Innovation, regional knowledge spillovers and R&D cooperation

We investigate the impact of knowledge spillovers and R&D cooperation on innovation activities in three German regions. We begin by estimating the knowledge-production function in order to test for interregional difference with regard to the efficiency of innovation activities. In a second step, we analyze the contribution of spillovers from R&D effort of other private firms and of public research institutions to explain these differences. The inclusion of variables for R&D cooperation in the model indicates that R&D cooperation is only of relatively minor importance as a medium for knowledge spillover.     

The structure and evolution of industrial clusters: Transactions, technology and knowledge spillovers

In this paper, we investigate the relationship between location patterns, innovation processes and industrial clusters. In order to do this we extend a transactions costs-based classification into a knowledge-based taxonomy of clusters, along the lines suggested by a critical revision of the main assumptions underlying most of the existing literature on spatial clusters. Our arguments show that the transactions costs approach and the innovation and technological regimes framework are broadly consistent, and that real insights into the microfoundations, nature, and evolution of clusters can be provided by these classification systems.     

The impact of cognitive communities on the diffusion of academic knowledge: Evidence from the networks of inventors of a French university

Looking at micro-data on the networks of inventors of a French science university, we investigate whether the kind of cognitive relationships between researchers influences the geography of their collaborations.The hypothesis we test (and confirm empirically) is that academic knowledge diffuses in a restricted geographic area when the connected researchers belong to epistemic communities, whereas communities of practice entail less localised effects. We also show that institutionally mixed research teams do not impede large knowledge diffusion.     

Investigating the interaction and mutual dependence between science and technology

Literature on the economics of science and technology (S&T) suggests not only that technological innovation demands the expansion of the institutional borders between universities, research institutes, industrial companies and the financial system, but also that science leads as well as follows technology. Medical innovation in particular is very dependent on scientific research, which represents a source of information that impels the productive sector. The latter introduces a series of questions that motivate the researchers in their attempt to understand how the human body reacts to certain products and therapies. This paper analyses the pattern of S&T interaction for both the national system of innovation (NSI) and the health innovation system. The panel data and simultaneous equations models analyze the interaction between S&T. The theory about the existence of a mutual dependence between them has been confirmed, which means that science moves technology and technology also influences scientific development. The estimated models, which use data from scientific papers and patents as proxies of science and technology, represent just the tip of the iceberg called NSI, known as a multifaceted and complex institutional arrangement.     

Scientific teams and institutional collaborations: Evidence from U.S. universities, 1981-1999

This paper explores recent trends in the size of scientific teams and in institutional collaborations. The data derive from 2.4 million scientific papers written in 110 top U.S. research universities over the period 1981-1999. The top 110 account for a large share of published basic research conducted in the U.S. during this time.We measure team size by the number of authors on a scientific paper. Using this measure we find that team size increases by 50% over the 19-year period. We supplement team size with measures of domestic and foreign institutional collaborations, which capture the geographic dispersion of team workers. The time series evidence suggests that the trend towards more geographically dispersed scientific teams accelerates beginning with papers published at the start of the 1990s. This acceleration suggests a sharp decline in the cost of collaboration. Our hypothesis is that the decline is due to the deployment of the National Science Foundation's NSFNET and its connection to networks in Europe and Japan after 1987.Using a panel of top university departments we also find that private universities and departments whose scientists have earned prestigious awards participate in larger teams, as do departments that have larger amounts of federal funding. Placement of former graduate students is a key determinant of institutional collaborations, especially collaborations with firms and with foreign scientific institutions. Finally, the evidence suggests that scientific output and influence increase with team size and that influence rises along with institutional collaborations. Since increasing team size implies an increase in the division of labor, these results suggest that scientific productivity increases with the scientific division of labor.     

Ag2O/NaNbO3纳米复合材料的制备及其光催化性质

采用共沉淀法合成了Ag2O/NaNbO3复合光催化剂,并利用X射线衍射(XRD)和扫描电子显微镜(SEM)分别对其物相和形貌进行表征,用紫外可见漫反射光谱仪对其光学性质进行研究。在可见光下以罗丹明B(RhB)为目标降解物,检测了Ag2O/NaNbO3光催化剂的光催化性能。结果表明,与纯的Ag2O和纯的NaNbO3相比,Ag2O/NaNbO3复合光催化剂具有较高的光催化活性,其光催化活性的提升可能归结于p-n结的形成,使得光生电子空穴对的复合机率大大降低。     

桌面PC数据传输瓶颈分析

桌面PC数据传输瓶颈，是造成处理器速度不能发挥，计算机整体性能提高与处理器主频提升不同步等现象的重要原因之一。本文从硬件层面出发，对目前桌面PC中存在的处理器总线与内存总线的数据传输瓶颈、I／O扩展总线的数据传输瓶颈和硬盘的数据传输瓶颈进行分析，并提出现实的处理方法。     

基于PLC的在线电网监控系统

为了加强对电网及非线性用电设备谐波的在线监测和抑制 ,本文介绍了一种基于远程I/O通信方式的电网质量监控系统 ,重点阐述了远程I/O通讯的原理及实现的方法     

Testing results analysis of contact materials＇ electrical contact performance

Because of the different ways in which contact materials work, the basic requirements for silver metal oxide contact materials are different. They are anti-welded and anti-erosion when closed, anti-erosion when broken, and arc easily moved and have smaller contact resistance. In this paper, La2O3 is used as a stable oxide in contact material to replace CdO. A new type of Ag/SnO2-La2O3-Bi2O3 contact material is first obtained through using powder metallurgical method. Then electrical contact material parameter tester is used to test the electrical contact performance of the contact material. Through experiments, the arcing voltage and current curves, arcing energy curves, fusion power curves while broken and contact resistance while closed were obtained. Analysis of the results showed that the addition of La2O3 makes the contact material have the following advantages： smaller electrical wear, smaller arc energy, smaller contact resistance and arc is more easily extinguished.     

催化光度法测定茶叶中铁

在HCl介质中在Fe(Ⅲ)催化作用下H2O2氧化S酸(即1-氨基-8-萘酚-4-磺酸)使之变色，变色程度与Fe(Ⅲ)的存在量之间有良好的线性关系，借此建立了新的催化光度法．本法操作简单，重现性好，选择性高，用于茶叶中铁的测定，结果满意。