求解化学反应动力学参数的一种方法

反应级数的确定在化学动力学研究中非常重要,现给出了利用计算机和用微分法确定反应级数的方法.为了使编程的程序简短、高效,采用MATLAB语言作为编程语言.     

Fiber optic biosensor of immobilized firefly luciferase

Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. TheK _m′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25°C respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10⁻⁹–10⁻⁵ mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.     

Reformation of VET and demands on teachers’ subject knowledge – Swedish vocational teachers’ recurrent participation in a national CPD initiative

This study investigates continuing professional development (CPD) of vocational teachers, with a focus on recurrent participation. Vocational teachers need to be competent as teachers and in relation to their vocational teaching subject. Reformation of Swedish vocational education in order to strengthen the working-life connection imposes demands on teachers to have up-to-date knowledge about the vocations related to their vocational subjects. To support the reform, vocational teachers have been offered to participate in a new national CPD initiative targeting their vocational competence. The study concerns participation in this initiative. Drawing on a socio-cultural perspective, vocational teachers’ CPD implies boundary-crossing between school and working-life. Theory concerning adults’ participation in education is considered relevant to understand conditions for such boundary-crossing, and learning, among vocational teachers. The article specifically investigates patterns in vocational teachers’ recurrent participation, which is expected to clarify the factors influencing further participation in professional development. The strongest predictor of recurrent participation, when adjusting for the influence of other factors, is the type of municipality that the teacher comes from, with low populated municipalities having the lowest likelihood of participation. Furthermore, recurrent participation is more likely by participating teachers from adult education or from privately owned schools, and by male teachers.     

A sociocultural perspective on mediated activity in third grade science

This ethnographic study of a third grade classroom examined elementary school science learning as a sociocultural accomplishment. The research focused on how a teacher helped his students acquire psychological tools for learning to think and engage in scientific practices as locally defined. Analyses of classroom discourse examined both how the teacher used mediational strategies to frame disciplinary knowledge in science as well as how students internalized and appropriated ways of knowing in science. The study documented and analyzed how students came to appropriate scientific knowledge as their own in an ongoing manner tied to their identities as student scientists. Implications for sociocultural theory in science education research are discussed. John Reveles is an assistant professor in the Elementary Education Department at California State University, Northridge. He received his Ph.D. from the University of California, Santa Barbara in 2005. Before pursuing his Ph.D., he worked as a bilingual elementary school teacher for 3 years. His research focuses on the development of scientific literacy in elementary school settings; sociocultural influences on students' academic identity; equity of access issues in science education; qualitative and quantitative research methods. Within the Michael D. Eisner College of Education, he teaches elementary science curriculum methods courses, graduate science education seminars, and graduate research courses. Gregory Kelly is a professor of science education at Penn State University. He is a former Peace Corps Volunteer and physics teacher. He received his Ph.D. from Cornell in 1994. His research focuses on classroom discourse, epistemology, and science learning. This work has been supported by grants from Spencer Foundation, National Science Foundation, and the National Academy of Education. He teaches courses concerning the uses of history, philosophy, sociology of science in science teaching and teaching and learning science in secondary schools. He is editor of the journal Science Education. Richard Durán is a Professor in the Gevirtz Graduate School of Education, University of California, Santa Barbara. His research and publications have been in the areas of literacy and assessment of English Language Learners and Latino students. He has also conducted research on after school computer clubs, technology and learning as part of the international UC Links Network. With support from the Kellogg Foundation, he is implementing and investigating community and family-centered intervention programs serving the educational progress of Latino students in the middle and high school grades.     

Pedro Gutiérrez Bueno’s Textbooks: Audiences, Teaching Practices and Chemical Revolution

Pedro Gutiérrez Bueno wrote two editions of a chemistry textbook between 1788 and 1802. The paper offers a comparative view of both editions taking into account Gutiérrez Bueno’s biography, his intended audience and the changes related to the so-called chemical revolution. Some conclusions are at odds with common images about scientific revolutions and the role of textbooks in science. The analysis aims to shed some light on the multiple historical forces shaping textbooks and the way in which scientific change is assimilated by their writers. This research was partially supported by the program BHA2002-04611-CO3-02     

Introduction to this Special Issue

In 2001, for the first time in the history of the International Association for Counselling, International Conference was held in a developing Asian country–India, with the theme Families in Transition–Counselling in Transition–Meeting the Challenges Ahead. This special issue contains some of the presentations made by Indian participants during this conference which best reflect the challenges and diversities of counseling efforts with families in India. The first article was specially written for this issue in order to give an international relationship of this journal an in depth contextual understanding of Indian families in transition and the challenges they pose to the contemporary Indian counselor. Two articles are reflected to counseling families affected by socio-politial and economic changes. Five authors have written on counseling related to physical and mental disability/addiction and last two articles are reflected to authors experiences as family counselors.     

Kinetics study on biomass pyrolysis for fuel gas production

Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China     

Early Childhood Services in Ireland

This paper gives background information on early childhood services in Ireland and presents the results of a survey of the preschool experiences of 1065 children. The results of the survey suggest that the majority of children experienced some form of early childhood service before starting school. The most common service was a playgroup although a significant proportion of the children had experienced home‐based care with a relative or family day care provider. The implications of the findings for the development of a policy on early childhood services are discussed.