"数列和式不等式"的解题策略

数列和不等式都是高中数学重要内容,而两者结合更能体现对学生综合知识和能力的考查,历来倍受命题者的青睐,在高考、联赛中频频出现.本文就以"数列和式不等式"问题解题策略作一阐述.     

如何"讲"数列不等式中的放缩法

如何讲好数列不等式问题的解题分析,让解题过程更贴近学生是一个重要的课题.在教学过程中要让学生在"知道"的基础上,整理"分类",形成模型;并在具体题目分析中发现解题的线索,使得学生的观察能力达到"入微",提高解题能力.     

数列求和问题探究

数列是高中数学的重点内容,与高等数学知识联系紧密.在数列知识中,数列求和问题显得尤为重要.要想在解题时迅速找到求和的方法,必须掌握一些基本公式、解题策略和解题规律.下面研究各种形式下如何解决数列求和问题.     

高中数学数列题的解题策略

在高中数学中,数列是重要内容,关系着不等式、数、方程、函数,在整个高中数学中,数列解题思路贯穿其中.在多年的高中数学教学中,数列解题一直是多数学生的难点,学生存在解题思路不清晰,解题方法不当等问题.本文对高中数学数列题的解题策略进行探讨,为学生提供参考.     

高考数列题的分析与解题策略

<正>在近几年的高考中,虽然对数列题目的考核比较灵活,但一些常考的题型也会反复出现在高考中。因此,掌握数列题目的重点题型及解题策略,对掌握数列知识和提高数列解题能力有重要意义。下面对几个常考、重点题型及其解题策略进行分析。一、求数列通项公式数列的通项公式是研究数列的重要内容     

高中数列问题的解题方法总结

<正>高中数学是一门逻辑性非常强的学科,要求学生能够最大限度地进行思维的发散,并且能够做到举一反三,因此,在解决数列问题时,要善于总结解题方法。下面从不同角度对高中数列问题的解题方法进行探究和总结。一、数列问题中基础性题目的解题方法在解决数列问题时,我们要高度重视对于解题方法的归纳和总结,在归纳和总结的过程不断地发     

"倒排相加法"解题举例

数列在整个高中数学中,处于知识和方法的汇合点,求等差数列前n项和的"倒排相加法",不仅是一个很好的方法,也为我们提供了一种很好的解题思路,现举数例为证.     

巧解数列题

数列知识在中学学习中占重要地位,掌握数列解题的方法与技巧,就会达到事半功倍的目的,我们共同来探讨数列解题中的技巧问题．     

关于数列解题方法的学习探讨和体会

高中数列问题是高中数学学习中比较基础和重要的部分,这部分知识相对于之前学过的知识更为抽象,关联内容多,学习起来有一定难度。所以文章从探讨分享数列解题方法入手,讲了精读题目,分析已知条件,梳理解题思路;转化思维,创新解题思路,提升解题速度;创新发散,熟练运用公式,综合快速解题等,以期为其他同学数列知识的学习提供一定的帮助。     

选准参考点 寻求突破口

<正>数列的应用需要依托等差数列、等比数列的通项公式和求和公式建模,于是我们不得不考虑数列的首项,它是求解数列问题的参考点,引领着我们的解题思维.若我们善于选择参考点,就能使得解题的思路清晰,从而提高解题效率.下面举例说明.     

再论一类数列的求和

在求某些离散型随机变量的数学期望时,我们会遇到一类数列的求和问题.将这类问题归纳、拓展为由两个等差数列对应项之积组成的数列的前n项的求和问题及两个等差数列、一个等比数列对应项之积组成的数列的求和问题.利用求和符号及初等数学方法得到这类问题的处理方法、结论及应用的实例.     

Z变换在级数和复变函数积分计算中的应用

利用Z变换及其性质,给出了计算一些级数和复变函数积分的方法,该计算方法使得计算过程变得简单又直接,计算量小.     

基于学习进阶的物理单元学习过程设计

单元学习过程设计是单元教学设计的重要组成部分,是在单元教学内容分析和学情分析的基础上,为了实现单元学习目标而把一系列由简单到复杂、由浅入深的学习事件组织起来的系统规划。基于学习进阶设计单元学习过程包括大概念与大思路的形成、学习方式转变等。单元学习过程设计应建构学习进阶假设,从整体上规划学生核心素养的发展。     

Learning progressions: significant promise, significant challenge

Over the past five years or so, the concept of alearning progression has gained traction in the United States (US) science education community. Learning progressions have been touted as a means of addressing a number of vexing and persistent problems facing science education in the US (and around the world). In particular, there is great excitement over the potential of learning progressions to provide much needed coherence to standards, curricula, and assessments. Although relatively new, this promising approach is already having a significant impact on the landscape of US science education. However, there are also concerns that this influence may be premature. A substantial challenge lies in the validation of learning progressions—how to ensure that these tools, which are rapidly being incorporated into policy and practice, have sufficient empirical justification. This paper discusses both the promise and challenge of work to validate learning progressions for use in science education reform.     

