共查询到20条相似文献，搜索用时 62 毫秒
1.
Conclusion Krishnaswami Venkataraman’s contribution to the chemistry of flavones and other natural products, and his work on dyes is
not limited to the examples very briefly recorded here. His work covered also the dyes developed for colouring cements, dyemetal
complexes, health concerns in case of food colourants, and many other aspects. He put his heart, soul and brainpower for the
growth and promotion of his chosen field of research, a good part of which is important even today. 相似文献
2.
Peter Brown 《Educational research; a review for teachers and all concerned with progress in education》2013,55(3):224-225
The My Class Inventory and two creativity measures ‐ one figural and one verbal ‐ were administered to a sample of 350 students selected from the Grade 6 population of elementary schools in the three Caribbean territories, namely Barbados, Grenada and St Vincent. Analyses pointed to Barbadian schools as having a more favourable classroom learning environment for creative production than the other two territories. The level of creativity demonstrated by Barbadian students was also significantly higher than that of their counterparts in Grenada and St Vincent. 相似文献
3.
Andrew Filarowski 《Resonance》2011,16(12):1140-1145
Those of us who owe our living in part to the global dyestuff and chemical industry should pause today and remember the beginnings
of this giant industry which started 150 years ago today with William Perkins’ discovery of mauveine whilst working in his home laboratory during the Easter holiday
on April 28, 1856. Prior to this discovery, all textiles were dyed with natural dyestuffs and pigments. 相似文献
4.
Clathrate are host-guest complexes. They are discussed with specific examples from different branches of chemistry. Clathrates
are formed in different environments, but ultimately yield cage type of structures. Depending on the type of host-guest molecules,
clathrates of different dimensions and properties are formed. 相似文献
5.
Ruth Wheeldon 《International Journal of Science Education》2013,35(9):1238-1261
ABSTRACTThe effect of intervention activities on the chemistry content knowledge of 92 preservice chemistry teachers (PSCT) was examined via a pre and post true/false with confidence level test focusing on ionisation energy values and the use of a common alternative conception (AC). Data were collected from three cohorts of PSCT each engaged in a one year full-time university-based teacher education programme. Comparison of pre-and post-test responses and discrimination differences between responses for each PSCT were used to identify the use of the AC and hence the efficacy of the intervention activities. Interviews with 14 of these PSCT allowed triangulation of the data. Findings suggest that the activities allow 71% of PSCT to identify this AC as non-scientific or become more confident in doing so. Interview data indicate that this rejection of this AC is sustained for 9 of the 11 PSCT whose test data indicated improvement. These data have implications for teacher education such that 2 hour intervention sessions can offer the opportunity for PSCT to develop their subject matter knowledge. As the accurate application of electrostatic concepts to electrons has wider application to bonding, these interventions offer PSCT more accurate chemical subject knowledge resources to draw on in their teaching. 相似文献
6.
Kristina Andersson 《Cultural Studies of Science Education》2017,12(2):425-433
Marie Ståhl and Anita Hussénius have defined what discourses dominate national tests in chemistry for Grade 9 in Sweden by using feminist, critical didactic perspectives. This response seeks to expand the results in Ståhl and Hussénius’s article Chemistry inside an epistemological community box!—Discursive exclusions and inclusions in the Swedish national tests in chemistry, by using different facets of gender awareness. The first facet—Gender awareness in relations to the test designers’ own conceptions—highlighted how the gender order where women are subordinated men becomes visible in the national tests as a consequence of the test designers internalized conceptions. The second facet—Gender awareness in relation to chemistry—discussed the hierarchy between discourses within chemistry. The third facet—Gender awareness in relation to students—problematized chemistry in relation to the students’ identity formation. In summary, I suggest that the different discourses can open up new ways to interpret chemistry and perhaps dismantle the hegemonic chemistry discourse. 相似文献
7.
8.
V. Krishnan 《Resonance》2011,16(12):1201-1210
One of the most important chemical reactions is electron transfer from one atomic/molecular unit to another. This reaction,
accompanied by proton and hydrogen atom transfers, occurs in a cascade in many biological processes, including photosynthesis.
The key chemical steps involved in photosynthesis and the many unsolved mysteries are described in this article. 相似文献
9.
Seshadri developed many reagents and synthetic procedures which he used for elucidation and synthesis of natural products,
in particular flavonoids. 相似文献
10.
Sebastian Habig Janet Blankenburg Helena van Vorst Sabine Fechner Ilka Parchmann Elke Sumfleth 《International Journal of Science Education》2018,40(10):1154-1175
ABSTRACTMany studies in science education acknowledge the positive effects of context-based learning on students’ interest and attitudes. However, little is known about the design criteria of contextual situations generating these effects and how facets of students’ situational interest are affected while learning in a contextualised setting. This paper ties in with this initial situation and reports results of two projects analysing the influence of context characteristics on students’ situational interest, referring to contexts as task parameters in the first project and as learning activities in the second. In the first project, everyday related and unique contexts are compared, and the effects of different contextual topics on student learning are investigated. Particularly, regarding the feeling- and value-related valence of situational interest, the results of different studies will be compared and interpreted. The second project investigated structures of interest related to activities along an adapted version of the ‘RIASEC’-model for different content areas and age groups. The chosen contents were embedded in personal as well as societal and professional context settings. Finally, we summarise the relevance of the different models, results and instruments to better understand different notions of interest and outline implications for further studies about teaching that improves student learning. 相似文献
11.
