Isekai Maou to Shoukan Shoujo no Dorei Majutsu - Volume 11 epilogue

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.

Like many medical students, Li Yong just succeeds finding an intern job in hospital with great efforts and yet still is going broke. He even has no money to pay the rent. However, by coincidence, he acquires a magic power of clairvoyant vision and rich experience from 80 medical experts, all because of a pendant passed down from his parents. With the magic power, he can see through human’s skin and finds out any illness beneath without any physical touching or examination! Since then, his life has been tremendously changed. Love, fame and wealth become within reach for him…

- Description from Novelupdates

Here martial arts are no longer intangible legends. They have been passed on from generation to generation and from century to century. After the confrontation with science and technology, they have completely integrated into modern society and all kinds of martial arts competitions are taking place across the country as superiority among scholars are hard to reach a consensus but not as difficult among martial artists!

Lou Cheng has found an unknown cultivation item that fuse with him and help him for the first part of martial arts, the meditation.

Towards his original dream and the glory in his heart, he will advances step by step, becoming the warrior of this modern city and the hero of the era!

- Description from Novelupdates

With a square halberd in the palm, and a red rabbit and horse under him, nowhere can the world go!

- Description from novelbuddy