扩展型企业网络：ATM在新的业务模式中的重要地位

网络设计者们再次受到新技术的冲击——而有些新技术只有在将来才可能实现。然而用户现在就要求更多的功能和增强的服务。今天在园区网核心里的决策,今后几年会波及到企业,正如早些时候LAN的决策已在当前的网络基础设施中实施一样。 如今,大多数设计者使新技术不断发展。他们明白在网络不断发展的同时,关键仍是技术对业务应用和业务流程的影响。网络战略的最大好处在于网络能转变传统企业经营模式,使企业比以往更快地运     

Predictors and Outcomes of Early vs. Later English Language Proficiency Among English Language Learners

The development of English language learners (ELLs) was explored from kindergarten through eighth grade within a nationally representative sample of first-time kindergartners (N = 19,890). Growth curve analyses indicated that, compared to native English speakers, ELLs were rated by teachers more favorably on approaches to learning, self control, and externalizing behaviors in kindergarten and generally continued to grow in a positive direction on these social/behavioral outcomes at a steeper rate compared to their native English-speaking peers, holding other factors constant. Differences in reading and math achievement between ELLs and native English speakers varied based on the grade at which English proficiency is attained. Specifically, ELLs who were proficient in English by kindergarten entry kept pace with native English speakers in both reading and math initially and over time; ELLs who were proficient by first grade had modest gaps in reading and math achievement compared to native English speakers that closed narrowly or persisted over time; and ELLs who were not proficient by first grade had the largest initial gaps in reading and math achievement compared to native speakers but the gap narrowed over time in reading and grew over time in math. Among those whose home language is not English, acquiring English proficiency by kindergarten entry was associated with better cognitive and behavioral outcomes through eighth grade compared to taking longer to achieve proficiency. Multinomial regression analyses indicated that child, family, and school characteristics predict achieving English proficiency by kindergarten entry compared to achieving proficiency later. Results are discussed in terms of policies and practices that can support ELL children's growth and development.     

拉文纳国立博物馆内16—17世纪盔甲上腐蚀产物的研究

绪言 在意大利拉文纳国立博物馆内有一个武备库,里面收藏着三百年前的兵器和盔甲。虽然库房不大,却是精品荟萃。它有270余件藏品,包括各种兵器、盔甲、销甲、销甲鳞片、附件、大炮和一些非欧洲的兵器。 借该博物馆筹办一个新的展览之机,这些藏品得到适当的修复。初看起来,情况不错,但进一步检测揭示出大量劣化、降解的     

美国自然灾害10年的研究要点

在处理自然灾害对人民生命财产影响方面，政府的任务是找出把生命财产减少到最小的方法和措施及提供量低限度的救济，为达此目的，制定了政策、法律及实施条例，设置机构，明确职责和分配基金，开发信息系统，确定研究要求及为研究提供资金。     

保加利亚女子优秀铁饼选手的训练计划

前言教练员一般都认为女铁饼选手的训练与铅球训练有许多共同点。然而,我的同事——保加利亚的拉什曼列夫却在其文章中指出,铁饼与标枪的训练有更多的类似之处。尽管他主要是搞标枪训练的,但囚其居住在一个小城镇里且是本地区内仅有的一名投掷教练,故而他也不得不教其它项目。因以前从未做过铁饼教练,所以他采取了一种全新的洲练方法。可以说他虚心认真地研究了这个项目,在我看来,他更加强调速度这一点一般是可以接受的,倘若比较一     

英国语言大师威·萨·毛姆

英国小说家威廉·萨默塞特·毛姆是二十世纪英国最受欢迎的作家之一,在创作上他以清新的文体及技巧而闻名于世。萨默塞特·毛姆于1874年1月25日出生于巴黎,父亲是英国使馆的法务官。他因两岁丧母,八     

物理学与未来

物理学在最近10年取得了重大进展,其中许多进展是开发和应用昂贵的大型研究装置的结果。合作是其进一步发展的关键,而国际组织起着特殊作用,因它们可以确保整个物理学界通过合作项目和人员培训在发达国家和发展中国家参与合作。