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On critical values concerning the evolution of the long period families

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Chinese Journal of Astronomy and Astrophysics 2009年第4期9卷 494-500页

作者： Xi-Yun Hou1,21 Astronomy Department, nanjing university, nanjing 210093, china 2 institute of space environment and Astronautics, nanjing university, nanjing 210093, china Astronomy Department Nanjing University Nanjing 210093 China institute of space environment and Astronautics Nanjing University Nanjing 210093 China

In a previous paper, we proposed another special critical value concerning the evolution of the long period family around the equilateral equilibrium points, besides the two values given by Henrard. Are there any other special critical values？ After studying the stability curves of the long period family carefully, we gave a negative answer. During the study, we found an interesting family of periodic orbits which we called the homo family. We studied the evolution of this family following the increase of μ. With these findings, we were able to explain the origin of the four branches of periodic families emanating from L4 and the stability results of the equilateral equilibrium points.

关键词： celestial mechanics

On the Station-Keeping and Control of the World space Observatory/Ultraviolet

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Chinese Journal of Astronomy and Astrophysics 2006年第3期6卷 372-378页

作者： Xi-Yun Hou Hai-Hong Wang Lin Liu Department of Astronomy Nanjing University Nanjing 210093 institute of space Enviromnent and Astronautics Nanjing University Nanjing 210093

Collinear libration points play an important role in deep space exploration because of their special positions and dynamical characteristics. Since motion around them is unstable, we need to control the spacecraft if we wish to keep them around such a libration point for a long time. Here we propose a continuous low-thrust control strategy, illustrated with numerical simulations combined with the orbit design and control of the World space Observatory/UltraViolet （WSO/UV）.

关键词： celestial mechanics - WSO/UV - low thrust

environmental archaeology of the Dachang region in the Daning Valley,the Three Gorges reservoir region of the Yangtze River,china

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Chinese Science Bulletin 2008年第S1期53卷 140-152页

作者： ZHANG Yun 1 &ZHU Cheng 2 1 State Key Laboratory of Vegetation and environmental Change,institute of Botany,Chinese Academy of Sciences,Beijing 100093, china 2 School of Geographic and Oceanographic Sciences,nanjing university,nanjing 210093,china State Key Laboratory of Vegetation and environmental Change Institute of Botany Chinese Academy of Sciences Beijing China School of Geographic and Oceanographic Sciences Nanjing University Nanjing China

environmental archaeology of archaeological sites on both sides of the Dachang section in the Daning River,the Three Gorges of the Yangtze River,shows that riverbed evolution has a great influence on the distribution of archaeological sites during the prehistorical and historical period,and it restricts human activity and the development of ancient *** investigation,dating data,paleocurrent analysis of 100 gravels on the riverbed and archaeological excavation reveal that the riverbed of the Dachang section developed in the Shuangyantang region during the early stage,after about 30 kaBP it shifted westward gradually and reached the present *** with the westward shift,the focus of ancient culture changed for several *** the Western Zhou Dynasty's period,the east riverbank of the Daning River was the main residential *** the Han Dynasty,along with the westward shift,the living space of ancient people was no longer confined to the east riverbank and the focus of culture moved *** the Zhangjiawan site became the main dwelling *** the late Han Dynasty, the villages were flooded and the ancients had to immigrate to a high *** of the Han and the Jin Dynasties outcropped on the flood plain of the east bank because their surface sediments were eroded by several flood events and the westward shift of the riverbed.

关键词： the Daning River environmental archaeology the Shuangyantang site the Zhangjiawan site tombs of the Han and the Jin Dynasties

NUMERICAL INVESTIGATION OF UNSTEADY DROPLET COMBUSTION PROCESS IN HOT QUIESCENT AIR environmentS (HQAE)

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Chinese Journal of Aeronautics 1997年第3期10卷 35-41页

作者： Zhu Guangsheng, Lin Junyi, Zhang Yuelin (nanjing university of Science and Technology, nanjing, 210094, china) Wu Chuijie (Air Force institute of Meteorology, nanjing, 211101, china)

A mathematical model has been presented for describing single droplet unsteady processes of vaporization, ignition and combustion in a hot quiescent air environment. The arbitrary Lagrangian Eulerian numerical method, incorporated with an effective adaptive mesh method, is applied. From the obtained time space distributions of gas temperature and species densities, the characteristics of droplet ignition and combustion process are clarified. It is also demonstrated that, due to the strong damping of the high temperature flame region around the droplet, the ambient conditions have little effects on the properties of the drop's surface; and that, due to the unsteady prediction of droplet heating time being much less than the corresponding quasi steady prediction under burning condition, the differences between unsteady and quasi steady results are much greater than those under pure vaporization.

