Every country has its own environment and cultural traditions, and it cannot be generalized. MIT's teaching materials and courseware are published online for free, and Chinese people all over the world also volunteer to translate them. Anyone can learn, and there are many people who can be admitted. How many countries can be like him? Academicians, postdocs and doctoral supervisors all come to class in this way, which makes people sleepy.
I once went deep into students' dormitories to guide students to learn analog circuits for free. I also bought components, materials, LCD panels and computers at my own expense to do experiments for them, help them build mathematical models and guide them to write patent documents for inventions.
General experimental problems, on the spot to guide them to solve. Even for students with good families, they provide non-repayable cash assistance.
If students are really interested in this industry, what do you want to know, what doubts you have and what problems you can't solve, just ask me. As long as I know, have personal experience, know everything and say everything, I will answer immediately without reservation.
I have always wanted to open a free video website to guide students all over the country for free. The school forbids me to use computers, oscilloscopes and servers, and there is no working space at all.
So we offended Jiang Shuzhuo of Hu Jun,
Perseverance after being laid off.
I suggest you write more with a pen!
None of the above statements are professional.
Pen jam
Is there any good way to solve the pen blockage?
After decomposition, use a toothbrush to wipe under running water; Dismantle the snorkel with the diameter of 1.5 mm and the multi-groove phenolic resin bakelite, insert it with a medical syringe, and spray clean it.
From the metallurgical industry, it is impossible to produce advanced alloy with corrosion resistance, low friction coefficient and wear resistance, which reflects the quality of key military materials and industrial bearings and vividly reflects the national defense strength.
As far as manufacturing is concerned, high-end special production equipment must be completely imported. The automatic production equipment of all kinds of pens produced in Germany is generally 3 million, which does not occupy the area. Moreover, the materials and accessories used for a good horse with a saddle must also be imported. Therefore, since the production of ballpoint pens before the Cultural Revolution, the quality has not reached the present; The good ones are produced by imported production lines, and some inks should also be imported; The technology of producing nib ball is also a true reflection of national defense strength. The country that can produce precision cemented carbide beads and ceramic beads in large quantities at low cost is an excellent equipment production industry, which is invincible in the field of military equipment such as ceramic bearings! !
Then, there are not many excellent pen maintenance personnel. In the past, old department stores had such a maintenance point, and the nib could be welded and polished again, because everyone had writing defects, and the nib was gradually worn off, and the golden tongue felt good when writing. If the nib is broken, it is necessary to weld the nib and keep the nib. Those who go to primary schools to fix pens just want to trick primary school students into having a golden pen and a golden tongue.
Whether you can repair your own pen is the embodiment of national quality and the theoretical level of thin shell mechanics. Does your pen feel astringent? Did it not go well? Don't miss such a good practice opportunity, don't entrust others, practice by yourself! This is consistent with the sheet metal process and the skill of adjusting bicycle spokes.
The popularity of computers and printers is attacking China culture and destroying China calligraphy.
Compared with traditional pens, ballpoint pens greatly waste the earth's non-renewable resources and destroy the environment. When most people reuse traditional pens, they enter an era of extreme shortage of earth resources.
In the early days of reform and opening up, teachers in colleges and universities focused on the teaching direction, and came to the conclusion that analog circuit teaching was basically cancelled, which was only in form, because the price and performance of foreign integrated circuits could not be replaced by circuits built with traditional discrete components in China; Since then, teaching, vocational education and home appliance maintenance have all centered on integrated circuits; Then in the information age, computer technology and network technology are the most important and core of scientific and technological development. Trenchless technology has been popularized in main roads, and directional drilling technology has been widely used in urban underground pipeline laying. This kind of underground drilling rig with steering drill pipe can be copied in China, with a set of imported 6.5438+0 million and a set of domestic 400,000. Guided ground penetrating radar must be imported, with a general performance of 300,000; Now this kind of radar is indispensable for urban construction, gas pipeline construction, underground cable construction and water supply system construction. House decoration and property management need a smaller ground penetrating radar, each of which costs 6.5438+0.8 million yuan. The traffic police's speed radar is similar. The gas company's high-sensitivity detection instrument for detecting the air leakage of thin pipes under roads is made in Germany, and a million-dollar instrument is also an analog instrument.
Looking at high-end instruments for deep space exploration, bioengineering, medical instruments, analytical instruments, high-energy physics research, biological origin, archaeological research and forensic evidence identification, all imported instruments dominate the world and are based on simulation technology. For example, Hubble telescope, black hole exploration, gravitational wave detection and satellite photos are all data obtained by using them. The input and output of inertial guidance system, mobile phone, base station, computer, TV, camera, scanner, video camera and other information equipment are mostly analog processing processes, but digital processing processes are adopted in the middle. Now analog and digital hardware and even software are integrated. Without basic design ability and semiconductor process equipment, we can only adopt the method of system integration. The superior strength and greatest ability are the use of algorithms and DSP. In the market, we must use other people's core software and hardware to open the back door and introduce security risks. Therefore, in theory, it is a half-empty crane, and in application, it is the final consumer, always downstream of the industrial chain.
