阮瑀之死与建安十七年文学情势

从文学年代学角度看,建安十三年、建安十七年均是建安文学发展和转变的重要年份,文人心态、文学创作的题材内容和风格前后均发生了一定的变化。建安十三年文人齐集邺城,建安文学开始进入创作繁荣期,建安十七年阮瑀之死对建安文人的心灵产生了重要影响,使建安文人的心态由乐转悲;表现在文学题材上便是大量以寡妇为描写对象的哀悼之作的产生,由此拓展了建安文学的创作题材;文学风格上则是哀感之心大于雄深之气,伤生之意多于哀世之情,使建安文学展现出多元化的风格倾向,在建安文学发展史上具有重要意义。     

Journal ranking should depend on the level of aggregation

Journal ranking is becoming more important in assessing the quality of academic research. Several indices have been suggested for this purpose, typically on the basis of a citation graph between the journals. We follow an axiomatic approach and find an impossibility theorem: any self-consistent ranking method, which satisfies a natural monotonicity property, should depend on the level of aggregation. Our result presents a trade-off between two axiomatic properties and reveals a dilemma of aggregation.     

一类三种群食物链差分系统的正周期解的存在性

本文利用Mawhin的重合度理论中的延拓定理研究了一类具多时滞的三种群食物链差分系统的正周期解的存在性,获得了保证该差分系统存在正周期解的新的充分条件.     

Who says you need to teach reading to 11–13-year-olds?

Research indicates that as students move through the school system, many begin to experience difficulties with reading. With this mind, this study explored current practices and perceptions about reading programmes for 11–13-year-old students in New Zealand schools. The study employed an online survey designed to investigate current reading literacy practices in a sample of New Zealand primary in years 7 and 8. Observations of practice and interviews with literacy leaders, teachers, principals and students were also carried out at five case study schools. The survey indicated that teachers may underestimate the importance of learner engagement and direct teaching strategies. The case studies exemplify the need for good professional development, supportive leadership, effective class management strategies, a positive and engaging learning environment, teachers with a passion for literacy and exemplary and sustained guided reading.     

基于环境扫描的“十三五”高校图书馆转型探索

[目的/意义]"十三五"期间,高校图书馆在新的信息环境、用户环境和高等教育环境下,必须重新进行自我审视和定位,转型发展势在必行。[方法/过程]对"十三五"高校图书馆面临的信息环境、用户环境和高等教育环境进行扫描,通过扫描发现其新的特点和发展趋势,探索新环境下图书馆转型策略。[结果/结论]高校图书馆应构建泛在化、智能化和专业化的知识服务体系,创建用户驱动的多类型的数字知识环境,营建创新学习与学术交流的第三空间,塑建基于职能拓展的协作式组织结构。     

吸铸La_(0.8)Ce_(0.2)Fe_(11.4)Si_(1.6)B_(0.5)合金磁熵变性能研究

本文研究了利用吸铸和短时间热处理方法制备的La0.8Ce0.2Fe11.4Si1.6B0.5化合物的微结构、磁性以及磁熵变性能.X射线衍射结果表明,与传统的长时间热处理方法(通常大于1周)相比,吸铸方法制备的La0.8Ce0.2Fe11.4Si1.6B0.5化舍物只需经过1373K真空退火处理2h后,全部转变为单相立方NaZn13型晶体结构.磁测量表明,样品具有较小的热滞和磁滞,B添加使居里温度Tc提高到197K,最大磁熵变为15.3 J/(kg·K).这些研究说明了吸铸短时退火是一种制备磁制冷材料的优异方法,该方法制备的La0.8Ce0.2Fe11.4Si1.6B0.5化合物是一种优良的磁制冷工质.     

Existence of three periodic solutions for a nonlinear first order functional differential equation

In this paper, we use Leggett-Williams multiple fixed point theorem to obtain different sufficient conditions for the existence of at least three nonnegative periodic solutions of the first order functional differential equation of the form

y^′(t)=-a(t)y(t)+λf(t,y(h(t))).     

New firm formation and regional knowledge production modes: Italian evidence

According to the knowledge-spillovers theory of entrepreneurship (KSTE), local knowledge spillovers affect entrepreneurial dynamics, because of knowledge asymmetries and uncertainty. Most of the empirical literature has tested this hypothesis using a measure of local knowledge stock. This paper is aimed at extending the framework by showing that the domains over which local knowledge spans are also important. The paper investigates the impact of the configuration of local knowledge bases on new firm formation dynamics by combining the KSTE framework with the recombinant knowledge approach. Local knowledge bases emerge from the combination of different knowledge inputs. These inputs may be closely or loosely related to one another. Technological differentiation and the relatedness degree of local competences can be interpreted as characteristics of the local knowledge base interacting with the knowledge filter and the entrepreneurial absorptive capacity. The paper proposes a taxonomy of regional modes of knowledge production and investigates new firm formation in 92 Italian NUTS 3 regions observed over the 1995–2009 time span. The results confirm that the availability of local knowledge pools is important, and show that the ‘rich integration’ mode is the configuration that favours the entrepreneurial process. Finally, the policy implications and avenues for further research are presented and discussed.     

Innovation: The interplay between demand-side shock and supply-side environment

We study the interaction between supply- and demand-side factors and its effect on innovation. Employing a quasi-natural experiment, we show that a shift in demand has an impact on innovation and this effect is conditional on an enabling supply-side environment. Specifically, we exploit a shift in product demand generated by Medicare approvals for reimbursement coverage of medical devices. Using a triple-difference approach, we find that innovation is significantly greater for medical device firms that experience a positive shock to demand due to the Medicare approvals when the firms are exposed to a more favorable supply-side environment. The highest level of innovation is accomplished when all three of our supply-side factors: venture capital (industry), universities (academia), and National Institutes of Health grants (government) are concentrated in one place. These findings show that (i) a positive interaction between supply- and demand-side factors fosters innovation, and (ii) the trilateral intersection of industry, academia, and government creates the highest level of innovation.     

再析ISBN号及其升13位的影响

介绍了ISBN号的定义、编排方法及升位情况,具体分析了ISBN号升13位的原因及其对图书出版、发行、流通、收藏等方面的影响,最后提出了相应的解决办法。