非齐次特征值的包含域及其推广

非齐次特征值问题在数学及其它领域有广泛的应用,本文给出了有关非齐次特征值问题的一些相关结论,并将这些相关的结论推广到非齐次块特征值问题,给出了一类特殊矩阵——块不可约阵的特征值包含域.     

非齐次块特征值的另一类包含域

非齐次特征值问题在数学和其它领域有许多应用，如线性方程组的稳定性研究，约束特征值问题等。本文将非齐次特征值问题进行了推广，并给出非齐次块特征值的另一类包含域。     

大型实对称特征值问题的块Jacobi-Davidson方法的不精确求解

块Jacobi—Davidson方法是计算大型实对称矩阵特征值问题的有效方法,可解决矩阵存在重特征值和密集特征值情况时的计算问题．块Jacboi—Davidson算法分为内外两层迭代,外层迭代计算矩阵特征对,内层迭代求解校正方程组,计算量主要花费是校正方程组的求解．针对校正方程的不精确求解,提出了几种构造预条件子的块不完全分解方法,并通过数值试验,对多种预条件子的效果进行比较．     

基于语料库的汉语“语块”识别初步探索

英语界和对外汉语界分别对语块的性质和类型做了有益的探索,这些研究增强了二语教材工具书编写者的语块意识,但在实际操作中更多依赖于编写者个人语感,原因在于现有研究对于语块的界定缺乏操作性.本文认为语块的识别必须基于语料库才能观察到语块各个成分的组合性质和语块的使用频率,并对汉语“语块”识别的操作原则和操作方法做了初步的探索.     

一类2×2块矩阵的特征值与特征向量分布

特征值问题在数学与工程应用中有着重要的现实意义。着重研究一类特殊的对称不定2×2块矩阵的特征值问题,充分利用其结构的特殊性,结合奇异值分解,推导出这类矩阵特征值与特征向量分布。     

块拟对角占优矩阵的几个充分条件及其应用

应用块拟对角占优矩阵的几个充分条件,研究块α-二重几何平均对角占优矩阵的非奇异性,特征值分布及以这类矩阵为系数矩阵的线性方程组的Jacobi迭代解法的收敛性等问题。     

预制语块的提取效应优势

预制语块是语言中的词汇语法单位,是英语中的一种特殊的多词汇现象.本文从预制语块的概念出发概括了预制语块的某些特征,同时结合影响心理词汇提取的因素首次阐述了预制语块所具有的词频、语义与语境效应优势,最后简要论述其对二语词块教学的启示.     

从行为主义理论重看预制语块

近年来,预制语块愈来愈受到语言学界与教学界的关注,人们也对预制语块特殊的语言形式和特点进行了各类研究.行为主义虽受到了一些批判,但在特定领域它仍具有一席之地.本文从行为主义理论出发,从刺激--反应、习惯形成和归纳学习的角度,探求对预制语块的教学的指导作用.     

语块理论与语块教学

语块融合了语法、语义和语境的优势,具有特定的表达功能,可作为整体储存和提取。语块的掌握有助于言语产出的流利性和选词的地道性。二语习得研究发现,语块能力是二语综合能力的一个重要指标。把语块理论应用于目标语教学,能丰富应用语言学的学科理论。在实施语块教学法的课堂上,可通过输入、内化和输出等一系列教与学的活动,引导学生辨认、学习、使用语块,从而使学生掌握并熟练运用语块,提高应用目标语的能力。     

国内二语词块研究综述

近几年,有关词块的研究已经成为研究者们关注的一个重要的方面。该文就近十几年来发表在国内核心期刊上的有关二语词块的研究进行了总结和梳理,主要涉及有关词块研究的五个方面,即词块的定义、分类和功能,词块的使用;词块的识别与习得,词块与教学,词块与心理语言学,并指出当前研究中尚且存在的问题以及对今后在此领域的研究方向进行了展望。     

Block Talk: Spatial Language During Block Play

Spatial skills are a central component of intellect and show marked individual differences. There is evidence that variations in the spatial language young children hear, which directs their attention to important aspects of the spatial environment, may be one of the mechanisms that contributes to these differences. To investigate how play affects variations in language, parents and children were assigned to 1 of 3 conditions: free play with blocks, guided play, or play with preassembled structures (Study 1). Parents in the guided play condition produced significantly higher proportions of spatial talk than parents in the other two conditions, and children in the guided play condition produced significantly more spatial talk than those in the free play condition. Study 2 established baselines of spatial language during activities not involving spatial materials. Proportions of spatial words were lower than those in any of the conditions of Experiment 1. In sum, interaction with blocks naturally elicits elevated levels of spatial language, especially in the context of guided play, suggesting simple‐to‐execute educational interventions.     

