检索结果-南通市图书馆

Potash-rich volcanic rocks and lamprophyres in western shandong Province:^(40)Ar-^(3.)Ar dating and source tracing

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2002年第2期47卷 91-99页

作者： QIU Jiansheng, XU Xisheng & LO Ching-Huastate Key Laboratory of Mineral Deposit Research of nanjing university, nanjing 210093. china department of {3. sciences, nanjing university, nanjing 210093. china department of Geology, Taiwan Unive state Key Laboratory of Mineral Deposit Research of nanjing university Nanjing China department of earth sciences Nanjing University Nanjing China department of Geology Taiwan University Taibei China

Highly precise 40Ar-3.Ar dating results demon-strate that the ages of potash-rich volcanic rocks in western shandong Province are 114.7-124.3.Ma, and that of the lamprophyres is 119.6 Ma. The potash-rich volcanic rocks have relatively high (87sr/86sr)i ratios ( 0.708715-0.711418) and distinctly negative εNd values ( -11.47--17.54), and are enriched in radiogenic lead (206Pb/204Pb=17.3.1-17.622, 207Pb/204Pb=15.525-15.53., 208Pb/204Pb=3..563.3..684). similarly, the lamprophyres also have quite low εNd values (-11.57 - -19.64). Based on the fact that the sr, Nd and Pb isotopic compositions of potash-rich volcanic rocks are very consistent with that of the clinopyroxene separates, and by integrating comprehensive analyses of their tectonic settings, and extensive comparisons of the sr, Nd isotopic composi-tions with that of the related simultaneous rocks, it is con-cluded that the potash-rich volcanic rocks and lamprophyres in western shandong Province were most possibly derived from the partial melting

关键词： potash-rich volcanic rocks lamprophyres 40Ar-3.Ar dating sr-Nd-Pb isotope tracing western shandong Province.

Incoherent control of two classes of finite-level quantum systems

在线全文

学校读者我要写书评

暂无评论

Journal of systems Engineering and Electronics 2011年第4期22卷 679-683页

作者： Chunlin Chen 1,2 and Zhenquan Qin 3.1.department of Control and system Engineering,nanjing university,nanjing 210093.P.R.china 2.state Key Laboratory for Novel software Technology,nanjing university,nanjing 210093.P.R.china 3.school of software,Dalian university of Technology,Dalian 116620,P.R.china department of Control and system Engineering Nanjing University Nanjing 210093 P. R. China state Key Laboratory for Novel software Technology Nanjing University Nanjing 210093 P. R. China school of software Dalian University of Technology Dalian 116620 P. R. China

The incoherent control of finite-level quantum systems is investigated. Following a brief introduction to coherent control paradigms in quantum control, a control problem that can not be accomplished using only coherent control is presented. For such a control problem, it is proved that it can be accomplished using incoherent control based on projective measurement and coherent control for two classes of finite-level quantum systems, i.e., eigenstate controllable quantum systems and wavefunction controllable quantum systems.

关键词： quantum control eigenstate controllability wavefunction controllability coherent control incoherent control.

Quasi-periodic solutions with prescribed frequency in a nonlinear schrdinger equation

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2010年第12期53卷 3067-3084页

作者： REN Xiu-Fang department of Mathematics, nanjing university, nanjing 210093. china 1. department of Mathematics Nanjing University Nanjing 210093 China

In this paper, one-dimensional (1D) nonlinear schrdinger equation iut-uxx + Mσ u + f ( | u | 2 )u = 0, t, x ∈ R , subject to periodic boundary conditions is considered, where the nonlinearity f is a real analytic function near u = 0 with f (0) = 0, f (0) = 0, and the Floquet multiplier Mσ is defined as Mσe inx = σne inx , with σn = σ, when n 0, otherwise, σn = 0. It is proved that for each given 0 1, the above equation admits a Whitney smooth family of small-amplitude quasi-periodic solutions with b-dimensional Diophantine frequencies, corresponding to b-dimensional invariant tori of an associated infinite-dimensional Hamiltonian system. Moreover, these b-dimensional Diophantine frequencies are the small dilation of a prescribed Diophantine vector. The proof is based on a partial Birkhoff normal form reduction and an improved KAM method.

