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11.
桑叶提取物对DPPH自由基的清除能力研究 总被引：2，自引：0，他引：2
以超声波法对桑叶有效成分进行提取,得到Ⅰ、Ⅱ、Ⅲ共3个提取物,然后采用二苯代苦味酰肼自由基（DPPH·）法对提取物进行了自由基清除试验。结果表明：3个桑叶提取物对DPPH自由基均具有较好的自由基清除能力,这说明了桑叶可作为自由基清除物质资源开发利用。 相似文献
12.
We extend the Profit from Innovation (PFI) framework (Teece, 1986) by combining it with open innovation insights: we explore when and how managers make the transition between closed and open innovation, and how they use appropriation (formal and informal defense mechanisms) and project strategies to capture the value generated from the innovation at the project level. Based on a radical innovation project at Jaguar (UK), we contribute to a process and temporal perspective of open innovation by shedding light on two core project processes and their enabling mechanisms which influenced the ability of Jaguar to maximize profits from the innovation. The first core project process was the choice of timing of the shift from a closed to an open model of innovation: it was enabled by a pro-active change in the formal defense strategy (i.e. submission of a patent), and by an internal loose coupling project strategy that involved autonomy of the project champion and internal engineers’ weak membership in the project. The second core process was an external loose coupling project strategy that was enabled by the deployment of two complementary informal appropriation mechanisms namely, the reduction of the scope of tasks allocated to external partners combined with the development of guarded relationships with them. 相似文献
13.
主动组织遗忘对企业组织实现突破式创新具有重要意义。利用江浙沪皖地区268家企业的515份样本数据,以外部知识搜寻宽度作为中介变量,研究主动组织遗忘和突破式创新的关系。研究结果显示:主动组织遗忘的两个维度忘却学习和避免恶习均对突破式创新产生显著的正向影响;外部新旧知识的搜寻宽度在主动组织遗忘和突破式创新之间均起到部分中介作用。 相似文献
14.
Despite the significant role of radical innovation as a driver of firm growth and performance, the consequences of resource constraints for radical innovation outcomes remain unknown. Our paper addresses this gap. We combine arguments from entrepreneurship theory and the theory of recombinative innovation to construct an overarching theoretical framework that argues why resource constraints can promote, rather than impede, radical innovation. We then build hypotheses on two specific resource constraints, knowledge and financial, and test these by a lagged-variable random-effects Tobit model with longitudinal data from an exceptionally large and detailed innovation survey. Controlling for absorptive capacity, firm age, and firm growth, we find full support for the hypothesis that knowledge constraints spur radical innovation and partial support for the hypothesis that financial constraints spur radical innovation. We discuss the theoretical significance of these findings and point to managerial implications and paths for future research. 相似文献
15.
John C. Sherblom 《Communication Research Reports》2013,30(1):45-50
Significant differences are reported in the use of the personal pronouns — “I”, “WE”, “YOU”, and “THEY” — in the electronic mail sent among members within an organization, and the mail sent into the organization from other offices. The communication function of the mail also had a significant effect on pronoun use. 相似文献
16.
《Educational Philosophy and Theory》2013,45(5):490-506
In adult education there is always a problem of prefabricated and in many respect fixed opinions and views of the world. In this sense, I will argue, that the starting point of radical education should be in the destruction of these walls of belief that people build around themselves in order to feel safe. In this connection I will talk about ‘gentle shattering of identities’ as a problem and a method of radical education. When we as adult educators are trying to gently shatter these solidified identities and pre‐packed ways of being and acting in the world, we are moving in the field of questions that Sigmund Freud tackled with the concepts of ‘de‐personalization’ and ‘de‐realization’. These concepts raise the question about the possibility of at the same time believing that something is and at the same time having a fundamentally sceptical attitude towards this given. In my article I will ask, can we integrate the idea of learning in general with the idea of strangeness to oneself as a legitimate and sensible experiential point of departure for radical learning? 相似文献
17.
