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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2. CHEN ZhengHao3 & ZHANG XiaoZhong4,5 1 Key Laboratory of Beam Technology & materials Modification of the Ministry of Education, Institute of Low Energy Nuclear Physics, beijing normal university,{2., China 2.beijing Radiation Center,{2., China 3 Laboratory of Optical Physics, Institute of Physics, Chinese Academy of sciences, beijing 100080, China 4 Key Laboratory of Advanced materials of the Ministry of Education, department of materials science and engineering, Tsinghua {12., beijing 100084, China 5 beijing National Center for Electron Microscopy, Tsinghua {12., beijing 100084, China Key Laboratory of Beam Technology & materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing China Key Laboratory of Advanced materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing China beijing National Center for Electron Microscopy Tsinghua University Beijing China

The LaMn1-xTexO3+δ (x=0.1, 0.2. 0.3) were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3+ ions are partly converted into Mn2. and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2., Mn3+ and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3+ is much larger or less than the sum of Mn2. and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3+ is close to the sum of Mn2. and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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Local and non-local sources of airborne particulate pollution at beijing——The ratio of Mg/Al as an element tracer for estimating the contributions of mineral aerosols from outside beijing

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science China Chemistry 2005年第3期48卷 253-264页

作者： HAN Lihui1, ZHUANG Guoshun1,2.3, SUN Yele1 & WANG Zifa3 1. The Center for Atmospheric Environmental Study, department of Chemistry, beijing normal university,{2., China 2. Center for Atmospheric Chemistry Study, department of Environmental science & engineering, Fudan university, Shanghai 2.0433, China 3. LAPC/NZC, Institute of Atmospheric Physics, CAS, beijing 10002., China The Center for Atmospheric Environmental Study Department of Chemistry Beijing Normal University Beijing China Center for Atmospheric Chemistry Study Department of Environmental Science & Engineering Fudan University Shanghai China Institute of Atmospheric Physics CAS LAPC/NZC Beijing China

A new element tracer technique has firstly been established to estimate the contri-butions of mineral aerosols from both inside and outside beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in beijing, of which mineral aerosol accounted for 32.―67% of total suspended particles （TSP）, 10%―70% of fine particles （PM2.5）, and as high as 74% and 90% of TSP and PM2.5, respectively, in dust storm. The sources from outside beijing contributed 62. （38%―86%） of the total mineral aerosols in TSP, 69% （52.―90%） in PM10, and 76% （59%―93%） in PM2.5 in spring, and 69% （52.―83%）, 79% （52.―93%）, and 45% （7%―79%） in TSP, PM10, and PM2.5, respectively, in winter, while only2.% in summer and autumn. The sources from outside beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in beijing. The contributions from outside Bei-jing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.

关键词： mineral aerosol local sources non-local sources dust storm re-suspended dust element tracer technique.

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Representation type of 0-Hecke algebras

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science China Mathematics 2011年第3期54卷 411-420页

作者： DENG BangMing1 & YANG GuiYu2.1department of Mathematics, beijing normal university,{2., China 2.chool of science, Shangdong university of Technology, Zibo 2.5049, China department of Mathematics Beijing Normal University Beijing China School of science Shangdong University of Technology Zibo China

In the present paper we determine the representation type of the 0-Hecke algebra of a finite Coxeter group.

关键词： Coxeter group 0-Hecke algebra representation type

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Functional central limit theorem for super α-stable processes

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science China Mathematics 2004年第6期47卷 874-881页

作者： HONG Wenmingdepartment of Mathematics, beijing normal university,{2., China department of Mathematics Beijing Normal University Beijing China

A functional central limit theorem is proved for the centered occupation time process of the super α-stable processes in the finite dimensional distribution sense. For the intermediate dimensions α 2. (0 2., the limiting process is a Gaussian process, whose covariance is specified; for the critical dimension d= 2. and higher dimensions d 2., the limiting process is Brownian motion.

关键词： super α-stable processes occupation time central limit theorem evolution equation

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Weighted estimates for commutators of singular integral operators with non-doubling measures

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science China Mathematics 2007年第11期50卷 1621-1641页

作者： Guo-en HU~1 Da-chun YANG~(2.) Dong-yong YANG~2.1 department of Applied Mathematics,university of Information{2.,Zhengzhou 450002.China 2.School of Mathematical sciences,beijing normal university,beijing 100875,China department of Applied Mathematics University of Information Engineering Zhengzhou China School of Mathematical sciences Beijing Normal University Beijing China

Letμbe a nonnegative Radon measure on R^d which only satisfiesμ(B(x,r))≤C_0r^n for all x∈R^d,r>0,and some fixed constants C_0>0 and n∈(0,d].In this paper,some weighted weak type estimates with A_(p,(log L)~σ)~ρ(μ) weights are established for the commutators generated by Calder■n-Zygmund singular integral operators with RBMO(μ) functions.

