科学本质教育的研究新趋势与中学生物学教学——从“共识观点”到“家族相似法”

科学本质是科学教育中的重要目标，是科学素养的重要组成部分。本文旨在梳理近20年来科学教育中科学本质的理论发展，关注科学本质教育研究的新趋势及其应用。     

"科学本质"的研究及其进展

“理解科学”是科学教育的目标之一,也是当今科学教育的一个新趋势。从传统的实在主义、理性主义等,到后现代主义(建构主义),科学本质经历了曲折的发展历程。从科学本质的哲学渊源、内涵、研究现状进行了总结。迄今为止,有关学生和教师的科学本质观的研究均显示他们对科学本质的理解不够,有待进一步提高。我们也应该从课程等各个方面增加相应的内容,以提高教师和学生的科学本质观,进而实现科学教育的课程目标。     

还科学史原貌，挖掘科学本质教育价值

科学史从科学知识、科学探究、科学事业3个维度揭示了科学本质,是开展科学本质教育的良好载体。从科学史教学中常见的问题出发,在还科学史原貌的基础上,剖析其反映的“科学知识的稳定性和发展性”“科学探究的实证性和创造性”“科学事业的技术依托性”等科学本质教育价值,并建议在科学史教学中准确把握科学发展原貌,有的放矢地呈现科学史,从而更好地实现其科学本质教育价值。     

对科学本质的一些探讨

说真的。在中学教了数十年的生物科学课程,一直都没有关注科学的本质究竟是什么。这些年参与中学生物学课程改革的研究和实践,渐渐地觉得这个问题很重要．因为生物科学教育是科学教育的一个重要领域,科学教育自然应揭示并使学生领悟科学的本质。在我们的课程标准中就有提及,例如义务教育生物学课程标准中,在“提高生物科学素养”的叙述中,就有“理解科学的本质”的要求。     

科学本质观中“科学知识可能随着研究的深入而改变”对科学教学的启示

作为科学本质观的组成要素之一,使学生理解"科学知识可能随着研究的深入而改变"是《普通高中生物学课程标准(2017年版)》提出的建议之一。在科学教育中,教师可使用科学史和科学探究教学,帮助学生了解和体会科学知识的暂时性、发展性及其内在原因,促使学生建立更成熟的科学本质观,更好地进行科学学习,提高科学素养。     

在科学教学中明确“社会文化”对科学的影响

《普通高中生物学课程标准(2017年版)》中强调,科学本质观对于目标的达成起到重要的帮助作用。其中,理解科学会受到社会和文化的影响是科学本质对生物学教学提出的建议之一。在科学发展历程中,社会文化与科学密切交织,互相影响,同时也改变着生物学课程教育的发展轨迹。通过融入科学史教学、参与社会性科学议题讨论,以及在课程中融入技术与工程学等方法,教师可帮助学生明确社会文化对科学的影响作用,进而更好地理解科学本质,促进学科核心素养的有效达成。     

合理构建教学 实现生命科学史的教育价值

高中新教材中生命科学史的引入无疑强化了科学探索精神的培养,有助于学生理解科学的本质和科学研究的方法。不同内容的科学史有其共同的教育价值,但也应该有其不同的教育价值。因此,在考虑教学设计时,就应该采用不同的教学策略,合理构建,活化科学史,真正实现科学史的教育价值。     

中学生物学教师科学本质观的探查研究

教师是教学中的一个重要组成部分,教师要提高其教学技能,必须提高对科学知识结构、功能、发展及科学本质的充分理解,然后将科学本质转换为教学知识.通过相应课程的8学时培训,利用Kimball的科学本质观测查量表对中学生物学教师的科学本质观进行研究.结果显示在接受课程培训后,他们的科学本质观都得到了不同程度的提高,而且科学本质观与教师的教龄存在一定联系,随教龄的增加,对科学本质的理解不断提高.     

