中学化学教学中"绿色化学"意识渗透浅谈

“绿色化学”可诠释为环境友好化学，笔者根据自己的教学实践和中学化学教学的特点，就如何在中学化学教学中自然、和谐、生动地渗透“绿色化学”意识教育作了初步探索。     

谈化学基本概念与理论的学习

中学阶段的化学学习,始终贯穿着概念与理论的学习,而且直接影响到化学知识的掌握。本文就概念与理论的学习谈一点粗浅的看法。一、化学概念与理论学习的一般过程化学概念与理论学习的一般过程可概括为:感知→加工理解、形成概念→联系、整合→运用、迁移。1.感知阶段:就是通过阅读、听课、观察、重复感     

高中微型化学实验的实践

介绍了高中微型化学实验体现在减量、减废、回收、密闭可控、处理尾气等方面的一些优点。     

化学消毒剂

用于杀灭病原微生物的化学药物称为消毒药或化学消毒剂 ,它与化学治疗剂如抗菌素等不同 ,因为它在杀灭或抑制病原体的浓度下 ,同样对人体也有损害 ,所以消毒药只能用于体表、器具、排泄物和周围环境等的消毒上。理想的消毒药应当是杀灭力强、价格低、无腐蚀 ,能保存、对人无毒或低毒的化学药品。消毒药可按其使用机理分为 :干扰微生物酶系统的药物 ;使蛋白质凝固或变性的药物。按临床用途则分为 :体表消毒药和环境、器械消毒药 ,此外也可按其化学结构加以分类。一、干扰微生物酶系统的消毒药1 卤素及能产生卤素的化合物这类物质主要有碘、…     

重视并实施化学用语教学

化学用语有化学专业术语和化学符号两类,通常指化学符号.它主要包括元素符号、原子结构示意图、离子符号、元素的化合价、物质的化学式及化学方程式.本文主要围绕化学用语教学进行粗浅探讨,希望给大家教学有所帮助.     

加强实验教学提高学生兴趣

化学的建立和发展跟化学实验紧密联系在一起。实验对化学科学来说不可缺少,对化学教学来说更是如此。化学实验(包括对实验的描述)可以帮助学生形成化学概念,理解、巩固化学知识,可以训练学生掌握了解化学实验方法,形成实验技能;可以培养学生分析、解决实际问题的能力;可以激发学生的学习兴趣,启发学生的思维,培养学生实事求是、严肃认真的科学态度,进行辩证唯物主义教育等等。     

“物质构成的奥秘”考点分析

“物质构成的奥秘”一直是中考化学中的重要组成与热点，它涉及到微粒知识、物质的组成与构成、元素符号、化学用语、化合价、化学式、相对分子质量等许多化学学习的基本知识，是我们走进化学世界、了解化学知识的基本工具与必备常识．[第一段]     

化学概念理论复习四注重

初中化学基本理论与基本概念的复习 ,是化学分类总复习的开始 ,它是化学的最基本内容与最基础的知识 ,这类知识的学习好坏直接影响到化学计算等其他类知识的学习成绩。因此 ,要想搞好化学总复习 ,一开始就必须把化学的基本概念与理论这一部分复习好。在复习基本概念与理论时 ,选择好复习方法尤为重要。笔者认为 ,要优化基本概念与理论的复习 ,必须注重以下四个方面的问题。一、注重知识的串联并联、网络成面化学概念与理论常分散于物质的组成、结构、性质、变化、分类中。我们可以根据知识的脉络 ,把各类知识点用连线与箭头串联与并联起来 ,…     

基础化学教学类4种期刊绿色化学教育文献统计分析

以《化学教学》、《化学教育》、《化学世界》、《大学化学》4种化学教育核心期刊为研究对象 ,对有关绿色化学教育文献进行统计 ,从计量学角度出发 ,对文献数量、内容、作者单位、作者所在区域、核心作者以及作者合作情况等方面进行统计分析和评价 ,试图为我国绿色化学教育研究提供某一角度的参考     

