国外网站网站目录　/　此网站目录下共收录5289个优秀网站

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  Physicsforums

  Bulletin boards on physics and related subjects. Includes related polls and a list of active threads.

  http://Physicsforums.com/
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  收录时间：2025-12-19
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  Nationalinterest

  A quarterly journal of international affairs and diplomacy founded by Irving Kristol. Noted for its issue featuring the "End of History" by Francis Fukuyama.

  http://Nationalinterest.org/
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  收录时间：2025-12-18
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  Opticsplanet

  On-line Store with wide selection of brand name binoculars, monoculars, telescopes, spotting scopes, rifle scopes, opera glasses, laser sights, range finders, and night vision equipment. Located in Illinois.

  http://Opticsplanet.com/
  百度权重：
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  收录时间：2025-12-18
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  Calculatorsoup

  Online calculators for finance, math, algebra, trigonometry, fractions, geometry, physics, time, statistics and conversions.

  http://Calculatorsoup.com/
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  收录时间：2025-12-19
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  Alldatasheet

  Free datasheet archive and search for electronic components and semiconductors.

  http://Alldatasheet.com/
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  收录时间：2025-12-18
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  Purplemath

  Includes illustrated tutorials, categorized links, homework guidelines, and a study skills survey.ey.

  http://Purplemath.com/
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  收录时间：2025-12-18
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  Mathworld.wolfram

  Glossary of terms. Material ranges from undergraduate to research level.

  http://Mathworld.wolfram.com/
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  收录时间：2025-12-18
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  Italki

  italki.com is an online destination for learning foreign languages. italki connects people from around the world in a friendly community to learn from each other. italki helps people meet online to do free language exchanges. italki also helps students connect with teachers for paid online lessons. In addition, italki has many free language learning features, such as questions and answers, group discussions, and multimedia materials for self-study. italki is both a social network and a marketplace. The social network helps bring people together to communicate and learn. The marketplace gives students, teachers, and companies the abililty to transact online.

  http://Italki.com/
  百度权重：
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  AlexaRank：0
  收录时间：2025-12-18
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  Newscientist

  Science and technology news from the weekly magazine includes daily updates from around the world. Includes Hot Topics, interviews, book reviews and job listings.

  http://Newscientist.com/
  百度权重：
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  AlexaRank：0
  收录时间：2025-12-19
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  R-project

  R, also called GNU S, is a strongly functional language and environment to statistically explore data sets, make many graphical displays of data from custom command line, shell has option to save one full environment per working directory. Descriptions, documents, downloads. [Open Source, GPL]

  http://R-project.org/
  百度权重：
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  AlexaRank：0
  收录时间：2025-12-18