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Wavelet estimation of the diffusion coefficient in time dependent diffusion models

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Science china Mathematics 2007年第11期50卷 1597-1610页

作者： Ping CHEN~(1,2.) Jin-de WANG~1 1 department of Mathematics,nanjing {2.,nanjing 210093,china 2.School of Science,nanjing {2. of Science and Technology,nanjing 2.0094,china department of Mathematics Nanjing University Nanjing 210093 China School of Science Nanjing University of Science Technology Nanjing 210094 China

The estimation problem for diffusion coefficients in diffusion processes has been studied in many papers,where the diffusion coefficient function is assumed to be a 1-dimensional bounded Lipschitzian function of the state or the time *** is no previous work for the nonparametric estimation of time-dependent diffusion models where the diffusion coefficient depends on both the state and the *** paper introduces and studies a wavelet estimation of the time-dependent diffusion coefficient under a more general assumption that the diffusion coefficient is a linear growth Lipschitz *** the properties of martingale,we translate the problems in diffusion into the nonparametric regression setting and give the Lr convergence rate.A strong consistency of the estimate is *** this result one can estimate the time-dependent diffusion coefficient using the same structure of the wavelet estimators under any equivalent probability *** example,in finance,the wavelet estimator is strongly consistent under the market probability measure as well as the risk neutral probability measure.

关键词： wavelet estimation time-dependent diffusion coefficient linear growth condition strong consistency

Variational construction of unbounded orbits in Lagrangian systems

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Science china Mathematics 2010年第3期53卷 617-624页

作者： CHENG Chong-Qing 1, & LI Xia 2.1 department of Mathematics, nanjing university,{2., china 2.department of Mathematics, Suzhou university of Science and Technology, Suzhou 2.5001, china 1. department of Mathematics Nanjing University Nanjing 210093 China2. Department of Mathematics Suzhou University of Science and Technology Suzhou 215001 China

We show the existence of unbounded orbits in perturbations of generic geodesic flow in T2.by a generic periodic potential. Different from previous work such as in Mather (1997), the initial values of the orbits obtain... 详细信息

关键词： positive definite Lagrangian variational method unbounded orbit

ABSOLUTELY E-PURE MODULES AND E-PURE SPLIT MODULES

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Acta Mathematica Scientia 2011年第1期31卷 207-220页

作者：阎舫宇 department of Mathematics Nanjing University department of Basic Courses China Pharmaceutical University

We first introduce the concepts of absolutely E-pure modules and E-pure split modules. Then, we characterize the IF rings in terms of absolutely E-pure modules. The E-pure split modules are also characterized.

关键词： Absolutely E-pure module E-pure split module IF ring copure flat module

Uniquely ergodic property of minimal probability measure in positive definite Lagrangian systems

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Science china Mathematics 2006年第12期49卷 1864-1866页

作者： CHEN Jing & BAI Yuzhen department of Mathematics, nanjing university,{2., china department of Mathematics, Qufu Normal university, Qufu 2.3165, china 1. department of Mathematics Nanjing University Nanjing 210093 China 2. department of Mathematics Qufu Normal University Qufu 273165 China

Mane conjectured that every minimal measure in the generic Lagrangian systems is uniquely ergodic. In this paper, we will show that the answer to the Mane's conjecture is negative by analyzing the structure of the sup... 详细信息

关键词： minimal probability measure,uniquely ergodic,Mather theory,Lagrangian systems.

Diophantine vectors in analytic submanifolds of Euclidean spaces

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Science china Mathematics 2007年第9期50卷 1334-1338页

作者： Rong-mei CAO~(1+) Jian-gong YOU~2.1 College of Science,nanjing university of Aeronautics and Astronautics,nanjing 2.0016,china 2.department of Mathematics,nanjing university,nanjing 210093,china 1. College of Science Nanjing University of Aeronautics and Astronautics Nanjing 210016 China 2. department of Mathematics Nanjing University Nanjing 210093 China

Let $\mathcal{M}$ be an m-dimensional analytic manifold in ? n . In this paper, we prove that almost all vectors in $\mathcal{M}$ (in the sense of Lebesgue measure) are Diophantine if there exists one Diophantine vect... 详细信息

关键词： diophantine vector analytic submanifold 32.05

THE WATER resources IN THE EUPHRATES RIVER AND THE TIGRIS RIVER VALLEYS AND POLITICAL RELATION BETWEEN COUNTRIES CONCERNED

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Journal of Geographical sciences 1997年第4期7卷 95-100页

作者： Ding Dengshan Bao Haosheng department of urban and {2. sciences, nanjing university, nanjing 210093 People’s Republic of china

Recently at home and abroad there appears a view that owing to scarcity of the water resources and rapid increase in population in the Middle East and existing of large rivers, such as the Euphrates River and the Tigris River, the contradictions over the water resources have become increasingly sharp among the countries concerned, and a war for water will soon break out in the region. The authors of the present paper, however, put forward a different view, believing that no war for controlling the water resources will take place in the region.