网上学校“化学园地”简介

为实施网上教育 ,美国 Peregrine出版公司于 1997年创立了化学园地 ( ChemistryPlace) ,生物园地 ( Biology Place)和心理学园地 ( Psychology Place)教育站点 ,并对这些站点进行经常性维护。本文简要介绍化学园地站点。化学园地站点以化学教师、学生以及其他化学爱好者为读者对象。站点开办的目的在于 :通过网上互动教学使读者掌握重要化学原理和化学过程 ;以国际著名教科书为蓝本设计模拟测验帮助读者掌握所学内容 ;为读者及时提供化学学科新闻 ;为读者与富有经验的化学教师交流学习心得提供方便 ;推荐因特网上重要化学资源。化学园地…     

Precise asymptotics in the law of the logarithm for random fields in Hilbert space

Consider the positive d-dimensional lattice d (d≥2) with partial ordering ≤, let {XK; K ∈ d } be i.i.d. random vari- ables taking values in a real separable Hilbert space (H, ||·||) with mean zero and covariance operator ∑, and set partial sums SN =∑K≤NXK, K , N ∈ d . Under some moment conditions, we obtain the precise asymptotics of a kind of weighted infinite series for partial sums SN as ε 0 by using the truncation and approximation methods. The results are related to the convergence rates of the law of the logarithm in Hilbert space, and they also extend the results of (Gut and Spǎtaru, 2003).     

On Turán type inequality with doubling weights andA * weights

LetH _n be the set of real algebraic polynomials of degreen, whose zeros all lie in the interval [−1,1]. The well known Turán type inequalities tell us that forf(x)∈H _n , it holds ‖f′‖≥C√n‖f‖. This note deals with the weighted Turán type inequalities with the weights having inner singularities underL ^p norm for 0<p≤∞. Our results essentially extend the result of Wang and Zhou (2002), and the method used in this paper is simpler and more direct than that of Wang and Zhou (2002). The results and methods have their own values in approximation theory and computation.     

Infrared Absorption Spectra of Serpentine Cat＇s Eye from Sichuan Province of China

Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.     

On semiotics and subjectivity: a response to Tony Brown’s “signifying ‘students’, ‘teachers’, and ‘mathematics’: a reading of a special issue”

In this response we address some of the significant issues that Tony Brown raised in his analysis and critique of the Special Issue of Educational Studies in Mathematics on “Semiotic perspectives in mathematics education” (Sáenz-Ludlow & Presmeg, Educational Studies in Mathematics 61(1–2), 2006). Among these issues are conceptualizations of subjectivity and the notion that particular readings of Peircean and Vygotskian semiotics may limit the ways that authors define key actors or elements in mathematics education, namely students, teachers and the nature of mathematics. To deepen the conversation, we comment on Brown’s approach and explore the theoretical apparatus of Jacques Lacan that informs Brown’s discourse. We show some of the intrinsic limitations of the Lacanian idea of subjectivity that permeates Brown’s insightful analysis and conclude with a suggestion about some possible lines of research in mathematics education.

Results on energies for trees with a given diameter having perfect matching

Let Γd2nbe the set of trees with a given diameter d having a perfect matching,where 2n is the number of vertex.For a tree T in Γd2n,let Pd+1be a diameter of T and q = d m,where m is the number of the edges of perfect matching inPd+1.It can be found that the trees with minimal energy in Γd2nfor four cases q = d 2,d 3,d 4,[d2],and two remarks aregiven about the trees with minimal energy in Γd2nfor2d 33q d 5 and [d2] + 1 q2d 33 1.     