Misconceptions of chemistry and chemical engineering university students concerning instrumental analysis have been established from coordinated tests, tutorial interviews and laboratory lessons. Misconceptions can be divided into： （1） formal, involving specific concepts and formulations within the general frame of chemistry; （2） operational/topical, dealing with specific capabilities, problems and operations in chemistry; （3） methodological, associated to peculiar methods of analytical chemistry and data treatment; and （4） social, regarding the relation of analytical data with the social frame. Such misconceptions define a non-structured view of analytical methods, procedures and protocols related with analytical instrumentation. Instruments are frequently viewed as an autonomous, error-free black box providing non-structured data with no need of calibration or control, whereas weak relationships are established between data and aims along the analytical process. 相似文献
12.
This paper describes beliefs held about teaching and learning chemistry by Turkish teachers and student-teachers. The study investigated different aspects of pre-service and in-service teachers’ belief structures. Part of the study examined teachers’ overall beliefs, based on participants’ drawings of classroom situations. A qualitative evaluation was employed to offer information on (student-)teachers’ beliefs about classroom organisation, their beliefs about teaching objectives, and their stance on epistemological beliefs. Beliefs ranged from very traditional, teacher-centred ideas to modern, student-centred ones. Data evaluation was triangulated using a quantitative approach, which focused on whether beliefs were characterised by either teacher-centredness or learner-centredness. Additionally, a Likert questionnaire was used to evaluate the educators` beliefs about the nature of good education. The results for the group of participants are presented and compared. Implications for chemistry teacher education in Turkey will also be addressed. 相似文献
13.
14.
Michael Tan 《Cultural Studies of Science Education》2012,7(3):653-657
In response to Goff, Boesdorfer, and Hunter??s article on the use of a multicultural approach to teaching chemistry and the nature of science, I forward this critical reflective essay to discuss more general curriculum aspects of the relationship between the nature of science and science education in school contexts. Taking a social realist perspective, I argue for a more nuanced understanding of the role of epistemology and ontology in science classrooms, and for a reconsideration of the role of knowledge in science classrooms. 相似文献
15.
Assessing high school chemistry students’ modeling sub-skills in a computerized molecular modeling learning environment 总被引：1，自引：0，他引：1
Much knowledge in chemistry exists at a molecular level, inaccessible to direct perception. Chemistry instruction should therefore
include multiple visual representations, such as molecular models and symbols. This study describes the implementation and
assessment of a learning unit designed for 12th grade chemistry honors students. The organic chemistry part of the unit was
taught in a Computerized Molecular Modeling (CMM) learning environment, where students explored daily life organic molecules
through assignments and two CMM software packages. The research objective was to investigate the effect of the CMM learning
unit on students’ modeling skill and sub-skills, including (a) drawing and transferring between a molecular formula, a structural
formula, and a model, and (b) transferring between symbols/models and microscopic, macroscopic, and process chemistry understanding
levels. About 600 12th grade chemistry students who studied the CMM unit responded to a reflection questionnaire, and were
assessed for their modeling skill and sub-skills via pre- and post-case-based questionnaires. Students indicated that the
CMM environment contributed to their understanding of the four chemistry understanding levels and the links among them. Students
significantly improved their scores in the five modeling sub-skills. As the complexity of the modeling assignments increased,
the number of students who responded correctly and fully decreased. We present a hierarchy of modeling sub-skills, starting
with understanding symbols and molecular structures, and ending with mastering the four chemistry understanding levels. We
recommend that chemical educators use case-based tools to assess their students’ modeling skill and validate the initial hierarchy
with a different set of questions. 相似文献
16.
Ryan S. Nixon Benjamin K. Campbell Julie A. Luft 《International Journal of Science Education》2016,38(10):1636-1654
Science teachers need to understand the subject matter they teach. While subject matter knowledge (SMK) can improve with classroom teaching experience, it is problematic that many secondary science teachers leave the profession before garnering extensive classroom experience. Furthermore, many new science teachers are assigned to teach science subjects for which they do not hold a degree. This study investigates the SMK of new secondary science teachers assigned to teach chemistry in their first three years of teaching. These new teachers do not have the advantage of years of experience to develop their SMK and half hold a degree in biology rather than chemistry. This qualitative study explores the effects of holding a degree in the subject area one teaches as well as classroom teaching experience on teachers’ SMK for two chemistry topics, conservation of mass and chemical equilibrium. Qualitative analysis of semi-structured interviews indicated that the SMK of teachers who had a chemistry degree and more extensive classroom experience was more coherent, chemistry-focused, and sophisticated than that of teachers who lacked this preparation and experience. This study provides evidence that new science teachers’ SMK is influenced by both holding a degree in the subject area and having classroom experience. 相似文献
17.
