无线传感器网络节点的物理层设计

比较和分析了无线传感器网络节点物理层设计的各种无线通信技术、现有的成熟标准、重要的射频参数以及不同的处理器方案,对节点物理层设计的各个主要方面进行了较为全面的研究.介绍了无线传感器网络节点的一种实现,给出了相关的测试数据以及一种“单处理器双工作频率”的新节能策略.分析了符合传感器网络MAC算法中节点周期性侦听要求的节点寿命估算问题.指出无线传感器网络节点物理层设计的关键考虑因素为:RF启动时间(决定MAC协议可以实现的最佳节点睡眠时间比例和最小的退避时间颗粒)、RF载波频率和调制方式(决定射频收发功耗)以及处理器工作在2个频率的片上系统的总体功耗.     

一水邻苯二甲酸钙的热分解及其脱水动力学分析

采用TG-DTA分析研究了一水邻苯二甲酸钙热分解过程,对其中的脱水过程进行了动力学计算. 由Friedman和Ozawa-Flynn-Friedman法得到脱水过程的活化能和指前因子,用Archar方法计算拟合了几种机理函数,确定了脱水过程的优化动力学参数及最佳机理模型. 脱水过程的活化能Ea为141.1576 kJ/mol,反应的机理模型为Bna,即f(α) =(1-α)n*αn.     

儒家恕道与中国古代法律文化

儒家恕道与中国古代法律化传统有着内在的不可分割的密切联系，使中国传统法律化表现出鲜明独特的公法化的个性特征。本从恕道的渊源、内涵及法化品性入手，阐述了其对于中国古代法律化的影响，并剖析了恕道、法律化传统与现实的关系。     

动物医学专业形态学实验教学模式改革初探

动物医学专业形态学实验教学是动物医学本科教学体系的重要组成部分,为了提高实验教学效果,对形态学实验教学模式进行了改革:将动物解剖学、组织胚胎学和病理学的实验内容划分为基本实验项目模块和形态学综合实验模块,通过实验课程内容的整合,减少了实验内容的重复率,加大了学科内容知识点的联系,增加了综合性实验和研究性实验内容.问卷调查显示,本次所进行的动物形态学实验教学模式改革取得了较好的效果.     

Forming shared inquiry structures to support knowledge building in a grade 5 community

This study explores the reflective processes by which a grade 5 science community co-constructed shared inquiry structures to focus and guide its inquiry about human body systems over a school year supported by a collaborative online environment. The co-constructed structures included a list of collective wondering areas as the shared focus of inquiry and models of the inquiry process in the form of “research cycle.” Qualitative analyses of field notes, classroom videos, student notebooks and interviews elaborate the evolution of the inquiry areas and the “research cycle” model as well as students’ adaptive use of the structures to guide deeper inquiry. Content analyses of students’ individual research questions and collaborative online discourse indicate that students used the structures to develop more advanced inquiry and make productive contributions. The results contribute to elaborating a reflective structuration approach to co-organizing and sustaining long-term, open-ended inquiry in knowledge building communities.     

美国中考试题的特点及其对中国的启示

本文通过分析美国的中考试题,阐述了试题中的几个特点并提出了对中国中考改革的几点启示.     

Fuzzy Comprehensive Assessment Method to Determine Tectonic Stress Patterns

The tectonic stress patterns were determined by a fuzzy comprehensive assessment method. Data of in-situ survey and fault information were utilized in the method. First, by making pressure and tension in the directions of along-river, cross-river, shear clockwise, and shear counterclockwise , 26 types of tectonic stress patterns were presented. And the stress vector of each pattern was obtained with FE software by taking unit displacement as boundary load. Then, by taking the 26 types of tectonic stress patterns as index set and 3 main stresses as factor set and choosing various operators, comparison of directions of computational stress vector and survey stress vector was made and the most possible tectonic stress pattern was obtained. Taking the 26 types of tectonic stress patterns as index set and strike angle as factor set, comparison of relationships between formation of fault and tectonic stress was made,and the tectonic stress patterns were assessed with known fault information. By summarizing the above assessment results, the most impossible tectonic stress pattern was obtained . Finally an engineering case was quoted to validate that the method is more feasible and reliable than traditional empirical method.     

从语用角度分析英汉复数第一人称指示语

人称代词是我们很熟悉的一种语言现象 ,但人称代词的所指和用法并不象所定义的那样简单 ,那样明确 ,有时会出现一些从语义上看似乎是异常的现象 ,这些现象只能从语用的角度借助语境去解释。     

远程开放教育学习者特征分析与元认知能力构建

如何在大规模的远程开放教育中培养学习者的元认知能力,教会学习者如何学习,是远程开放教育领域日益关注的问题.文章首先阐述了远程开放教育学习者构建元认知能力的必要性,然后对开放教育学习者特征数据进行分析,试图针对学习者的特征找到提升元认知能力的策略,从而更好地提升教育教学质量.     

父权文化与女性形象及当代女性解放

人类进入私有制后，在传统的父权文化的统治下，女性的形象受到丑化和弱化。新中国的建立使中国女性得到了巨大的解放。可以说，没有妇女的解放就没有全人类的解放，妇女问题的解决和妇女解放程度的提高是人类文明进步的更高标志。