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61.
This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow
through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction
by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional.
The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature
field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs. 相似文献
62.
63.
NICHD Early Child Care Research Network 《Early education and development》2007,18(2):337-368
Research Findings: Data on more than 900 children participating in the National Institute of Child Health and Human Development Study of Early Child Care were analyzed to examine the effect of age of entry to kindergarten on children's functioning in early elementary school. Children's academic achievement and socioemotional development were measured repeatedly from the age of 54 months through 3rd grade. With family background factors and experience in child care in the first 54 months of life controlled, hierarchical linear modeling (growth curve) analysis revealed that children who entered kindergarten at younger ages had higher (estimated) scores in kindergarten on the Woodcock—Johnson (W-J) Letter-Word Recognition subtest but received lower ratings from kindergarten teachers on Language and Literacy and Mathematical Thinking scales. Furthermore, children who entered kindergarten at older ages evinced greater increases over time on 4 W-J subtests (i.e., Letter-Word Recognition, Applied Problems, Memory for Sentences, Picture Vocabulary) and outperformed children who started kindergarten at younger ages on 2 W-J subtests in 3rd grade (i.e., Applied Problems, Picture Vocabulary). Age of entry proved unrelated to socioemotional functioning.
Practice: The fact that age-of-entry effects were small in magnitude and dwarfed by other aspects of children's family and child care experiences suggests that age at starting school should not be regarded as a major determinant of children's school achievement, but that it may merit consideration in context with other probably more important factors (e.g., child's behavior and abilities). 相似文献
Practice: The fact that age-of-entry effects were small in magnitude and dwarfed by other aspects of children's family and child care experiences suggests that age at starting school should not be regarded as a major determinant of children's school achievement, but that it may merit consideration in context with other probably more important factors (e.g., child's behavior and abilities). 相似文献
64.
This article examines the historical fantasy world created by Joan Aiken in the eleven volumes of her Wolves of Willoughby Chase series. In particular it looks at her subversion of historical reality by the creation of an alternative yet recognisable representation of our own world, using a wide range of events, and the remoulding of aspects of language and geography. It also discusses her reasons for writing in this form and explores the character of Dido Twite as heroine and major raison dtre of the series.This revised version was published online in May 2005 with corrections to the article title. 相似文献
65.
The exploratory study focused on describing typical routines of preparing for winter outdoor play with preschool children
and their teachers. Naturalistic observations, interviews and photographs resulted in extensive examples of children’s development
in cognitive understanding of winter and winter-related concepts. Observations of teachers and assistants revealed task-oriented
perspectives including detailed strategies and planning. Asynchronous communication and directive language were typical of
teacher/child communication. Photo analyses confirmed physical skills used by preschoolers to accomplish dressing tasks and
extensive curricular changes to indoor environments. 相似文献
66.
This article focuses on educational enterprises outside the formal sector, such as museums, botanical gardens and interactive
science centres. International research is drawn on to illuminate how design, culture, educational strategies and settings
combine to affect the way in which young people respond to experiences on offer, leading to analysis of the impact of such
settings in promoting learning, and the likely implications for those who staff such venues. Aikenhead’s concept of the educator
as ‘culture broker’ is developed to suggest ways in which learning might be best supported. It envisages a shift from ‘delivery’
strategies targeted at large groups towards approaches which focus on what learners choose to know about using dialogue between
children and ‘known and trusted people’. Analysis of observed responses in various settings is undertaken from a sociocultural
perspective using the notion of communities of practice. Implications for the roles of education managers and their staff
in further research are developed. 相似文献
67.
Formal models for service composition have been proposed with the variation of the requirements of service developers. Some
famous models have provided checking and verification techniques and tools for the behavior of service composition. These
models generally focus much on the message flow of web services and neglecting the data contained in the exchanged messages
among services, which restrict the application range of these models and also the web service techniques. As new kind of services
with different protocols and communication methods have appeared, it is needed to model service composition from a new view
which is adapted to the new development in service area. In this paper we offer a function oriented model of service composition
which treats the composite service as a software system and specify the function of services which can be directly used to
the realization by service providers. 相似文献
68.
The author articulates key stressors in the lives of families who are homeless. These stresses often combine with barriers such as lack of job opportunities and/or insensitive professionals. Strategies for helping homeless families overcome these barriers and related issues are presented. 相似文献
69.
用法治理性建构校园和谐 总被引:7,自引:0,他引:7
建设校园和谐关系,以法治理性的价值判断和价值选择审视并优化校园环境,是坚持以人为本、以民主法治原则建设校园和谐关系的关键所在。以民主法治原则构建现代校园和谐关系是法治理性的基本要求;尊重人权是法治理性的真谛;校园和谐需要法治理性的宽容精神;法治理性包含对法制的敬畏和行使自由权利的节制;校园和谐关系呼唤体现法治理性的校园文化。学校教育通过尊重和保护青年学生的正当权利并使其自觉践行义务的过程,使他们长期浸润在崇尚法治的文化氛围里,培养并形成他们未来人生中自觉的、理性的遵纪守法和护法精神。 相似文献
70.
Pigeons' keypecking was reinforced by food on baseline schedules of multiple variable interval (VI) x VI x and on contrast schedules of multiple VI x VI y. Deprivation of food was varied by maintaining subjects at 75%, 85%, and 95% (+/- 2%) of their free-feeding weights. Positive and negative behavioral contrast were observed. The size of the contrast was not systematically altered by changes in deprivation. Positive and negative contrast were both larger later in the session than they were earlier. Within-session decreases in responding were steeper for the baseline than for the contrast schedules for positive contrast. Within-session decreases were steeper for the contrast than for the baseline schedules for negative contrast. These results were predicted by the idea that different amounts of habituation to the reinforcer during the baseline and contrast schedules contribute to behavioral contrast. The results show that contrast occurs under conditions that reduce the effect of the following component. The results support the assumption that positive and negative contrast are produced by symmetrical theoretical variables. 相似文献