英汉翻译中基本语篇结构模式的构建

对翻译的研究从信达雅到忠实 ,对等 ,各种流派层出不穷 ,大多是从词义修辞等方面进行考量。文章认为似乎还可以从篇章结构这一宏观角度进行考虑。文章试图从宏观层面对英汉翻译中基本语篇结构进行分析和研究 ,并建立相关模式。     

美国NAEP科学素养评价新趋向

2009NAEP科学评价框架依据学生科学学习的认知发展,构建了清晰明确的4、8、12年级评价内容,结合认知诊断评价学生四类科学能力,并增添组合题、计算机交互式任务、概念图等新的评价项目,深入有效地评价学生科学素养。框架还着眼于评价学生的学习进步,使NAEP科学评价为课程实施反馈更科学、更有效的信息。     

美国NAEP科学素养评价新趋向——基于美国2009NAEP科学评价框架的分析研究

2009 NAEP科学评价框架依据学生科学学习的认知发展,构建了清晰明确的4、8、12年级评价内容,结合认知诊断评价学生四类科学能力,并增添组合题、计算机交互式任务、概念图等新的评价项目,深入有效地评价学生科学素养。框架还着眼于评价学生的学习进步,使NAEP科学评价为美国科学课程实施反馈更科学、更有效的信息。     

英语报纸与广播新闻语篇主位推进程序的对比研究

文章采用黄国文提出的主位推进程序理论对二十篇英语报纸与二十篇广播新闻语篇进行了对比分析,找出这两种新闻语体在句子排列方面的各自特点和不同之处,揭示这两种语体的语篇构成规律。研究结果显示：平行、延续和集中型主位推进程序较多出现在英语报纸新闻语篇中,而交叉和派生型多出现在英语广播新闻语篇中。由此可见,传播方式的不同对新闻媒体的语言特点、语篇结构具有一定的影响。     

INFORMING A LEARNING PROGRESSION IN GENETICS: WHICH SHOULD BE TAUGHT FIRST,MENDELIAN INHERITANCE OR THE CENTRAL DOGMA OF MOLECULAR BIOLOGY?

The Framework for Science Education and the Next Generation Science Standards in the USA emphasize learning progressions (LPs) that support conceptual coherence and the gradual building of knowledge over time. In the domain of genetics there are two independently developed alternative LPs. In essence, the difference between the two progressions hinges on conjectures regarding the accessibility of Mendelian versus molecular genetics, the conceptual dependencies between them, and the order in which they should be taught. The discrepancies between the two progressions stem, in part, from gaps in the current research base. To address the question of whether learning one aspect of genetics, Mendelian or molecular, supports the learning of the other, we analyzed correlations between students’ test scores on item subsets for Mendelian and molecular genetics on written pre-post assessments. Students were seventh graders who received intensive instruction in Mendelian and molecular genetics. We found that students’ pretest scores on the molecular items were moderately correlated with their posttest scores on the Mendelian genetics item set (but not the other way around). This suggests that molecular genetics understandings may bootstrap the learning of Mendelian genetics. Implying that, in contrast to prevalent practice, molecular genetics should be taught before Mendelian genetics.     

Linking a learning progression for natural selection to teachers' enactment of formative assessment

Learning progressions, or representations of how student ideas develop in a domain, hold promise as tools to support teachers' formative assessment practices. The ideas represented in a learning progression might help teachers to identify and make inferences about evidence collected of student thinking, necessary precursors to modifying instruction to help students advance in their learning. The study reported in this article took the novel approach of using a learning progression for natural selection to support teachers' enactment of formative assessment. Sources of data include interviews and videotapes of six high school biology teachers leading assessment conversations around the same formative assessment questions. Results indicate that while teachers picked out and made inferences about student ideas related to the learning progression during assessment conversations, they did not use all parts of the learning progression in the same way. Furthermore, several of the teachers seemed to use the learning progressions simply as catalogs of misconceptions to be “squashed” rather than drawing upon the developmental affordances offered by a learning progression. Results are framed in terms of the utility of learning progressions as supports for classroom practice. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 1181–1210, 2012