关键词： schrdinger equation Hamiltonian system Birkhoff normal form quasi-periodic solution

Origin of the Red earth sequence on the northeastern Tibetan Plateau and its implications for regional aridity since the middle Miocene

在线全文

学校读者我要写书评

暂无评论

science china earth sciences 2006年第5期49卷 505-517页

作者： WANG Xianyan1,7, LU Huayu1,2, JI Junfeg3. WANG Xiaoyong1,7, ZHAO Jingbo4, HUANG Baochun5 & LI Zhen6 1. sKLLQG, Institute of earth Environment, Chinese Academy of sciences, Xi’an 710075, china 2. department of Urban and Resources sciences,{3., nanjing 210093. china 3. department of earth sciences,{3., nanjing 210093. china 4. department of Geography, shaanxi Normal university, Xi’an 710062, china 5. Institute of Geology and Geophysics, Chinese Academy of sciences, Beijing 100029, china 6 department of Geography, Qinghai Normal university, Xining 810008, china 7. Graduate school of the Chinese Academy of sciences, Beijing 10003., china 1. sKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 7. Graduate school of the Chinese Academy of sciences Beijing 100039 China 2. department of Urban and Resources sciences Nanjing University Nanjing 210093 China 3. department of earth sciences Nanjing University Nanjing 210093 China 4. department of Geography Shaanxi Normal University Xi’an 710062 China 5. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 6. department of Geography Qinghai Normal University Xining 810008 China

The Red earth deposit around Xining, northeastern Tibetan Plateau, has beenstudied in terms of soil micro-structure, grain-size distribution, major- and trace-elementchemistry and magne-tostratigraphy. Field investigations indicate that the Red earth sequenceconsists of 25 visually definable yellow-brown and weakly-developed soils interbedded with reddishstrongly-developed soils, and has a similar structure to the aeolian Red Clay deposit on the ChineseLoess Plateau. Grain-size analysis shows that the Red earth deposit is very fine-grained with anegligible sand fraction ( > 63.μm). Thin-section observations under light microscopy show that thedeposit has a clayey texture and the coarse fraction ( > 10 μm) mainly consists of quartz,feldspar and micas. Pyroxene and hornblende were also observed. This mineralogical composition ofthe coarse fraction is similar to that of the Quaternary loess. In addition, all of the mineralgrains are semi angular semi-angular and are generally finer than 63.μm. There is a good agreementbetween the major and minor trace element chemistry of loess-soil units and the Red earth *** REE distributions of the loess-soil and the Red earth deposit are similar in shape, withenriched LREE and fairly flat HREE profiles and a clear negative Eu anomaly. The geochemicalcharacteristics of the Red earth deposit are also identical to those of upper continental crust,thus indicating a wind-blown origin. Magnetostratigraphic investigation shows that onset of the Redearth deposition predates 11.4 Ma BP (13.6 Ma at a nearby site). The distribution of the reportedMiocene aeolian loess at Qin''an of the Loess Plateau is still unknown. Our results indicate thatthis aeolian deposit had extended to the northeastern Tibetan Plateau by at least the middleMiocene. The similarity of the element geochemistry between the Red earth deposit and the overlyingloess shows that they may have similar sources and dynamic transport system, and may indicate thatthe

关键词： Red earth deposit, Northeastern Tibetan Plateau, aeolian deposit, aridity of Asia, the middle Miocene.

Birkhoff's theorem and viscosity solutions of Hamilton-Jacobi equations

在线全文

学校读者我要写书评

暂无评论

science china Mathematics 2009年第8期52卷 1796-1800页

作者： CHENG Wei department of Mathematics, nanjing university, nanjing 210093. china department of Mathematics Nanjing University Nanjing 210093 China

We obtain a partial generalization of Birkhoff's theorem of invariant curve to higher dimesional case in the context of viscosity solutions of Hamilton-Jacobi equations, or weak KAM theory. This is a new approach afte... 详细信息

