Huang Han attaches great importance to scientific and technological inventions, pays attention to investment, and pays attention to cultivating talents, so he is not afraid to spend money at all.

The scientific research class of the University Hall of Tiger Den City focuses on the research and development of civilian products, and the number of students has reached six or seven hundred, and the scientific research class of the Qingniwa University Hall focuses on weapons and navigation technology, and the number of researchers has reached more than 1,000.

The students study, research a variety of majors, medical classes often get Wu Youxing, Li Zhongzi and other Ming medical masters to teach to participate in research and development, now after Huang Han opened the golden finger, blood group identification has been proficient, blood transfusion to save people has been successful cases in the laboratory.

Iron and steel mills, weaving mills, watch factories, weapons factories, etc., all cooperate with the university hall located in Tiger's Den City, Qingniwa, and many craftsmen with practical experience are tutors of scientific research classes.

Three months later, the new product of the towel was born in the Tiger's Den City Weaving Factory, and now this good thing for washing the face and bathing is extremely comfortable has become popular in the rich circle of Beijing, and the buildings and halls will think that they are outdated if they do not use towels.

It's just that I didn't expect that the white towel could be used as a white flag when surrendering, and at this moment, Wu Xiang took out the white towel for washing his face and waved it, which actually made the charging Houjin army understand his intention to surrender, and slowed down the horse.

Wu Xiang surrendered with Wu Sangui, and there were less than 200 ironclad soldiers and more than 1,000 Ming cavalry under their command.

The red gang was in a good mood when he saw Wu Xiang, the surrendered Ming chief military officer, gave Wu Xiang enough face, gave him a second-class chief military officer, gave Wu Sangui a third-class general military officer, and still let them lead the original army, but added three white-armored soldiers and more than 20 horse armors and infantry armor to restrain this biao people.

Wu Xiang's father and son are very single, knowing that surrendering Jiannu will embark on the road of no return from now on, and they will only have a good end if they make Jiannu strong enough to defeat the Ming Dynasty.

So the father and son took the initiative to ask for an order from the Red Gangster, asking to rush to Datong to try to persuade the uncle and nephew of Cao Wenzhao, who was in the past.

The reason why Cao Wenzhao's uncle and nephew were able to lead the men and horses to re-settle in Datong was thanks to Wu Xiang's father and son, because Jiannu needed to concentrate the three or four thousand people of Wu Xiang to encircle and suppress Wu Xiang, so he withdrew the siege under Huairen City.

Wu Xiang and Cao Wenzhao were comrades-in-arms and had a good relationship before, which was of course caused by Wu Xiang's exquisite personality, and the generals in the Guanning Army basically did not have a bad relationship with Wu Xiang.

During this time, Cao Wenzhao was very depressed, he broke away from the Guanning military system and entered the customs to suppress the Kou, since the attack was invincible, the battle was invincible, and he was promoted to the chief military officer of Datong, and controlled the four battalions of Zheng, Qi, Yuan, and You, plus several garrison battalions, with a total of 20,000 thousands.

Originally, he thought that with his current strength, he would fight in his hometown again, and it should be the right time, place, and people.

Who knew that the ideal was very full, the reality was too cruel, and the confident uncle and nephew of Cao Wenzhao led 15,000 men and horses to fight, and the Houjin army, which was almost the same as the strength outside Huairen City, did it, and the Ming army was overwhelmed by the array without even holding it for half an hour.

Fortunately, the city of Huairen is close at hand, Cao Wenzhao is a native of Datong, and he is the current chief military officer of Datong, Huairen garrison belongs to his moderation, and he opened the city gate in time to put in thousands of people who have been frightened.

In this battle, he lost more than half of the infantry, and also lost the courage to fight, and then Cao Wenzhao could only choose to sit in the city.

He was always worried about the safety of Datong, knowing that in case Datong Jiancheng was lost, it was not only as simple as immeasurable losses, because there was a Ming vassal king in the city, Zhu Yi, the acting king.

