热力学统计物理中化学势的计算

以能量、熵和吉不斯函数为依托,对化学势进行计算,分别对理想气体、玻色气体的化学势进行了理论推导,得到了其化学势与温度及压强的确定函数关系,并分析了化学势在玻色-爱因斯坦凝聚现象中的一些应用.进而用matlab语言编写相关计算程序,计算出费米气体的化学势等,并介绍化学势在费米分布中所起到的重要影响.     

化学势(μi)的涵义及其应用

阐述了化学势概念的涵义及一些因素对化学势的影响;阐明了化学势在多组分多相平衡体系及化学反应平衡体系中的应用.     

热力学·统计物理中的化学势

化学势是一个非常重要的物理量,它贯穿热力学与统计物理两部分,它具有能量特征,能从某一侧面反映系统的某一性质;尤其在统计物理中,化学势更是起到了非常重要的作用.本文主要在于厘清化学势的定义,阐明如何用热力学方法和统计物理方法计算理想气体化学势.并在此基础上进一步阐述了化学势的一些重要作用.     

化学势的取值分析与化学势的作用

本文论述了热力学及统计物理中关于化学势取值的相对性和化学势的作用,特别是对近独立粒子系统分布函数中化学势的正负进行了讨论,并用数字代入方法证明了费米－狄拉克分布中化学势的正负取决于系统的温度高低。     

理想气体化学势μ的统计属性

计算出弱简并理想气体的化学势μ，与非简并理想气体和简并性理想气体的化学势μ比照发现，理想气体的化学势μ随温度丁而减小，且是粒子数密度n(=N／V)的函数；结合所导出的多元系粒子的最概然分布，揭示了理想气体化学势μ的统计关联本质．     

关于化学势概念及应用

关于化学势概念及应用乌风歧，徐德智众所周知，水可以从高处自动地向低处流，其驱动力是存在着水位差．电流可以从电势高的正极，流向电势低的负极，驱动力是存在着电势差．在相变过程和化学反应过程中，物质的迁移其驱动力则是化学势．１化学势的定义关于化学势的定义可...     

浅析稀溶液中物质化学势及标准态化学势

通过对拉乌尔定律和亨利定律的热力学表达式的推导,得到稀溶液中溶剂和溶质的化学势的表示,并对标准态化学势进行解释.     

浅析稀溶液中物质化学势及标准态化学势

通过对拉乌尔定律和亨利定律的热力学表达式的推导,得到稀释溶液中溶质的化学势的表示，并对标准态化学势进行解释。     

标准化学势和热力学标准态（Ⅱ）凝聚相和溶液中物质B的标准化学势和热力学标准态

若定义了标准化学势u,其他标准热力学量可从μ和热力学函数之间的关系通过数学计算得到,本文定义了凝取相和 物质B和标准化学势,根据标准化学势选取了相应的标准态,并讨论了活度,活度系数以及渗透系等, 对方程中有关符号和术语也予以详细说明。     

化学势定义式及应用

本文推导了化学势四个定义式之间的关系,并以导出凝固点降低公式和讨论在等温等压条件下多组分体系变化中物质i的迁移方向和限度为例,阐明了化学势在化学热力学中的重要应用。     

论逻辑图的表达能力

随着新句法机制的引入,逻辑图的表达能力不断得到提高：文恩图在表达能力上等价于不带等词的一元一阶逻辑,蜘蛛图等价于带等词的一元一阶逻辑,而建立在约束图基础上的“可视一阶逻辑”被证明具有一阶谓词逻辑的表达能力。研究逻辑图表达能力的一个重要意义在于．图式逻辑可能有望为一阶逻辑产生重要的可判定片段。     

运用内力图规律快速绘制剪力图和弯矩图

根据荷载集度与剪力、弯矩之间的导数关系,找出了绘制内力图的规律,应用此规律画剪力图和弯矩图不必列内力方程,只需依据梁在不同荷载作用下剪力图及弯矩图的图形特征计算出控制截面的内力值,即能简便、快捷地画出内力图。     

Correct Interpretation of Chemical Diagrams Requires Transforming from One Level of Representation to Another

Volunteer non-major chemistry students taking an introductory university chemistry course (n = 17) were interviewed about their understanding of a variety of chemical diagrams. All the students’ interviewed appreciated that diagrams of laboratory equipment were useful to show how to set up laboratory equipment. However students’ ability to explain specific diagrams at either the macroscopic or sub-microscopic level varied greatly. The results highlighted the poor level of understanding that some students had even after completing both exercises and experiments using the diagrams. The connection between the diagrams of the macroscopic level (equipment, chemicals), the sub-microscopic level (molecular) and the symbolic level (equations) was not always considered explicitly by students. The results indicate a need for chemical diagrams to be used carefully and more explicitly to ensure learner understanding. Correspondingly, students need to interpret visual chemical diagrams using meta-visualization skills linking the various levels of representation, and appreciating the role of the diagrams in explanations need to be developed.     

Students' Visualization of Diagrams Representing the Human Circulatory System: The use of spatial isomorphism and representational conventions

This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14–15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented aspects of the circulatory system. All diagrams used in the interviews had been used by their teacher when teaching the topic. Students' interpretations were expressed by their verbal response and their drawing. Dual coding theory was used to interpret students' responses. There was evidence that one student relied on verbal recall as a strategy in interpreting diagrams. It was found that students might have relied unduly on similarities in spatial features, rather than on deeper meanings represented by conventions, of diagrams when they associated diagrams that represented different aspects of the circulatory system. A pattern of students' understanding of structure–behaviour–function relationship of the biological system was observed. This study suggests the importance of a consistent diagrammatic and verbal representation in communicating scientific ideas. Implications for teaching practice that facilitates learning with diagrams and address students' undue focus on spatial features of diagrams are discussed.     

