"You're a mechanical engineering expert who has drunk foreign ink, and you've never seen a walk-behind tractor?"

Seeing Xu Kunjun shaking his head, Zhang Ran looked surprised, full of incredulity - after all, now, although the country is still an industrial desert, the imperialist powers have long been fully industrialized, and there are many families with cars!

- After all, compared with a car, the difficulty of manufacturing a walk-behind tractor is simply easier than that of a child building blocks - how could Xu Kunjun not have seen it?

Hearing Zhang Ran's words, Xu Kunjun's expression was very hurt, there was a kind of grievance that a well-informed city person was despised by a hillbilly, and he said that he had indeed drunk foreign ink, but this walk-behind tractor, I don't want to say I've seen it, I've never heard of it-can I blame it?

Zhang Ran was speechless, knowing this, I was afraid that he took it for granted!

In fact, it is indeed Zhang Ran who took it for granted!

In his opinion, walk-behind tractors, which are low-content compared to cars, are not difficult to manufacture and practical, so the current imperialist countries must be full of them, and Xu Kunjun cannot have not seen them.

But in fact, the emergence of a thing is not only related to the simplicity or practicality of the manufacturing difficulty, but also depends on whether it is suitable or not!

The place where Xu Kunjun drinks foreign ink is the United Kingdom.

Britain is indeed the birthplace of the Industrial Revolution, and it is indeed the region with the best industrial base, and there is really no pressure to make a walk-behind tractor......

In fact, as early as the era of the steam engine, when industrial civilization had just begun, the British used steam-powered machinery to build the prototype of a walk-behind tractor to help plough the fields and reduce the labor intensity of British native farmers......

But soon, this relatively primitive mechanical tool was quickly phased out!

The reason is actually very simple - the agricultural areas of England, more of which are vast plains, use the machine of walk-behind tractors to plough the fields, which is too inefficient!

Therefore, the British directly replaced the status of the original walk-behind tractor with a larger machine, and the walk-behind tractor has not been used on a large scale in the land of the British, where did Xu Kunjun go?

Of course, this is by no means to say that there is no space for walk-behind tractors, otherwise, Zhang Ran himself would not have often seen walk-behind tractors running all over the street when he was very young!

The large-scale application of walk-behind tractors after being eliminated is more of a suitable result for the place - for example, the field area is small, but this simple machinery needs to be used to release labor in the area, such as the local area of the little devil, such as the mountainous area of China.

The area where walk-behind tractors appeared on a large scale is in Japan, and not at the moment!

At present, the little devils have poured all their strength into this war, and the whole country is serving the military industry, and there is no time to think about liberating the labor force.

After the defeat, the homeland of the little devils was in ruins, and a large amount of labor was needed to complete the reconstruction, but the little devils paid a heavy price for starting this war, and their prime labor force died on the battlefield in large numbers, and they could not provide sufficient labor for the reconstruction of the country......

In this case, the little devil had to design a large number of machinery suitable for the domestic terrain, and at the same time cheap and easy to control, the walk-behind tractor, which also came into being at this time, and was used in a large area in the country of the little devil.

After the founding of the People's Republic of China, China faced the same predicament as the little devils, so it imitated the walk-behind tractors in the little devils and popularized their use in China.

That's how the walk-behind tractor in Zhang Ran's memory came about.

Therefore, although this walk-behind tractor does not have much technical content, but because of its limitations and the times, Xu Kunjun has never seen it at all, not to mention referring to the prototype of the walk-behind tractor to design a tractor!

Of course, these were things that Zhang Ran couldn't have thought of before.

However, after making sure that Xu Kunjun had not seen any walk-behind tractors, Zhang Ran immediately realized that he was a little taken for granted, and apologized again and again: "I'm sorry, I'm sorry, it's my fault......"

Then, he immediately got someone to bring pen and paper, and in three or two clicks he drew a simple composition of a walk-behind tractor on the paper.

Of course, with Zhang Ran's mechanical knowledge and composition level, it is completely impossible to draw all kinds of details, and his composition is more to provide Xu Kunjun with a solution, and the rest, Xu Kunjun, an expert, is naturally to fill in various details.

Therefore, the composition drawn by Zhang Ran is a long frame supporting a small square representing the engine, which is simple and outrageous!

But Xu Kunjun still understood it at the first time - all kinds of steering and direction control are directly completed by the long armrest, and there is no need for torque transmission at all!

"I can't believe that this can be done!"

After understanding the composition, Xu Kunjun was extremely excited, looked at Zhang Ran and complained: "If the captain had handed over this composition to me earlier, wouldn't I have thought about the tea and food for so many days?" Maybe we've got this tractor done! ”

As he said this, he also touched most of his thinning hair......

"Stop talking nonsense, hurry up!"

Zhang Ran waved his hand angrily, and said in his heart I haven't even blamed you for not even seeing such a simple thing as a walk-behind tractor, are you still embarrassed to blame me?

I've never seen a walk-behind tractor, and you mean a mechanical engineering expert who has drunk foreign ink?

After finishing the matter here, Zhang Ran went to the secret pharmaceutical R&D team presided over by Han Jinshan to take a turn and check the training of the trainees.

The injuries of the seriously injured were controlled, the effect of penicillin was also affirmed, and the dosage was also well controlled......

However, the mass production of penicillin is obviously not something that can be done with the help of some technical personnel, and there are many, many technical problems that need to be overcome......

At this stage, the detachment's penicillin preparation level is still at the level of penicillin that can also be cultivated and isolated from unit strains and the purity is also used for human injection, but no progress has been made in preservation and processing!

Now, the trainees who have undergone simple training have begun to gradually accept the work of cultivating and isolating penicillin in large quantities, while Han Jinshan himself has learned more through experiments how long the isolated pure penicillin can be stored without being too heavily polluted when various processes are not mature enough, and it can also be used as a clinical aspect!

Of course, these experiments will no longer take a huge risk to directly use large living people for experiments, so many dogs in the base area have fallen into blood mold......