To Block or Not To Block: That's Not the Question

Abstract

The block schedule emerged in the late 1980s as one structuring practice that allowed educators to address several problems associated with the traditional high school schedule. Among its posited advantages is the opportunity for teachers to engage students in active teaching strategies that require more time than the traditional schedule allows. Research on the use of teaching strategies in traditional and block schedule high schools is limited. Similarities and differences in survey responses of more than 2,000 teachers working in traditional- and block-schedule schools were described and analyzed in this study. In general, few differences were evident in opinions about level of use, appropriateness, and training for a variety of instruction approaches.     

几类分块矩阵的行列式

利用Laplace展开定理的特例一分块三角阵的行列式，研究了几类分块矩阵的行列式，得到了三个结果。并利用得到的结果计算一些特殊的行列式，能达到简化计算的目的。     

分块矩阵的对角化方法

本定义了分块矩阵的初等变换与初等分块矩阵，给出了非满秩情况下分块矩阵可以对角化的条件。     

学前儿童故事情境化积木建构水平及其与家庭积木游戏环境的关系

目的:考察4～6岁幼儿的故事情境化积木建构水平以及他们的家庭积木游戏环境,进一步分析两者之间的关系。方法:分别采用实验法和问卷调查法。结果:(1)故事情境化积木建构水平有显著的年级差异,但无显著的性别差异;(2)家庭游戏经验、支持环境与故事情境化积木建构水平存在相关。结论:故事情境化积木建构水平随年龄而提升;积木游戏经验越多,支持环境越好,学前儿童的故事情境化积木建构水平就越高。     

块H-矩阵的判定

基于广义α-对角占优矩阵与日一矩阵的等价性，给出了几个带参数a的块日一矩阵的充分条件．     

分块矩阵的应用讨论

在解决矩阵的某些问题时,对于级数较高的矩阵,常采用分块的方法,将一个矩阵分割成若干个小矩阵,在运算过程中将小矩阵看成元素来处理,对问题的解决往往起到简化的作用。     

试论木刻版画技法的发展演变

雕版技术是一门制作严谨的印刷技术,分为文字印刷和图像印刷两部分,印刷的过程是先制作原稿,再把原稿反转固定在木板上,由技术娴熟的技师雕刻,完毕后上墨印刷,可以批量印刷,具有复数性。     

重塑当代版画的精神内核

中国版画有着上千年的历史,但20世纪30年代以前的版画仍然是复制版画。自1931年起,由鲁迅倡导的新兴木刻才开始了我国有创作版画的史页,历经半个多世纪,曾出现过几次高潮时期,产生了一大批优秀的版画家和在国内外有影响有重要价值的版画作品,发展健全了各个版种。中国版画艺术取得了辉煌的成就,但我们也应该看到,当下进入转型时期的中国版画面临一定的困境,一些作品刻意追求版画的形式语言,片面追求作品的印痕美感等本体语言,使作品只停留在技术层面,疏离了版画作品本身的内在精神,缺少深刻的内涵和思想,缺少生命力。"形而上者谓之道,形而下者谓之器"。版画要走出低谷寻求新的发展,由"技"进乎"道"是当务之急。     

Pictures Block the Learning of Sightwords

Young children were taught to name 12 single words, six in the presence of appropriate pictures (compound stimuli) and six in their absence (simple stimuli). There were two compound conditions: one in which the picture was a large line drawing above a small printed word (enhanced salience condition) and one in which it was a small line drawing below a large printed word (reduced salience condition); and two corresponding simple conditions of a large word alone (enhanced salience condition) and a small word alone (reduced salience condition). Each child experienced all four conditions with three different words in each condition in a series of randomly ordered learning and test trials, until each child achieved the criterion of three consecutive correct responses for each of the words in at least one of the conditions. Two experimental studies were completed with 16 children in each, and the percentage of correct responses was calculated for each presentation condition. Comparisons of the compound (picture) and simple (no‐picture) conditions showed that twice as many words were correctly recognised in the simple (no‐picture) conditions in both experiments. No reliable differences were detected between the different levels of salience, and it was concluded that prior association between the picture and the naming response to the picture ‘blocked’ the acquisition of a new association between the written word and the naming response to it.