As the closest celestial body to the Earth, the moon is a hot spot for international space science research at present. Countries around the world have conducted lunar exploration time after time, among which, China’...As the closest celestial body to the Earth, the moon is a hot spot for international space science research at present. Countries around the world have conducted lunar exploration time after time, among which, China’s Lunar Exploration Program has achieved 6 consecutive successful lunar missions. China has made a series of significant achievements in deep space exploration, and its cooperation with international partners is increasingly strengthened. In order to gather global space power and scientists’ wisdom, the International lunar Research Station(ILRS) is proposed by China and will be jointly constructed by many countries, which will be equipped with the support capabilities of energy supply, central control, communications and navigation, space-Earth round-trip transportation, lunar surface scientific research, and ground support. All international partners are encouraged to jointly develop and build the ILRS, and to jointly initiate the establishment of the International Lunar Research Station Cooperation Organization(ILRSCO) to achieve the long-term effective, operation and management of the station. The vast universe sparks the exploration dream of humankind, so let’s set sail together.展开更多
At 18:30 on October 24,2007, Xinhua.com flashed the news to the world:'Beijing Aerospace Control Center announced Chang'e 1 satellite precisely entered the preset orbit and the satellite launch achieved succes...At 18:30 on October 24,2007, Xinhua.com flashed the news to the world:'Beijing Aerospace Control Center announced Chang'e 1 satellite precisely entered the preset orbit and the satellite launch achieved successes.'The news told all people of the world that China had begun its journey to the moon.展开更多
TT&C System This system is primarily based on China's exi sting threeband space TT&C netwo rk,and supplemented by the very long ba seline interferometry(VLBI) astronomical measurement system. The TT&C ...TT&C System This system is primarily based on China's exi sting threeband space TT&C netwo rk,and supplemented by the very long ba seline interferometry(VLBI) astronomical measurement system. The TT&C and communications system belonging to the Phase I of China Lunar Exploration Program (CLEP)is based on the existing USB space monitoring and control network. After a technological transformation,展开更多
The phenomenon of panicle enclosure in rice is mainly caused by the shortening of uppermost internode.Elucidating the molecular mechanism of panicle enclosure will be helpful for solving the problem of panicle enclosu...The phenomenon of panicle enclosure in rice is mainly caused by the shortening of uppermost internode.Elucidating the molecular mechanism of panicle enclosure will be helpful for solving the problem of panicle enclosure in male sterile lines and creating new germplasms in rice.We acquired a monogenic recessive enclosed panicle mutant,named as esp2 (enclosed shorter panicle 2),from the tissue culture progeny of indica rice cultivar Minghui-86.In the mutant,panicles were entirely enclosed by flag leaf sheaths and the uppermost internode was almost completely degenerated,but the other internodes did not have obvious changes in length.Genetic analysis indicated that the mutant phenotype was controlled by a recessive gene,which could be steadily inherited and was not affected by genetic background.Apparently,ESP2 is a key gene for the development of uppermost internode in rice.Using an F 2 population of a cross between esp2 and a japonica rice cultivar Xiushui-13 as well as SSR and InDel markers,we fine mapped ESP2 to a 14-kb region on the end of the short arm of chromosome 1.According to the rice genome sequence annotation,only one intact gene exists in this region,namely,a putative phosphatidylserine synthase gene.Sequencing analysis on the mutant and the wild type indicated that this gene was inserted by a 5287-bp retrotransposon sequence.Hence,we took this gene as a candidate of ESP2.The results of this study will facilitate the cloning and functional analysis of ESP2 gene.展开更多
Deep space exploration is the term used for the exploration of the Moon and the celestial bodies or space beyond the Moon, which is an important part of human space activities. Firstly, the development of deep space e...Deep space exploration is the term used for the exploration of the Moon and the celestial bodies or space beyond the Moon, which is an important part of human space activities. Firstly, the development of deep space exploration (not including the Moon) during the last few decades is summarized. Secondly, the development trend of different space countries and regions is analyzed. Then the experience and enlightenment of deep space exploration are briefly discussed. Some suggestions for China's future deep space exploration are given in the end.展开更多
A set of recombinant inbred lines (RIL) derived from Yuyu22, an elite hybrid widespread in China, was used to construct an immortalized F2 (IF2) population comprising 441 different crosses. Genetic linkage maps were c...A set of recombinant inbred lines (RIL) derived from Yuyu22, an elite hybrid widespread in China, was used to construct an immortalized F2 (IF2) population comprising 441 different crosses. Genetic linkage maps were constructed containing 10 linkages groups with 263 simple sequence repeat (SSR) molecular markers. Twelve and ten quantitative trait loci (QTL) were detected for plant height in the IF2 and RIL populations respectively, using the composite interval mapping method, and six same QTL were identified in the two populations. In addition, ten unique heterotic loci (HL) located on seven different chromosomes were revealed for plant height using the mid-parent heterosis as the input data. These HL explained 1.26%―8.41% of the genotypic variance in plant height heterosis and most expressed overdominant effects. Only three QTL and HL were located in the same chromosomal region, it implied that plant height and its heterosis might be controlled by two types of genetic mechanisms.展开更多
