So let's think about how we can classify single and double and triple bonds, which is what we're really used to dealing with in terms of these sigma bonds and these pi bonds.

The reciprocity between the orbits of π bond and π anti bond and the empty 2p orbit of the atom H build new molecular orbits when atom H connects the π bond atom. Such as structure called π→ p conjugate system.

当H原子和形成π键的原子相连时，π成键轨道和π反键轨道与H原子的2p空轨道相互作用，组成新的分子轨道，这样的结构称为π→p共轭体系。

互联网摘选

The results showed tha the conjugated π bond of the layered Carbon materials may be broken by absorbing Ar ion beam energy and the interaction may result in the destruction of the carbon layered structures.

研究结果表明，Ar离子束与层状碳材料作用后，构成层状结构的以sp2杂化为基础的C－C共轭π键被Ar离子束打断，形成了新的C－C键。

互联网摘选

The electronic structure and chemical bond of molybdenum cluster compounds in higher oxidation states-multiple centric d-p π bond and mo-mo'metal bond

高氧化态钼簇合物的电子结构和化学键&多中心d-pπ键的存在和性质

互联网摘选

The d-p back bonding formed between Cu () and 5-substituted phenanthroline, and Hammett parameters of substituents were discussed.

探讨了Cu（）和5-取代邻菲罗啉之间的d-p反馈π键及其取代基Hammett诱导效应的关系。

互联网摘选

So would you expect this to be a pi bond or a sigma bond her PROFESSOR: OK, so I'm hearing some mixed answers.

你们觉得这是一个π键还是sigma键？，我听到有不同的答案。

互联网摘选

So that's exactly what our definition of a pi bond is, so we have one sigma bond, and one pi bond.

这是我们对π键的定义，我们有一个sigma键，和一个π键。

互联网摘选

The electron in the π bond of S-ylide-like radical appears mainly near the C atom. It has π( C → S) bond character, therefore it is weaker than the C-S bond in the corresponding product.

类硫叶立德自由基（·CHSH2）中单电子π键中的电子主要在碳原子附近运动，属于单电子π（C→S）配键，所以其C&S键的强度比相应的产物要弱。

互联网摘选

But once you have a double bond here, we have our pi bond, as well as our sigma bond.

但一旦你有了双键，我们有π键，也有sigma键。

互联网摘选

So if we have a single bond here, would you consider that a sigma bond or a pi bond?

如果这里有个单键，你觉得这是sigma键还是π键？

互联网摘选

Monomers used include the acrylic, the-bond, the Si-OR silicone in bifunctional structures and the straight ( or ring-like) silicone.

所用单位有丙烯酸类A，和既有π键又有硅氧烷基的双官能结构硅氧烷单体B，以及直链（或环状）硅氧烷D；

互联网摘选

We want to discuss sigma bonds and pi bonds.

我们要讨论sigma键和π键。

互联网摘选

They generally consist of a flat, rigid and large conjugated aromatic structure.

作为DNA嵌入剂，它们一般都具有平面刚性结构和大共轭π键。

互联网摘选

Is that a sigma or a pi bond?

这是sigma键还是π键？

互联网摘选

So we can kind of flip it this way this will be one pi bond, this will be another interacting between these p orbitals.

我们可以把它这样翻一下，这是一个π键，这是另外一个p轨道之间，相互作用的π键。

互联网摘选

It's like an executive I once knew who confided that he was not fulfilled.

我曾经认识一位主管,他透露说他很不满意他的现状.

互联网摘选

For high head pressure, the operation of conventional adding sand fracture treatment tech can not fulfilled.

由于施工井口压力高, 常规加砂压裂工艺无法实施作业.

互联网摘选

But I was not accomplished ; because it's really too long to go.

未遂 因为它真的太长了.

互联网摘选

You never can tell.

谁也说不准.

互联网摘选

But you never can tell.

可是谁也说不准.

互联网摘选

And you never can tell how close you are.

你永远不能确定距离成功有多么近.

互联网摘选