rule. That was to say, variation of the positive or negative anomaly advanced or lagged for 1 -2 years. [ Conclusion] The research had reference value for studying global climatic variation.展开更多
文摘Change＇4 Lunar Probe will softly land on the farside of the Moon for the first time of all mankind and carry out in-situ and rovering exploration. In this paper, the scientific significance and engineering difficulties of Change＇4 are introduced and the probe＇s general design, including the aspects of landing site selection, relay communication, trajectory design of relay satellite is explained. Besides, four key technologies, namely safe landing strategy on complex terrain, orbit design and control of libration point 2, relay communication on L2, radioisotope thermoelectric generator （RTG） and electric-thermal utilization, as well as how to realize them are also discussed. Finally the prospect of the prominent technological breakthrough of Change＇4 is described.
基金the National 863 Projects(Nos.2006AA06Z111,2006AA06201-3,and 2006AA09A101-3)National Special Project(No.SinoProbe-01-05)Open Project of the National Key Laboratory for Geological Processes and Mineral Resources(No.GPMR0942).
文摘Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify igneous rock bodies.Aimed at the characteristics of gravity and magnetic fields in the South China Sea,several potential field processing methods are preferentially selected.Reduction to the pole by variable inclinations in the area of low magnetic latitudes is used to perform reduction processing on magnetic anomalies.The preferential continuation method is used to separate gravity and magnetic anomalies and extract the gravity and magnetic anomaly information of igneous rocks in the shallow part of the South China Sea.The 3D spatial equivalent distribution of igneous rocks in South China Sea is illustrated by the 3 D correlation imaging of magnetic anomalies.Since the local anomaly boundaries are highlighted gravity and magnetic gradients,the distribution characters of different igneous rocks are roughly outlined by gravity and magnetic correlation analysis weighted by gradient.The results show the distribution of igneous rocks is controlled and influenced by deep crustal structure and faulting.
基金This work was supported by National Key Research and Development Program of China(Grant No.2022YFF0503100)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB 41000000).
文摘The Moon has been divided into three terranes:Procellarum KREEP Terrane(PKT),Feldspathic Highland Terrane(FHT),and South Pole-Aitken Terrane(SPAT),using globally measured Th and FeO.Many lunar evolu-tion models have predicted that a lunar magma ocean will produce a residual layer enriched in incompatible elements such as K,REE,and P(i.e.,KREEP)in the late age of crys-tallization;and that the distribution of thorium can be used as a proxy for determining the global distribution of KREEP.The thorium distribution in these three terranes is inhomo-geneous.The highest concentration of thorium is in PKT,the medium concentration of thorium is in SPAT,and almost none in FHT.Then what is the specific distribution in each of the terrane and what enlightenment can it tell us?Here we present and describe the detailed thorium distribution in PKT,SPAT,and FHT and provide some information for the origin of asymmetries on the lunar surface.
基金supported by the National Key Basic Research Program of China ("973" Progject) (Grant No. 2007CB714100)
文摘The particular challenges of modeling control systems for the middle route of the south-to-north water transfer project are illustrated.Open channel dynamics are approximated by well-known Saint-Venant nonlinear partial differential equations.For better control purpose,the finite difference method is used to discretize the Saint-Venant equations to form the state space model of channel system.To avoid calculation divergence and improve control stability,balanced model reduction together with poles placement procedure is proposed to develop the control scheme.The entire process to obtain this scheme is described in this paper,important application issue is considered as well.Experimental results show the adopted techniques are properly used in the control scheme design,and the system is able to drive the discharge to the demanded set point or maintain it around a reasonable range even if comes across big withdrawals.
文摘The anomalous change of two polar sea ice and tropical ocean SST is a very important index for global climate monitoring and prediction. In this paper, wave resonance principle is used to calculate month by month running crosscouple correlation coefficient time series between sea ices in different sea areas of the two poles, as well as between themand five elements of El Nino event, to analyze their variation features. and to find out their resonance periods. The reso nance period of two waves is just the strongest interaction period.borne results are as follows: 1. The Arctic sea ice to the Pacific-side (NP11) and Atlantic-side (NP12 ) shows a mu tual strong positive-negative feedback impact with the Antarctic Ross Sea ice (SP12) in equal intensity. 2. Both NP11 andNP12 give a strong positive and negative feedback to the Antarctic Wedded Sea ice (SP13) while it is rather weak in con verse status. It means that the Arctic sea ice plays a leading and controlling role on the Wedded Sea ice. 3. SST of Nino4 area in the central equatorial Pacific has a best resonance period with SP12 in a cycle period of 132 months. It closely re lates to quasi-11-year oscillation period of both. SST of Nino 4 area also has a resonance period with SP13 in a cycle of 61months. There also exist strong interaction periods between the Antarctic sea ice and other elements of El Nino event butweaker than SST of Nino 4 area.
基金Supported by National Key R&D Program of China(2020YFE0202100)Beijing Municipal Science and Technology Commission(Z181100002918003)。
文摘China has carried out four unmanned missions to the Moon since it launched Chang’E-1,the first lunar orbiter in 2007.With the implementation of the Chang’E-5 mission this year,the three phases of the lunar exploration program,namely orbiting,landing and returning,have been completed.In the plan of follow-up unmanned lunar exploration missions,it is planned to establish an experimental lunar research station at the lunar south pole by 2030 through the implementation of several missions,laying a foundation for the establishment of practical lunar research station in the future.China successfully launched its first Mars probe on 23 July 2020,followed in future by an asteroid mission,second Mars mission,and a mission to explore Jupiter and its moons.
文摘[ Objective] The research aimed to contrast and analyze meteorological factors between Zhongshan station of the South Pole and Chi- nese inland. [ Method ] Based on meteorological observation data at Zhongshan station of the South Pole since established, contrast and analysis were taken on the atmospheric temperature, relative humidity and atmospheric pressure with that at Shanghe station of Chinese inland, to find out variation laws of the each meteorological factor in the two stations, and to analyze different change relations among factors. [ Result] Although geo- graphic positions of the two stations were different, and they were respectively in south and north hemispheres, each meteorological factor at the two stations had same change rules. Interannual anomaly relationship of the meteorological factor had certain rule. That was to say, variation of the positive or negative anomaly advanced or lagged for 1 -2 years. [ Conclusion] The research had reference value for studying global climatic variation.
