轴流泵叶片的水动力性能研究

根据叶片绕流理论,用保角变换和级数展开的方法推导出由变换系数表示的叶片表面的速度分布,给出了轴流泵可调叶片的水动力矩数学模型及可靠性分析。最后,对某泵可调叶片的水动力矩进行了计算。研究表明,方法是可靠的,结果令人满意。     

Communicating data to schools

The article explores the communication of data to schools by researchers and evaluators. The stance is taken that the research process is one in which the participants are involved in a mutually supportive enterprise in which the relationship should be viewed as co-operation between professional colleagues, i.e., a relationship in which perceived status is minimised but one in which different knowledge and expertise exists on both sides. It is argued that the obtaining of data at school sites requires the researcher to provide data to their sources. Careful consideration needs to be given by researchers to the process and methods of communication of data to school communities. Issues addressed include audience, terminology, prose and other forms of presentation. A case is made for the researcher to become involved in dialogue to enhance the “meaning-making” of practitioners and themselves. The article concludes with a set of guidelines for researchers.     

Assessment of Teacher Reactions to a Standards-Based Teacher Evaluation System: A Pilot Study*

This article reports on teachers' reactions to a pilot implementation of a new standards-based teacher evaluation system in a medium-sized Midwestern school district. The system, based on the Framework for Teaching (Danielson, 1996), was intended to serve as the foundation for a new knowledge and skill pay plan for teachers. Teacher reactions were measured using both interview and survey methods. Teachers' overall favorableness toward the system, as measured by the survey, was correlated with acceptance of the teaching standards, perception of the evaluation process as fair and the evaluator as capable and objective, and perception that the evaluation system had a positive impact on their teaching. In interviews, teachers perceived both positive and negative aspects of the system, and for many these more or less balanced each other. While most teachers accepted the evaluation standards and the need for an evaluation system, many also perceived that the system added too much to teachers' workloads and did not provide enough feedback. Based on these results several changes were made in the evaluation system prior to full implementation. The results are discussed with reference to previous research and the Personnel Evaluation Standards.     

Bullying and the Unique Socioemotional Needs of Gifted and Talented Early Adolescents: Veteran Teacher Perspectives and Practices

Much is written at the elementary school level concerning bullying and the socioemotional needs of gifted and talented (GT) students; however, in the last 10 years, little qualitative research exists concerning the early adolescent GT age group. In the social environment of classroom life, early and current research indicates that many of these students experience neurotic perfectionism, overexciteabilities (OEs), developmental asynchrony, and bullying. The formation of autonomous classes (GT-only classes) has afforded some hope concerning the amelioration of such problems; nevertheless, in this study, detailed evidence of classroom bullying in the form of social ostracism and teasing has been found with this GT age group. If left unchecked, psychological autopsies have shown these students suffering emotional difficulties and even committing suicide as a result of school and classroom torment. With such potential for classroom bullying problems, few studies address what veteran teachers of early adolescent GT students do to keep students psychologically safe. Within the social milieu of classroom life, and in comparison to research standards, this study explores three efficacious teacher perspectives and practices.     

THE ROLE OF RELIABILITY IN CRITERION-REFERENCED TESTS

In discussion of the properties of criterion-referenced tests, it is often assumed that traditional reliability indices, particularly those based on internal consistency, are not relevant. However, if the measurement errors involved in using an individual's observed score on a criterion-referenced test to estimate his or her universe scores on a domain of items are compared to errors of an a priori procedure that assigns the same universe score (the mean observed test score) to all persons, the test-based procedure is found to improve the accuracy of universe score estimates only if the test reliability is above 0.5. This suggests that criterion-referenced tests with low reliabilities generally will have limited use in estimating universe scores on domains of items.     

薄膜结构最优化裁剪分析

用最优化理论提出一种新的薄膜结构裁剪方法，并用Ｂ样条曲线对裁剪图边界进行光滑处理，提高了裁剪分析的精度．最后给出了一个张拉式薄膜结构裁剪分析实例．