Three years have passed in a flash.

A spring evening, a corner of the city.

The setting sun hangs over the rolling mountains to the west, and the red glow fills the sky, reflecting the green earth beneath your feet.

In this timeline, the shrimp civilization did not launch any counterattack plan, and it was naturally impossible to talk about the blight that swept the world.

After decades of ups and downs in human civilization, after that global counterattack, it has regained its former calm.

Pang Xuelin took Chrissy's hand and strolled along the city's landscape riverside.

Big Murphy took Little Murphy's hand and ran around laughing in front of him.

Chrissy smiled: "Husband, Murphy, this girl, is really, she will be a bride in a month, and she is still like a child." ”

Pang Xuelin showed a gentle smile on his face and said: "This is also good, I hope she can be so happy in the future." ”

Chrissy gave him a blank look and said, "What about me?" ”

Pang Xuelin hugged Chrissy's waist and said, "Of course you are the same." ”

……

A month later.

Pang Xuelin and Murphy got married.

That night, after a fierce battle, Pang Xuelin looked at his wife, who was already sleeping beside him, and finally decided to choose to return.

He had already asked the system that within this new timeline, after his return, time on Earth would come to a standstill.

If he wants to come back later, he can come back at any time.

He had been in the interstellar world for many years, and Kagantuya's journey, because of the relativistic effect, made him unsure of how long the real world had been.

He had to go back and see.

In addition, Qi Xin was also detained in the hands of the United States, and he had to go back and find a way to get the girl back.

Pang Xuelin took a deep breath and said silently in his heart: "System, settle the task reward, and return to the real world." ”

In the next second, the picture in front of Pang Xuelin's eyes flashed, and he reappeared in the lottery space of the system.

"Congratulations to the host for successfully completing the Interstellar World Mission, and rewarding the host with a chance to return to the world they have experienced. So far, the host has had two such opportunities. ”

"In addition, the host can be rewarded with a random selection of Native Technology."

Pang Xuelin turned his gaze to the Russian roulette wheel in front of him, and on the roulette wheel, a total of four technologies were divided.

1. Anti-gravity technology

By shielding the gravitational pull of the planet, the gravitational effect of the planet on the vehicle is relieved, allowing the vehicle to go into space with extremely low energy consumption.

A landmark technology for a civilization to enter the Age of Interstellar Discovery, from which technologies such as curvature engines, gravitational wave communications, gravity bombs, and artificial black holes can be derived.

2. Hibernation technology

Through the interaction of drugs and hibernation fluids, the person enters a state of deep sleep for a long time.

During sleep, the human body consumes very little nutrients, allowing humans to span hundreds or even thousands of years.

One of the key technologies for interstellar travel in carbon-based civilizations can also be used for time migration (hibernation to the future), and once this technology spreads on a large scale, it is likely to cause a social and ethical crisis.

3. High-power Hall thruster technology

The electric field generated by the magnetic field accelerates charged ions to form a plasma jet that propappels the spacecraft forward. This approach will provide a more efficient and safe propulsion system for long-term missions. In addition to being used for asteroid missions, the new propulsion system will also be used in missions such as establishing bases on Mars and launching large amounts of cargo into space. It is an essential technology for deep space exploration in the star system, one of the key technologies for space industrialization, which can be used in the fields of planetary exploration, space city and space factory orbit maintenance, asteroid mining and other fields.

4. Molten salt nuclear reactor technology

One of the fourth-generation nuclear reactor technologies, the basic principle is that the core uses fluoride salts of lithium, beryllium, sodium, zirconium and other metals and dissolved uranium, plutonium and thorium as fuel, and forms a molten salt stream at 600 to 700 °C and low pressure conditions directly into the heat exchanger for heat exchange.

Among them, lithium fluoride, beryllium fluoride, sodium fluoride and zirconium fluoride are used as carrier salts to provide a melting carrier and improve the physical and chemical properties of the eumelt. Uranium fluoride and plutonium fluoride are fission fuels that produce heat and neutrons; Thorium fluoride and uranium fluoride are used as breeder fuels, which absorb neutrons to produce new fission fuels, uranium or plutonium, which are re-entered into the reaction cycle after online extraction.

The fuel produced by a molten salt reactor can be re-equipped with a new reactor after a few years of operation, which is extremely economical.

At the same time, due to the direct heat exchange of fuel, it has the advantage of being able to be miniaturized, so it has a bright future for powering ships and aircraft.

……

"Let's start the lottery."

Compared with before, now Pang Xuelin has become more and more indifferent to drawing these prizes.

