中和热测定实验释疑

1 测定酸碱中和热为什么要用稀溶液 中和热是酸碱在稀溶液中发生中和反应生成lmol水时所放出的热量,这里的稀溶液一般要求酸溶液中的C(H )≤1mol/L或碱溶液中的C(OH-)≤1mol/L.这是因为如果在浓溶液中,即使是强酸或强碱,由于得不到足够的水分子,因此也不能完全电离为自由移动的离子.在中和反应过程中会伴随着酸或碱的电离及离子的水化,电离要吸收热量,离子的水化要放出热量,不同浓度时这个热量就不相同,所以中和热的数值就不相同,这样就没有一个统一标准了.     

打造专业新格局,树电大普专品牌——对电大普通专科教育教学计划制订与实施的思考

对于省级电大，电大普通专科教育已成为电大发展进程中的一个重要组成部分。随着高等教育大众化的日益推进，各类高校招生规模的不断扩大，电大普通专科教育正日益面临生存的挑战。本文从专业设置与专业建设的角度出发，以体现专业设置的教学计划为切入点，对普专教育教学计划的制订与实施现状进行了分析，提出了打造专业新格局、树电大普专品牌的设想与思考。     

PERSONNEL NEEDS IN SCHOOL PSYCHOLOGY: A 10‐YEAR FOLLOW‐UP STUDY ON PREDICTED PERSONNEL SHORTAGES

Concerns regarding whether a sufficient supply of school psychologists exists have been evident for decades. Studies have predicted that school psychology would face a critical personnel shortage that would peak in 2010, but continue into the foreseeable future. The current study is a 10‐year follow‐up investigation based on previously published personnel shortage projections. Data derived from the National Association of School Psychologists 2009–2010 national study were used to examine current personnel shortages as well as to project the extent to which personnel shortages are likely to continue. Findings indicate that the field of school psychology continues to experience a personnel shortage that will continue through 2025. Additionally, greater rates of retirements are projected for the field for school psychologists who are males, who possess a doctoral degree, and for university faculty. Analyses based on the U.S. Census Regions indicate that notable differences are likely to occur in the match between the supply of and demand for school psychologists based on geographical location. Implications are discussed relating to the recruitment and retention of school psychologists and to the services they deliver.     

试析中国英语课堂上教师的语码转换现象

近年来,外语课堂上的语码转换现象已成为国外学者们关注和研究的焦点。而这一点在国内还没有引起学者们的普遍关注。从语言教学的角度,语码转换这一国内英语课上的普遍现象还没有被视为教学步骤加以分析。那么国内英语课上的语码转换现象对学习者英语语言习得的利弊究竟如何以及教师该如何有效把握语码转换这一教学策略进行英语教学将是本文探讨的内容。     

通信原理可视化辅助教学研究

为了提高通信原理课程的课堂教学效果,用Visual Basic可视化编程设计制作了通信原理演示系统。演示系统涵盖了通信原理的三大主要基本原理及方法,即模拟通信系统、数字基带系统和数字频带系统。将此演示系统应用于通信原理的课堂教学中,既增加了教学的趣味性和实效性,又提高了教学效果。     

基于任务的听力教学设计研究

本文尝试从交际语言能力的界定、/语言使用任务及语言材料真实性,三个层面来探讨基于任务的语言教学理论;并以此为理论依据,尝试进行基于任务的听力教学设计研究,即从语言学习者需求出发,将雅思听力材料引入大学英语听力教学,选择合适的听力任务,进行任务教学,以期达到培养学习者英语交际能力的目标。     

Promoting Teacher Learning Through Learning Study Discourse: The Case of Science Teachers in Singapore

The potential of a theory of variation-framed learning study, a teacher professional development approach, to help teachers overcome curricular and pedagogical challenges associated with teaching new science curricula content was explored. With a group of Singapore teachers collaboratively planning and teaching new genetics content, phenomenographic analysis of data corpus from classroom observations, teacher meetings and interviews revealed teacher learning that manifested in the teachers’ experiences. These were captured as (1) increased degrees of student-centered pedagogy and challenges to teachers’ prior assumptions about science pedagogy, (2) increased awareness of possibilities and limitations of their beliefs about science pedagogy, and (3) emergence of new understandings about new curricular content and science pedagogy. The possibility of transformative and generative learning is also discussed.     

耶律楚材家族边塞与赠别思归作品分析

在丝绸之路上,有一定数量的契丹文化遗存.其中,耶律楚材祖孙三代在随蒙元大军西征东讨时,走过丝绸之路并创作了许多诗文.这些诗文大体可分为两类,一类为描写边塞战争之作,一类为赠别思归之作.其边塞战争作品包含四类内容,一是征战场景,二是止战优抚,三是劝谏开疆拓土,四是抒写征人思妇之情.其赠别思归作品一为赠别,一为思归,赠别作品主要包含四类,一是惜别伤怀,二是劝说留客,三是欣然相送或劝人建功立业,四是劝诫勉励侄孙后辈;思归作品主要包含两类,一是思亲,二是思乡.     

高等教育自学考试“试题”模式化倾向及调整

衡量高等教育自学考试水平高低最直接的量尺是试题。然而,在经常性进行的高等教育自学考试中,试题存在着诸如格式化、书本化、一纸化、内容固定化、普通教育化等模式化倾向。高等教育自学考试的试题,应该把"导学"功能放在第一位,引导应试者掌握系统的学科专业知识,强化知识技能的应用价值。当然,可以通过增加自主选择试题,或者尝试用计算机考试来顺应考试的新变化。     

Relooking Assessment: A Study on Assessing Developmental Learning Outcomes in Toddlers

In most countries the funding for early childhood education has increased and governments in some countries have taken serious steps to bring about positive change in the profession. However, the increase in funding by governments and other funding organisations around the world has, understandably, attracted increased accountability as these organisations need to know that their financial investments are achieving desired outcomes. To seek evidence that positive learning outcomes have indeed been achieved through these investments is a reasonable request, and there is a shared responsibility and accountability for professionals to provide appropriate evidence. The downside, however, can be the request for standardised test information, as if performance on such tests provides proof of all desired outcomes. More than ever before, it is important for early childhood educators to be able to provide accurate, objective information about children’s assessment in ways other than by standardised testing, which may not reflect the complex reality of children’s lives. This paper reports on a research study in Singapore that investigated curriculum effectiveness using developmental learning outcomes as a means of assessing children. The research was devised to examine if eight specified broad developmental learning outcomes could measure the effectiveness of the curriculum by assessing children’s learning as shown in qualitative data. Practical examples showed evidence of children’s learning and the role of the educator in facilitating and documenting developmental learning outcomes.