Da Tang Shuang Long Zhuan - Book 1 - Chapter 7 – Jade Annulus of the He Clan

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

I am Supreme

Liu Yan, an ordinary office worker from Earth, unexpectedly traveled to a strange world.

The heroes of the ages are on the side, embarking on a journey to conquer the heavens.

- Description from novelbuddy

An ordinary young man on earth, Xia Feng, traveled to a world of sword and magic, and took the body of Lucien Evans, another ordinary young man.

Seemingly this was a world of traditional western fantasy, yet he discovered the astonishing similarities between the earth and this world, and between science and the so-called arcane magic…

“Knowledge is power”? Soul, magic, quantum, Theory of Relativity, cognitive world, music and real world……

What was the true nature of that world?

- Description from Novelupdates