The seedlings of indica rice cultivar Dular are susceptible to chlorosis under low temperature conditions.Our previous studies indicated that low temperature-induced seedling chlorosis is controlled by a recessive gen...The seedlings of indica rice cultivar Dular are susceptible to chlorosis under low temperature conditions.Our previous studies indicated that low temperature-induced seedling chlorosis is controlled by a recessive gene,located between SSR markers RM257 and RM242,on the long arm of chromosome 9.We temporarily named the gene cisc(t).Using a large F2 population derived from a cross between Dular and the japonica cultivar Lemont,which displays a normal green color at low temperatures,cisc(t)was fine mapped to within a 12-kb interval.There is only one annotated gene in this interval,which encodes a pentatricopeptide repeat(PPR)protein.Sequence analysis indicated that 8 bases were deleted at the 60th base in the Dular allele,resulting in a frame-shift mutation and loss of function of the gene.This is consistent with the chlorosis mutant phenotype of Dular.In addition,previous studies have shown that many chlorosis mutants of seedlings are related to PPR proteins.Hence,we presume that the PPR gene is the candidate for cisc(t).展开更多
Tobacco(Nicotiana tabacum) is one of the most economically important nonfood crops,and flue-cured tobacco accounts for approximately 80% of world tobacco production.An extremely narrow genetic diversity in the tobacco...Tobacco(Nicotiana tabacum) is one of the most economically important nonfood crops,and flue-cured tobacco accounts for approximately 80% of world tobacco production.An extremely narrow genetic diversity in the tobacco pool has led to a low efficiency of PCR-based molecular markers(such as AFLP and SSR).Diversity Arrays Technology(DArT) is a high-throughput hybridisation-based marker system that has been developed in many plants including wheat,which,like tobacco,has a complex genome.In this study,we developed a tobacco DArT chip that included 7680 representative sequence tags based on typical tobacco accessions.The 1076 DArT markers of flue-cured tobacco were identified and most(82.1%) of their polymorphism information contents(PICs) were greater than 0.4.An integrated linkage map that included 851 markers(238 DArT and 613 SSR),which is the highest density map of flue-cured tobacco to date,was constructed.This chip-based DArT system provides an alternative in high-throughput marker genotyping for tobacco.展开更多
The interest in the periodic orbits of the restricted three-body problem continues to grow for their significant practical application.This paper focuses on the interplanetary transfers between periodic orbits of two ...The interest in the periodic orbits of the restricted three-body problem continues to grow for their significant practical application.This paper focuses on the interplanetary transfers between periodic orbits of two different three-body systems,whose invariant manifolds have no intersection in phase space.A novel design method is proposed to obtain the optimal transfer employing the invariant manifolds and planetary gravity assist.The periapsis Poincare map is used to analyze the periapsides of invariant manifolds.On the basis of hyperbola approximation,the impulses performed on the periapsis of invariant manifolds are calculated with a simple iterative algorithm.The propellant-efficient escape and capture trajectories can be found by comparing the impulses magnitudes corresponding to different invariant manifolds,which can provide the appropriate initial guess for optimization.Further,the trajectory design is formulated as an unconstrained optimization problem under the perturbed restricted three-body model.An efficient algorithm combining simplex method and differential correction is adopted to obtain the optimal solution.The validity of the proposed approach is demonstrated through several interplanetary low energy transfer trajectories.展开更多
The next generation space internet （NGSI） is based on all-IP-based mobile network that merges land-based network, sea-based network, sky-based network, spacebased network, deep space-based network together using exi...The next generation space internet （NGSI） is based on all-IP-based mobile network that merges land-based network, sea-based network, sky-based network, spacebased network, deep space-based network together using existing assess network technologies. There are high signal propagation delays, high error rate, bandwidth variation and time-variety in NGSh In order to adapt to various space communication environment constraints and bandwidth variation, we propose a reduced dimension scalable video coding scheme based on CCSDS IDCS algorithm and quality of service （QoS） control method by cross layer design （CLD）. The experimental result shows that this new method has better performance than that of existing algorithms, and can be adaptive to the bandwidth variation dynamically.展开更多
文摘As the closest celestial body to the Earth, the moon is a hot spot for international space science research at present. Countries around the world have conducted lunar exploration time after time, among which, China’s Lunar Exploration Program has achieved 6 consecutive successful lunar missions. China has made a series of significant achievements in deep space exploration, and its cooperation with international partners is increasingly strengthened. In order to gather global space power and scientists’ wisdom, the International lunar Research Station(ILRS) is proposed by China and will be jointly constructed by many countries, which will be equipped with the support capabilities of energy supply, central control, communications and navigation, space-Earth round-trip transportation, lunar surface scientific research, and ground support. All international partners are encouraged to jointly develop and build the ILRS, and to jointly initiate the establishment of the International Lunar Research Station Cooperation Organization(ILRSCO) to achieve the long-term effective, operation and management of the station. The vast universe sparks the exploration dream of humankind, so let’s set sail together.
