对铜与氯化铁溶液反应的再研究

实验表明铜与氯化铁溶液反应不但与氯化铁溶液是否酸化有关,还与氯化铁溶液的浓度有关.当过量铜与浓度较高的氯化铁溶液反应时,除发生常见的离子反应Cu +2Fe3+ =Cu2+ +2Fe2+外,还得到Cu(Ⅰ)与Cl-形成的配合离子,同时采用数字化实验手段表征铜与氯化铁溶液反应,全面剖析铜与氯化铁溶液反应体系的离子行为.     

铜离子选择电极测还原糖鉴别蜂密纯度

用铜离子选择电极测定蜂蜜与 SB试剂反应后剩余的二价铜离子 ,计算出蜂密中还原糖的含量。该方法准确、快速、简便 ,是一种可行的蜂蜜鉴别方法     

尿素能与双缩脲试剂反应吗

中学生物学2011年第二期的42页,朱东跃老师在"谈实验异常设置对实验教学的甄别作用"一文中,提到了"对刚采集的尿液进行蛋白质检测,若尿液呈紫色,说明尿液中含有蛋白质——这是学生的观点,但教师指出这一结论不科学,并呈现了关于尿素分子结构的示意图,当学生看到尿素的分子结构时,疑惑顿消"。     

铜的化合物与氨的反应

通过实验和理论计算对铜的化合物在氨水中的溶解性进行了讨论 ,侧重讨论了铜的难溶化合物 ,认为铜的难溶化合物在氨水中的溶解性主要取决于难溶物的溶度积常数和铜氨配离子的稳定常数 .     

铁（Ⅲ）离子与硫氰酸钾的配合反应

对配合反应的表示法、配离子的电荷、配位体的性质、配离子的稳定性及颜色等，作了系统全面的归纳和论述。     

淀粉与碘的颜色反应与还原糖含量的关系

将糖的定性实验和定量实验相结合，我们测定了淀粉遇碘呈不同颜色反应阶段还原糖的含量，给出定性实验一个量化的结果。当底物淀粉浓度为2g／L，加入α-淀粉酶为0．5u／mL时，0—2．5min呈蓝色，2．5—5．5min呈紫色，5．5—13．5min呈红色，13．5min后呈无色。对应颜色变化点还原糖的分解比率分别为45％(蓝色→紫色)，66％(紫色→红色)，76％(红色→无色)。     

缺项氧化还原反应离子方程式的配平

所谓缺项方程式，即某些反应物或生成物的化学式未写出的方程式。这些反应物或生成物一般为水、酸、碱。 　　配平的关键：一是氧化剂和还原剂中被还原和氧化的元素化合价变化的数值相等；二是反应前所有离子所带电荷的代数和与反应后所有离子所带电荷的代数和相等。 　　配平的难点：未发生化合价变化的元素的原子数的配平，特别是氢、氧原子的配平。 　　〔例 1〕 配平在酸性溶液中进行的反应。 □＋□＋□□──□ Mn2＋＋□＋□□ 　　先使反应前后元素化合价变化的数值相等。 2＋ 5＋□□── 2Mn2＋＋ 5＋□□ 　　再使反应前后氢、…     

氧化还原反应与酸碱反应的类似性

本文从共轭关系的角度出发。与酸碱反应相对照。较详细地讨论了氧化还原反应中的共轭关系。     

氧化—还原反应教学的尝试

氧化-还原反应这节课是学生从初中升入高中在化学学习上遇到的第一个难关，这主要是由于氧化还原反应基本概念较多，且概念之间十分容易混淆，针对存在问题，几年来，在教学的基础上不断总结，不断尝试，也初步形成一些做法，希望得到同行，专家的指导。     

A reaction to the commentaries

In this chapter, conclusions are drawn and implications are suggested. Of the non-cognitive variables included in the study, the students’ Priorities were the most important in predicting GPA. In general, non-cognitive variables provided important information on admissions. Furthermore, explicit conceptual models, analyzed with relatively sophisticated statistical techniques, are needed to further our understanding of variables directly and indirectly related to college success.     

A wearables-based approach to detect and identify momentary engagement in afterschool Makerspace programs

Educational activities and programs associated with the Maker movement, which emphasizes creation of physical and digital artifacts as part of the learning experience, are presumed to be highly engaging for youth. However, there has been limited research examining what features of Maker learning activities are associated with youth engagement. We describe a research approach using wearable electrodermal activity sensors and wearable cameras to obtain data from two afterschool programs at a community Makerspace for adolescent girls (N = 12, 13). Using data obtained from these two sources along with daily survey data, we compare what is revealed from these different data sources. We observe a moderate correlation between electrodermal activity and engagement from survey responses. We also observe that activities emphasizing personal expression elicited engagement from many youth. From the EDA data and first-person video, we also identify 23 moments when groups of participants had several concurrent EDA responses suggesting high levels momentary engagement. Key features associated with those moments were opportunities for peer socialization, interactive instructional discourse, and physical making activities when objects were being assembled and manipulated.     

A summer program designed to educate college students for careers in bioinformatics

A summer program was created for undergraduates and graduate students that teaches bioinformatics concepts, offers skills in professional development, and provides research opportunities in academic and industrial institutions. We estimate that 34 of 38 graduates (89%) are in a career trajectory that will use bioinformatics. Evidence from open-ended research mentor and student survey responses, student exit interview responses, and research mentor exit interview/survey responses identified skills and knowledge from the fields of computer science, biology, and mathematics that are critical for students considering bioinformatics research. Programming knowledge and general computer skills were essential to success on bioinformatics research projects. General mathematics skills obtained through current undergraduate natural sciences programs were adequate for the research projects, although knowledge of probability and statistics should be strengthened. Biology knowledge obtained through the didactic phase of the program and prior undergraduate education was adequate, but advanced or specific knowledge could help students progress on research projects. The curriculum and assessment instruments developed for this program are available for adoption by other bioinformatics programs at http://www.calstatela.edu/SoCalBSI.     

生物实验设计题的应答策略

实验设计题能较好地考察学生的科学素质和实验能力,在各类考试中占有的比重呈上升趋势.生物实验设计题应答及在实验设计过程中必须遵循设立对照、单一变量、平行重复三个基本原则.     

生物实验设计题的应答策略

实验设计题能较好地考察学生的科学素质和实验能力，在各类考试中占有的比重呈上升趋势。生物实验设计题应答及在实验设计过程中必须遵循设立对照、单一变量、平行重复三个基本原则。     

对认定学校学生伤害事故责任归责原则的法理剖析

要妥善处理学校学生伤害事故，首先应认定事故责任。认定事故责任的归责原则是：在遵循一般过错责任原则的基础上，兼顾公平责任原则，基本不考虑无过错责任原则。     

BLAKE: A language designed for Programming I

The process of comprehending a problem, strategically developing a solution and translating the solution into an algorithm is arguably the single most important series of skills acquired during the education of an undergraduate computer science or information technology major. With this in mind, much care should be taken when choosing a programming language to deploy in the first University programming course. BLAKE, Beginners Language for Acquiring Key programming Essentials, is designed specifically for use in a Programming I class. BLAKE aids in enforcing fundamental object-oriented practices while simultaneously facilitating the transition to subsequent programming languages. BLAKE’s major features include; consistent parameter passing, single inheritance, non-redundant control structures, a simple development environment, and hardware independent data types. The syntax remains relatively small while still facilitating a straightforward transition to industry standard programming languages.