The crime of losing the feudal domain is terrible, and the head of the chief military officer of Datong will definitely be moved, and there is a good chance that he will be exiled from his house.

Datong is where the town is located, the scale is not small, the circumference is fifteen miles, the city wall is as high as more than four zhang, close to the square city wall, the four corners of the city wall are built with corner towers, there are fifty-four watchtowers standing around the city wall, there are nearly one hundred nests for hiding soldiers.

At this time, Zhang Zongheng, the governor of Xuanda, Jiao Yuanpu, the governor of Datong, Sun Maolin, the chief eunuch of the supervising army, and other senior officials were all in Datong.

It is not that these people are in order to command the battle against Jiannu nearby, but because Datong City is strongly garrisoned with soldiers and horses, and there is a king here, and Cao Wenzhao, a famous general who has won many battles in recent years, serves as the chief military officer of Datong.

Jiannu was killed, Cao Wenzhao's uncle and nephew led the men and horses to take the initiative to fight and suffered defeats and retreated to Huairen, Xuanda Governor Zhang Zongheng, Datong Governor Jiao Yuanpu and other civil and military generals were shocked every day.

The acting king also learned that after Cao Zongbing led his men and horses to attack, he was cut off by Jiannu and sent Changshi to question him many times.

At this time, a group of three or four thousand guest soldiers came recklessly outside Datong City, and Wu Xiang, the main general who led the troops, was actually the brother-in-law of Zu Dashou, a person who might surrender to Jiannu at any time.

In recent years, there are countless stories of Jiannu using generals to earn a strong city, and the civil and military generals are now simply familiar, and it has become an iron law to strictly investigate the spies to prevent civil strife and prevent the entry of guest soldiers who do not know the depths of the city.

Fortunately, Wu Xiang, who was refused to enter the city, led the troops away, and Jiannu seemed to have retreated, and three days later, Cao Wenzhao led more than 7,000 people to return to the town, so that the civil officials and military generals of Datong celebrated each other, and everyone knew that with such strength, Jiannu no longer had the ability to attack Datong City.

The day after Cao Wenzhao returned to Datong, Wu Xiang's father and son, who had been refused to enter the city, came again, this time without carrying three or four thousand men and horses, and only a dozen horsemen by his side.

This time, Wu Xiang did not ask to open the city gate and let him in, but arranged for the family to shout loudly, asking the chief military officer Cao Wenzhao to talk to the head of the city.

Cao Wenzhao's uncle and nephew, who got the news, immediately had an ominous premonition, because they led 15,000 men and horses to fight in the field, and they couldn't withstand the sharp blow of the Jiannu, so they had to retreat into the city to defend it tightly.

That Wu Xiang is a general who has always been a slippery leader, and there are only three or four thousand people under his hands, how could he swagger and appear under Datong City at this time.

The uncle and nephew learned that the old man's request to see was of course impossible to refuse, and immediately rushed to the city gate to board the city, and the eunuch Sun Maolin felt that something was wrong and also ran to the city gate building with four little eunuchs.

Wu Xiang's surrender was purely forced to be helpless, he was a good official in the Ming Dynasty, did a good job in business, and lived a prosperous life. After that, I don't know how much sin I will suffer when I follow those wild people.

When he saw Cao Wenzhao at first glance, Wu Xiang couldn't help but feel sad and cried.

He said sadly: "Lord Cao, this official is because your brother is the chief military officer in Datong so he galloped under the city of Datong and asked to enter the city to assist in defense, who knows that the official said that he didn't get his wish, and now I know that you were not in the city at that time."

Alas! The Wu family was hurt by the civil and military generals of Datong, the official was less than 4,000 people, and the Dajin army came to chase and intercept 20,000 or 30,000, and the official was unwilling to die in battle, and now he has joined Dajin. ”

Unfortunately, Cao Wenzhao and Cao Bianjiao glanced at each other, and they both showed painful expressions, and their former comrades-in-arms surrendered to Jiannu, of course they felt uncomfortable.