关键词： non-doubling measure weight singular integral operator commutator

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Linear estimation and distribution of the limit cycles bifurcated from a kind of degenerate polycycles

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science China Mathematics 2007年第3期50卷 334-344页

作者： Li-qin ZHAO department of Mathematics, beijing normal university,{2., China department of Mathematics Beijing Normal University Beijing China

In this paper, we investigate the number and the distribution of the limit cycles bifurcated from a kind of degenerate planar polycycles through three singular points: a saddle-node P 0, a fine saddle P 1 with finite order m ∈ N, a contractive (attracting) saddle P 2.with the hyperbolicity ratio q 2.0) ? Q. The connection between P 0 and P 1 is of hh-type and the connection between P 0 and P 2.is of hp-type. It is assumed that the connections between P 0 to P 2.and P 0 to P 1 keep unbroken. We obtain that the cyclicity of this polycycle is not more than 3m + 1, which is linearly dependent on the order of the resonant saddle P 1. We also show that the cyclicity is not more than m + 3 if q 2.0) > m, and that the nearer q 2.0) is close to 1, the more the limit cycles are bifurcated.

关键词： degenerate polycycle cyclicity finitely-smooth normal form transition map 34C05 34C2. 58F14

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A secure multi-party computation solution to intersection problems of sets and rectangles

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Progress in Natural science:materials International 2006年第5期16卷 538-545页

作者： LI Shundong, DAI Yiqi, WANG Daoshun and LUO Ping (department of Computer science and Technology,{2., beijing 100875, China department of Computer science and Technology, Tsinghua university, beijing 100084, China) department of Computer science and Technology Beijing Normal University Beijing 100875 China department of Computer science and Technology Tsinghua University Beijing 100084 China

Secure multi-party computation (SMC) is a research focus in international cryptographic community. At present, there is no SMC solution to the intersection problem of sets. In this paper, we first propose a SMC solution to this problem. Applying Cantor encoding method to computational geometry problems, and based on the solution to set-intersection problem, we further propose solutions to points inclusion problem and intersection problem of rectangles and further prove their privacy-preserving property with widely accepted simulation paradigm. Compared with the known solutions, these new solutions are of less computational complexity and less communication complexity, and have obvious superiority in computational and communication complexity.

关键词： Cantor encoding secure multi-party computation set-intersection rectangle-intersection computational complexity.

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On asymptotics of t-type regression estimation in multiple linear model

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science China Mathematics 2004年第4期47卷 628-639页

作者： GUI Hengjiandepartment of Mathematics, beijing normal university,{2., China department of Mathematics Beijing Normal University Beijing China

We consider a robust estimator (t-type regression estimator) of multiple linear regression model by maximizing marginal likelihood of a scaled t-type error *** marginal likelihood can also be applied to the de-correlated response when the withinsubject correlation can be consistently estimated from an initial estimate of the model based on the independent working assumption. This paper shows that such a t-type estimator is consistent.

关键词： t-type regression estimator, M-estimator, one-step estimate, consistency, asymptotic normality.

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Intrinsic ultracontractivity on Riemannian manifolds with infinite volume measures

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science China Mathematics 2010年第4期53卷 895-904页

作者： WANG FengYu 1,2.1 School of Mathematical sciences,beijing{2. university,beijing 100875,China 2.department of Mathematics,Swansea university,Singleton Park,Swansea SA2.8PP,UK School of Mathematical sciences Beijing Normal University Beijing China department of Mathematics Swansea University Swansea UK

By establishing the intrinsic super-Poincar'e inequality,some explicit conditions are presented for diffusion semigroups on a non-compact complete Riemannian manifold to be intrinsically *** conditions,as well as the ... 详细信息

关键词： intrinsic ultracontractivity intrinsic super-Poincar’e inequality Riemannian manifold diffusion semigroup

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Recent progress on the structure of Ser/Thr protein phosphatases

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science China(Life sciences) 2008年第6期51卷 487-494页

作者： WANG BaiJing1,2. ZHANG Peng1 & WEI Qun1 1 department of Biochemistry and Molecular Biology, beijing normal university,{2. Key Laboratory, beijing 100875, China 2.School of Life science, Changchun normal university, Changchun 130032. China department of Biochemistry and Molecular Biology Beijing Normal University Beijing Key Laboratory Beijing China School of Life science Changchun Normal University Changchun China

PP1, PP2. and PP2., belonging to the PPP family of Ser/Thr protein phosphatases, participate in regulating many important physiological processes, such as cell cycle control, regulation of cell growth and division regulation, etc. The sequence homology between them is relatively high, and ter- tiary structure is conserved. Because of the complexity of the structure of PP2. and the diversity of its regulatory subunits, its structure is less well known than those of PP1 and PP2.. The PP2. holoen- zyme consists of a heterodimeric core enzyme, comprising a scaffolding subunit and a catalytic sub- unit, as well as a variable regulatory subunit. In this study, the subunit compositions, similarities and differences between the Ser/Thr protein phsphatases structures are summarized.

关键词： Ser/Thr phosphatases subunit composition similarities and differences crystal structure

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