There are many angles to observe China's scientific and technological progress. Among them, the most intuitive angle is the daily life around us. For example, flying on the high-speed rail with independent intellectual property rights; the most shocking angle is watching the major space launch activities. For example, the Long March 5 lift tianwen-1 soared into the sky with thunderous momentum; the simplest angle is reading Read a list of technologies. For example, the latest version of China's catalogue of Technologies Prohibited from export and restricted by export (hereinafter referred to as "the latest catalogue") jointly published by the Ministry of science and technology and the Ministry of Commerce recently.

The "latest catalogue" is formed by the adjustment of the relevant documents issued by the Ministry of science and technology and the Ministry of Commerce on the basis of the relevant documents issued by the two departments in 2008. A total of 53 technical items are involved: 4 items of technology items prohibited from export are deleted; 5 items of technology items are deleted with restrictions on export; 23 items are added to the technical items with restrictions on export; 21 items are involved in the modification of control points and technical parameters Item. A careful examination and analysis of these adjusted technical items shows that China's science and technology has made great strides in many fields in the past ten years, whether they are new additions, deletions, control points and parameter modifications. The "latest catalogue" is an adjustment of the catalogue of technologies that were prohibited from export and restricted by China before, and is an upgraded version of the technology "striving for success" created by China for more than ten years.

A big dredging country

Give birth to heavy equipment

I believe many people were deeply impressed by China's export control policy in 2017. On May 25 of that year, the Ministry of Commerce and the General Administration of Customs of the people's Republic of China issued announcement No. 28 of the year, declaring that, in order to safeguard national security, export control shall be implemented on several types of large dredgers, and no unit or individual shall be allowed to sell without permission. As a result, China's large-scale dredgers have entered the public's view as a special category of marine engineering equipment. People familiar with the development of domestic large-scale dredgers will immediately associate with the two famous names in the industry, "Tianjing" and "Tiankun", and realize that Announcement No. 28 is actually aimed at the heavy equipment of several major offshore engineering countries, including them.

As a big country in water conservancy and shipping, China has been committed to dredging the ports and seaports of rivers and channels. However, due to its lack of dredger manufacturing capacity, it is not only expensive to import, but also unable to obtain high-end products, resulting in low efficiency and limited effect of dredging. There is only one way for China to develop independently. In 1994, the first self-propelled trailing suction dredger with bow blowing device was built successfully. After that, the design of the first domestic environmental protection dredging project, Dianchi Caohai polluted sediment dredging and disposal project, was completed. In 2006, based on the breakthrough of durable alloy and preparation method for dredging machinery and the computer-aided decision-making system of cutter suction dredger, the first large cutter suction dredger with modern level was built and launched in China. As a result, China's dredging equipment manufacturing innovation has entered the fast lane. At the beginning of 2010, the "Tianjing" was officially put into operation with six Asian records, namely, the largest total installed power, the largest cutter power, the strongest digging capacity, the strongest production capacity, the most advanced integrated control technology and the strongest operation adaptability. Six years later, the construction of the "Tiankun" with further improved performance was started, and China's dredger construction technology advanced to the forefront of the world. In this context, the Ministry of Commerce and the General Administration of Customs comprehensively studied and decided to implement export control on large dredgers.

In November 2017, "Tiankun" was successfully launched in Qidong, Jiangsu Province. With a length of 140 meters and a width of 27.8 meters, the cutter motor has a maximum power of 7500 kW, making it the largest self-propelled cutter suction dredger in Asia. The ship is equipped with the most advanced intelligent integrated control system of cutter suction dredger in China, which can real-time display the three-dimensional soil quality of dredging, calculate the tide level, etc. through simple operation, it can automatically locate and carry out dredging operation. In order to adapt to various harsh sea conditions, the 1600 ton bridge of "Tiankun" is equipped with the world's largest wave compensation system. By lifting and shrinking the hydraulic cylinder, the influence of waves on the cutter bridge can be reduced, and the construction safety can be ensured even under the condition of heavy wind and waves. The completion of "Tiankun" marks the further upgrading of the R & D and construction capacity of China's dredging equipment, reaching the world's advanced level.

Highlight scientific and technological innovation and breakthrough

Gradually build a mature system

Due to import restrictions, it was forced to carry out independent research and development, and finally entered the forefront of the world after suffering hardships. This is the story of China's scientific and technological innovation in the field of dredgers. Similar stories continue to occur in other fields. Together, they form a magnificent cluster of China's scientific and technological innovation, which supports the gradual improvement of China's comprehensive national strength. In order to cope with the fierce international competition situation, maintain national security, maintain competitive advantage, and counter some countries' export control to China, China has gradually formed a set of export control system. Jiang Hui, associate professor of China University of metrology, said that since China joined the IAEA in 1984, China has implemented necessary export controls on key technologies and products in important fields and has formed a set of systems.

On the overall development process of China's export control, Jiang Hui said that the focus of export control in the early stage of reform and opening up was limited to "non-proliferation", and the controlled objects included nuclear, biological and chemical weapons. By the end of the 20th century, many strategic resources had been included in the export control list. Since the new century, breakthroughs have been made in technological innovation of China's high-tech industries,