蒸锅水物质成分定性检测的实验探究

以常用仪器及微型仪器对蒸锅水的物质成分进行了定性检测的实验探究,结果显示:常压下置1000mL自来水于蒸锅中加热至沸腾并持续加热,随着蒸锅中开水的蒸发体积逐渐减少,水中Ca2+、Cl-、Mg2+、Zn2+浓度逐渐增大;Fe3+、Al3+浓度先逐渐增大,后逐渐降低;开水蒸发至150mL后检出有NO2-,后随水的继续蒸发,水中NO2-的浓度逐渐增大.烧开水时切不可煮沸时间太久,且不宜饮用蒸锅水、千滚水.     

试论V后QP的定性问题

从主语和宾语的关系、补语和定语的分类及空间观念着手,探讨了动词后的数量短语的成分归属问题。认为仅从语序和位置来确定数量短语的语法成分会有失偏颇,只有综合语义关系、时空关系,结合多变的划分方法,才能顺利解决数量短语定性问题。     

高中物理定性实验在习题教学中的应用

在新课改进程不断加快的教学环境下,高中物理教学模式的改革与调整进程也备受关注。在具体教学中,可利用物理定性实验使教学过程变得生活化、实践化、技能化及科学化。学生对物理习题的解答能力是反映教学模式优劣的重要指标,在习题教学中应用定性实验,对提高习题教学实效有一定的积极作用。本文简要阐述了定性实验的相关概念,并在此基础上探讨了高中物理定性实验在概念性及规律性物理习题教学中的应用。     

定性实验与定量实验的完美结合——《碳酸钠与碳酸氢钠化学性质的探究》听后感

传统的中学化学实验教学侧重定性实验,较少有定量实验。这给学生从量的角度认识化学变化的本质造成了一定的困难。如何能在日常教学中逐渐渗透定量实验,让学生能直观地感受实验的变化,值得每个老师思考探索。苏州中学徐惠老师在讲授碳酸钠与碳酸氢钠的化学性质时．     

将法拉第电磁感应定律探究实验由定性改为定量的建议

教材中只提供了定性实验方案探究法拉第电磁感应定律,学生缺乏定量探究的过程,因此无法准确建立物理观念,仍处于被动记忆的学习过程中。提供了一个定量探究的实验方案,旨在帮助学生从被动记忆过程转变为主动探究认知过程,并正确理解法拉第电磁感应定律。     

适当"量化"中学生物学定性实验

目前中学生物学实验以定性实验居多，适当量化中学生物学定性实验对提高学生的科学素质、创新思维和逻辑思维有重要作用。本文就如何对中学生物学定性实验做适当的量化作了些初步的探讨。     

定量关系的定性应用

很多物理规律或公式都有一定的使用范围和使用条件,当公式的使用条件不严格时,不能使用该公式进行定量计算,但可以进行定性分析,我们可以称之为“定量关系的定性应用”．以功的公式W=FS为例,该公式只适用于恒力,当力不恒定时当然不能根据此公式来计算功的大小,但可以根据此公式来比较功的大小,也就是将定量关系推广到定性的情境中．     

设计小实验 推断物质成分

化学是一门以实验为基础的自然科学，在一些平时的习题中，有一类判别物质化学式的题目，教师普遍难于下手，学生更不知其所以然的问题，我们不妨应用实验的手段来解决，这样既激发了学生学习化学的兴趣，又加强了学生的认知效果，培养厂学生思考解决问题能力。笔者针对“粉笔的主要成分是什么”这一问题设计了一个推断性的实验，学生普遍反映良好。现将实验用品及步骤摘录如下：     

Gender Differences in the Experience of Higher Education: quantitative and qualitative approaches

This paper reviews the evidence for differences between men and women in their experience of higher education. It is generally agreed that students manifest a number of different approaches to learning, and these have been operationalised in terms of quantitative measures derived from responses to formal questionnaires. Nevertheless, there is little consistent or valid evidence for gender differences in the responses to these instruments. Other researchers have used qualitative methodologies in order to identify different stages of intellectual development among students in higher education. Their findings indicate the existence of parallel, but distinct developmental schemes in male and female students.     