Using diagrams as tools for the solution of non-routine mathematical problems

The Mathematics education community has long recognized the importance of diagrams in the solution of mathematical problems. Particularly, it is stated that diagrams facilitate the solution of mathematical problems because they represent problems’ structure and information (Novick & Hurley, 2001; Diezmann, 2005). Novick and Hurley were the first to introduce three well-defined types of diagrams, that is, network, hierarchy, and matrix, which represent different problematic situations. In the present study, we investigated the effects of these types of diagrams in non-routine mathematical problem solving by contrasting students’ abilities to solve problems with and without the presence of diagrams. Structural equation modeling affirmed the existence of two first-order factors indicating the differential effects of the problems’ representation, i.e., text with diagrams and without diagrams, and a second-order factor representing general non-routine problem solving ability in mathematics. Implicative analysis showed the influence of the presence of diagrams in the problems’ hierarchical ordering. Furthermore, results provided support for other studies (e.g. Diezman & English, 2001) which documented some students’ difficulties to use diagrams efficiently for the solution of problems. We discuss the findings and provide suggestions for the efficient use of diagrams in the problem solving situation.     

Cognitive activities in complex science text and diagrams

Ainsworth’s (2006) DeFT framework posits that different representations may lead learners to use different strategies. We wanted to investigate whether students use different strategies, and more broadly, different cognitive activities in diagrams vs. in running text. In order to do so, we collected think-aloud protocol and other measures from 91 beginning biology majors reading an 8-page passage from their own textbook which included seven complex diagrams. We coded the protocols for a wide range of cognitive activities, including strategy use, inference, background knowledge, vocabulary, and word reading. Comparisons of verbalizations while reading running text vs. reading diagrams showed that high-level cognitive activities—inferences and high-level strategy use—were used a higher proportion of the time when comprehending diagrams compared to when reading text. However, in running text vs. diagrams participants used a wider range of different individual cognitive activities (e.g., more different types of inferences). Our results suggest that instructors might consider teaching students how to draw inferences in both text and diagrams. They also show an interesting paradox that warrants further research—students often skipped over or superficially skimmed diagrams, but when they did read the diagrams they engaged in more high-level cognitive activity.     

Effects of Diagrams on Mathematics Performance

Research on the facilitative effect of diagrams on solving mathematics problems is both inconsistent and inconclusive. This study investigates the effects of diagrams on 124 Singaporean pupils in three classes: Primary One and three, and Secondary One. Pupils' performance was measured with the use of teacher-written mathematics problems in the form of worksheets. Number of errors made on problems accompanied with and without diagrams were compared. Whether or not pupils benefit from diagrams was estimated by their patterns of errors made in the presence or absence of diagrams. Results both confirm and disconfirm previous findings and shed further light on the use of diagrams in mathematics.     

Learning from maps and diagrams

This review of learning from maps and diagrams consists of two sections. The first section presents a theoretical framework for learning from maps and diagrams. The case is made that the symbol systems of maps and diagrams are sufficiently similar for them to be considered together. The theoretical framework is built around what is known of pre-attentive and top-down psychological processes. It accounts for the way people discriminate between symbols used in maps and diagrams and how they group them into clusters. The second section comprises a review of psychological and instructional research. This research provides support for a number of hypotheses arising from the theoretical framework. Many of these are based on the notion that maps and diagrams communicate a considerable amount of information by the way in which components are placed relative to each other and to the frame surrounding them. Evidence that configuration and discrimination are fundamental to learning from maps and diagrams is summarized in 10 concluding points.     

The role of diagrammatic representation in learning sequences,identification and classification as a function of verbal and spatial ability

Grade 9 subjects learned the evolutionary sequence of dinosaurs and to classify them by type. Instruction was by menas of flow diagrams that showed the evolutionary sequence running across the page either from left to right or reversed from right to left, with or without drawings of dinosaurs. It was found that subjects seeing left-right ordered diagrams scored better on tests of sequence and classification than those seeing reversed diagrams. Also, the addition of drawings helped subjects identify dinosaurs by type. Verbal ability predicted learning as a function of treatment. Spatial ability did not. However, some evidence was found that high-spatial low-verbal subjects could classify the animals equally well from normal-order or reversed diagrams, while high-verbal subjects who were also low-spatial could classify them better if they had seen normal-order diagrams. These results suggest that diagrams provide different types of information and that learners may process each type differently.     

The impact of technology on the teaching and assessment of ‘systems’ diagrams in two online environmental management modules

Abstract

The context and tools used to create diagrams may hinder or help students in learning how to represent a situation and how to learn about diagramming and the situation at the same time. These equally provide opportunities and challenges to tutors in teaching, assessing and providing feedback on these diagrams, particularly for students studying at a distance. Two online undergraduate modules, dealing with environmental management at The Open University UK, require students to share diagrams with other students, to work collaboratively on diagrams in small groups and include diagrams in all assignments. This paper reports on students’ and tutors’ experiences of using diagrams before, during and outside involvement with both modules to better understand the main factors that influence their educational value, in particular the part that familiarity, experience and confidence in the techniques, the technologies and acts of sharing played in supporting learning or not.