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Compactness of the commutators of parabolic singular integrals

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Science china Mathematics 2010年第10期53卷 2633-2648页

作者： CHEN YanPing1 & DING Yong2,3 1Department of Mathematics and Mechanics,university of Science and Technology beijing,beijing 100083,china 2school of Mathematical Science,beijing normal university,beijing 100875,china 3Laboratory of Mathematics and Complex Systems (BNU),Ministry of Education of china,beijing 100875,china 1. Department of Mathematics and Mechanics University of Science and Technology Beijing Beijing 100083 China2. School of Mathematical Science Beijing Normal University Beijing 100875 China3. Laboratory of Mathematics and Complex Systems (BNU) Ministry of Education of China Beijing 100875 China

In this paper,the authors prove that the commutator [b,T] of the parabolic singular integrals is a compact operator on Lp(Rn)(1 < p < ∞) if and only if b ∈ VMO(Rn,ρ).The result is substantial improvement and extens... 详细信息

In this paper,the authors prove that the commutator [b,T] of the parabolic singular integrals is a compact operator on Lp(Rn)(1 al improvement and extension of some known results.

关键词： parabolic singular integrals commutators compactness BMO VMO

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, beijing 100875, china 2school of Science, Shangdong university of Technology, Zibo 255049, china 1. Department of Mathematics Beijing Normal University Beijing 100875 China2. School of Science Shangdong University of Technology Zibo 255049 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

Coexistence of unbounded solutions and periodic solutions of Liénard equations with asymmetric nonlinearities at resonance

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Science china Mathematics 2007年第8期50卷 1205-1216页

作者： Zai-hong WANG school of Mathematical sciences,Capital normal university,beijing 100037,china 1. school of Mathematical sciences Capital Normal University Beijing 100037 China

In this paper, we deal with the existence of unbounded orbits of the mapping $$\left\{ \begin{gathered} \theta _1 = \theta + 2n\pi + \frac{1}{\rho }\mu (\theta ) + o(\rho ^{ - 1} ), \hfill \\ \rho _1 = \rho + c - \mu '(\theta ) + o(1), \rho \to \infty \hfill \\ \end{gathered} \right.$$ , where n is a positive integer, c is a constant and μ(θ) is a 2π-periodic function. We prove that if c > 0 and μ(θ) ≠ 0, θ, ∈ [0, 2?], then every orbit of the given mapping goes to infinity in the future for ρ large enough; if c 2π], then every orbit of the given mapping goes to infinity in the past for ρ large enough. By using this result, we prove that the equation x″+f(x)x′+ax +?bx ?+?(x)=p(t) has unbounded solutions provided that a, b satisfy $1/\sqrt a + 1/\sqrt b = 2/n$ and ?(x) satisfies some limit conditions. At the same time, we obtain the existence of 2π-periodic solutions of this equation.

关键词： Liénard equations unbounded solutions periodic solutions 34C11 34C25

Automatic generalization of metro maps based on dynamic segmentation

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Science china(Technological sciences) 2010年第S1期53卷 158-165页

作者： DONG WeiHua 1,TIAN Yuan 2 & ZHANG Yi 2 1 Institute of Geography and Remote Sensing,beijing normal university,beijing 100875,china 2 Institute of Remote Sensing and Geographic Information System,Peking university,beijing 100871,china 1. Institute of Geography and Remote Sensing Beijing Normal University Beijing 100875 China 2. Institute of Remote Sensing and Geographic Information System Peking University Beijing 100871 China

A metro map is usually optimized for the readability of connections and transportation networks *** order to assure good readability and meet aesthetic considerations,a set of principles for good metro map layout are *** to these principles,a new methodology based on dynamic segmentation is presented to produce the metro maps ***,routes are constructed according to the line attribute similarity and geometry *** a set of cartographic generalization methods about the shape,angle,length,and topology are presented for these *** method is validated by beijing metro plan *** the experiment results,it can be concluded that this new method is more effective than the static segmentation method to produce metro maps with better readability for route plans.

关键词： metro maps generalization dynamic segmentation visualization

Effect of Bcl-2 and caspase-3 on calcium distribution in apoptosis of HL-60 cells

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Cell Research 2000年第3期10卷 213-220页

作者： ZHANG MIN, HONG QING ZHANG, SHAO BAI XUE (Department of Biology, beijing normal university, beijing 100875, china) DepartmentofBiology BeijingNormalUniversityChina.

