知识经济时代企业管理变革的六大趋势

知识经济的到来,必将引起企业管理发生一系列的变革以与其相适应.文章浅析了企业管理变革的六大趋势.     

不定形耐火材料的制备技术与应用技术走向

2.4作业性能由于在不定形耐火材料中引入了超细粉,尤其是无定形、球状的氧化硅超细粉,同时采用了人工加工后的粒形(改变了自然颗粒形状,由片状、棱柱状、针状等形状加工成近等轴球状)和合理的粒度级配,不定形耐火材料的作业性能,尤其是耐火浇注料的作业性能发生了很大变化.……     

不定形耐火材料的制备技术与应用技术走向

1引言 　　不定形耐火材料的制备技术与应用技术近一、二十年来取得了很大的进展,使得不定形耐火材料的综合使用效果(如劳动生产率、施工效率、适应性、节能、使用寿命等)超过定形耐火制品.同时,应用领域也由低、中温气氛炉向高温熔炼炉扩展,导致工业窑炉,尤其是冶金工业熔炼炉的日常消耗性耐火材料中,定形耐火制品大部分被不定形耐火材料取代.可以说,现代不定形耐火材料的应用范围已今非昔比. 　　……     

Conceptions of geological time among primary teacher trainees,with reference to their engagement with geoscience,history, and science

People's grasp of geological time is under-researched, despite attention being devoted to the philosophy of time. Research carried out with 179 pre-service primary teachers suggests they perceive events in Earth's geological past as falling into three distinct clusters: extremely ancient, less ancient and geologically recent. Respondents' grasp of relative time is more secure than their grasp of absolute time and instruments which address absolute time generate less conclusive evidence than do those requiring simple sequencing. Trainee teachers vary in their geoscience interests and classroom experiences and are more comfortable and imaginative with their teaching of history than with their geology, despite the parallels. In order to render more secure people's learning of geoscience concepts and processes, a deep time framework is needed for each learner, individualized to accommodate learner characteristics and local geoscience features.     

Deep time framework: A preliminary study of U.K. primary teachers' conceptions of geological time and perceptions of geoscience

As part of a continuing research program on the understanding of geological time (deep time) across society, a total of 51 in‐service teachers of 7‐ to 11‐year‐old children was studied in relation to their orientations toward geoscience phenomena in general and deep time in particular. The first purpose of the research was to identify the nature of idiosyncratic conceptions of deep time: a cognitive deep time framework of pivotal geo‐events. The second was to propose a curricular Deep Time Framework that may form the basis for constructivist approaches to in‐service and pre‐service teacher training which places deep time center stage. Three research questions were posed, addressing: (1) perceptions of geoscience phenomena and teachers' actual encounters with these in the classroom; (2) conceptions of deep time; and (3) approaches to teaching two curriculum areas (history and geology) which involve the interpretation of material evidence to reconstruct the past. Results enable the selection of 20 geoscience phenomena to be located in relation to teachers' interests and classroom encounters, those of high interest and high encounters being proposed as pivotal areas for further attention in teacher training. Results also reveal that in‐service teachers conceive events in the geological past (geo‐events) as having occurred in three distinct clusters: extremely ancient; moderately ancient; and less ancient. Within each category there is a strong lack of consensus on time‐of‐occurrence. Results suggest that primary teachers exhibit greater imagination in their teaching of history compared with geology and that aspects of deep time and past environments are not perceived as being of any great significance in the interpretation of geological specimens. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 191–221, 2001     

An investigation into understanding of geological time among 10‐ and 11‐year‐old children

This research focused on the understanding of geological time among UK children aged 10 and 11 years. The empirical study, in two stages, involved a total of 189 children in activities designed to reveal knowledge and understanding of geological time. The preliminary study with 12 children was designed to identify the most powerful and appropriate techniques to use in the Main Study. It also resulted in some findings concerned with the place of deep time in children's conceptualization of Earth events. The Main Study, with 177 children, involved the sequencing of geological events in three separate but almost identical tasks. Results indicate that children of this age have a general awareness of major events such as the Ice Age and moving continents, but that a clear chronology is almost entirely lacking. Children conceive of events as falling into two distinct time zones: the ‘extremely ancient’ and the ‘less ancient’.     

滇池污染现状、趋势及其综合防治对策

近年来滇池草海属异常富营养化水体,外海属富营养化水体,水中TN比TP增加快.以至于滇池水质污染程度在短短十多年时间已上升了一个台阶.应从污染源治理和控制、内源综合治理、水污染防治管理和法制建设等方面采取综合防治对策.     

Gender‐related consequences of early school transfer at 11+ years

A unique early transfer scheme is described for one English secondary school and its eight feeder primary schools whereby all Year 6 children transfer to secondary school four weeks before the end of the summer term. The scheme has many implications. The main focus here comprises gender contrasts in children’s perceptions of school life and curriculum subjects. Questionnaires were administered to all children before and after the four‐week induction period, in 2004 and 2005. Prior to transfer, there were few gender differences in anxiety and in perceptions of curriculum subjects. Girls expressed higher levels of general anxiety and subject‐oriented worry than did boys at most stages, although the gender contrast diminished in 2005. PE alone generated a relative increase in anxiety among girls during the induction period, arising from a greater improvement among boys set against a modest improvement among girls. The induction period enhanced gender differences in perceptions of subject ‘usefulness’.     

Interpreting Primary Children's Representations of Mountains and Mountainous Landscapes and Environments

This paper reports research into children's understanding of mountainous landscapes and mountain genesis as revealed in their drawing and modelling representations and in subsequent interviews. A sample of 444 children aged 7‐11 years was drawn from five UK inner-city schools. Comparisons between the younger (7‐9 years) and older (9‐11 years) children showed significant differences in perception, conception and priorities. The naive interpretation of children's drawings and models is questioned: interview data indicated that children use sophisticated techniques to represent mountains and mountain environments. Children are able to interpret stereotypical representations of mountain landscape features they encounter in books and elsewhere. They make use of a range of conventions in their own drawings that are revealed only in subsequent interviews. Research based solely on the interpretation of children's pictures is shown to be problematic and somewhat unreliable. Children perceive the differences between reality and pictorial representation and make full and conscious use of the range of conventions, including stereotypical forms.