关键词： drops (liquids) combustion ignition droplet unsteady theory droplet quasi steady theory

Synthesis and Structure of the Copper(I) Complex Containing Bis(diphenylphosphino)ethane

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Chinese Journal of Structural Chemistry 2002年第1期21卷 51-54页

作者： LIN Kun-Hua1,2 XIE Qing1 YANG Rui-Na1② XING Li-Ping1 JIN Dou-Man3 (1Henan institute of Chemistry, Zhengzhou 450002, china) (2Zhengzhou university, Zhengzhou 450006, china) (3State Key Laboratory of Coordination Chemistry, nanjing university 210093, Chin Henan institute of Chemistry Zhengzhou 450002 配位化学国家重点实验室配位化学国家重点实验室 Nanjing 210093

The mononuclear copper(I) complex, [Cu(dppe)2](PF6)(CH3COCH3) [dppe = bis-(diphenylphosphino)ethane] has been synthesized and characterized by X-ray crystallography. The crystal belongs to monoclinic, Mr=1062.3, space group P21/n with cell parameters a =14.741(2), b =19.354(8), c =18.587(3) ? = 91.41(1)°, V = 5301.5 3, Z = 4, Dc=1.302 g/cm3, F(000)= 2200, = 6.16cm-1, R=0.062, Rw = 0.068. A total of 9679 independent reflections were collected, of which 4574 reflections with I >3σ(I) were observed. The central Cu atom is coordinated by four P atoms from dppe to form a distorted tetrahedral environment. In the coordination sphere the bond lengths of CuP(1), CuP(2), CuP(3) and CuP(4) are 2.298(2), 2.305(2), 2.311(2) and 2.295? respectively; and the PCuP bond angles vary from 87.52(9) to 120.12(9)?

关键词：铜配合物合成晶体结构双(二苯基膦基)2烷

Synthesis and Crystal Structure of Ni3（admt）6（NCS）6·C2H5OH·2H2O

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Chinese Journal of Structural Chemistry 2000年第2期19卷 81-85页

作者： LIU Jia Cheng SONG You ZHUANG Jin Zhong * YOU Xiao Zeng (Coordination Chemistry institute, State Key Laboratory of Coordination Chemistry, nanjing university, nanjing 210093) HUANG XIAO Ying HUANG Zi Xiang(State Key Laboratory of Stru Coordination Chemistry institute State Key Lab. of Coord. Chemistry Nanjing University Nanjing 210093 China State Key Lab. of Struct. Chemistry Fujian Inst. Res. Struct. of Matter Chinese Academy of Sciences Fuzhou Fujian 350002 China

Reaction of nickel (II) perchlorate with 4 amino 3,5 dimethyl 1,2,4 triazole (admt) and NH 4NCS gave a trinuclear complex Ni 3(admtrz) 6(NCS) 6·C 2H 5OH·2H 2O, C 32 H 58 N 30 Ni 3O 3S 6. The compound crystallizes in the orthorhombic space group Pbca (#61) with a=13.551(3), b=25.146(6), c=16.553(4) , V=5640(2) 3, Z=4, M r=1279.47, D c =1.507 g/cm 3 ; μ (Mo Kα )=12.70 cm -1 and F (000)=2656. The final refinement with 2543 observed reflections is converged with R =0.058 and R w =0.069. In the Ni 3(admt) 6(NCS) 6 molecule, the central nickel atom is coordinated in a distorted octahedral environment by four triazole bridges and two thiocyanate bridges. The terminal nickel atoms are in addition coordinated by two thiocyanate and one admtrz ligand, and thus also have a distorted octahedral geometry. Ni-N distances are 2.040(7)-2.222(7), Ni-Ni distances are 3.411(1).

关键词： trinickel(II) complex 4 amino 3 5 dimethyl 1 2 4 triazole thiocyanate crystal structure

Another Fast and Simple DEM Depression-Filling Algorithm Based on Priority Queue Structure

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Atmospheric and Oceanic Science Letters 2009年第4期 213-218页

作者： LIU Yong-He 1,ZHANG Wan-Chang 2,and XU Jing-Wen 1 1 Key Laboratory of Regional Climate-environment Research for Temperate East Asia,institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,china 2 Center for Hydro-Sciences Research,nanjing university,nanjing 210093,china Key Laboratory of Regional Climate-environment Research for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Center for Hydro-Sciences Research Nanjing University Nanjing 210093 China