Mansoor Niaz 《Science & Education》2009,18(1):43-65
The objective of this study is to facilitate progressive transitions in chemistry teachers understanding of nature of science in the context of historical controversies. Selected controversies referred to episodes that form part of the chemistry curriculum both at secondary and university freshman level. The study is based on 17 in-service teachers who had registered for an 11-week course on ‘Investigation in the teaching of chemistry’ as part of their Master’s degree program. The course is based on 17 readings drawing on a history and philosophy of science perspective with special reference to controversial episodes in the chemistry curriculum. Course activities included written reports, class room discussions based on participants’ presentations, and written exams. Based on the results obtained it is suggested that this study facilitated the following progressive transitions in teachers’ understanding of nature of science: (a) Problematic nature of the scientific method, objectivity and the empirical basis of science; (b) Myths associated with respect to the nature of science and teaching chemistry; (c) Science does not develop by appealing to objectivity in an absolute sense, as creativity and presuppositions also play a crucial role; (d) The role of speculation and controversy in the construction of knowledge based on episodes from the chemistry curriculum; (e) How did Bohr confirm his postulates? This goes beyond the treatment in most textbooks; (f) Differentiation between the idealized scientific law and the observations. It is concluded that given the opportunity to reflect, discuss and participate in a series of course activities based on various controversial episodes, teachers’ understanding of nature of science can be enhanced. 相似文献
18.
The goal of this research was to examine how Israeli chemistry teachers at high school level use Facebook groups to facilitate learning. Two perspectives were used: Teachers’ TPACK (Technological Pedagogical Content Knowledge) and the self-efficacy beliefs of chemistry teachers for using CLFG (chemistry learning Facebook groups). Three different case studies were chosen and qualitative and quantitative research tools were used to learn about the teachers’ self-efficacy beliefs and knowledge. More specifically, a validated questionnaire for measuring teachers’ self-efficacy beliefs for using Facebook and for integrating Facebook into teaching was developed. We show that the initial beliefs (not based on a real acquaintance of Facebook) were replaced by more realistic efficacy-beliefs after the teachers started to work with the CLFG and that the technological support provided to each teacher, together with their mastery experience, supported the development of strong self-efficacy beliefs regarding the use of CLFG. Teachers’ TPACK was investigated by analyzing their interviews and the interactions in their CLFG. We found that the notion regarding what constitutes learning in the CLFG had not changed during the experiment but rather, the teachers knew better how they can facilitate this leaning. In addition they better integrated links to videos and visualizations that supported understanding abstract chemistry concepts. Interestingly, the intervention that was conducted did not influence teachers’ perceptions of learning; however, it was found to serve as an additional tool for supporting their self-efficacy beliefs by providing vicarious experience for the teachers. We therefore recommend performing a longer intervention in the future. 相似文献
19.
Tamjid Mujtaba Richard Sheldrake Michael J. Reiss Shirley Simon 《International Journal of Science Education》2018,40(6):644-667
There is a widespread concern that relatively few students, especially those from disadvantaged backgrounds, continue to study chemistry and other science subjects after compulsory education. Yet it remains unclear how different aspects of students’ background and home context, their own attitudes and beliefs, and their experiences of particular teaching approaches in school might limit or facilitate their studying aspirations; concurrently, less research has specifically focused on and surveyed disadvantaged students. In order to gain more insight, 4780 students were surveyed, covering those in Year 7 (age 11–12 years) and in Year 8 (age 12–13) from schools in England with high proportions of those from disadvantaged backgrounds. Predictive modelling highlighted that the students’ aspirations to study non-compulsory science in the future, and to study the particular subject of chemistry, were strongly associated with their extrinsic motivation towards science (their perceived utility of science, considered as a means to gain particular careers or skills), their intrinsic interest in science, and their engagement in extra-curricular activities. Additionally, their self-concept beliefs (their confidence in their own abilities in science), some teaching approaches, and encouragement from teachers and family alongside family science capital had smaller but still relevant associations. 相似文献
20.
The goal of this study was to investigate whether integrating a website into chemistry teaching influences 10th‐grade students' perceptions of the classroom learning environment, their attitudes regarding the relevance of chemistry, and their understanding of the concept of chemical bonding. Two groups participated in this study: an experimental group and a comparison group. The main study was conducted during the academic year 2005. The teachers in the experimental group were asked to implement four relevant activities from the website that was developed, all dealing with the concept of chemical bonding. Quantitative tools of the study included: A Chemistry Classroom Web‐Based Learning Environment Inventory to assess students' perceptions regarding the relevance of chemistry to their life and attitude towards chemistry studies, a feedback questionnaire that examined the students' response after performing the website activities, and an achievement test that assessed their knowledge and understanding of the concept of chemical bonding. We found that the experimental group outperformed the comparison group significantly in most of the research categories. This led us to conclude that the web‐based learning environment has potential to enhance the comprehension of chemistry concepts, students' attitudes and interests and to increase students' awareness regarding the relevant aspects of chemistry to daily life. 相似文献