Oxygen as O2 is stable enough to be abundant in the environment and is required for many forms of life. But from the standpoint of theory, dioxygen’s stability is curious: Its highest occupied molecular orbitals contain two unpaired electrons, making it a diradical. Instead of wafting around as O2, the molecule should be busy abstracting hydrogen atoms or forming oligomers; isoelectronic sulfur, for example, is most stable as S8. The key to dioxygen’s reactivity lies . . .
Experts learn from Exxon Valdez and Deepwater Horizon to plan for future accidents
Five years ago this week, engineers capped the leaking Macondo well 1,500 meters below the surface of the Gulf of Mexico, effectively ending the largest marine oil spill in U.S. history. The Gulf spill started three months earlier, when the Deepwater Horizon (DWH) oil rig exploded into fire—an accident that killed 11 workers—and then sank into the sea.
Conventional wisdom among chemists has been that most lanthanide elements could exist in compounds only in the +3 oxidation state. Overturning that long-standing assumption, researchers have now synthesized complexes with lanthanide ions in the +2 oxidation state for the entire series, minus promethium. The new results could lead the way to new chemical transformations.
Muck Rack makes it simple to find people, tweets, or articles that mention any name, keyword, company, hashtag etc. We've compiled this guide to help you make the most of your search.
Selecting a term
Start searching tweets, articles from media outlets, articles mentioned in tweets, journalists'
names, titles and bios with some suggested searches:
Companies or Topics (e.g. iPhone, Microsoft)
Phrases (e.g. "cloud computing") — use quotes to keep the terms together
Twitter handles (e.g. @username) — returns those who have mentioned or replied to
Names (e.g. "David Pogue")
Hashtags (e.g. #sxsw, #london2012)
Bio details (e.g. vegan, Olympics, father)
Muck Rack's Advanced Search allows for many boolean operators.
Find results that mention multiple specified terms, use AND or
+. For example, ensure each result contains both Elon Musk and Mark Zuckerberg by
searching Obama AND Romney or Obama + Romney.
Use the operators OR or , to broaden your search when you'd like either of
multiple terms to appear in results. (This is the default behavior of our search when no operators
are used.) For example, search for democrat OR republican to find results that refer to
Democrats and/or Republicans.
Use NOT or - to subtract results from your search. For
example, searching Disney will yield results about the Walt Disney Company as well as Walt Disney
World Resort. To exclude mentions of Disney World, search for Disney -World or Disney
When using one of these operators with a phrase, enclose it in quotation marks. For example, you can
find results about smartphones excluding Apple's iPhone 4S by searching smartphone -"iPhone
Exact case matching or punctuation
If you're searching for a brand name or keyword that relies on specific punctuation marks or capitalization, you can
find results that match your exact query by adding matchcase: before the keyword you're searching for, like matchcase:E*TRADE .
Use parentheses to separate multiple
boolean phrases. For example, to find journalists talking about having fun in Disney World or
Disneyland, search for ("disney world" OR disneyland) AND fun.
An asterisk can be used to search for any variation of a root word truncated by the asterisk. For example, searching for admin* will return results for administrator, administration, administer, administered, etc.
A near operator is an AND operator where you can control the distance between the words. You can vary the distance the near operation uses by adding a forward slash and number (between 0-99) such as strawberries NEAR/10 "whipped cream", which means the strawberries must exist within 10 words of "whipped cream".