对高校《世界地理》教材中澳大利亚地理环境结构特征的不同看法

澳大利亚仅仅是降水量的分布由北、东、南三面沿海向内陆逐渐减少,呈半环状分布图式。在降水量呈半环状分布的特征影响下,从北、东、南三面沿海向内陆植被由森林逐渐变为草原,再变为荒漠。但是由此得出,气候类型和自然带的分布也有类似的图式,“地理环境呈半环状结构”是不妥当的。澳大利亚的气候类型、植被和自然带的分布,都表现出明显的纬向地带性特征,都是与一定的纬度位置、海陆位置密切相联系的。这样理解既有利于掌握全球地理环境分布的规律性,也有利于突出区域地理环境的特征。     

School mathematics in culture-conflict situations

In times of cultural change, education plays an especially important role. The writer suggests that even mathematics curricula, which have traditionally been considered culture-free, have a role to play in fostering mutual understanding amongst members of different cultures, after a period of cultural upheaval. Anthropological and educational sources are used to suggest points of relevance when a mathematical curriculum is designed for multi-cultural classrooms.The substance of this paper is the same as that in an article written for the journal,Cultural Dynamics.     

On the construction of transitional filter nomographs

The construction of nomographs for transitional classical filters is described. Gain functions of classical filters are related to filter requirements resulting in a formulation for the general gain nomograph. The transitional filters that are products of approximating polynomials are incorporated into the general gain nomograph resulting in transitional filter nomographs that are sums of the individual nomographs. Nomographs for transitional filters using alternative forms where poles are interpolated are also considered. The resulting nomographs allow for quick optimization of transitional filter frequency response in many cases. Design examples are submitted and discussed. The proposed transitional filter nomographs provide the engineer with increased insight into the selection of classical transitional filters with optimum frequency response.     

Play power

These games are excerpted from Play Poweravailable from Play Power Publishing, P.O. Box 2186, Orinda, CA 94563.     

On semiotics and subjectivity: a response to Tony Brown’s “signifying ‘students’, ‘teachers’, and ‘mathematics’: a reading of a special issue”

In this response we address some of the significant issues that Tony Brown raised in his analysis and critique of the Special Issue of Educational Studies in Mathematics on “Semiotic perspectives in mathematics education” (Sáenz-Ludlow & Presmeg, Educational Studies in Mathematics 61(1–2), 2006). Among these issues are conceptualizations of subjectivity and the notion that particular readings of Peircean and Vygotskian semiotics may limit the ways that authors define key actors or elements in mathematics education, namely students, teachers and the nature of mathematics. To deepen the conversation, we comment on Brown’s approach and explore the theoretical apparatus of Jacques Lacan that informs Brown’s discourse. We show some of the intrinsic limitations of the Lacanian idea of subjectivity that permeates Brown’s insightful analysis and conclude with a suggestion about some possible lines of research in mathematics education.

A transcultural study of dyslexia: Analysis of reading disabilities in 425 Chinese children simultaneously learning to read and write in English and in Chinese

Annals of Dyslexia -     

Uncontrollable Mental Imagery: Graphical Connections Between A Function And Its Derivative

The view that imagery might be a disadvantage on certain tasks might surprise some mathematics educators who contend that a learner's conceptual understanding is increased whenever visual imagery is used. One of the limitations of imagery found in the literature comes to bear on a unique aspect of mathematics teaching and learning. This is the notion of an uncontrollable image, which may persist, thereby preventing the opening up of more fruitful avenues of thought, a difficulty which is particularly acute if the image is vivid. Although one calculus student's images supported high levels of mathematical functioning, occasionally his vivid images became uncontrollable, and the power of these images did more to obscure than to explain. This type of imagery can be a major hindrance in constructing meaning for mathematical concepts — contrary to the panacea view of imagery which is sometimes expressed.This revised version was published online in September 2005 with corrections to the Cover Date.