URI和数字对象唯一标识符*

数字对象唯一标识符作为数字图书馆的基础设施，具备网络环境下数字对象的标识、定位、管理等多种职能。本文分析了唯一标识符的类型、组成和构造原则，从逻辑标识、命名域相关、复杂性、完整性和互操作等角度论述唯一标识符的需求。在W3C提供的URI背景下，比较URI、URL和URN，并分析了相关命名语法和标识框架。最后介绍了COOL URL的概念和命名需求。     

The Significance of the Learning Society for Women and Men with Learning Difficulties

This article draws on work undertaken as part of the Economic and Social Research Council's Learning Society Programme. The project from which data are drawn, entitled 'The Meaning of the Learning Society for Adults with Learning Difficulties', focused on lifelong learning opportunities available to people with learning difficulties and experiences of these services. The article begins by examining theories of late modernity, their use by feminist and disability studies theorists and their relationship to ideas of a learning society. Subsequently, using case study material, it is argued that the identities of people with learning difficulties are not chosen freely from a range of options but are socially ascribed. The status of learning difficulties is used as a dominant category to justify deprivation of basic political and economic rights. In addition, the lives of people with learning difficulties are structured by gender and class, and these intersect with the category of learning difficulties. For both women and men, the advantages of middle-class social and economic capital are overridden by the negative category of learning difficulties. In relation to gender, men with learning difficulties are more likely to receive post-school training, but in inappropriate areas of the labour market. Their domestic needs are also likely to be attended to by others, but in the absence of employment, they find themselves without any valued social role. Women with learning difficulties are also likely to be excluded from the labour market, but are more likely to be involved in reciprocal, albeit limited, social relationships. It is concluded that postmodernist theories are inadequate to describe the structuring of the lives of people with learning difficulties.     

Emotional and Behavioral Predictors of Preschool Peer Ratings

It was predicted that social cognitive, behavioral, and affective aspects of young children's social development would predict stable peer ratings of their likability. Measures of likability, emotion knowledge, prosocial and aggressive behavior, peer competence, and expressed emotions (happy and angry) were obtained for 65 subjects (mean age = 44 months). Sociometric ratings, particularly negative, were stable over 1- and 9-month time periods. Correlational analyses showed that emotion knowledge and prosocial behavior were direct predictors of likability. Prosocial behavior mediated the relations of gender and expressed emotions with likability (i.e., gender and expressed emotions were each related to prosocial behavior, and prosocial behavior was related to likability, but neither gender nor expressed emotions were related to likability with prosocial behavior partialled out). Knowledge of emotional situations similarly mediated the age-likability relation. Results uphold the early development of stable peer reputations and the hypothesized centrality of emotion-related predictors of likability.     

Concurrent and predictive validity of parent reports of child language at ages 2 and 3 years

The MacArthur-Bates Communicative Development Inventories (CDI; Dale, 1996; Fenson et al., 1994), parent reports about language skills, are being used increasingly in studies of theoretical and public health importance. This study (N = 113) correlated scores on the CDI at ages 2 and 3 years with scores at age 3 years on tests of cognition and receptive language and measures from parent-child conversation. Associations indicated reasonable concurrent and predictive validity. The findings suggest that satisfactory vocabulary scores at age 2 are likely to predict normal language skills at age 3, although some children with limited skills at age 3 will have had satisfactory scores at age 2. Many children with poor vocabulary scores at 2 will have normal skills at 3.     

Integrating inquiry science and language development for English language learners

The traditional approach to the education of language minority students separates English language development from content instruction because it is assumed that English language proficiency is a prerequisite for subject matter learning. The authors of this article take the alternate view that the integration of inquiry science and language acquisition enhances learning in both domains. The report describes a conceptual framework for science–language integration and the development of a five‐level rubric to assess teachers' understanding of curricular integration. The science–language integration rubric describes the growth of teacher expertise as a continuum from a view of science and language as discreet unrelated domains to the recognition of the superordinate processes that create a synergistic relationship between inquiry science and language development. Examples from teacher interviews are used to illustrate teacher thinking at each level. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 664–687, 2002     

Blocking in landmark-based search in honeybees

Two experiments tested blocking in landmark-based search in honeybees. Honeybees in the experimental group were trained in Phase 1 with a single landmark in a constant spatial relation to the target (sugar water). In the compound training second phase, the landmark used in Phase 1 (blocking landmark) and a new landmark (blocked landmark) were presented at constant spatial relations to the target. The blocking and blocked landmarks differed from each other in color and position, and the blocking landmark retained the same spatial relationship to the target as in Phase 1. In Experiment 1, the control group experienced only Phase 2 training with two landmarks. In Experiment 2, the control group was trained with a different landmark in a different position in Phase 1. Blocking was found in both cases.