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

James D. Adams  Grant C. Black  Paula E. Stephan 《Research Policy》2005,34(3):259-285

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.  相似文献   

Intellectual property protection mechanisms in research partnerships   总被引：1，自引：0，他引：1  

Henry R. Hertzfeld  Nicholas S. Vonortas 《Research Policy》2006,35(6):825-838

A set of US-based companies is investigated regarding the effectiveness of intellectual property protection mechanisms (IPPMs) in the formation of research partnerships. Patents are the most frequently used IPPM to protect both background and foreground knowledge in partnerships. Other IPPMs are used to protect know-how, especially in the early, forming stages of a partnership. Existing IP titles are quite useful when negotiating new partnerships. IPR negotiations are reported to be more complex in horizontal partnerships and when universities are involved.  相似文献   

浅谈java与数据库的存取技术     

徐红梅 《四川职业技术学院学报》2006,16(2):117-118

数据库存取技术在计算机应用系统中涉及很广泛,本文主要阐述了在Java中用使用JDBC访问数据库的方法,连接数据及其主流存取技术。  相似文献   

对青少年运动员胫骨疲劳性骨膜炎的实验研究   总被引：2，自引：0，他引：2  

山灵团 《河西学院学报》2002,18(2):72-74

笔者针对青少年运动员中胫骨疲劳性骨膜炎发病率高的特点，自1999年以来，以来 往信函和个别访谈的方法，对河南、湖南、湖北、广东和广西五省35所高级中学、10所高等 院校体育系和8所体校的410例患者采用1/1000Hg2(NO3)2．2H2O（千分之一硝酸亚汞）进行 局部贴敷，并配合理疗、点穴按摩等方法，取得显著疗效，治愈率高达96%，深受青少年体 育爱好者的欢迎．  相似文献   

水杨醛甲胺磷合铜(Ⅱ)配合物稳定常数测定     

党元林  卓立宏 《南阳师范学院学报》2002,1(2):63-64

用pH法测定了水杨醛甲胺磷席夫碱合铜 (Ⅱ )配合物的稳定常数 ,K =4 .2× 10 14 ,说明该配合物是稳定的。  相似文献   

CuO/γ-Al2O3上H2催化还原氮氧化物的初步研究     

顾立军  谢颖  刘宝生  陈小平  王乐夫 《茂名学院学报》2004,14(1):5-8

采用γ—Al2O3和CuO／Y—Al2O3作为H2催化还原氮氧化物的催化剂，考察了反应温度、活性组分添加、原料配比以及原料气空速等对NO转化率的影响。结果表明：γ—Al2O3本身对于NO还原有一定的催化活性；Cu的添加可以使γ—Al2O3催化剂的NO还原活性明显提高；在考察的温度范围内，CuO／Y-AlO3催化剂活性随反应温度的升高明显增加，最高可达100％。随着反应原料气H2／NO(mol)的降低，NO转化率下降。  相似文献   

Ag2O/NaNbO3纳米复合材料的制备及其光催化性质     

李强  李世平  卢笑笑  马相东  韩浩  王康 《宜春学院学报》2020,(3):27-30

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。  相似文献   

磁性纳米Fe3O4的制备及性能表征     

周曾艳 《铜仁学院学报》2006,8(3):92-96

本文介绍纳米Fe3O4微粒和以纳米Fe3O4为核磁体的靶向药物的制备，对它们的性质进行XRD、IR、TEM、SEM、EDS表征，并对纳米Fe3O4微粒和以Fe3O4为载体的靶向药物进行了扩大化实验。  相似文献   

大气污染对云冈石窟的风化侵蚀及防护对策     

李海 《雁北师范学院学报》2003,19(5):60-63

云冈石窟地区大气污染较为严重.大气中的污染物主要是SO2、工业粉尘及粉尘中的金属元素,其含量皆严重超标.在有水份的环境中,通过金属离子的催化作用,SO2容易生成H2SO4或酸性物质,再与石质文物表层中CaCO3作用,生成CaSO4*2H2O, 导致风化侵蚀.  相似文献   

桌面PC数据传输瓶颈分析     

谢建民 《宁波广播电视大学学报》2003,1(1):71-73

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。  相似文献