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Existence of Invariant Tori for Certain Weakly reversible Mappings

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Acta Mathematica Sinica,English Series 2002年第4期18卷 701-718页

作者： Bao She WEI department of Mathematics, nanjing univ.r.ity.{2.. P. r. china department of Mathematics Nanjing University Nanjing 210093 P. R. China

In this paper, we consider certain mappings. M, sufficiently close to an integrable one, which is weakly reversible with respect to the mappings G sufficiently close to an involution of type (m.n). where m, n∈Z_+ are arbitrary. Under some weak non-degeneracy condition, we construct a uniform KAM iteration for proving the existence of a Cantor family of m-tori invariant under the reversible mappings M and the reversing mapping G.

关键词： Weakly reversible mappings Weakly undegenerate condition Invariant tori

rb-Sr isochron ages and significance of bimodal volcanic association in Baimianshi uranium ore-field, South china

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Chinese Science Bulletin 1999年第S2期44卷 3-4页

作者： CHEN Peirong~1, WANG Yinxi~2. NI Qisheng~1, KONG Xinggong~2.and ZHANG Bangtong~2.1. State Key Laboratory of Mineral Deposits, department of earth {2., nanjing univ.r.ity, nanjing 210093, china 2. Center of Modern Analysis, nanjing univ.r.ity, nanjing 210093, china State Key Laboratory of Mineral Deposits Department of Earth Sciences Nanjing University Nanjing 210093 China Center of Modern Analysis Nanjing University Nanjing 210093 China

1 Geologic background THE volcanic U-deposits are generally associated with felsic to intermediate volcanic rock and their sedimentary derivatives. However, uranium mineralization has been found to be spatially associated with thebasalt of bimodal volcanic associations in Baimianshi uranium ore field. Baimianshi uranium ore-field islocated in Baimianshi volcanic-sedimentary basin of south Jiangxi Province. The cover rocks of the basinconsist of a suite of bimodal volcanic-sedimentary sequences. Its basement rocks are two-mica granites ofBaimianshi rock body. The basalt of cover rocks is interbedded with arkoses in lower sequence, and rhyolite or rhyolitic tuff in upper sequence. Uranium minerals mainly occur as disseminations in the

关键词： rb-Sr isochron ages bimodal volcanic rocks uranium ore-field south china.

Evolution of chlorite composition in the Paleogene prototype basin of Jiyang Depression, Shandong, china, and its implication for paleogeothermal gradient

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Science china earth {2. 2007年第11期50卷 1645-1654页

作者： ZHAO Ming1, CHEN XiaoMing1, JI JunFeng1, ZHANG Zhe1 & ZHANG Yun2.1 State Key Laboratory for Mineral Deposits research, department of earth {2., nanjing univ.r.ity, nanjing 210093, china 2.Jiangsu Survey Institute of Engineering and Physics, nanjing 2.0008, china 1. State Key Laboratory for Mineral Deposits research Department of Earth Sciences Nanjing University Nanjing 210093 China 2. Jiangsu Survey Institute of Engineering and Physics Nanjing 210008 China

The Dongying Basin, Huimin Basin, and Zhanhua Basin constitute the Jiyang Depression in Shandong Province. They are major oil and gas exploring districts within the depression. Through reconstructions of the paleotemperature of the three basins facilitated with the chlorite geothermometry, the thermal history of the Paleogene prototype basin in Jiyang Depression and its geologic significance were explored. This study reveals that the Si^(4+) component in chlorites reduces gradually as its buried depth increases, while the AI~Ⅳ component increases accordingly. The chlorite type changes from silicon-rich diabantite to silicon-poor ferroamesite and prochlorite. The prochlorite in this district only appears in the deep buried depth, high temperature, and relatively old stratigraphies; while the diabantite appears in the shallower buried, low temperature, and newly formed strata; the ferroamesite exists in the conditions between prochlorite and diabantite formation. The diagenetic temperatures of the chlorites in these Paleogene basins are 171 — 2.8℃ for the Dongying Basin, 160—2.2. for the Huimin Basin, and 135—180℃ for the Zhanhua Basin. The differences of the chlorite diagenetic temperatures in the three basins were controlled by the duration time of the structural depressing processes. Higher temperature indicates longer depression time. The relationship between the chlorite diagenetic temperature and its buried depth indicates that the average paleogeothermal gradient is about 38.3℃ /km in the Paleogene prototype basin of Jiyang Depression. It was higher than the present geothermal gradient (2.—30℃/km). This phenomenon was attributed to the evolution of the structural dynamics in the depression basin.

