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Symmetric centre. of braided monoidal categories

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Science China Mathematics 2000年第4期43卷 384-390页

作者：蔡传仁江宝歆 Department of Mathematics Yangzhou University Yangzhou 225002 China Department of Mathematics Yangzhou University Yangzhou 225002China

This paper introduces the concept of ‘symmetric centre.’ of braided monoidal categories. LetH be a Hopf algebra with bijective antipode over a fieldk. We address the symmetric centre.of the Yetter-Drinfel’d module category: and show that a left Yetter-Drinfel’d moduleM belongs to the symmetric centre.of and only ifM is trivial. We also study the symmetric centre. of categories of representations of quasitriangular Hopf algebras and give a sufficient and necessary condition for the braid of, H? to induce the braid of , or equivalently, the braid of , whereA is a quantum commutativeH-module algebra

关键词： Yetter-Drinfel’d module braided monoidal category symmetric centre.

Cathodoluminescence of diamond synthesized from silicon-carbide

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Chinese Science Bulletin 1996年第3期41卷 208-212页

作者：洪时明 KANDA Hisao 芶立 National Institute for Research in Inorganic Materials Namiki 1-1 Tsukuba Ibaraki 305 Japan

As a wide energy gap semiconductor, diamond is expected to play a role in UV light-emitting diode or laser. However, the impurities and vacancies in diamond exert a great influence on optical properties of the crystals. It is important, therefore, to study the relation between impurities and the optical properties, and furthermore, to study the control of the impurities.

关键词： high pressure synthesis diamond cathodoluminescence optical centre.

Measure centre.and Minimal centre.of Attraction

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Chinese Science Bulletin 1993年第7期38卷 542-545页

作者：周作领 Lingnan College Zhongshan University Guangzhou 510275 PRC

In this note, we give the definition of the minimal centre.of attraction for self-mapping on a compact metrizable space (for the case of flow, see Ref. [1]) and prove that the minimal centre.of attraction coincides wi... 详细信息

关键词： self-mapping minimal centre of attraction invariant measure weakly almost periodic point measure centre.

Qualitative Research Methods in Spatial Urban Development： A Methodological Investigation of Approaches into Urban Development Based on Centralities in the Context of a Medium-Sized European City

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Journal of Civil Engineering and Architecture 2016年第11期10卷 1288-1296页

作者： Martin Brabant Projektkrafi Building Brands Rheinboldtstrasse 1 2362 Biedermannsdorrf Austria

Dispersed and peripheral spaces in the urban core are influenced both by the trend towards constant growth as well as social ways of life which are constantly evolving. Following a connotation, these two factors therefore play a crucial role in defining the alternation of urban space--in particular, that of the centers. The main focus of this research article is on the methodology used in the survey and evaluation of ＂centralities＂ as well as their developments over the past four decades （1974-2014） in approaches to urban development that has been developed in Graz.~ The analysis has drawn on the four editions （＂evolution＂） of approaches to urban development as conceived by the city of Graz in order to examine their verbal characteristics in regard to centralities. At the same time, the analysis does not examine presentations of plans which exist in supplementary forms （e.g., explanatory reports and supplemented plans）--it restricts itself solely to the various plans set out in the STEKs.2 The highest degree of accuracy has been applied to the notion of ＂centralis＂ in approaches to urban development. The goal of the research project was to depict the modulation of the notion of ＂centrality＂ in the urban context as a space-forming dimension. Furthermore, it clearly shows the extent to which the notion of the ＂centre. （in the widest sense of the word） has become distanced from qualitative, spatial development and at the current time of urban development is experiencing a sort of Renaissance. In the field of ＂urban development＂, architectural references in the context of＂centrality＂ have scarcely been researched. This has led to the opening-up of a complex interdisciplinary research field. In order to make the complex architectural determinants of ＂centrality＂ more accessible to the participating disciplines, approaches to urban development have been explored in the form of a social and spatial analysis.

关键词： Social space analysis qualitative research methods in urban development processes classification of city sizes urban centre.