关键词： the Euphrates River the Tigris River Middle East water resources geopolitics.

Formation and evolution of X-ray binaries

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 9-13页

作者： LI XiangDong department of Astronomy,nanjing {2.,nanjing 210093,china 1. department of Astronomy Nanjing University Nanjing 210093 China

We review recent progress in theoretical understanding of X-ray binaries,which has largely been driven by new *** select several topics including formation of compact low-mass X-ray binaries,the evolutionary connection between low-mass X-ray binaries and binary and millisecond radio pulsars,and ultraluminous X-ray sources,to illustrate the interplay between theories and observations.

关键词： X-ray binaries pulsars mass transfer stellar evolution

Refinement of the crystal structure for a new mineral──antimonselite

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Chinese Science Bulletin 1998年第5期43卷 413-416页

作者： MIN Maozhong 1, ZHAI Jianping 1, WANG Xiangyun 1,SHEN Baopei 2. WEN Guangdou 2.and FAN Tao 2.. department of Earth sciences,{2., nanjing 210093, china 2. Uranium Geology Bureau of Central-South china, Changsha 410000, china department of Earth sciences Nanjing University Nanjing China Uranium Geology Bureau of Central-South china Changsha China

The crystal structure of a new mineral of the stibnite group, Sb-2.e-3, has been determined. The cell constants, obtained by least-squares calculation from direct θ -value’s measurements on the diffractometer are: a =1.158 8(5), b =1.174 4(4), c =0.395 5(2. nm; orthorhombic; V =0.538 2. nm+3; Z =4. The space group is Pbnm. X-ray single crystal data, using Mo K α radiation, were measured on a RIGAKU RASA-5RP automated diffractometer and refined to a final R index of 0.048 1. Sb-2.e-3 is isostructural with Sb-2.-3 and Bi-2.-3. Each Sb(1) atom is six-coordinated by 3 Se(1), 1 Se(2. and 2.Se(3) atoms at distances 0.2.6 0-0.32. 6 nm. Each Sb(2. atom is seven-coordinated by 2.Se(1), 2.Se(2. and 3 Se(3) atoms at distances of 0.2.8 1- 0.346 7 nm. The crystal structure consists of chains parallel to c or needle axis. The strongest bonds (shortest separations) are within the chains. Many important physical properties of antimonselite (optical, ferroelectric, etc.) are related to its crystal structure.

关键词： new mineral antimonselite crystal structure.

Regioselective aminohalogenation of β-nitrostyrenes using NCS and NBS as nitrogen/halogen sources

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Science china Chemistry 2010年第1期53卷 140-146页

作者： ZHI SanJun1,2.SUN Hao2.LIN Chen2.ZHANG GuangQian2.LI GuiGen4 & PAN Yi2.3 1 department of Chemistry,Huaiyin Normal university,Huai’an 2.1003,{2. 2.School of Chemistry and Chemical Engineering,nanjing university,nanjing 210093,{2. 3 State Key Lab of Coordination Chemistry,nanjing university,nanjing 210093,{2. 4 department of Chemistry and Biochemistry,Texas Tech university,Lubbock,Texas 79409-1061,USA 1. department of Chemistry Huaiyin Normal University Huai’an 221003 China2. School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China4. Department of Chemistry and Biochemistry Texas Tech University Lubbock Texas 79409-1061 USA3. State Key Lab of Coordination Chemistry Nanjing University Nanjing 210093 China

Aminohalogenation reaction of β-nitrostyrenes with N-halosuccinimides(N-chloro and N-bromosuccinimides) has been successfully conducted by using nickel acetate as a catalyst in the presence of potassium carbonate and succinimide as *** reaction was easily performed at room temperature under nitrogen gas protection to give dihalorinaed haloamino products in good to excellent yields(60%-98%).The structure has been confirmed by X-ray crystal structure analysis.

关键词： aminohalogenation vicinal haloamines β-nitrostyrenes NBS NCS