查询词典 backbonds

Similar to the oxidation process of Si(111)-7×7 by water,the gradual insertion of S atom into Si_a-Si_s backbond is possible to occur,and the insertion pathway,which begins with directly destroying Si_a-Si_s backbonds by a foreign H_2S molecule,remains more favorable.However,when H_2S attacks at the Si_a site to split Si_a-Si_s backbond with its S or H atom,there is no distinct thermodynamical and kinetical difference between these two attacking behaviors,whereas Si_a-Si_s backbond is easilier broken when H_2O attacks at the Si_a site with its O atom.This mainly lies in the fact that the electronegativity of oxygen is larger than that of sulfur.

5类似于H_2O对Si(111)-7×7的氧化历程，S原子逐步插入Si_a-Si_s键是可以发生的，且H_2S直接打开Si_a-Si_s键进而使S原子插入的途径仍是动力学上较为有利的，但H_2S以S或H原子进攻Si_a位从而打开Si_a-Si_s键的两种反应机制在动力学和热力学上并没有表现出明显的差别，而当H_2O以O原子进攻Si_a位时，Si_a-Si_s键则较容易断裂，这应归因于O的电负性比S大。

For the oxidation channel from OH group migration to O atom insertion,the activation energy barriers for OH migration are 58.4,65.3, and 79.2 kcal/mol,respectively,whereas those for O atom insertions beginning with directly destroying Si_a-Si_s backbonds by a foreign H_2O molecule are much lower,the respective values are 19.0,16.7,and 24.8 kcal/mol.

对于先经过OH迁移致使O原子插入Si_a-Si_s backbond的氧化途径，OH迁移所克服的能垒依次为58.4、65.3和79.2 kcal/mol，而H_2O以O原子进攻Si_a位来打开Si_a-Si_s键进而使O原子插入的能垒则相对较低，仅为19.0、16.7和24.8 kcal/mol。

Now he worked in ajoint venture.

现在他在一家合资企业工作。

More troops in Afghanistan won't change any of the foregoing.

更多的在阿富汗的军队也不会改变之前的状况。