关键词： Paleogene,Jiyang depression,chlorite component,chlorite geothermometry,paleotemperature,paleogeothermal gradient

Single zircon LA-ICPMS U-Pb dating of Weishan granite (Hunan, South china) and its petrogenetic significance

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Science china earth {2. 2006年第8期49卷 816-827页

作者： DING Xing1, CHEN Peirong1, CHEN Weifeng1, HUANG Hongye2.& ZHOU Xinmin1 1. department of earth Science,{2., nanjing 210093, china 2. research Institute No.2.0, CNNC, Changsha 410011, china 1. department of earth Science Nanjing University Nanjing 210093 China 2. research Institute No.2.0 CNNC Changsha 410011 China

A detailed microstructure analysis and LA-ICPMS U-Pb dating have been done for zir- cons of Weishan granite from Hunan Province, South china. The results indicate that the Weishan granite is a multistage batholith formed during the late Indosinian-early Yanshanian time. The intruded time of the late Indosinian granite is 2.1.0±1.6Ma and 2.5.7±1.9Ma (two samples), whereas that of the early Yanshanian granite is 187.4±3.5Ma and 184.5±5.1Ma (two samples). In combination with other geochronological data for Indosinian rocks of South china and the adjacent region, it is inferred that the late Indosinian granites of South china (especially Hunan Province) are probably formed under extension regime as a consequence of post-collision stress relaxation, which is a spontaneous response to intracontinental thickening attributed to the collision and extrusion of two Indosinian seams, namely Qinling-Dabie and Song Ma. Moreover, it is also deduced that the early Yanshanian granites of Hunan Province could not be directly related with the subduction of Paleo-Pacific plate towards Eurasian continent, and they are most likely derivation of the mid- or lower-crustal materials because of decompressional melting under the continuous extension setting.

关键词： CL images, LA-ICPMS U-Pb dating, granite, Weishan, Hunan.

Strongly peraluminous granites of Mesozoic in Eastern Nanling range, southern china: Petrogenesis and implications for tectonics

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Science china earth {2. 2005年第2期48卷 165-174页

作者： SUN Tao, ZHOU Xinmin, CHEN Peirong, LI Huimin, ZHOU Hongying, WANG Zhicheng & SHEN Weizhou department of earth {2., nanjing univ.r.ity, nanjing 210093, china Tianjin Institute of Geology and Mineral resources, china Geological Survey, Tianjin 300170, china 1. department of earth {2. Nanjing University 210093 Nanjing China 2. Tianjin Institute of Geology and Mineral resources China Geological Survey 300170 Tianjin China

The strongly peraluminous granites (SPGs) of Eastern Nanling range (ENr) are a characteristic of all bearing highly aluminous minerals, such as muscovite±AI-rich biotite± tourmaline±garnet, and lack of cordierite. In respect of petrography, geochemistry, Nd isotope, and single grain zircon U-Pb dating, the representative granite bodies of them are studied. The research shows that these granites were emplaced in two stages, namely 2.8-2.5 Ma BP and J2.3 159-156 Ma BP, belonging to Indosinian and early Yanshanian periods, respectively, and they have low εNd(t) values (-10.6--11.1), high A/CNK, rb/Sr ratios and tDM values (1887-1817 Ma), and rEE's tetrad effect (TE1,3=1.13-1.34). In comparison with related geology, petrology and chronology of granites in adjacent regions, it is suggested that Indosinian SPGs of ENr formed in the circumstance of post-collisional extension 2. Ma after the major collision of Indosinian Movement (2.8-2.3 Ma BP) in Indo-china Peninsula, and early Yanshanian SPGs formed in the background of back-arc extension setting controlled by paleo-Pacific tectonic domain, and J1, the interval of two stages, is the interim from Tethyan to Pacific tectonic domains in South china. These SPGs have similar geological and geochemical characteristics, because they all crystallized from the magma of partial melting of early Proterozoic metasedimentary rocks when the thickened crust (≤50 km) became thinning, decompression, and transmitting of water.

关键词： Nanling range, strongly peraluminous granite, petrogenesis of granite, South china.

