but it goes wrong:
RuntimeError: a leaf Variable that requires grad has been used in an in-place operation.

when I use the same way as you referred in pre-reflection by
nn.ReflectionPad2d((1, 1, 1, 1)),   # block 4
nn.Conv2d(256, 512, 3, 1, 0)

instead of using
nn.Conv2d(256,  512, 3, 1, 1)