Single bonds can rotate around their axis no problem, but double bonds lock a structure into place.

单链可以轻易地绕轴转动，但双链将结构固定于特定的位置。

These are of two varieties, known as single and double bonds.

化学键有两种，单键和双键。

Teflon, by the way, is held together by carbon-fluorine bonds, which are the single strongest bond in organic chemistry.

顺便说一下，聚四氟乙烯是靠碳氟键聚合起来的，这是有机化学里最牢固的键，没有之一。

Single bonds, also called sigma bonds, are pretty simple, and carbon atoms attached by them can rotate around the bond freely.

单键，也称为西格玛键，非常简单，它们所附着的碳原子可以围绕键自由旋转。

Certain reactions open up a double or triple bond to insert various atoms, leaving only a single bond between the carbons.

某些反应会打开一个双键或三键以插入各种原子，只在碳之间留下一个单键。

But once that's done, the hydrogen atoms readily attach to the hydrocarbon molecule, converting a double bond to a single bond.

但是一旦完成，氢原子就会很容易地附着在碳氢化合物分子上，将双键转化为单键。

But in Europe, where officials have flirted with qt for months, the European Central Bank (ecb) is yet to let go of a single bond.

但在欧洲，官员们几个月来一直在与 qt 调情，欧洲中央银行 (ecb) 尚未放弃单一债券。

In general, if you are an individual investor, buying a single bond will not be the most effective way to put your money to use.

一般来说，如果您是个人投资者，购买单一债券并不是最有效的资金使用方式。

It's made of a polymer called " polyethylene terephthalate" , which has rings of carbons separated by chains of carbons, some of which have single and double bonds, to oxygen atoms.

它是由聚对苯二甲酸乙二醇酯聚合物组成的，它有分离的碳链，相对于氧原子而言，一些含有单键和双键。

So three words representing three different groups of organic compounds: alkanes for all single bonds, alkenes if they contain double bonds, and alkynes if they contain one or more triple bonds.

所以三个词代表三组不同的有机化合物：所有单键的烷烃，含有双键的烯烃，含有一个或多个三键的炔烃。