NSDL国家科学图书馆是美国的一个数字在线图书馆，主要涉及科学、技术、工程和数学方面的教育和研究。为教师和图书馆员免费提供多媒体资源。H78一点就转

H78一点就转

　　NSDL为中小学教师、大学生和图书馆员提供以国家数学课程标准为核心的免费数学课程和活动。专家博客也有丰富的师资资源、教案和多媒体资源。H78一点就转

　　NSDL is an online science library with links to high quality science, technology,H78一点就转

　　engineering, and math resources for K-12 teachers, faculty, librarians, students and informal learners.H78一点就转

　　The National Science Digital Library provides high quality online educational resources for teaching and learning, with current emphasis on the sciences, technology, engineering, and mathematics (STEM) disciplines—both formal and informal, institutional and individual, in local, state, national, and international educational settings.H78一点就转

　　NSDL does not hold content directly—instead, we provide structured descriptive information (metadata) about web-based educational resources held on other sites by their providers, who contribute this metadata to NSDL for organized search and open access to educational resources via NSDL.org and its services.H78一点就转

　　Most resources in the library adhere to principles of Open Educational Resource (OER) access, although some resources are restricted to provider site membership, or may have a cost associated with them (indicated in the full record of the resource).H78一点就转