acs.org的 10 大竞争对手

rsc.org

Find out more about our information, advice and guidance to help you make decisions on learning, training and work.

pubchem.ncbi.nlm.nih.gov

PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.

chem.libretexts.org

The LibreTexts libraries collectively are a multi-institutional collaborative venture to develop the next generation of open-access texts to improve postsecondary education.

ptable.com

Interactive periodic table showing names, electrons, and oxidation states. Visualize trends, 3D orbitals, isotopes, and mix compounds. Fully descriptive writeups.

sigmaaldrich.com

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sciencenotes.org

Sun candle (subsun) explained: what it is, how it forms, where to see it, and how it differs from sun pillars and sundogs.

iop.org

Promoting physics and bringing physicists together for the benefit of all

aps.org

The American Physical Society is a nonprofit membership organization working to advance physics by fostering a vibrant, inclusive, and global community dedicated to science and society.

aip.org

In early 2026 the Department of Labor is expected to post a notice of proposed rulemaking to revise upward the pay employers must offer to foreign workers who would have an H-1B visa or an employment-based green card. A prior rulemaking attempt offers clues as to how pay might be affected for…