文摘At 18:30 on October 24,2007, Xinhua.com flashed the news to the world:'Beijing Aerospace Control Center announced Chang'e 1 satellite precisely entered the preset orbit and the satellite launch achieved successes.'The news told all people of the world that China had begun its journey to the moon.
文摘TT&C System This system is primarily based on China's exi sting threeband space TT&C netwo rk,and supplemented by the very long ba seline interferometry(VLBI) astronomical measurement system. The TT&C and communications system belonging to the Phase I of China Lunar Exploration Program (CLEP)is based on the existing USB space monitoring and control network. After a technological transformation,
基金supported by the National Transgenic Projects of China (2009ZX08009-109B)Natural Science Foundation of Fujian Province (2010J01077)+1 种基金the National High Technology Research and Development Program of China (2006AA10Z128)New Century Excellent Talents in University of Fujian Province (KY0010057)
文摘The phenomenon of panicle enclosure in rice is mainly caused by the shortening of uppermost internode.Elucidating the molecular mechanism of panicle enclosure will be helpful for solving the problem of panicle enclosure in male sterile lines and creating new germplasms in rice.We acquired a monogenic recessive enclosed panicle mutant,named as esp2 (enclosed shorter panicle 2),from the tissue culture progeny of indica rice cultivar Minghui-86.In the mutant,panicles were entirely enclosed by flag leaf sheaths and the uppermost internode was almost completely degenerated,but the other internodes did not have obvious changes in length.Genetic analysis indicated that the mutant phenotype was controlled by a recessive gene,which could be steadily inherited and was not affected by genetic background.Apparently,ESP2 is a key gene for the development of uppermost internode in rice.Using an F 2 population of a cross between esp2 and a japonica rice cultivar Xiushui-13 as well as SSR and InDel markers,we fine mapped ESP2 to a 14-kb region on the end of the short arm of chromosome 1.According to the rice genome sequence annotation,only one intact gene exists in this region,namely,a putative phosphatidylserine synthase gene.Sequencing analysis on the mutant and the wild type indicated that this gene was inserted by a 5287-bp retrotransposon sequence.Hence,we took this gene as a candidate of ESP2.The results of this study will facilitate the cloning and functional analysis of ESP2 gene.
基金supported by the National Science and Technology Major Project on Lunar Exploration Program and the National High Technology Research and Development Program ("863" Program) (Grant Nos. 2010AA122206 and 2010AA7030506C)
文摘Deep space exploration is the term used for the exploration of the Moon and the celestial bodies or space beyond the Moon, which is an important part of human space activities. Firstly, the development of deep space exploration (not including the Moon) during the last few decades is summarized. Secondly, the development trend of different space countries and regions is analyzed. Then the experience and enlightenment of deep space exploration are briefly discussed. Some suggestions for China's future deep space exploration are given in the end.
基金Supported by the State Key Basic Research and Development Plan of China (Grant No. 2001CB10801)the National High-Technology Project of China (Grant No. 2002AA207008)
文摘A set of recombinant inbred lines (RIL) derived from Yuyu22, an elite hybrid widespread in China, was used to construct an immortalized F2 (IF2) population comprising 441 different crosses. Genetic linkage maps were constructed containing 10 linkages groups with 263 simple sequence repeat (SSR) molecular markers. Twelve and ten quantitative trait loci (QTL) were detected for plant height in the IF2 and RIL populations respectively, using the composite interval mapping method, and six same QTL were identified in the two populations. In addition, ten unique heterotic loci (HL) located on seven different chromosomes were revealed for plant height using the mid-parent heterosis as the input data. These HL explained 1.26%―8.41% of the genotypic variance in plant height heterosis and most expressed overdominant effects. Only three QTL and HL were located in the same chromosomal region, it implied that plant height and its heterosis might be controlled by two types of genetic mechanisms.