Sylvia Pantaleo 《Literacy》2007,41(1):16-25
Research has revealed how students draw upon other texts when writing their own texts. This article explores how the writing of Alyssa, a 10‐year‐old Grade 5 student, was influenced by her engagement with literature with Radical Change characteristics, as well as by her knowledge of and experience with other texts. Dresang's Radical Change taxonomy is used as a framework for analysing the storybook created by Alyssa. The article concludes with discussions of the intertextual nature of the literature used in the study, and the social nature of intertextuality in the research classroom. 相似文献
18.
Kenneth Tobin 《Cultural Studies of Science Education》2007,2(3):529-538
This article reviews the significance of the contributions of Ernst von Glasersfeld to research in science education, especially
through his theoretical contributions on radical constructivism. As a field shaper, Glasersfeld’s subversive ideas catalyzed
debate in the science education community and fuelled transformation of many facets including research methods, ways of thinking
about teaching and learning, curriculum, and science teacher education. Perturbations emanating from the debates on constructivism
forged new pathways that led to the development and use of many of the sociocultural frameworks employed by authors in Cultural
Studies of Science Education.
Kenneth Tobin is Presidential Professor of Urban Education at the Graduate Center of City College. In 2004 Tobin was recognized by the National Science Foundation as a Distinguished Teaching Scholar and by the Association for the Education of Teachers of Science as Outstanding Science Teacher Educator of the Year. Prior to commencing a career as a teacher educator, Tobin taught high school science and mathematics in Australia and was involved in curriculum design. His research interests are focused on the teaching and learning of science in urban schools, which involve mainly African American students living in conditions of poverty. A parallel program of research focuses on coteaching as a way of learning to teach in urban high schools. Recently Tobin published a book with Wolff-Michael Roth entitled Teaching to learn: A view from the field and edited two volumes entitled The culture of science education: Its history in person and Science, learning, and identity: Sociocultural and cultural-historical perspectives. In 2006 Tobin edited Teaching and learning science: A handbook. 相似文献
| Kenneth TobinEmail: |
Kenneth Tobin is Presidential Professor of Urban Education at the Graduate Center of City College. In 2004 Tobin was recognized by the National Science Foundation as a Distinguished Teaching Scholar and by the Association for the Education of Teachers of Science as Outstanding Science Teacher Educator of the Year. Prior to commencing a career as a teacher educator, Tobin taught high school science and mathematics in Australia and was involved in curriculum design. His research interests are focused on the teaching and learning of science in urban schools, which involve mainly African American students living in conditions of poverty. A parallel program of research focuses on coteaching as a way of learning to teach in urban high schools. Recently Tobin published a book with Wolff-Michael Roth entitled Teaching to learn: A view from the field and edited two volumes entitled The culture of science education: Its history in person and Science, learning, and identity: Sociocultural and cultural-historical perspectives. In 2006 Tobin edited Teaching and learning science: A handbook. 相似文献
19.
有氧训练及热应激对运动大鼠肾脏组织NO、NOS及自由基代谢的影响 总被引：2，自引：0，他引：2
目的：探讨有氧耐力训练对运动热应激大鼠肾脏组织NO、NOS及自由基代谢的影响。方法：对大鼠进行为期6w的递增负荷运动训练，并在运动末次施加热应激，测定大鼠肾脏组织NO、NOS、MDA和SOD含量或活性。结果：（1）运动加热应激使大鼠肾脏组织NO、NOS、iNOS和MDA显著高于安静组和急性运动组，SOD和SOD／MDA显著低于安静组和急性运动组；（2）训练安静组与安静对照组相比，MDA均显著下降，NO、NOS均显著上升；（3）训练后运动热应激大鼠肾脏组织NO、NOS、iNOS、MDA显著下降，SOD显著上升。结论：（1）在热环境下运动，机体NO、NOS和自由基代谢增加，抗氧化酶活性下降；（2）在常温下进行有氧耐力训练练，可以适当提高机体的耐热性，降低运动热应激对机体的损伤。 相似文献
20.
本文综述了影响肺组织自由基代谢的三方面因素 ,以及自由基代谢发生改变时 ,肺组织形态结构的变化 相似文献