教师更应该关注学生什么

邻居的儿子亮亮是一名小学五年级的学生,他的上课时间和我们一样,都是八点钟,但是,每天早上我上班时,几乎很少看到亮亮,因为他已经提前上学走了。     

Learning qualitative and quantitative reasoning in a microworld for elastic impacts

From a psychological point of view efficient teaching by means of an intelligent tutoring system necessarily involves that the communication of knowledge is adapted to the requirements of the learner: to her cognitive abilities, her pre-instructional knowledge and her learning capabilities. To tackle these topics in a precise way, we have developed the artificial-intelligence-based microworld DiBi (disk billiard) and MULEDS, a multi-level diagnosis system. The microworld DiBi sets up a learning environment which simulates elastic impacts as a subtopic of classical mechanics. DiBi enables and supports reasoning on different levels of mental domain representation ordered along the dimension ‘qualitative/quantitative’. This way of representing the domain provides a basis for passive adaptation in an advanced way. Correspondingly, active adaptation is supported by MULEDS, wherein student modeling is realized by assessing the student’s correct and/or incorrect domain-specific knowledge at these different levels. Within this psychological perspective, the use of instructional tools, such as the microworld DiBi and the computerized diagnosis system MULEDS, aims at gradually supporting and guiding the student in the construction of more and more powerful an sound domain representations. The progression through these levels of domain representation will enable the student to solve the problems posed by the domain in a flexible way.     

Novice use of qualitative versus quantitative problem solving in electrostatics

Problem-solving behavior of six novice subjects attempting to solve an electrostatics problem in second-semester calculus-based college physics was observed and recorded. Five of the subjects were characterized as “A” or “B” students and one subject as a “D” student in introductory college physics. Although the A or B subjects were able to arrive at a “correct” solution to the problem, they exhibited major misconceptions about the problem situation as well as minimal qualitative understanding of the problem situation. The A or B subjects were successful in identifying, either from memory or written notes, equations relevant to electrostatics, whereas the D subject was not. The implication of this study is that current instruction in introductory calculus-based college physics and the students' previous science learnings place a premium on acquisition of correct quantitative solutions at the expense of qualitative understanding of physics problem situations.     

Integrating qualitative and quantitative methods to monitor an intervention program

Teachers in one-teacher schools have often experienced problems when implementing enquiry-based science programs. An innovation was developed to address these problems in isolated one-teacher schools in the far-west of NSW. It consisted of 18 science kits and an associated teaching sequence. Each kit contained 15 student activity sheets, equipment and supplementary resources. An intervention program was designed to support the implementation of the innovation. The purpose of this study was to monitor the teacher's process of change and to ascertain the outcomes of the intervention program in one of the schools. Data were collected using, diagnostic dimensions from the Concerns-Based Adoption Model Project as well as qualitative methods. The results indicated that the teacher's concerns about the innovation focused on how it affected the students. The teacher used the innovation to support her student-centred teaching methods and the students had positive perceptions about learning science. Specializations: K-6 Science and Technology curriculum and instruction.     

When quantitative details impair qualitative understanding of multimedia lessons

In the present study, we explored why interspersing quantitative details through a multimedia lesson detracts from learners’ qualitative understanding. Three experimental conditions were created. In each, participants had to study a qualitative text on the formation, propagation, and dispersion of ocean waves. In the concise condition no quantitative details were added to the text; in the expanded‐interspersed condition, quantitative details were interspersed throughout the text; and in the expanded‐after condition, quantitative details were provided after the text. The results showed that qualitative understanding was poorer in the expanded‐interspersed condition than in the concise and the expanded‐after conditions, with no difference between the latter two conditions. Furthermore, reading time of the qualitative text was comparable across the three conditions. By contrast, reading time of the quantitative information was lower in the expanded‐interspersed condition than in the expanded‐after condition. These findings are interpreted in terms of a disruption hypothesis.     

材料虚拟实验室的建设与实践

现代信息技术的快速发展正推动着教育信息化的发展,通过虚拟实验室建设实现优质实验教学资源数字化也是教育信息化的一个发展方向。材料虚拟实验室建设,一方面可以作为当前实验教学的深化和补充,另一方面也为优质实验教学资源共享提供了有效途径。材料虚拟实验在教学中的应用表明,虚拟实验对学生的学习有明显的促进和提高作用。     

定量分析化学实验教学浅探

在定量分析化学实验教学中，创新、改进实验内容，强化基本操作技能，提高理论与实验的结合能力，培养严谨、求是的科学态度。