“低熔点物质熔化和凝固系统”的研发及应用

为了做好初中物理中的一个难做实验——"低熔点物质的熔化和凝固"实验,更好地展示晶体、非晶体熔化和凝固的特征,有物理教师结合教学实践研发了结构简单、成本低廉的"低熔点物质熔化和凝固系统"。在具体实验中,若能调整所用的材料,则可大大提高实验教学效果。     

研究物质燃烧条件的微型设计

1．引言 微型化学实验是体现绿色化学理念的一种化学实验的新技术和新方法。它不仅具有减少污染、现象明显、快速、节约、安全等优点,而且更重要的是微型实验本身也是对学生环境保护意识最生动、最现实的教育,并为以学生动手操作为主的化学活动课、第二课堂实验、家庭化学小实验等活动拓宽了途径,对提高学生化学学科的素养,激发学生学习化学的兴趣具有重要的作用。本文设计了研究物质燃烧条件的微型实验,不妥之处还请同行指正。     

对物质燃烧条件实验的改进

1实验改进的原因 初中化学教材在探究物质燃烧的条件时,常用的方法是在烧杯中加热水,烧杯口部放一薄铜片,然后在热水中放一小块白磷,铜片上不同的位置分别放一小块白磷和少量红磷,通过比较热水中的白磷、铜片上的白磷和红磷燃烧的现象得出可燃物的燃烧条件．     

初中化学基础实验“物质燃烧的条件”的探究与设计

《义务教育化学课程标准(2011年版)》规定了初中学生必做的8项基础实验,据此编写的沪教版新教材(2012年版)的第3个学生基础实验是“物质燃烧的条件”.基于课标与教材研究,本文重新研究并设计了初中化学基础实验3,增加了2个实验目的,调整了实验用品和实验方案,加设了实验“安全提醒”,突出了实验的基本观察要点、知识要点与操作要点,确定了实验探究要点.设计后的基础实验3通过了苏州市区100多位初中化学老师的操作验证和研讨,获得了肯定与好评.     

“细胞大小与物质运输的关系”实验的改进

笔者阐述了“细胞大小与物质运输的关系”这一实验中使用的琼脂块的具体制备过程,以及琼脂回收再利用的方法,并对实验中的操作难点进行了说明。提出了该实验步骤的改进方法,提高了实验效果．体现了生物实验中的绿色环保理念。     

以学生前概念为基础的改进实验突破教学重难点——以“探究物质燃烧的条件”为例

实验是初中科学教学的基础,以华师大版科学七年级下册第2章第3节《氧气》一节内容中探究物质燃烧条件为例,阐述如何以学生前概念为基础改进实验,突破教学重难点。     

利用键能数据,正确理解不饱和键的性质

1问题的产生 在人教版《普通高中课程标准实验教科书化学选修3物质结构与性质》（以下简称人教版《物质结构与性质》）     

利用实验探究法的“物质溶解时的吸热和放热现象”的教学设计

作为科学探究中的最常用方法之一＂实验探究法＂已成为当前课程改革的一个重要内容。所谓＂实验探究法＂指的是通过实验来进行的一种探究活动,它是科学探究在化学实验教学中的具体化。它是化学教学中最常见、最主要的探究活动。     

人教版九年级化学“探究物质燃烧条件”实验的改进简

一、问题的提出 人民教育出版社,义务教育教科书《化学》九年级上册第128页中有两个探究物质燃烧条件的实验,在教学中做这两个实验时常会遇到下列问题.     

Making sense of boiling points and melting points

The boiling and melting points of a pure substance are characteristic physical constants of that substance in its pure state. Although it is not possible to predict these physical constants for a given substance, it is, however, possible to rationalize these values on a relative basis for given substances, taking into account the type of chemical bonding, the intermolecular forces and other factors. S Prahlada Rao is an R & D consultant for chemical industries with teaching as a hobby. Shravan Sunkada is a 5th year student at Indian Institute of Technology, Bombay, pursuing a dual degree programme in Material Science and Metallurgical Engineering.     