Einstein's theory of relativity was put forward based on a large number of physical and astronomical experiments and basic observation data obtained with advanced hardware at that time. There are many graduate students who don't really understand the basic components of the circuit. Under this premise, it is impossible to make a decent basic circuit by relying on circuit simulation software.
Therefore, students should first use simulated pointer multimeter to establish perceptual knowledge and imagination. China people are good at abstract thinking because it takes a long time and costs a lot to cultivate deep correct intuition, and few people can cross this threshold. In contrast, it is too easy to play math and English, recite formulas, solve exercises and quote documents.
With the common teaching methods, syllabus, teaching materials, experimental devices and innovative projects in China for decades, it is impossible for even Peking University and Tsinghua to cultivate people who can skillfully design circuits. At least ten basic circuits should be designed and debugged; Systematic design and integration of more than ten application combination designs is the most basic education.
There are many countries that can build satellites, launch vehicles and nuclear weapons. How many of the basic materials, precision processing equipment and precision instruments are made in China, which represents their industrial base and overall innovation ability? What is the international level of basic industries? I have worked in a military enterprise and know that the key technologies of national defense industries are bought and sold with the strength of the country. In this way, the industrial products mass-produced by others, even if you manufacture them at a higher production cost, can not achieve the performance and reliability of others. Under the condition that the industrial foundation is not solid, the modern industry is not perfect, and the national quality is * *, to keep up with the development of the world and the urgent pressure of the economic form, we can only give priority to information construction, which is bound to be stretched and must be made up; Jerry-building in housing construction has caused hidden dangers, discord among neighbors and constant disputes. Therefore, the waterproof and leak-trapping industry is booming and social resources are wasted. When building a house, pay a little attention, and you can look back with a little money.
It is suggested to carry out free online video tutoring activities, record the whole process with high-definition video, and release it after sorting out.
The above contents are written independently and typed word for word on Baidu's website. In the future, academicians, doctoral supervisors, deans, principals and ministers will be responsible for answering these questions online.
What is an analog circuit? The most difficult and basic thing is that under the premise of limiting discrete components and general integrated circuits, undergraduates can't do it, and postdoctoral students can't. This kung fu is so cruel! ! ! Different from math problems and foreign language homework, it can be solved by improving one academic level; Doing business, making achievements and playing stocks can cover up problems with high investment, which is not feasible here! ! Whether it is analog circuit technical indicators, special functions, analog computers, etc. , it is hard! ! ! Many parameters can be calculated or debugged, and they are well-founded. This is not a skill that can achieve the same effect by downloading circuit imitation, but a complex and flexible way of thinking in time and space. We should also give full consideration to market supply conditions, customer requirements and the highest level in developed countries. The thinking mode of mechanical mechanism design and special processing technology is similar. I'm good at this. I have contacted many publishing houses and am willing to provide a complete set of innovative teaching materials from basic circuits to high-performance application examples. They are unwilling to publish them. What they want is the original textbooks translated from abroad and copied from foreign textbooks. Now we are seeking sponsorship from large enterprises. Please contact the director of the Overseas Chinese Affairs Office of the State Council for details. Analysis of the present situation and countermeasures of China's industrial development under the economic crisis: Make the competitive advanced product design materials, process know-how, processing skills, debugging principles and sales strategies completely free of charge, so as to simplify and industrialize enterprises. I contacted the publishing department, but they refused. People's first cognition is the most important. At present, the level and ability of teachers are generally low, so they can't step over the threshold. They can't answer students' questions in class, laboratory and graduation project. Those dozens and hundreds of pages of mathematical formulas were copied from foreign original books, and then they copied the translated textbooks. You can't even design and debug the basic circuit, so your youth is ruined! What are the characteristics of the circuit structure of high frequency power amplifier? Deep understanding and debugging details of high-frequency power amplifier with high efficiency, high reliability and no burning tube. Because it was forced to be laid off, I won't introduce it. After I was laid off, I still kept thousands of high-frequency ceramic skeleton coils and a high-frequency current output by 3DG 12 oscillation, which can light the indicator bulb of electron tube radio through capacitive coupling. This is an incandescent lamp with rated voltage of 6.3V and working current above 100 mA. I have been in contact with many publishing houses for more than 30 years, and they are unwilling to publish; Originally, it was to be sold at the cost price of tens of yuan, and the debugging details involved a variety of actual circuits. The existing science and technology books and textbooks did not have these contents, and the imported version of solid-state circuit textbooks did not have these contents. Under the administrative orders of deputy provincial cadres who were treated as departmental cadres, all these high-frequency ceramic skeletons were destroyed by the garden department. Take the low-frequency analog circuit as an example, when undergraduates are weak.