排序方式： 共有36条查询结果，搜索用时 15 毫秒
1.
The young field of neuroeconomics converges around behavioral deviations from the model of the human being as Homo economicus, a rational actor who calculates his choices to maximize his individual satisfaction. In a historical moment characterized by economic, health, and environmental crises, policymakers have become increasingly concerned about a particular deviation for which neuroeconomics offers a biological explanation: Why do humans value the present at the expense of the future? There is contentious debate within the field over how to model this tendency at the neural level. Should the brain be conceptualized as a unified decision-making apparatus, or as the site of conflict between an impetuous limbic system at perpetual odds with its deliberate and provident overseer in the prefrontal cortex? Scientific debates over choice-making in the brain, we argue, are also debates over how to define the constraints on human reason with which regulative strategies must contend. Drawing on ethnographic and archival research, we explore how the brain and its treatment of the future become the contested terrain for distinct visions of governmental intervention into problems of human choice-making. 相似文献
2.
In most transistors which are useful to engineering, densities of electrons and holes are low enough so that random energies have the classical Maxwell-Boltzmann distribution. Also, the customary large ratios of majority-to-minority carrier densities result in majority-carrier flow occurring in response to electric gradients, and minority-carrier flow by diffusion due to concentration gradients. Steps using these principles to derive junction transistor volt-ampere characteristic equations are: 1) interface contact potential determination, 2) expression of emitter and collector currents in terms of random-motion interface penetration, 3) boundary-value solution of the diffusion-flow differential equation, to give minority-carrier density distributions, 4) expression of currents in terms of at-interface density distribution gradients, 5) elimination of at-interface minority-carrier densities between 2) and 4), giving the Ebers and Moll volt-ampere equations. These equations show how base thickness, diffusion lengths, and relative majority carrier densities in emitter, base, and collector affect the characteristics. The residual collector current is found to be a measure of electron-hole pair generation. The relation of this current to surface energy states, and to the associated double layer of charge at and near the surface, is discussed. 相似文献
3.
4.
We draw on theories of policy enactment to explore the ways in which the situated, material and external contexts and professional cultures in adult literacy in the UK have influenced practitioners. Our analysis of the transnational (OECD, EU) and UK external policy contexts found that skills-related education is prioritised, with a focus on economic growth through increased productivity and accountability. This can lead to a narrow conceptualisation of literacy as a set of information processing skills needed for employment that limits the curriculum so that the knowledge of the participants is ignored. However, our findings show that there is not a one-way flow from the transnational to the local. Instead, literacy practitioners translate and enact policy texts based on their situated contexts and professional cultures leading to approaches to teaching and learning that keep learners and their goals at the centre of the curriculum. We conclude that shared understandings of good practice and an underpinning value system, along with creative ways of delivering pre-set outcomes, allow practitioners to resist to some extent the neoliberal discourse whilst meeting the requirements of policy and funding. However, how feasible delivering this alternative curriculum is over the longer term remains to be seen. 相似文献
5.
Gwyneth Hughes 《Learning, Media and Technology》2009,34(4):291-305
Enthusiasts for new social software do not always acknowledge that belonging to e‐learning communities depends upon complex and often unresolved identity issues for learners. Drawing on the author’s previous research on belonging in social learning, the paper presents a theory of identity congruence in social learning and brings to the foreground the importance of identities which arise from expressions of gender, class, ethnicity, age, etc. in the social, operational and, in particular, the knowledge‐building aspects of learning. These three dimensions of identity congruence are used to evaluate the potential of new social software. While social software might encourage some learners to engage in social and operational identity work, there are disadvantages for others, and learner‐generated knowledge and e‐assessment practices can be divisive. Inclusive e‐learning depends upon pedagogies and assessments which enable learners to shift and transform identities, and not solely on widening the range of technologies available. Such caution should underpin future research. 相似文献
6.
7.
Marguerite R. Dow 《Peabody Journal of Education》2013,88(2):122-126
In light of the 50th anniversary of the Brown v. Board of Education (1954) ruling, this article focuses on how the majority opinion in Brown set a precedent for the use of social science research in defining and examining inequity in education. This article argues that following Brown, social science research has gained prominence in its social function in shaping the debate in equal educational opportunity. Whereas Brown introduced racial desegregation in the governmental agenda, social science research since the 1960s has sustained the societal concerns on the challenge of inequality. This article examines how the use of social science research in Equality of Educational Opportunity (J. S. Coleman et al., 1966), an extensive study of schools and schooling under the direction of James Coleman of Johns Hopkins University and Ernest Campbell of Vanderbilt University during the mid 1960s, shaped the course of education research and policy toward the notion of equal educational opportunities. Further, this article discusses the more recent work of William Julius Wilson (1987) that shifts the equality of opportunity debate out of the courts and from individual and group opportunities to the equality of life chances. 相似文献
8.
Dow SC 《Medical reference services quarterly》1990,9(3):31-41
The development of user-friendly search systems has enabled physicians to perform their own MEDLINE searches These physicians are recognizing a need to learn how to organize their growing reprint collections. Librarians at the University of Michigan, Alfred Taubman Medical Library have developed a unique course that presents a variety of techniques to meet the needs of a wide audience. For some users, such as students or house officers who have limited funds or lack support devices, a variety of manual methods are presented. Advantages and disadvantages of using manual versus computerized systems are discussed. Following the illustration of the manual methods, users are introduced to a simple computerized method using a utility type database management package, PC-FILE. Hands-on training under the direction of librarians allows students to develop and use a practice database while having experts available to answer questions. Users are encouraged to take a copy of PC-FILE (shareware) with them to experiment with before committing themselves to a more expensive database management software package. Before the class ends, those interested in a more sophisticated package with specialized report formats and downloading/uploading capabilities are given a brief demonstration of PRO-CITE. Evaluations have shown that there is interest in all three methods. 相似文献
9.
10.