音视频传输系统中的网络融合

基于音视频系统对IT技术的需求,分析在进行AV传输系统设计中,重点考虑网络拓扑结构、服务质量管理、PTP时钟三个问题。     

Boundary Crossing and the Professional Learning of Teacher Educators in New International Contexts

In this collaborative self-study, two teacher educators examine their experiences of working in new international contexts and the impact of those experiences on their professional learning and identities. Mandi moved from a major research university in one country to another, while Judy co-led a group of pre-service teachers on an international practicum for three weeks each year for three years. Using the concept of boundary crossing as a theoretical and analytical framework, each teacher educator identified a boundary-related critical incident or experience that occurred during her work in new international contexts. Through individual and collaborative analysis of their critical incidents, they found that working as a teacher educator in new international contexts involves the crossing and re-crossing of multiple personal, professional, linguistic and cultural boundaries. Working in these boundary spaces involved learning how to negotiate new kinds of relationships with colleagues and students, manage changed roles and responsibilities and, ultimately, a search for a renewed sense of self, as each sought to understand herself differently within a new professional context.     

一个具有混合边界条件的Laplace算子谱分析

给出了Minkowski内维数和容量的定义,计算了一个三维分形边界区域上具有混合边界条件的Laplace算子的特征值的形式为：λm,n,p=mπa2＋nπa2＋pπa2,其中m,n=0,1,2,…,p=1,2,3,…,其Minkowski维数为δ=ln26ln3,为这类问题的谱分析奠定基础.     

Designing for communication at work: A case for technology-enhanced boundary objects

In this article we conceptualise the challenges of communication between a mortgage company and its customers in terms of crossing boundaries between communities. Through an ethnographic study we first address the question: what are the challenges of communication between sales agents and customers of a mortgage company around mathematical artefacts? Insight into these challenges formed the basis for an intervention in which we designed technology-enhanced boundary objects (TEBOs) that were reconfigurations of problematic symbolic artefacts. Secondly, we ask what the sales agents learned from the intervention. The data suggest that the intervention with the TEBOs helped employees to develop a better understanding of the mathematics behind the mortgages they sold, and to improve communication with their customers.     

非线性2m阶微分方程边值问题解的存在性和多重性

利用强单调映象原理和临界点理论讨论2m阶微分方程边值问题{（-1）^m·u^（2m）（t）=f（t,u（t））,t∈[0.1] u^（2i）（0）=u^（2i）（1）=0 （i=0,1…,m-1）,其中f：[0,1]xR^1→R^1连续,得到其解的存在性和多重性．     

企业联盟、企业集团与“共谋垄断”的边界——兼论培育中国企业国际竞争力的新思路

企业联盟作为企业间合作博弈战略,是“市场———准市场组织———企业”三分析框架的产物,与外部一体化的市场安排相比,企业联盟是一种“组织化市场”;与内部一体化的层级制度安排相比,企业联盟是一种“市场化组织”。企业联盟与企业集团连接纽带、法律地位、经营目标等方面形貌相似,极易对之发生认识上的偏差,但二者具有实质的差别。中国企业集团化面临着产权模糊、行政干预等现实障碍。中国企业应转变战略视角,以联盟而非以集团化作为培育具有国际竞争力企业的首选。但作为企业间的契约结合与股权结合形式,联盟应时刻警惕其与“共谋垄断”的界限。     

兰州市城区稳定边界层变化规律的初步研究

兰州市城区空气污染严重与其特殊的大气边界层密切相关。利用兰州市城区现有大气边界层探测资料 ,采用多种稳定度参数计算方法 ,统计分析了该市大气层结稳定度的时空分布规律及其与天气形势的关系 ,发现兰州市城区冬季大气稳定边界层日间存在发生或发展的特有现象 ,并探寻了其形成机制 ,从而为兰州市开展空气污染预报提供可靠的理论依据     

基于抽象协调性质层次的应急网络组织治理中的协调机制构建

针对应急网络组织治理的特征、协调方式的有效性等方面综合考虑,从试图达到较为理想的协调效果的目标出发,从治理基础和治理手段两方面分析,强调应急网络组织治理中协调机制的重要性,并从新的视角科学地构建出应急网络组织治理七层次协调机制,即:混合层、激励层、协商层、交易层、规约层、技术层、自治层。这7个层次对应说明了其协调问题的难易程度:混合层应当解决的是最难协调的问题,其次是激励层等,自治层应当解决的是最易协调的问题。协调问题的难易程度不同,协调目标的理想程度也不同,分别从协调问题的相对难易程度、协调目标的相对理想程度、协调问题的相对显性程度三方面展开论述。     

K/T界线的研究进展——兼论元素演化与恐龙灭绝的可能关系

本文通过总结近一、二十年来K/T界线的研究进展和恐龙绝灭的相关假说，认为前人在K/T界线和恐龙灭绝的研究方面确实取得了很大的成果，但同时,大多数的研究都是集中在对灾变大环境的求证上。只有少数学者注意到Co、Cr、Ni、Mn、V等这些在界线处变化较大的元素同时也是生物必需微量元素，而另外一些异常元素（如REE、Pb、Sr等）也可能对生物的正常生理机能产生重要影响，这些元素的异常变化很可能与恐龙灭绝存在着一定的关系，但这方面的系统研究还相当缺乏，今后应加强元素的生物机能和与生命活动密切相关的元素在K/T界线附近的演化与恐龙灭绝的关系等方面的研究。