规模扩大对高中学校组织结构的影响

学校规模与组织结构变迁之间存在着密切关系,本研究希望通过探讨规模扩大对学校组织结构的影响,分析现存的问题,并提出建议。     

Importance of spatial proximity between venture capital investors and investees in Germany

Based on 1182 dyads of venture capitalists and German portfolio companies involved in a financing round between 2002 and 2007, the study here examines the importance of spatial proximity between investors and investees in a dense economy. Analysis of this data shows that the probability of a financing relationship decreases by 8% if the journey time increases by one standard deviation. For deals involving very small or very large investment sums, and for less experienced venture capitalists and lead investors, spatial proximity is particularly important. The results suggest that even in economies with a dense infrastructure such as Germany spatial proximity between investor and investee impacts the likelihood of an investment.     

C波段双栅砷化镓场效应管三倍频器的研制

本文介绍了将双栅GaAs MESFET应用在三倍频器上的工作原理,设计思想,实验研制及在C波段的实验结果.这种三倍频器具有一定的倍频增益.目前国内还未见到同类产品.     

频率复用系统同信道干扰抑制因子的研究

随着中国加入WTO及中国经济的发展,国外、国内企业的国际直接投资、融资需求将进一步扩大。因此,招商引资中介服务将越来越重要。但目前在我国国际直接投、融资中介方面还存在诸多问题,不能适应发展的需要。将传统的方式与现代的网络技术相结合,把整合营销的观念引入招商引资中,发展招商引资中介业,促进国际资本流动和我国经济的发展,有着重要的意义。     

变频技术在数控机床上的应用

介绍了采用数控车床的主轴驱动中变频控制的系统结构与运行模式,并简述了无速度传感器的矢量变频器的基本应用。     

Algorithms to compute CM- and S-estimates for regression

Constrained M-estimators for regression were introduced by Mendes and Tyler in 1995 as an alternative class of robust regression estimators with high breakdown point and high asymptotic efficiency. To compute the CM-estimate, the global minimum of an objective function with an inequality constraint has to be localized. To find the S-estimate for the same problem, we instead restrict ourselves to the boundary of the feasible region. The algorithm presented for computing CM-estimates can easily be modified to compute S-estimates as well. Testing is carried out with a comparison to the algorithm SURREAL by Ruppert.     

CEPA条件下安徽民营高新技术企业的发展对策研究

安徽民营高新技术企业在近些年来取得了巨大的发展,规模不断壮大。但总体来看,安徽的民营高新技术企业还很弱小,面对CEPA,机遇与挑战并存。我们应该抓住机遇,迎接挑战,尽快的发展壮大我们的民营高新技术企业。     

Anthropogenic and topographic correlates of natural vegetation cover within agricultural landscape mosaics in Turkey

Natural vegetation enhances the value of agricultural landscapes for people and wildlife. However, the role of anthropogenic versus topographic factors in driving the extent of natural vegetation cover within agricultural lands at large spatial scales remains unexplored. I assessed the influence of anthropogenic and topographic variables on the extent of agricultural mosaics with high natural vegetation cover in the country of Turkey where a large extent of natural and semi-natural vegetation is maintained by traditional agriculture. GIS layers depicting human land use, elevation, slope, roads and population data were obtained and summarized at two spatial scales, within provinces and for 100 km² grid cells covering the country’s entire agricultural land area. Average farm size was also obtained at province level. Hierarchical Partitioning was conducted to determine the independent effect of anthropogenic and topographic variables on the variation in agriculture with high natural vegetation. Slope had the largest independent effect on the variation in the proportion of agricultural mosaic with high natural vegetation cover. The extent of agricultural and settlement area also explained much of the variation in natural vegetation across both grid cells and provinces. The proportion of natural vegetation increased as human population and road density decreased across grid cells and as average farm size decreased across provinces. These results suggest that while topography is the primary driver of natural vegetation cover within agricultural mosaics in Turkey, the pressures associated with urban development and agricultural industrialization may also influence the cultural and wildlife value of agricultural landscapes.     

集聚、研发要素流动与产业竞争力 ——以高端服务业为例

利用新经济地理学理论构建了高端服务业集聚、研发要素流动影响高端服务业竞争力的理论模型。理论分析表明,高端服务业竞争力与高端服务业集聚度、研发要素流动、劳动力数量、工业品支出份额正相关,与产品间替代弹性负相关。继而,利用中国31个省市自治区（因数据缺失,不包含港澳台地区）2003—2018年数据,空间探索性分析发现中国省域间高端服务业竞争力存在明显空间正自相关性。空间面板计量模型检验结果也很好地支持了理论模型的结论。表明高端服务业聚集度、R&D人员流动量和R&D资本流动量的提升正向促进高端服务业竞争力,但三者的总效应主要是由直接溢出效应决定的。本文结论为我国进一步促进高端服务业集聚,统筹区际间研发要素流动,进而提升中国高端服务业竞争力提供政策启示。     

创新驱动先前实践对建设目标的影响

基于各省出台的创新型省份建设方案,运用省级政府面板数据,实证研究了创新型省份建设对预期建设目标的影响。结果发现,创新型省份建设仅对可操控程度较高、完成难度较低的建设目标具有显著影响,而对可操控程度较低、完成难度较高的建设目标无显著影响;高强度激励对建设目标实现的影响作用较大。公开建设方案、科学设定建设目标、促进多部门参与、建立监督和评估机制是改进创新型省份建设和推进创新驱动发展战略实施的重要突破口。