带时滞的单种群在n个斑块中持续生存的条件

对[2]中的单种群扩散模型进行了推广与改进,研究了fi(xi(t-τ))=ai(t) di(t)(∑j=1xjnxj-1)n ε bi(t)xi(t-τ)-ci(t)xi2(t-τ)(i=1,2,…,n)与gi(xi(t-τ)=ai(t) di(t)(∑j=1jnxj-1)-ε bi(t)xi(t-τ)-ci(t)x2i(t-τ)(i=1,2,…,n)的正根存在性及种群密度函数的特性,利用数学分析的方法证明了在条件ai(t)≥εdi(t)下,该种群是持续生存的。     

关于柳宗元被贬后对待挫折的心理分析

通过对柳宗元被贬后的复杂心态及行为反应的分析，认为被贬谪后的柳宗元对待挫折是采取了积极进取的建设性反应。他根据实际情况调整了行为方式，致力于总结历史经验和文学创作，绕过难于在官场上有所作为的障碍，继续为国家的统一和社会的进步而呼唤呐喊，最终实现了“取贵于后”的人生价值。因而，他不是一受挫折即一蹶不振的懦夫，而是在失败后依然坚持斗争的成功者。     

二维非定常对流扩散方程的高精度紧致半显式差分格

在已有文献的基础上,发展了一种求解二维非定常对流扩散方程的高精度紧致半显式差分格式,其截断误差为O（τ2 ＋h4）,该格式形式上是隐式,但实际上可以显式计算.利用Fourier分析法证明该格式是无条件稳定的.数值实验结果验证了该格式的精确性和可靠性.     

New Directions in the Evaluation of the Effectiveness of Educational Technology

Summary

Drawing from work by Shadish, Cook, and Leviton (1991) on social program evaluation, the authors discuss recent changes in evaluation theory and practices, and they connect these changes to technology and student learning. Concluding with a list of recommendations for evaluating the effectiveness of technology in teaching and learning, the authors challenge the purposes of education and prevalent goals for evaluation. After questioning how technology can impact student learning, they call for new and expanded definitions of student learning outcomes. Recommendations include redefining technology as a process rather than as a product, conducting implementation evaluations prior to outcome evaluations; reducing the reliance on standardized test scores as the primary outcome measure; and adopting multifaceted evaluation approaches (including case studies).     

The intra-firm diffusion of complementary innovations: Evidence from the adoption of management practices by British establishments

This paper presents a simple profitability-based decision model to show how synergistic gains generated by the joint adoption of complementary innovations may influence the firm's adoption decision. For this purpose a weighted index of intra-firm diffusion is built to investigate empirically the drivers of the intensity of joint use of a set of complementary innovations. The findings indicate that establishment size, ownership structure and product market concentration are important determinants of the intensity of use. Interestingly, the factors that affect the extent of use of technological innovations do also affect that of clusters of management practices. However, they can explain only part of the heterogeneity of the benefits from joint use.     

基于创新扩散的耐用品品牌扩散模型探析

基于创新扩散理论并依据耐用品品牌的市场特征,系统地提出了耐用品品牌的垄断品牌扩散模型、寡头品牌扩散模型、品牌竞争扩散模型和品牌竞争扩散一般模型;采用中国移动通信产业品牌的实际数据对前三个模型进行了验证。     

基于耗散结构理论的知识大众生产系统演化机制研究

知识的大众生产是知识经济时代知识由大众来创造的新生产模式,以往的知识生产理论都以企业组织作为研究对象,而没有在大众生产的环境下分析知识的生产过程.知识大众生产是一种典型的复杂系统涌现现象.通过知识特性的雏度(追求至善的知识一追求多元化的知识)和知识生产系统特性的维度(有规则系统一无规则系统)将知识大众生产划.分为四种模式.借鉴耗散结构理论.指出在知识生产系统中熵是衡量知识流有序程度的标量,其中追求至善系统中的有序是指知识流从生产到需求的有效性和最优化.而追求多元化系统中的有序是指知识流从生产者到需求者的匹配,知识生产系统的演化机制是系统熵的变化过程,是不断从无序走向有序的过程.     

非均质后发大国技术空间扩散的影响因素——基于扩散系统的分析框架

非均质后发大国的异质性决定了技术空间扩散系统对技术空间扩散具有重要影响.以技术空间扩散系统中扩散源、扩散汇和扩散环境为分析框架,技术空间扩散受到空间距离、技术差距、产业联系和政府四大因素影响.其中,空间距离所产生的空间依赖性和产业联系与技术扩散正相关,技术差距与技术扩散负相关.政府在资金投入上存在的结构性差异使得政府实现的社会应用成果并不明显,因此,政府对技术空间扩散在政策方向和执行力度上的支持有待进一步提高.     

以北京为源头的技术市场扩散与区域生产率

 北京地区集聚了全国较大比例的科技资源,但是对于全国科技和经济水平的提升起到多大的作用却常常受到质疑。本文在技术扩散和经济增长的理论基础上,通过对以技术市场为代表的技术扩散与区域生产率的定量研究,肯定了以北京为源头的技术扩散确实推动了全国其它地区生产率的提高。同时对影响北京地区技术扩散效果的因素进行了研究,为如何实现更高的扩散效率提供了启示。     

Knowledge translation and research careers: Mode I and Mode II activity among health researchers

Defining knowledge translation activities using Gibbons and Nowotny's Mode I and II forms of knowledge production, health researcher (N = 240) characteristics are compared with their knowledge translation activities. Applied researchers (n = 168) engaged in more Mode II activity (p < .001), perceived their work as having more impact (p < .001), and reported higher levels of relational capital (p < .001) when compared to basic researchers (n = 72). Those from medical schools (n = 128) had more publications (p = .004) as did applied researchers in medical school compared to applied researchers from other faculties (p = .001). These findings provide early empirical insights into emerging tensions in environments where Mode I and Mode II activities co-exist; tensions that may extract unintended costs from researchers. Such costs may be paid in the currency not only of tenure and promotion, but also of successful grant and career scientist award acquisition.