Supposer et postuler pour produire des connaissances scientifiques: une évidence ou une conquête théorique? Une étude des points de vue d'étudiants

Résumé De manière générale, l'évidence sensorielle et, plus particulièrement, visuelle constitue pour les étudiants le principal fondement du savoir scientifique: nul besoin de supposer pour connaître, tout est donné ou presque. Du point de vue de l'enseignement des sciences, cette croyance à saveur réaliste est particulièrement critique, notamment parce qu'elle conduit à penser que les concepts, lois et théories scientifiques procèdent d'un monde de matérialités plutôt que d'un monde de modèles et de relations. Au cours d'une recherche effectuée auprès d'un groupe-classe de 35 étudiants durant douze semaines, nous avons pu observer que, pour la majorité des étudiants, la compréhension du caractère construit et consensuel du savoir scientifique était facilitée par le développement d'une métaréflexion sur leurs propres productions de connaissance et les inévitables postulats et suppositions qui les fondent. Nous avons également pu observer qu'il découle de cette activité réflexive un modèle de science qui se distingue des modèles initialement tenus par les étudiants, par le pouvoir créateur et, surtout, le pouvoir de théoriser qu'il comporte: postuler, supposer, jauger collectivement de la plausibilité des résultats plutôt qu'en appeler à une instance occulte, voilà quelques-unes des conquêtes théoriques qu'ils ont effectuées et sur lesquelles nous allons nous attarder.

---

Sensorial, and more specifically, visual evidence is generally regarded by students as the basis for scientific knowledge: no need to postulate to understand, all is almost or practically given. From a science-teaching standpoint, this rather realistic approach is critical and leads to the belief that scientific concepts, laws, and theories stem from a world of materiality rather than from a world of models and relationships. During a 12-week study a group of 35 college students, we observed that for the majority of them, the development of metareflection on how they produce knowledge, with the inevitable and inherent postulates and conjecture, facilitated their understanding of the constructed and consensual character of scientific knowledge. We also observed that this reflexive activity facilitated the development of a new approach to science that differed from those models previously used by the students in its creative potential and, more importantly, in the power of its theoretics: to postulate, suppose, and collectively estimate the plausibility of results rather than calling up occult instances. These and other theoretical achievements will be discussed in this paper.

     

Māori science education in Aotearoa New Zealand

Abstract    This article reports on the first two phases of a multiphase science education development project in predominantly Māori kura (school communities) in the central region of the North Island of Aotearoa New Zealand. The development project in its entirety employs an action research methodology and by so doing endeavors to support the improvement of science education delivery in accordance with school community aspirations. The full project (a) establishes the current situation in Year 1–8 science education in the communities; (b) identifies developmental aspirations for stakeholders within the communities and identifies potential contributors and constraints to these aspirations; (c) implements mechanisms for achieving identified aspirations; and finally; (d) evaluates the effectiveness of such mechanisms. In its focus on the first two phases, this article incorporates the analytical lenses of Kaupapa Māori Theory and Bronfenbrenner’s bio-ecological model. It concludes by outlining some priorities to consider for science education development based on the outcomes of our preliminary discussions.

一矩阵方程组的反射解

We derive necessary and sufficient conditions for the existence and an expression of the （anti）reflexive solution with respect to the nontrivial generalized reflection matrix P to the system of complex matrix equations AX = B and XC = D. The explicit solutions of the approximation problem min x∈Ф ｜｜X - E｜｜F was given, where E is a given complex matrix and Ф is the set of all reflexive （or antireflexive） solutions of the system mentioned above, and ｜｜·｜｜ is the Frobenius norm. Furthermore, it was pointed that some results in a recent paper are special cases of this paper.     

Surviving Rescue: A Feminist Reading of Scott O’Dell’s <Emphasis Type="Italic">Island of the Blue Dolphins</Emphasis>

Scott O’Dell’s Island of the Blue Dolphins tells the archetypal story of the young, virgin, orphan girl who is vulnerable to either debauchery or rescue. That such a girl must succumb to either one or the other is a necessary element of the archetype. In O’Dell’s work—one intended, after all, for children—the heroine is rescued by a paternalistic figure and re-inscribed into the patriarchal world. Yet, in the hands of young readers, Island—part fairytale, part rescue narrative, part feminist parable—becomes a story of independence and survival, despite the heroine’s “rescue” at the end.