关键词： Hamilton-Jacobi equation viscosity solution semiconcave function

Parabolic equation of the m-Laplacian with nonlinear boundary condition

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第11期43卷 905-908页

作者： WANG shu+ 1, 2, WANG Mingxin 3. XIE Chunhong 1 1. department of Mathematics, nanjing university, nanjing 210093. china 2. department of Mathematics, Henan university, Kaifeng 475001, china 3. department of Applied Mathematics, southeast university, department of Mathernntics Nanjing University Nanjing China department of Mathematics Henan University Kaifeng China department of Applied Mathematics Southeast University Nanjing China

The existence and nonexistence of global positive weak solutions of parabolic equation of the m-Laplician with nonlinear boundary condition are dealt with. The necessary and sufficient conditions on the existence of a... 详细信息

关键词： nonlinear boundary condition parabolic equation of m-Laplacian global solution blow-up.

Nonlinear boundary value problems for discontinuous delayed differential equations

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2010年第1期25卷 9-17页

作者： sUN Wu-jun department of Finance & Insurance, Business school of nanjing university, nanjing 210093. china department of Finance and Insurance Business School of Nanjing University Nanjing China

In this paper nonlinear boundary value problems for discontinuous delayed differen- tial equations are considered. some existence and boundedness results of solutions are obtained via the method of upper and lower solutions, which may be discontinuous. Our analysis can be applied to those phenomena from physics and control theory which have been successfully described by delayed differential equations with discontinuous functions, such as electric, pneu- matic, and hydraulic networks. It is also an important step to precede the design of control signals when finite-time or practical stability control are concerned.

关键词： Nonlinear boundary value problems upper and lower solutions discontinuous delayed differentialequations Carath^odory conditions existence of solutions.

Discovery of Corallina fossil from the Middle Cambrian of Taijiang County, Guizhou Province, china

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2000年第6期45卷 544-547页

作者： YANG Ruidong & ZHAO Yuanlong department of earth sciences, nanjing university,{3. department of Resources, Guizhou university of Technoiogy, Guiyang 550002, china department of earth sciences Nanjing University Nanjing China department of Resources Guizhou University of Technology Guiyang China

Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, china. Corallina Paraamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, china. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae.

关键词： Corallina Middle Cambrian Guizhou Province china.

Water in peridotite xenoliths from south china

在线全文

学校读者我要写书评

暂无评论

science china earth sciences 2011年第10期54卷 1511-1522页

作者： WANG Rong 1,2,3.& ZHANG BaoMin 3.1 Faculty of Land Resource Engineering, Kunming university of science and Technology, Kunming 650093. china 2 state Key Laboratory for Mineral Deposits Research, nanjing university,{3. 3.Faculty of earth science, china university of Geosciences, Wuhan 43.074, china 1. Faculty of Land Resource Engineering Kunming University of Science and Technology Kunming 650093 China2. State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing 210093 China3. Faculty of Earth Science China University of Geosciences Wuhan 430074 China

The water contents of nominally anhydrous clinopyroxene （cpx）, orthopyroxene （opx） and olivine （ol） in peridotite xenoliths hosted by Cenozoic basalts from Yingfengling, Zhangchouchun, Fujitian and Lindi, south china, were measured by Micro- FTIR. All cpx and opx grains contained a certain amount of water, which was indicated by the presence of hydroxyls in the crystal structure. The water contents （H20, ppm） of cpx and opx from peridotite xenoliths of the study areas were 293.981, 183.752, 73.586 and 51-423.ppm, and 82-471, 74-571, 53.170 and 9-13. ppm, respectively. No prominent OH absorption bands were detected for any ol grains, indicating that the water contents were below the detection limit （approximately 2 ppm）. The entire rock contents recalculated according to mineral volume proportions were 49-163. 48-168, 21-111 and 8-40 ppm, respectively. Combined with previously reported data describing the water contents of peridotite xenoliths worldwide, the results presented here suggest that water distribution in the continental lithospheric mantle is spatially heterogeneous at a global scale. The lithospheric mantle of south china is much richer in water than that of the North china Craton, and is close to that typical of off-craton localities, such as the Basin and Range Province, and Massif Central.

关键词： FTIR water peridotite xenoliths south china