Of these technologies, the most attractive is undoubtedly anti-gravity technology.

However, if anti-gravity technology is brought to the real world, there are still many engineering difficulties to be solved in order to be truly realized.

Not to mention anything else, the gravitational shield alone needs to carry out a major upgrade to the basic industry of human beings to do it, and the reason why human beings in the interstellar world were able to get anti-gravity technology so quickly is entirely because of the industrial foundation left by the shrimp civilization.

The second hibernation technology, this technology is not very difficult to implement in the real world, the trouble is that it cannot be applied on a large scale in a short period of time.

Unless there is a big leap in human space technology and the ability to carry out large-scale manned interstellar exploration on the periphery of the asteroid belt, this kind of round trip requires a long journey on a year-by-year basis, and hibernation technology will have a certain use.

As for the large-scale application in the real world for some terminally ill patients, theoretically it is possible, but how to solve the ethical problems in it, the sociological difficulty is even higher than the difficulty of its technical implementation.

The third high-power Hall thruster technology, this technology is dispensable for Pang Xuelin, because he has previously obtained a complete set of technical systems for electromagnetic orbital launch technology, including the related technology of Hall thrusters.

On the contrary, it is the last molten salt reactor, which is more relevant in the real world.

In the real world, it is difficult to break through commercial controlled nuclear fusion in a short period of time, so the fourth generation reactor technology has become the focus of breakthroughs among countries.

The molten salt reactor is one of the most talked-about fourth-generation nuclear reactor reactors.

Therefore, compared with several others, Pang Xuelin prefers molten salt reactor technology.

Perhaps it was Pang Xuelin's thoughts that played a role, and a minute later, the pointer slowly stopped on the Russian roulette.

"Congratulations to the host for obtaining a full set of technical process data for molten salt nuclear reactors."

"Ha, I didn't expect to draw this."

Pang Xuelin smiled slightly, this interstellar journey through the world, an opportunity to return to the dimensional world, plus a full set of technical information for a set of molten salt reactors, is completely enough.

At present, the fourth-generation reactors under development in various countries can be divided into two types according to neutron energy: three types of fast neutron reactors and three types of thermal neutron reactors.

The molten salt reactor is one of the three types of thermal neutron reactors, and because of its various advantages, it has become the most high-profile reactor type.

First of all, molten salt reactors have a high level of safety.

Liquid molten salt reactors use high-temperature molten salt as nuclear fuel and double as a heat carrier, and do not need to make special fuel assemblies, thus eliminating the possibility of core melting accidents.

In addition, the low vapor pressure of molten salt reduces the occurrence of breach accidents, and even if a breach accident occurs, the molten salt will solidify quickly at ambient temperature, which can prevent further expansion of accidents.

Second, molten salt reactors can make efficient use of nuclear resources and prevent nuclear proliferation.

Especially for thorium-based molten salt reactors, since the thorium used in thorium-based molten salt reactors cannot be used in the manufacture of nuclear weapons, the promotion of thorium-based molten salt reactors can greatly reduce the risk of nuclear proliferation.

Moreover, China's uranium reserves are not outstanding, but its thorium reserves are among the highest in the world.

In other words, once thorium-based molten salt reactors are put into commercial operation, China will have little to worry about the source of nuclear fuel.

Thirdly, molten salt reactors have high thermal power density and power generation efficiency.

The relatively simple core structure of molten salt reactors allows them to be designed as small reactors with high power output.

At the same time, the molten salt reactor can use the Brayton cycle, and the power generation efficiency is as high as 45%-50%.

In addition, the molten salt reactor has the characteristics of no need for control rods, non-stop reactor refueling, long life, and easy adjustment of power, so that it can be used in nuclear-powered submarines, surface ships and even various space vehicles in the future.

Finally, molten salt reactors have a diverse range of functions.

Molten salt reactors not only generate electricity, but also generate high-temperature process heat for industrial manufacturing.

In addition, the molten salt reactor also has functions such as heating, coal gasification, methane reforming, hydrogen production, etc., which can be said to be an all-rounder, which is of great help to Pang Xuelin's future development in the real world.

After the reward was determined, the voice of the system sounded in Pang Xuelin's mind again.

"Excuse me, host, do you want to return to the real world?"

"Let's go back."

Pang Xuelin said lightly.

The lottery picture in front of him gradually dimmed, and Pang Xuelin opened his eyes again, faintly smelling the smell of disinfectant potion.