融科学史哲于科学教学研讨会在浙江师范大学举行

正2017年10月30—31日,"促进科学本质的理解——融科学史哲于科学教学研讨会"在浙江师范大学举行,来自全国各地的生物学教研员、生物学骨干教师、浙江科学课骨干教师和教研员,以及浙江师范大学科学教育专业的研究生300余人参加了此次研讨会。来自澳大利亚的科学     

“活”用生物科学史实现科学史的教育价值

“科学是一个发展的过程,学习科学史能使学生沿着科学家探索生物世界的道路,理解科学本质和科学研究方法,学习科学家献身科学的精神.”科学史的教育价值被越来越多的教师所重视.6年的新课程教学实践,笔者发现大多数教师对科学史在高中生物学教学中的教育价值持肯定态度.但是,在具体的教学实践中要实现其教育价值并不容易.笔者以“孟德尔的豌豆杂交实验(一)”为例,论述如何实现科学史的教育价值.     

音乐治疗效应的动物实验研究

近年来国内外关于音乐治疗效应的动物实验研究认为：音乐能影响动物的情绪;音乐还对动物的免疫功能、学习及记忆能力、以及动物的神经系统结构和功能等均有一定影响。该领域的研究有利于深入探索音乐疗法的作用机理。     

Time on task effects on safety

Reviewing the literature on time on task effects on safety shows contradictory evidence, especially with regard to 12 h shifts. It is argued that this might depend on methodological problems associated with the analysis of accident data, e.g. selectivity of samples, validity of data bases and study designs, especially for analyses at the company level. Analyses of aggregated data seem to indicate an exponential increase of accident risk with time on task beyond the normal working day. This is supported by some recent studies based on data from the Federal Republic of Germany.     

Perspectives on hair evolution based on some comparative studies on vertebrate cornification

Hair evolution contributed to the biological success of mammals. Hair origin from synapsid scales is speculative and requires extensive modifications of the morphogenetic process transforming lens-shaped dermis of scales into small dermal papillae in hair. Hair evolution from glands is hypothetical but is supported from studies on the signaling control of hair vs. glandular morphogenesis. Based on immunocytochemical and comparative studies, it is hypothesized that the onion-like organization of hair derived from glandular pegs which central part produced lipids and some keratin. In a following stage, involucrin, trichohyalin, and keratins were produced in the central cells of the gland and formed a solid medulla surrounded by keratinocytes of the inner root sheath. The origin of this protohair was possibly related to increased concentration of beta-catenin and other signaling molecules in epithelial cells following the evolution of a dermal papilla. The latter activated the keratogenic genes, already utilized in cells of the claws, in concentric layers of cells of the glandular peg. Lipidogenic genes were depressed. As new genes evolved in the genome of synapsids, new circular layers of keratinocytes containing specialized hard keratins and keratin-associated proteins were formed around medullary cells. The new keratinocytes probably originated the cortex separating medulla from the external cells that became the inner root sheath. The hypothesis indicates that in a following stage, the medulla was obliterated or replaced by cortical cells while the external part of the cortex formed a cuticular surface due to the different growth rate with inner root sheath cells.     

Studies on Biosynthesis on Biotin by Microorganisms

The accumulation of biotin-vitamers in the culture media of a large number of microorganisms (about 700 strains) was studied. The contents of the biotin-vitamers were quantitatively determined by microbiological assays with Lactobacillus arabinosus and Saccharomyces cerevisiae.

It was found that large amounts of biotin-vitamers were accumulated by various microorganisms such as Streptomyces, molds and bacteria, and that the yield of biotin-vitamers was enhanced by the addition of pimelic acid or azelaic acid to the media. It was also found that the main portion of the vitamers accumulated by many microorganisms did not support the growth of Lactobacillus arabinosus, while it did support that of Saccharomyces cerevisiae. The small amounts of true biotin were observed in the culture media of various Streptomyces and molds, but hardly in the culture media of bacteria.

The identification of biotin-vitamers accumulated by various microorganisms is described, and the distribution of the vitamers in microorganisms is also described.

The results presented in this paper show that the main component of the vitamers accumulated by many microorganisms is identified as desthiobiotin by anion exchange column chromatography, paper chromatography and chemical analysis. Small amounts of fraction B (unidentified vitamers) and Fraction D (biotin) were also detected in the culture media of various molds and Streptomyces. However, these fractions were not observed in the culture media of any bacteria tested.

It was also found that large amounts of an unknown biotin-vitamer was accumulated by various bacteria. The vitamer was avidin-uncombinable, and, from the paper electrophoretic studies, it was assumed that the vitamer might be an analogue of pelargonic acid.