为什么有的温度计里装酒精,有的装水银

为了准确的表示温度的高低,我们常用温度计来测量温度,温度计是利用液体热胀冷缩的原理制成的。温度计中有红色的液体,有银白色的液体,这些液体是什么东西?红色的液体是酒精,银白色的液体是水银。     

Why there is no education ethics without principles

Moral education and ethical reflection are always dependent on the content of the internalized norms, principles and values of the individual. As we demonstrate, this also means that there is no instance of feeling, emotion, spontaneity, or care that can be independent of norms, rules, and values outside human discourse. In light of this, Noddings’ theory of the ethic of care is a contentious theory of child education, as it is linked with the presupposition that we can turn a blind eye to the symbolic field, to the network of rules/principles and their values, when we educate. Education that is derived only from caring, without being derived from reflection on education’s specific values, can lead to education that supports, for instance, racist ideology and racist education. This is not, of course, something that the ethic of care would advocate; however, as an educational theory, it is flawed in that, due to the rejection of reflection through principles in general, it fails to provide the educator with a conceptual apparatus through which he/she could analyze and reflect upon—could understand—what he/she is doing with regard to the norms of his/her culture. Society and educators cannot tacitly allow or be benevolent toward such fundamental mistakes in moral education.     

两种单稳态电路的暂稳态时间为何不同

单稳态电路可以由门电路和555定时器组成，但两种单稳态电路的暂稳时间不同，由门电路组成的单稳态电路，其暂稳时间为0．7RC：由555定时器组成的单稳态电路，其暂稳时间为1．1RC。本文就两种单稳态电路的暂稳态时间的不同所造成的原因及如何确定进行探讨。     

高职英语教学中后进生成因分析及对策

随着高等职业技术学院的增多和招生的不断扩大,英语差生面越来越广,所以补差工作迫在 眉睫.本文主要分析高职英语后进生成因以及对策。     

高中化学中物质熔沸点内容的教学探讨

在高中化学教学辅导书中,时常出现一些判断物质熔沸点的规律或判断熔沸点高低的题目.在分析、解决这类题目时,常常出现以偏概全的现象,抑或运用大学化学知识来进行解释,没有准确地定位教学的内容和难度.针对这种现象,在分析文献、课程标准、教材和高考试题的基础上,提出定位物质熔沸点教学内容及难度的重要性的建议.     

Progress in selective laser melting equipment,related biomedical metallic materials and applications

This paper introduces the latest achievements of the South China University of Technology in basic research on selective laser melting (SLM), applications of SLM manufacturing equipment, and biomedical metallic materials manufactured by SLM. First, we describe the use of DiMetal-100 equipment to study the process parameters, microstructure, and mechanical properties of three kinds of metal medical materials manufactured by SLM, including 316L stainless steel, CoCrMo, and Ti6Al4V. Second, we describe the application of 316L stainless steel manufactured by SLM to personalized lingual orthodontic brackets and surgical guide plates, the application of CoCrMo manufactured by SLM to knee prostheses and dental crowns and bridges, and the research results of Ti6Al4V manufactured by SLM in the treatment of pelvic fracture bone plates and personalized cranial prostheses. Finally, we introduce the development directions and research plans for SLM technology at the South China University of Technology, including the manufacture of a new porous structure by SLM directly, the manufacture by SLM of various material products simultaneously, SLM + material-reducing hybrid manufacturing, improving the negative feedback systems of SLM equipment, and developing SLM manufacturing processes using ceramics and new metals.     

浅析苏轼归老常州而又未葬于常州的原因

苏轼买田阳羡,归老常州的主要原因在于对仕途的厌倦和畏惧,常州的秀关山水,常州人民及好友的真挚情谊等等,又因苏洵葬于嵩山下,其子也要去河南颍州投靠苏辙为生,所以最终苏轼葬于嵩山下。