"I'm ...... In the hospital again? ”

Pang Xuelin was a little helpless, this time he entered the interstellar world, the time he traveled was 2043, and he went to Kagantuya should be in 2063, but in the process of falling into Kagantuya, the space-time distortion near the black hole was too strong, and he couldn't calculate how many years had passed in the outside world during Kagantuya's time.

In addition, with the help of high-dimensional humans, he later returned to 2038, and then stayed in another timeline until 2041 before returning to the real world.

He also has no clue how to calculate the time and reality in this.

But since I'm still in the hospital, I should be safe in the real world.

Pang Xuelin turned his head and saw a girl with long hair pillowed at the head of the bed, with the back of her head facing her, neither the imaginary Yao Bingxia nor his life secretary Zuo Yiqiu.

Pang Xuelin was lying down, unable to see the girl's front, and faintly felt that this back was a little familiar.

Pang Xuelin propped up his upper body, maybe he had been lying down for a long time, he felt that his muscles were a little stiff, but the problem was not big, after drinking the genetic optimization drug, his physical fitness had been greatly improved, and his body did not have the feeling of being sore, weak and weak after lying in bed for a long time.

"Hey, wake up, wake up!"

Pang Xuelin reached out and pushed the girl.

The next second, the girl looked up sleepily.

Pang Xuelin was stunned for a long time, but he didn't expect that it was Qi Xin who was guarding his ward.

Qi Xin opened her eyes and saw Pang Xuelin, she was stunned, and then, a look of extreme surprise flashed in her eyes, and she was just about to get up and scream, Pang Xuelin hurriedly stretched out his hand to pull her: "Shhh Xiao Xin, call someone later, I'm fine. ”

After that, Pang Xuelin asked again: "Xiao Xin, when did you come back, and how long have I been asleep?" ”

Qi Xin was excited and joyful, and said with tears in the corners of his eyes: "It's been nearly a week since I came back, and thanks to Sister Wang Zhi, I was able to return to China so smoothly." Plus, you've been in a coma for twenty days......"

"It's only been twenty days?"

Pang Xuelin was slightly stunned.

He thought that Qi Xin was back, and it would take a year and a half to pass this time, but he didn't expect it to be so short.

If the ratio of 10,000 to one is calculated normally, that is to say, more than 200 years have passed since the few hours when I fell into Kagantuya.

Pang Xuelin couldn't help but sigh a little emotionally, the vicissitudes of life are nothing more than this.

If he is still in the interstellar world, has not met high-dimensional humans, and has not returned to 2038, even if he can come out of Kagantuya alive, I am afraid he will not see little Murphy.

"Learn ...... Junior brother, are you alright? ”

Qi Xin looked at Pang Xuelin and said.

Pang Xuelin shook his head, grabbed Qi Xin's hand and said, "I'm fine." Xiao Xin, tell me what happened outside during this time. ”

Qi Xinqiao's face flushed, and with the force of his right hand, he couldn't break free from Pang Xuelin's hand, so he had to give him a helpless look and said, "Well, that's the ......"

……

Next, Qi Xin told Pang Xuelin what had happened in the past twenty days in full.

Twenty days ago, Pang Xuelin suddenly fell into a coma, causing an uproar at home and abroad.

You must know that not long after the announcement of the Golden Dragon Battery, the United States detained Qi Xin for the Golden Dragon Battery, and had a bad relationship with the Chinese side, and the relationship between the two sides fell into an unprecedented state of tension.

In this case, as the chief scientist of the Golden Dragon battery project, Pang Xuelin suddenly fell into a coma, which naturally caused an uproar in the outside world.

Both the domestic media and the public are pointing the finger at the United States.

Even the people of many other countries believe that this is the work of the Americans.

After all, with Qi Xin's matter in front, people from all over the world have become accustomed to the fact that Americans have no bottom line.

For a time, the United States was at a loss for words.

The Chinese government duly announced that it would terminate negotiations with any country on the export of King Long batteries before Pang Xuelin woke up.

For a time, the international situation was unpredictable.

At the same time, just after Pang Xuelin woke up, WikiLeaks, which had been suppressed by the Americans and was dying, suddenly broke the news in the media, providing the media with complete evidence that the CIA senior management ordered Qi Xin to be framed, and even the testimony and video materials of the CIA agents.

This incident caused an uproar in the United States, and the Democratic Party even submitted the presidential impeachment motion to Congress again, adding tremendous pressure from the Chinese side.

In the end, the U.S. side announced that after investigation, it was a misunderstanding, and the materials in Qi Xin's suitcase were not the new electrolyte materials lost in the Princeton University laboratory, so they agreed to release Qi Xin unconditionally.

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