基于简化相分量法的低压配电网线损量化分析

本文提出了低压配电网的简单相间去耦的相分量法。本文又提出了考虑无功功率的线损简化计算方法,使得线损计算更加准确,并且便于无功补偿的分析。     

Components of Conceptual Ecologies

The theory of conceptual change is criticized because it focuses only on supposed underlying logical structures and rational process processes, and lacks attention to affective aspects as well as motivational constructs in students’ learning science. This is a vast underestimation of the complexity and diversity of one’s change of conceptions. The notion of conceptual ecology provides a context for understanding individuals’ conceptual change learning, as it is the environment through which all information is interpreted. This research investigated how high school students’ statements, made in answering questions, reflect selected components of their conceptual ecologies. Data for this study was collected from six interviews in which seven students took part. The data also include the science teacher’s profiles of each student, the students’ personal journals, their assignments, and their examinations and answers in class. The analysis presented will here include only those components that were represented in the discourse of the seven high school students who were interviewed. When students were asked questions, there was evidence of the engagement of the various components of conceptual ecologies. These components include: epistemological commitments, metaphysical beliefs, the affective domain and emotional aspects, the nature of knowledge, the nature of learning, the nature of conceptions, and past experience. Evidence from this study suggests that these components might function as constraints to learning. This study contributes to the field by expanding our knowledge of the components of high school students’ conceptual ecologies through its definition of the categories and themes associated with those components. In examining across the range of components, the study illustrates the variety and sources of science conceptions within high school students’ conceptual ecologies.     

部首刍议

部首主要用于给汉字分类，从古至今，部首经历了三个发展阶段，由《说文解字》至《字汇》为第一阶段，这一时期的部首主要指出汉字的意义所属，凡是属于同一意义范畴的字归在同一部首；由《字汇》至《康熙字典》为第二阶段，这一时期的部首既重视表意。又注意到表形，凡是属于同一意义范畴的字，形体偏旁相同的排列在一起；由《康熙字典》至今为第三个阶段，这一时期的部首偏重汉字的形体，主要是为了人们检字方便，只要是具有共同形体偏旁的字即使不属同一意义范畴也归在同一部首。     

数学学院学生评教问卷的一种新设计

及时反馈学生对课程设置、对教师教学效果的评价是十分重要的，它对改进教学工作，优化课程设置具有不可替代的作用。学生评教问卷应做到各项指标明确、具体，每项评价等级可分为7等，应将其尽可能转换为便于学生操作的“语义”。指标体系应尽可能设计得统计不相关。以简化问卷。     

现代电力电子器件的现状与发展浅析

简单回顾了电力电子技术及电力电子器件的发展过程,介绍了IGBT,IGCT,IPEM等主流现代电力电子器件的工作原理、现状和发展动态,探讨了新型材料电力电子器件及其发展方向.     

佛山市顺德区人才环境评价与分析

一个国家或地区对人才是否具有吸引力,起决定作用的往往不是物质条件,而是人才发展环境。综合考虑影响人才环境的各个要素,在人才理论和实践相结合的基础上,构建了人才环境评价指标体系,运用主成分分析法对顺德区的人才环境进行定量化研究,用具体的数字来刻画顺德区人才发展环境。     

基于小波去噪的快速定点ICA及其在振源识别中的应用

在多源激励情况下,从传感器阵列输出的高维响应中分离、识别不同振源的性质,对于大型结构振动分析以及对其状态监测与健康评价有着重要的意义.本文结合大型结构振动的性质,介绍了小波阈值去噪原理,使用其改进的快速定点算法实现了多源激励情况下振源信息分离的方法.文中通过实例给出了这种方法的应用效果.     

后浇带造成的临时悬挑构件在施工中的问题

在现代建筑施工中，为了解决混凝土收缩、不均匀沉降等问题往往设置了后浇带。而后浇带的设置使得通过此位置的连续梁、板构件变为悬挑构件。施工人员在施工期间如何处理这些构件的问题上常存在着一些误解。本文在总结以往实践经验的基础上，提出了处理这一问题的新的方法和程序。     

一种新的BP神经网络人脸识别方法研究

BP神经网络在人脸识别方面的研究中,原始样本数据不进行预处理与特征提取,不仅使识别结果准确降低,而且使BP神经的结构复杂化.主成分分析法能提取代替样本的少数几个主成分,这些主成分彼此不相关,符合特征优化的要求.在BioID人脸数据库实验表明,将主成分分析与BP神经网络相结合,与传统单一的BP神经网络识别相比,能够提高识别的正确率,减少训练时间,同时简化网络结构,减少很大的计算量.     

贵义·尚贤·尚同·尚力·崇俭——墨子理想社会的构成要素

墨子在救治社会的基础上提出了理想社会的重要构成要素。贵义是重视治国的基本道德规范,反映了民众对社会正当行为的渴望;尚贤主张用人制度以能力为本位,尚同侧重讲按照"天志"来统一全国思想与行动,二者是治政之根本;尚力重视分工合作,各尽所能、各得其所;节俭体现了生活用度的合理安排,这一原则在日常消费中表现为"节用"、"节葬"、"非乐"等。墨子这些思想对于我们当前社会建设仍具有启发意义。