基金supported by the Fujian Natural Science Foundation(2007J0054)the Fujian Science and Technology Project(2006F5020)
文摘The seedlings of indica rice cultivar Dular are susceptible to chlorosis under low temperature conditions.Our previous studies indicated that low temperature-induced seedling chlorosis is controlled by a recessive gene,located between SSR markers RM257 and RM242,on the long arm of chromosome 9.We temporarily named the gene cisc(t).Using a large F2 population derived from a cross between Dular and the japonica cultivar Lemont,which displays a normal green color at low temperatures,cisc(t)was fine mapped to within a 12-kb interval.There is only one annotated gene in this interval,which encodes a pentatricopeptide repeat(PPR)protein.Sequence analysis indicated that 8 bases were deleted at the 60th base in the Dular allele,resulting in a frame-shift mutation and loss of function of the gene.This is consistent with the chlorosis mutant phenotype of Dular.In addition,previous studies have shown that many chlorosis mutants of seedlings are related to PPR proteins.Hence,we presume that the PPR gene is the candidate for cisc(t).
基金supported by Yunnan Provincial Tobacco Company(08A05//2011YN04)China National Tobacco Company (110200701023/110201201003(JY-03))
文摘Tobacco(Nicotiana tabacum) is one of the most economically important nonfood crops,and flue-cured tobacco accounts for approximately 80% of world tobacco production.An extremely narrow genetic diversity in the tobacco pool has led to a low efficiency of PCR-based molecular markers(such as AFLP and SSR).Diversity Arrays Technology(DArT) is a high-throughput hybridisation-based marker system that has been developed in many plants including wheat,which,like tobacco,has a complex genome.In this study,we developed a tobacco DArT chip that included 7680 representative sequence tags based on typical tobacco accessions.The 1076 DArT markers of flue-cured tobacco were identified and most(82.1%) of their polymorphism information contents(PICs) were greater than 0.4.An integrated linkage map that included 851 markers(238 DArT and 613 SSR),which is the highest density map of flue-cured tobacco to date,was constructed.This chip-based DArT system provides an alternative in high-throughput marker genotyping for tobacco.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2012CB720000)the National Natural Science Foundation of China (Grant No. 11102021)Foundation of Science and Technology on Space Intelligent Control Laboratory
文摘The interest in the periodic orbits of the restricted three-body problem continues to grow for their significant practical application.This paper focuses on the interplanetary transfers between periodic orbits of two different three-body systems,whose invariant manifolds have no intersection in phase space.A novel design method is proposed to obtain the optimal transfer employing the invariant manifolds and planetary gravity assist.The periapsis Poincare map is used to analyze the periapsides of invariant manifolds.On the basis of hyperbola approximation,the impulses performed on the periapsis of invariant manifolds are calculated with a simple iterative algorithm.The propellant-efficient escape and capture trajectories can be found by comparing the impulses magnitudes corresponding to different invariant manifolds,which can provide the appropriate initial guess for optimization.Further,the trajectory design is formulated as an unconstrained optimization problem under the perturbed restricted three-body model.An efficient algorithm combining simplex method and differential correction is adopted to obtain the optimal solution.The validity of the proposed approach is demonstrated through several interplanetary low energy transfer trajectories.
基金the National Natural Science Foundation of China (Grant Nos. 60773137 and 60573112)the National 863 Project (Grant No. 2007AA01Z297)the National Foundation (Grant No. 1320061262)
文摘The next generation space internet （NGSI） is based on all-IP-based mobile network that merges land-based network, sea-based network, sky-based network, spacebased network, deep space-based network together using existing assess network technologies. There are high signal propagation delays, high error rate, bandwidth variation and time-variety in NGSh In order to adapt to various space communication environment constraints and bandwidth variation, we propose a reduced dimension scalable video coding scheme based on CCSDS IDCS algorithm and quality of service （QoS） control method by cross layer design （CLD）. The experimental result shows that this new method has better performance than that of existing algorithms, and can be adaptive to the bandwidth variation dynamically.