Some depression cells with heights lower than their surrounding cells may often be found in Grid-based digital elevation models (DEM) dataset due to sampling *** depression-filling algorithm presented by Planchon and Darboux works very quickly compared to other published *** its simplicity and deli-cacy,this algorithm remains difficult to understand due to its three complex subroutines and its recursive *** fast algorithm is presented in this *** main idea of this new algorithm is as follows:first,the DEM dataset is viewed as an island and the outer space as an ocean;when the ocean level increases,the DEM cells on the island’s boundary will be inundated;when a cell is inundated for the first time,its elevation is increased to the ocean level at that moment;after the ocean has inun-dated the entire DEM,all of the depressions are *** depression-removing processing is performed using a priority ***,this new algorithm is a fast algorithm despite the fact that it runs more slowly than Planchon and Darboux’s *** time-complexity in both the worst case and in an average case is O(8nlog 2 (m)),which is close to O(n).The running speed of this algorithm depends mainly on the insertion operation of the priority *** shown by the tests,the depres-sion-filling effects of this algorithm are correct and valid,and the overall time consumption of this algorithm is less than twice the time consumed by Planchon & Darboux’s method for handling a DEM smaller than 2500×2500 *** importantly,this new algorithm is simpler and easier to understand than Planchon and Darboux’s method This advantage allows the correct program code to be written quickly.

关键词： digital elevation models depression remov-ing priority queue quick algorithm

The δ^(18)O variation of a stalagmite from Qixing Cave,Guizhou Province and indi-cated climate change during the Holocene

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Chinese Science Bulletin 2001年第22期46卷 1904-1908页

作者： CAI Yanjun, ZHANG Meiliang, PENG Zicheng, LIN Yushi, AN Zhisheng, ZHANG Zhaofeng & CAO YunningState Key Laboratory of Loess and Quaternary Geology, institute of Earth environment, Chinese Academy of Sciences, Xi’an 710054, china Karst Dynamics Laboratory, Ministry of Land and Resources, Guilin 541003, china Department of Earth and space Science, university of Science & Technology of china, Hefei 230023, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Karst Dynamics Laboratory Ministry of Land and Resources Guilin China Department of Earth and space Science University of Science & Technology of China Hefei China

A stalagmite from Qixing Cave, Guizhou Province was dated with the TIMS U-series method and its oxygen isotope composition was analyzed. On the basis of the ages and the variations of the δ18O of the stalagmite, the climate change of the last 7.7 ka has been reconstructed in this area: 7.7-5.8 ka, summer monsoon maximum period; 5.8-3.8 ka summer monsoon weakening period; 3.8-0.15 ka, weakened summer monsoon and high amplitude climate fluctuations period. We put forward that the increasing trend of δ18O of the stalagmite reflected not only the weakening of the summer monsoon, which was caused by the decreasing of solar radiation in the Northern Hemisphere, but also the possibly decreasing contribution of the southwest monsoon to the rainfall of this area. These results are consistent with the output of the numerical climate-model modeling. The high amplitude fluctuation of the δ18O may imply the quick shift of the contributions of different moisture sources to the precipitation in this area.

关键词： stalagmite Holocene southwest monsoon.

Effects of Martian crustal magnetic field on its ionosphere

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Science china(Technological Sciences) 2010年第6期53卷 1717-1724页

作者： ZOU Hong,CHEN HongFei,YU Ning,SHI WeiHong,YU XiangQian,ZOU JiQing & ZHONG WeiYing institute of space Physics and Applied Technology,Peking university,Beijing 100871,china institute of space Physics and Applied Technology Peking University Beijing China

The effect of the Martian crustal magnetic field is one of the hot topics of the study of Martian *** studies on this topic are summarized in this *** data of the Martian ionosphere were resulted from radio occultation *** to the observations,the electron density scale height and the peak electron density of the Martian ionosphere are influenced by its crustal magnetic *** strong horizontal magnetic field prevents the vertical diffusion of the plasma and makes the electron density scale height in the topside ionosphere close to that in the photo equilibrium *** the cusp-like regions with strong vertical magnetic field,the enhanced vertical diffusion leads to a larger electron density scale height in the diffusion equilibrium *** observation of radio occultation experiment onboard Mars Global Surveyor (MGS) showed that the averaged peak electron density observed in the southern hemisphere with strong crustal magnetic field was slightly larger than that in the northern hemisphere with weak crustal magnetic *** Mars advanced radar for subsurface and ionosphere sounding (MARSIS) onboard Mars Express (MEX) was the first topside sounder to be used to observe Martian *** MARSIS results confirmed that the enhancement of the peak electron density occurred in cusp-like regions with open field lines,and the amount of the enhancement was much larger than that observed by the radio occultation *** are two possible mechanisms for the peak electron density enhancement in the cusp-like crustal magnetic field regions:One is the precipitation of the energetic particles and the other is the heating by the waves excited by plasma ***'s difficult to determine which one is the key mechanism for the peak electron density *** on these studies,several interesting problems on the Martian ionosphere and plasma environment are presented.

关键词： Mars exploration Martian crustal megnetic field Martian ionosphere energetic particles detection plasma wave detection