Update memory.md

Author: yueyinqiu

docfx/articles/memory.md

@@ -395,7 +395,7 @@ class MyDataset : torch.utils.data.Dataset
 }
 ```
 
-Also, if you want a "`Lazy`" collate function, do not directly save the tensors that are passed in. And `DetachFromDisposeScope` does not work in this case because they have been moved to another list. Instead, you could create aliases for them.
+Also, if you want a "`Lazy`" collate function, do not directly save the tensors that are passed in. And `DetachFromDisposeScope` does not work in this case because they are kept in another list instead of dispose scopes, due to some multithreading issues. Instead, you could create aliases for them.
 
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