Molecular design and application of luminescent materials composed of group 13 elements with an aggregation-induced emission property

Complexation of π-conjugated ligands by metal or semimetal ions leads to the enhancement of the planarity and rigidity of π-conjugated systems. Boron, especially, has played a central role in the design of luminescent main-group complexes. However, these complexes still suffer the disadvantage of aggregation-caused quenching as well as typical organic fluorophores. It has recently been reported that some types of boron complexes exhibit the aggregation-induced emission (AIE) property. Moreover, AIE behavior from complexes and organometallic compounds composed of the other group 13 elements, such as aluminum and gallium, has emerged in this decade. These observations greatly encourage us to develop advanced functional materials based on the group 13 elements. Indeed, recent research has demonstrated that these classes of materials are potentially versatile scaffolds for constructing chromic luminophores, efficiently emissive π-conjugated polymers and so on. This review mainly describes AIE-active group 13 complexes with four-coordinate structures and their application as photo-functional materials. Proposed mechanisms of the origins of AIE behavior are briefly discussed.     

Exploring features for the automatic identification of user goals in web search

Queries submitted to search engines can be classified according to the user goals into three distinct categories: navigational, informational, and transactional. Such classification may be useful, for instance, as additional information for advertisement selection algorithms and for search engine ranking functions, among other possible applications. This paper presents a study about the impact of using several features extracted from the document collection and query logs on the task of automatically identifying the users’ goals behind their queries. We propose the use of new features not previously reported in literature and study their impact on the quality of the query classification task. Further, we study the impact of each feature on different web collections, showing that the choice of the best set of features may change according to the target collection.     

Role of the microcomputer‐based laboratory display in supporting the construction of new understandings in thermal physics

Teachers' failure to use the microcomputer‐based laboratory (MBL) more widely may be a result of not recognizing its capacity to transform laboratory activities. This research aimed to increase understanding of how MBL activities designed to be consistent with a constructivist theory of learning support or constrain student construction of understanding. The first author conducted the research with his Year 11 physics class of 15 students. Dyads addressed 10 tasks in thermal physics using a predict–observe–explain format. Data sources included video and audio recordings of students and teacher during four 70‐minute sessions, students' computer data and written notes, semistructured student interviews, and the teacher's journal. Analysis of students' discourse identified many instances in which students' initial understandings of thermal physics were mediated in multiple ways by the screen display. The findings are presented as eight assertions. Recommendations are made for developing pedagogical strategies incorporating MBL activities that will likely catalyze student construction of understanding. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 165–185, 2004     

The Relative Efficiency of Departments at a Turkish Engineering College: A Data Envelopment Analysis

In this study, Data Envelopment Analysis is used to measure relative efficiencies of academic departments of an engineering college. Input and output criteria are determined and measured utilizing the academic personnel performance measurement scheme of the College. New measures are developed to compare departments of different disciplines. The discriminating power of the measurement models is improved by restricting criteria weights directly and by using a multiple criteria decision making approach. Sensitivity of the results to exclusion of a criterion and changes in relative importance of the criteria is analyzed. Evaluation of the results jointly by the college administration and the departments is explained for a successful efficiency improvement mechanism.     

成吉思汗在西南的后裔

在我国西南的云南、贵州、四川、重庆，生活着近7万名蒙古族民众，其中成吉思汗所属的奇渥温部后裔约占半数以上。几百年来，在对西南环境的适应过程中，他们形成了以山区农业为主的经济生活，原来的游牧化也随之发生了变化。但是，他们通过家谱、墓碑、口授的方式，传承着家族的历史和自己作为蒙古人的执信念。西南蒙古族具有明显的民族特征，其中内涵着宝贵的民族人资源。     

THE POLYMERIZATION OF METHYL METHACRYLATE WITH A NEW TIN-BRIDGED YTTROCENE/Al(i-Bu)_3

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Four dialogues and metalogues about the nature of science

We analyse and explore, in the form of dialogues and metalogues questions about the dialogic nature of beliefs and students belief talk about the nature of science and scientific knowledge. Following recent advances in discursive psychology, this study focuses not on students' claims but on the discursive resources and dialogical practices that support the particular claims they make. We argue that students' discourse is better understood as a textual bricolage that is sensitive to conversational context, common sense, interpretive repertoires, and textual resources available in the conversational situation. Our text is reflexive as it embodies the discursive construction of knowledge and undercuts any claims to authoritative knowledge. The very conception of “belief” is itself an expression or construction from within the mundane idiom.... We learn to use “belief” in conditions when the “objective facts” are unknown or problematic and we want to indicate the tenuous character of our claim.... The notion of “real world” or “objective reality” is embedded in an extensive, pervasive language game which includes as an intelligible move or possibility the use of the very concept of “belief” itself. (Pollner, 1987, p. 21)     

Maintaining the reversibility of foldings: Making the ethics (politics) of information technology visible

This paper will address the question of the morality of technology. I believe this is an important question for our contemporary society in which technology, especially information technology, is increasingly becoming the default mode of social ordering. I want to suggest that the conventional manner of conceptualising the morality of technology is inadequate – even dangerous. The conventional view of technology is that technology represents technical means to achieve social ends. Thus, the moral problem of technology, from this perspective, is the way in which the given technical means are applied to particular (good or bad) social ends. In opposition to this I want to suggest that the assumed separation, of this approach, between technical means and social ends are inappropriate. It only serves to hide the most important political and ethical dimensions of technology. I want to suggest that the morality of technology is much more embedded and implicit than such a view would suggest. In order to critique this approach I will draw on phenomenology and the more recent work of Bruno Latour. With these intellectual resources in mind I will propose disclosive ethics as a way to make the morality of technology visible. I will give a brief account of this approach and show how it might guide our␣understanding of the ethics and politics of technology by considering two examples of contemporary information technology: search engines and plagiarism detection systems.