This book studies generalized Donaldson-Thomas invariants $\bar{DT}{}^\alpha(\tau)$. They are rational numbers which `count' both $\tau$-stable and $\tau$-semistable coherent sheaves with Chern character $\alpha$ on $X$; strictly $\tau$-semistable sheaves must be counted with complicated rational weights. The $\bar{DT}{}^\alpha(\tau)$ are defined for all classes $\alpha$, and are equal to $DT^\alpha(\tau)$ when it is defined. They are unchanged under deformations of $X$, and transform by a wall-crossing formula under change of stability condition $\tau$. To prove all this, the authors study the local structure of the moduli stack $\mathfrak M$ of coherent sheaves on $X$. They show that an atlas for $\mathfrak M$ may be written locally as $\mathrm{Crit}(f)$ for $f:U\to{\mathbb C}$ holomorphic and $U$ smooth, and use this to deduce identities on the Behrend function $\nu_\mathfrak M$. They compute the invariants $\bar{DT}{}^\alpha(\tau)$ in examples, and make a conjecture about their integrality properties. They also extend the theory to abelian categories $\mathrm{mod}$-$\mathbb{C}Q\backslash I$ of representations of a quiver $Q$ with relations $I$ coming from a superpotential $W$ on $Q$.
剧场这一术语,被中国戏剧教授李亦男在特定语境下加以介绍和定义。这本独特的选集收录了其与九位1980年代后期在不同方面贡献卓著的中国戏剧人的访谈。这些与拥有不同的成长背景、年龄、艺术观点的剧场人的对话彰显了剧场这一概念开放和包容的特质。受访者们都曾在不同时期,不同时代精神下活跃在中国戏剧界,彼此之间拥有深刻的联结并相互影响。该选集是一部剧场人立足于创作实践,从崭新的视角看待当代中国戏剧不断变化形态的开创之作。 The term juchang is introduced, contextualized and defined by leading professor of theatre in China, Li Yinan, and forms a unique and individual selection of interviews with nine juchang theatre-makers from different periods after 1980, who have contributed to different and interesting developments. All have different backgrounds, ages and perspectives on theatre that reflect the open and inclusive nature of the concept of juchang. The interviewees were all active in Chinese theatre when a different creative spirit reigned, and yet they seem to have had extensive cohesion between, and influence on, each other. A ground breaking look at the changing shape of contemporary Chinese theatre from the perspectives of those who are in the process of creating it.
Dislocation Based Crystal Plasticity: Theory and Computation at Micron and Submicron Scale provides a comprehensive introduction to the continuum and discreteness dislocation mechanism-based theories and computational methods of crystal plasticity at the micron and submicron scale. Sections cover the fundamental concept of conventional crystal plasticity theory at the macro-scale without size effect, strain gradient crystal plasticity theory based on Taylar law dislocation, mechanism at the mesoscale, phase-field theory of crystal plasticity, computation at the submicron scale, including single crystal plasticity theory, and the discrete-continuous model of crystal plasticity with three-dimensional discrete dislocation dynamics coupling finite element method (DDD-FEM). Three kinds of plastic deformation mechanisms for submicron pillars are systematically presented. Further sections discuss dislocation nucleation and starvation at high strain rate and temperature effect for dislocation annihilation mechanism. Covers dislocation mechanism-based crystal plasticity theory and computation at the micron and submicron scale Presents crystal plasticity theory without size effect Deals with the 3D discrete-continuous (3D DCM) theoretic and computational model of crystal plasticity with 3D discrete dislocation dynamics (3D DDD) coupling finite element method (FEM) Includes discrete dislocation mechanism-based theory and computation at the submicron scale with single arm source, coating micropillar, lower cyclic loading pillars, and dislocation starvation at the submicron scale
Focusing on two case studies from East Asia and Europe, Yinan He argues that the key to interstate reconciliation is the harmonization of national memories.
The Shanghai basic education system has garnered significant attention since its extraordinary performance in the 2009 and 2012 Programme for International Student Assessment (PISA), a global assessment of 15-year-olds’ educational abilities. Among the 65 participating economies in 2012, Shanghai-China ranked first on all three major domains of PISA, i.e. mathematics, reading, and science. Shanghai also stands out for having the world’s highest percentage of “resilient students†?, students from socio-economically disadvantaged backgrounds who emerge as top performers. Shanghai’s PISA story has generated intense discussions and diverse speculations in field of international educational development, and numerous studies have been done in the attempt to unravel the mystery. Missing from the picture however is a more comprehensive, systematic, in-depth, and objective rendition of the policies and practices of Shanghai basic education, benchmarked against others in key dimensions. This report presents an in-depth examination of how Shanghai scored highest in the areas of reading, science, and mathematics on PISA. It documents and benchmarks key policies in basic Shanghai education, provides evidence on the extent to which these policies have been implemented in schools, and explores how these policies have affected learning outcomes. The report uses PISA 2012 data to analyze Shanghai student achievement variation and to examine the extent school variables may be associated with the variation beyond family and student background. It also uses the World Bank’s Systems Approach for Better Education Results (SABER), an existing systems diagnostic and benchmarking tool, as an organizing framework and for data collection. School-based surveys and other existing research shed further light on educational impact and implementation. While the report attempts to adopt a systems approach, particular emphasis is placed on teachers, education financing, balancing autonomy and accountability, and student assessment.
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