The purpose of buff these research options is to make them have reasonable returns, simpler effects, and historical consistency.
Uranprojekt: Even after the last buff, this card's benefit is still too low compared to Manhattan, and it has little historical relevance. The new, simple effect better reflects the terror of nuclear weapon. To fit the current meta, destroy has been changed to remove.
Pressurized cabin version 1: since we want to show the relationship with the B-29, let's temporarily add one.
Pressurized cabin version 2: The damage is equal to the attack of B-29, and it has the same effect as firebomb, as they are dropped by B-29s.
Synthetic rubber: The original effect is fair, but it could only work fully on a subset of targets, which could be annoying sometimes. I want to fix this.