The pronunciation of the word science seems to vary based on which part of the world you're in. I have heard it pronounced "sai-ens" and "saains" (think "signs"). I have check the dictionary, but ...
In words such as salad /sæləd/, you have a VCV pattern (vowel-consonant-vowel), in which the first vowel is short. The syllable division of such words is generally done after the consonant, i.e, as ...