Wait, but the user's example in the question has "Isıl Özellikler" where "Isıl" is replaced? Let me check. The user's original text includes "Isıl Özellikler" and "Elektrik Özellikleri", which are categories. Since the user said proper nouns stay, those titles should remain. In the following text, however, the descriptive parts are to be replaced.

"Mekanik" properties might be replaced by "mekaniksel", "mekanik", "mühendisliksel". Not sure if these are standard. Alternatively, "mekanik", "kimyasal", "fiziksel" but those are different categories. Wait, the original text mentions "fiziksel, kimyasal ve mekanik", so maybe "mekanik" is one of three types. Not helpful for alternatives.

But in the example response given by the user (after "Sonuç"), they have converted "Malzemelerin mekanik özellikleri" to Cisimler fiziksel özellikleri... Hmm, in the example, the user has used "özellikleri" as a spintax option with two changes. Wait, perhaps the example is part of the user's input, but in the actual task, I need to generate spintax for each term. So I should treat each word except proper nouns as candidates for spintax with three options.

Then "ısıl" becomes "termal|ısısal|şiddetli ısı."

"Metal malzemeler, yüksek elektrik iletkenliği, yüksek ısıl iletkenliği ve yüksek mekanik dayanımı ile karakterize edilir." Then the example part is "Örnek olarak çelik, alüminyum ve bakır verilebilir."

So my approach should be:

The user wants each such word to have three alternatives. I need to make sure that each replacement is accurate in the context and that three valid Turkish synonyms exist. Some words may not have three good alternatives, so I might skip those or find the best three options possible.

So when processing, the description words (after the colon) excluding "Metal" need to be replaced. The examples are kept.