Selective search, sectoral patterns, and the impact on product innovation performance     

Christian Köhler 《Research Policy》2012,41(8):1344-1356

The shift toward more open and interconnected innovation activities has been a major topic in recent academic and practitioner discussions. Firms must connect their in-house R&D activities with external partners, such as leading customers or universities, to increase the effectiveness of their innovation activities. Hence, management needs to define where to search for valuable knowledge in its environment. In this paper we argue that knowledge search has to reflect the heterogeneity of various knowledge sources with regard to the knowledge they can provide and how these sources can be activated. We hypothesize that search strategies driven by science, suppliers and the product market will contribute differently to innovation success with new-to-market versus imitated products. Moreover, we explore the effect of these types of knowledge search within different sectoral patterns of innovation. Our empirical analysis rests on a sample of almost 5000 firms from five Western European countries. The results support our hypotheses and highlight the potentials and shortcomings of different types of knowledge search.  相似文献   

论词块理论在二语词汇习得中的作用     

邓之宇 《海外英语》2010,(5)

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景天三七中总黄酮提取条件和含量分析   总被引：2，自引：0，他引：2  

付煜荣  姚荣章 《河北北方学院学报(医学版)》2010,27(1):13-15

目的：研究不同提取溶剂对景天三七中总黄酮的含量影响及最佳提取条件下总黄酮的含量。方法：采用盐酸一镁粉法和醋酸铅法对景天三七中总黄酮进行检识,并用不同溶剂对景天三七中总黄酮进行了提取,以分光光度法测定总黄酮含量,以芦丁为标准品,以10％AI（NO2）3-5％NaNO2为显色剂,在508nm波长处进行测定。结果：检识试验证明景天三七中含有黄酮类物质,且最佳提取溶剂为80％乙醇（P〈0．05）。在此提取条件下,测得景天三七中总黄酮的含量为18．39mg·g～,RSD为2．2％（n=5）。总黄酮测定线性范围为15．20-45．60beg·mL^-1。（r=0．9997）,平均回收率为95．74％,RSD为0．98％（n=6）。结论：景天三七中黄酮类物质的最佳提取溶剂为80％乙醇。本法准确可靠,重现性好,结果稳定,适合于景天三七中总黄酮含量分析。  相似文献   

二语习得关键期假说探讨     

应丽娜 《中国科教创新导刊》2010,(10):79-80

本文首先介绍了二语习得关键期假说及其理论背景,之后通过前人的各项研究探讨关键期假说是否具有合理性,希望对教学有启示作用。  相似文献   

Effect of the geometric shapes of specimens on impact tensile tests     

Wei-fang Xu  Xi-cheng Huang  Zhi-ming Hao  Yang Wang  Yuan-ming Xia 《浙江大学学报(A卷英文版)》2010,11(10):817-821

The geometric shapes of specimens are important in impact tensile tests because geometric shapes determine the stress states of the specimens, and precise geometric shapes can obtain proper material properties without non-material factors. The aim of this study was to investigate the 1D form of the stress by changing the length-to-diameter （L/D） ratios of specimens. The experiments were carried out on a split Hopkinson tensile bar （SHTB）-rotating disk indirect bar-bar tensile impact apparatus. The L/D ratios of the LY12CZ specimens used in the test ranged from 1 to 5. Results show that the specimens can be used to obtain exact parameters of materials under the proposed conditions when the L/D ratio is greater than 2. This is because the longer length will reduce or eliminate the effects of the interfaces.  相似文献   

母语提纲对大一学生二语写作的影响     

陈松菁 《兰州教育学院学报》2010,26(5):71-72,80

英语新四级考试作文主要以英语题目加母语提纲为出题方式,大一学生在写作时是否受到母语提纲的负迁移影响？本文将通过对比两个非英语专业的大一班级按照同一题目不同提纲（母语提纲和英语提纲）写的课堂作文,探讨母语提纲对学生作文的影响。  相似文献   

An Empirical Research on DDL in L2 Writing     

An  Xue-hua Xu  Ming-ying 《美中教育评论》2013,(9):693-701

L2 （second language） writing teaching and research is greatly influenced by the advent of computer technology. This paper reviews papers, in the field of DDL （data-driven learning） in L2 writing, published in international journals and in Chinese journals, and differences are found in research methodology, research perspective, and research realm. Based on the analysis of the differences, the study aims at finding out the effects of the application of DDL in L2 teaching classroom. The present study, employing semi-structured writing and learning journals, explores how English learners perceive the use of corpora in their writing process. Based on the statistics, it is concluded that DDL in L2 writing is beneficial for vocabulary acquisition. However, corpus consultation does not work well for all learners. Learners＇ attitudes toward the use of corpus are various. The major findings may find application in teaching practice, and implications for teaching are discussed.  相似文献   

基于单片机的智能测角仪设计     

李尚富  饶连周  魏名捷  曾金顶  林永福  陈俊玮 《三明高等专科学校学报》2013,(4):39-42,87

研究了一种基于STC12C5A60S2单片机的智能测角仪。该测角仪由加速度传感器模决MMA7455、时钟模块DS1302、温湿度模块DHT11、语音模块ISD4004组成,实现了角度、时间、温湿度的显示、存储以及语音播报的功能,具有一定的推广价值和实用性。  相似文献   

基于L2TP／IPSec的企业远程移动办公网的构建     

刘学普  周阳 《宁波职业技术学院学报》2013,(5):99-101

研究了安全的企业远程移动办公网络,首先介绍了L2TP和IPSec的相关概念和工作原理．然后介绍了基于L2TP／IPSec的企业网络方案,最后给出了该方案的具体构建方法。  相似文献   

认知隐喻学视域下的二语词汇习得研究     

吴胜伟 《河西学院学报》2013,(1):108-111

词汇是语言大厦的基石,传统的死记法导致词汇学习费时低效。词汇在语音、形态、语义和逻辑等方面存在着理据,化抽象为具体的认知隐喻学在词汇习得方面有着广阔的前景和用武之地,能够帮助学习者深入了解词汇的本源与实质,有助于提高二语词汇学习效果。  相似文献