Apoptosis manifests in two major execution programs downstream of the death signal: the caspase pathway and organelle dysfunction. An important antiapoptosis factor, Bcl-2 protein, contributes in caspase pathway of apoptosis. Calcium, an important intracellular signal element in cells, is also observed to have changes during apoptosis, which maybe affected by Bcl-2 protein. We have previously reported that in Harringtonine (HT) induced apoptosis of HL-60 cells, there’s a change of intracellular calcium distribution, moving from cytoplast especially Golgi’s apparatus to nucleus and accumulating there with the highest concentration. We report here that caspase-3 becomes activated in HT-induced apoptosis of HL-60 cells, which can be inhibited by overexpression of Bcl-2 protein. No sign of apoptosis or intracellular calcium movement from Golgi’s apparatus to nucleus in HL-60 cells overexpressing Bcl-2 or treated with Ac-DEVD-CHO, a specific inhibitor of caspase-3. The results indicate that activated caspase-3 can promote the movement of intracellular calcium from Golgi’s apparatus to nucleus, and the process is inhibited by Ac-DEVD-CHO (inhibitor of caspase-3), and that Bcl-2 can inhibit the movement and accumulation of intracellular calcium in nucleus through its inhibition on caspase3. Calcium relocalization in apoptosis seems to be irreversible, which is different from the intracellular calcium changes caused by growth factor.

关键词： Apoptosis calcium caspase-3 bcl-2 laser scanning confocal microscopy (LSCM).

Designing regional pattern for ecosystem restoration:A case study

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Science china(Technological sciences) 2006年第z1期49卷 86-97页

作者： LI Guoqiang , MA Keming, FU Bojie & LIU Shiling State Key Lab of Systems Ecology, Research Center for Eco-environmental sciences, Chinese Academy of sciences, beijing 100085, china Department of Water Environment, china Institute of Water Resources and Hydropower Research, beijing 100038, china school of Environmental sciences, beijing normal university, beijing 100875, china 1. State Key Lab of Systems Ecology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China 2. Department of Water Environment China Institute of Water Resources and Hydropower Research Beijing 100038 China 3. school of Environmental sciences Beijing Normal University Beijing 100875 China

Designing regional pattern is challenging for ecosystem restoration both in theory and in practice. The present study proposed a new approach to design regional pattern for ecosystem restoration with a case in the arid valley of Upper Minjiang River, SW china. The procedures are: (1) Determine the regional pattern of main environmental factors based on the relationships between the important environmental factors and the main geographical factors generated from DEM data. (2) Overlay the maps of the main environmental factors. (3) Generate a lookup table according to the species selection rule we proposed to link the candidate restoration species to the main environmental factors.(4) Determine the regional pattern of ecosystem restoration by positioning the restoration species in the map of environmental factors according to the lookup table. The regional restoration pattern designed in this way would be applicable not only to restoring a region, but also to predicting the future landscape change.

关键词： environmental factors, GIS, restoration species, Upper Minjiang River Valley.

Geographical Agglomeration of Chinese Manufacturing Industries

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中国人口·资源与环境：英文版 2007年第2期5卷 3-11页

作者： Zhang Hua 1, 2, Zheng Wei3 1. Institute of Geographical sciences and Natural Resources Research, Chinese Academy of sciences, beijing 100101, china 2. Graduate school of the Chinese Academy of sciences, beijing 100039, china 3. school of Geography, beijing normal university, beijing 100875, china Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Graduate school of the Chinese Academy of sciences Beijing 100039 China school of Geography Beijing Normal University Beijing 100875 China

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of china, this paper ex- amines the geographical agglomeration of Chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of Chinese manu- facturing industries in 1996, 2001 and 2004, agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–2004.

关键词： industrial agglomeration manufacturing industries the MS index

Plus cupping degrees do not form an ideal

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Science in china(Series F) 2004年第5期47卷 635-654页

作者： LI Angsheng1,2 & ZHAO Yicheng1 1. Institute of Software,Chinese Academy of sciences,beijing 100080,china 2. school of Information sciences,beijing normal university,beijing 100871,china 1. Institute of Software Chinese Academy of Sciences 100080 Beijing China 2. school of Information sciences Beijing Normal University 100871 Beijing China

A computably enumerable (c.e.,for short)degree a is called plus cupping,if every c.e. degree x with 0all plus cupping *** the present paper,we show that PC is not closed under the join operation ∨ by constructing two plus cupping degrees which join to a high degree. So by the Harringtons noncupping theorem,PC is not an ideal of ε.

关键词： computably enumerable set Turing degree definability.

COMPUTATIONal COMPLEXITY IN WORST, STOCHASTIC AND AVERAGE CASE SETTING ON FUNCTIONal APPROXIMATION PROBLEM OF MULTIVARIATE

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Acta Mathematica Scientia 2005年第3期25卷 439-448页

作者：房艮孙叶培新 school of Mathematical sciences beijing normal university school of Mathematical sciences and LPMC Nankai university

The order of computational complexity of all bounded linear functional ap proximation problem is determined for the generalized Sobolev class Wp?（Id）, Nikolskii class H|∞k（Id） in the worst （deterministic）, stochastic and average case setting, from which it is concluded that the bounded linear functional approximation problem for the classes Wp?（Id） and H∞k（Id） is intractable in worst case setting, but is tractable with respect to stochastic and average case setting.

关键词： worst (deterministic) case stochastic case average case setting bounded linear functional error estimate