Galactic kinematics and structure defined by open clusters

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research in Astronomy and Astrophysics 2009年第12期9卷 1285-1302页

作者： Zi Zhu department of Astronomy Nanjing University Nanjing 210093 China

On the basis of recently published astrophysical parameters of the open clusters, we have selected 301 clusters with measurements of their kinematical parameters to trace the local structure and kinematics of the Galactic disk. The present sample covers a range of over 3.0 kpc from the Sun and gives significant estimates of the disk structure and kinematical parameters of the Galaxy. We derive the disk scale height, vertical displacement of the Sun to the Galactic plane, solar motion with respect to the local standard of rest, circular speed of the Galactic rotation, Galactocentric distance from the Sun, etc. We found that the average scale height of the disk defined by the open clusters is Zh = 58 ± 4pc, with a vertical displacement of the Sun below the Galactic plane of z0 -= - 16±4 pc. Clusters with ages older than 50 Myr are less concentrated in the average plane （Zh=67 ±6pc） than the younger clusters （Zh = 51±5pc）. Using the approximation of axisymmetric circular rotation, we have derived the distance to the Galactic center from the Sun r0 = 8.03 ±0.70 kpc, which is in excellent agreement with the best estimate of the Galactocentric distance. From a kinematical analysis, we found an agedependent rotation of the Galaxy. The older clusters exhibit a lower velocity of vorticity, but have the same shear as the younger clusters. The mean rotation velocity of the Galaxy was obtained as 2.5 ± 10 km s-1.

关键词： Galaxy: disk -- Galaxy: kinematics and dynamics -- Galaxy: open clustersand associations: general -- Galaxy: structure

More on Bounding Introspection in Modal Nonmonotonic Logics

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Acta Mathematica Sinica,English Series 2000年第4期16卷 555-564页

作者： Xishun Zhao Decheng Ding department of Mathematics. nanjing univ.r.ity.{2., P. r. china department of Mathematics Nanjing University Nanjing 210093 P. R. China

By L. we denote the set of all propositional fornmlas. Let C be the set of all clauses. Define C_n=C(Lη:η∈C}.In Sec. 2.of this paper. we prove that for normal modal logics S, the notions of (S. C_)-expansions and S-expansions coincide. In Sec. 3. we prove that if I consists of default clauses then the notions of S-expansions for I and (S.C)-expansions for I coincide. To this end. we first show. in Sec *** the notion of S-expansions for I is the same as that of (S.L)-expansions for I.

关键词： Modal nonmonotonic logic Expansion Bounding Introspection Default clause

A CONSTrUCTIVE PrOOF OF THE INVErSION FOrMULA FOr ZONAL FUNCTIONS ON SL(2. r)

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Chinese Annals of Mathematics,Series B 1996年第1期17卷 81-88页

作者： XIAO CHANGBAI ZHENG WEIXING SU WEIYI (department of Mathematics, nanjing univ.r.ity{2., china.) nanjing univ DEPT MATHNANJING 210093PEOPLES R CHINA

A constructive proof is given for the inversion formula for zonal functions on SL(2. r). A concretely constructed sequence of zonal drictions are proved to satisfy the inversion formula obtained by Harish-Chandra for compact supported infinitely differentiable zonal *** use of the property of this sequence somehow similar to that of approxination kernels,the authors deduce that the inversion formula is true for continuous zonal functions on SL(2. r)under some condition. The classical result can be viewed as a corollary of the results here.

关键词： Inversion formula Zonal function Approximation kernel

Almandine megacrysts from Yingfengling Cenozoic basalt in Leizhou Peninsula and their parental magma origin

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Chinese Science Bulletin 2001年第14期46卷 1215-1219页

作者： YU Jinhai & S. Y. O’reilly1. National Key Laboratory of Metallogenic Mechanism of Endogenetic Deposits, department of earth {2., nanjing univ.r.ity, nanjing 210093, china 2. National Key Center of GEMOC, department of earth and Planetary {2., Macquarie univ.r.ity, North ryde, NSW 2.09, Australia National Key Laboratory of Metallogenic Mechanism of Endogenetic Deposits Department of Earth Sciences Nanjing University Nanjing China National Key Center of GEMOC Department of Earth and Planetary Sciences Macquarie University North Ryde Australia

The garnet megacrysts from Yingfengling basalts are characterlzed by high FeO (>2.%), CaO (7.02. -8.16%) and low MgO (5.88%-10.87%). Significant composition variations are observed in these megacrysts, of which Ni, V, Sc, Co, and HrEE are positively correlated with their Mg# and Zr, Hf, Ga, Y, Sr, Nb, Zn and LrEE-MrEE are negatively correlated with Mg#. Megacryst parent magma is a highly evolved residual melt with strongl depletion in Ti, Sr, Hf, Nb and HrEE. This parental magma was generated by more than 60% of crystallization fractionation of clinopyroxene, garnet, plagioclase and ilmenite from quartz tholeiitic magma. It has not erupted to the surface, but stayed at the upper mantle and formed the megacrystic cumulate. Megacrysts and their host basalt are in disequilibrium.

关键词： almandine megacryst geochemistry LAM-ICPMS Lei-zhou Peninsula.