Making Connections: Learning and Teaching Chemistry in Context

Even though several studies have reported positive attitudinal outcomes from context-based chemistry programs, methodological obstacles have prevented researchers from comparing satisfactorily the chemistry-learning outcomes between students who experience a context-based program with those who experience a content-driven program. In this narrative inquiry we are able to address the question: how do the recalled experiences of a student and her teacher in context-based and concept-based chemistry programs compare? From the student’s unique perspective of experiencing both programs with the same teacher, we have constructed our collective account around four themes; namely, the extent to which the student makes connections between chemistry concepts and real-world contexts, developing research independence through engaging in extended experimental investigations related to contexts, learning chemistry concepts through contexts, and conceptual sequencing in a context-based program. The student reported real-world connections between chemistry concepts and contexts, found her engagement in the context-driven tasks interesting and productive, and identified connected sequences of concepts across the contexts studied. Despite difficulties for teachers who are required to shift pedagogies, the student’s lived experiences and outcomes from a context-based program provide some encouragement in working through these issues.     

Establishing a Competence Profile for the Role of Student-centred Teachers in Higher Education in Belgium

The increasing importance of constructivism in higher education has brought about a shift in pedagogy from a focus on the teacher to a focus on the student. This has important implications for teaching and assessment. A student-centred pedagogy implies a different role for the teacher. What exactly does student-centred teaching require from teachers’ actual teaching practice? What is expected from them in order to teach in a student-centred way? It is in order to respond to these questions that this research project has been carried out establishing a core competence profile of student-centred teachers in higher education. Qualitative data were collected by means of semi-structured in-depth interviews with teachers from different institutions for higher education in Belgium, known for their student-centred way of teaching. This research method is innovative compared to the methods used for existing competence lists in the literature, which were usually developed on the basis of conversations with pedagogical experts. By exploring practice and having teachers participate in the development of a competence list, the acceptance of a competence profile is much higher. The result of the project is a validated competence profile which takes into account the critiques on existing competence lists. The competence profile provides a further insight in the functioning of teachers within a student-centred pedagogy and can be used as a starting point for the educational development of teachers within this pedagogy.     

Assessing the counselling needs of high school students in Kenya

The Student Counselling Needs Scale (SCNS) was administered to 867 participants recruited from high schools in Kenya. The data were analyzed using exploratory factor analysis yielding five factors: human relationships, career development, self development, social values, and learning skills were assessed. The findings highlighted the importance of using assessment instruments to identify students’ counselling needs in Kenya.     

The Impact of Learner’s Prior Knowledge on Their Use of Chemistry Computer Simulations: A Case Study

It is complicated to design a computer simulation that adapts to students with different characteristics. This study documented cases that show how college students’ prior chemistry knowledge level affected their interaction with peers and their approach to solving problems with the use of computer simulations that were designed to learn electrochemistry. Students with different prior knowledge levels were found to use different approaches to solving problems with the use of computer simulations. In particular, the cases showed that students with a high level of prior knowledge tended to use the equations and formulas to accomplish the learning tasks and then use the computer simulations to confirm their predictions. Students with a low level of prior chemistry knowledge used the computer simulations as the main resources to accomplish their tasks. Considerations of individual differences and the integration of learning materials were suggested for further research on instructional use of computer simulations.     

固支Mindlin 板弯曲问题的辛本征解

Hamiltonian system for the problem on clamped Mindlin plate bending was established by introducing the dual variables for the generalized displacements in this letter. By separation of variables, the transverse eigen-problem was derived based on the sympletic geometry method. With the solved sympletic eigen-values, the generalized sympletic eigen-solution was derived through eigenfunction expansion. An example of plate with all edges clamped was given. The sympletic solution system was worked out directly from the Hamiltonian system. It breaks the limitation of traditional analytic methods which need to select basis functions in advance. The results indicate that the sympletic solution method could find its more extensive applications.     

Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

Novel high torque bearingless two-sided rotary ultrasonic motor

Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide suffi-ciently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting of a two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using ex-perimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.     

Confronting Challenges to the Liberal Arts Curriculum: Perspectives of Developing and Transitional Countries

Contemporary international higher education scholarship tends to focus on the global financial crisis,on massification,privatization,cross-border education,university ranking,and student mobility.However,few studies deal with the development of liberal arts programs around the world and they are often related to Western systems of higher education or that of the US,where liberal arts education has long been seen as a fundamental issue.Comparative studies,however,could help scholars to become aware of critical trends and reforms,also the impact they might have on a global society.