The story behind the change of the hottest wechat

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The story behind the launch page change

is the app we use most at ordinary times. It has evolved from a simple chat tool to a comprehensive social platform. In 2016, the number of monthly active users reached a staggering 806million. It has become an indispensable part of daily life and work. On september25,2017, as usual, people clicked on it, only to find that the earth, which had not moved for six years on the launch page, moved

comparison chart before and after

a chart that gradually changes may not be found if you are careless. Why do you change the chart after using it for 6 years? There are still many stories in it. The original start-up map (left above) uses the first complete picture of the earth published by NASA around the world, called "Blue Marble", which is the first time that human beings have seen the whole picture of the earth from space. The picture shows the African continent. As for the reason for choosing this photo as the material, the team revealed that: "the African continent is the origin of human civilization. We take the cloud image over Africa as the background image of the launch page, and also hope to give the meaning of 'origin' to the launch page.

the current launch image (top right) has become a picture taken by China's independently developed fengyun-4 satellite, FY-4 satellite is a second-generation geostationary orbit (GEO) quantitative remote sensing meteorological satellite developed by the eighth Research Institute of China Aerospace Science and Technology Corporation (Shanghai Aerospace Technology Research Institute). It has been eight years since it was approved in 2008 and officially launched in December 2016. This is a milestone in China's aerospace industry. The display of the pictures taken by 'fengyun-4' also implies the historical development from 'human origin' to 'Chinese civilization', and aims to show hundreds of millions of users the beautiful landscape of China. "

at the launch site of FY-4

to evaluate the level of FY-4, it mainly depends on the performance of the instruments installed on the satellite platform. The main instrument loaded on the American goes-16 is called abi. The above is the operating procedures, installation and commissioning of the hydraulic universal material testing machine shared with you. The European MTG is loaded with FCI, while our fengyun-4 is a radiometer. We can simply understand the radiometer as an instrument for taking pictures of the earth. These three series of 20 lightweight aggregate concrete can be said to be three pillars in the United States and Europe. If only from the perspective of radiometer, its performance index is slightly worse than that of ABI in the United States and FCI in Europe. However, another heavyweight instrument, the atmospheric vertical detector, is also loaded on Feng Si, which is the world's first atmospheric vertical detector in geostationary orbit

looking at the launch time, the United States' goes-16 was launched on November 19 last year, and China's fengyun-4 was launched on December 11 last year, while the European MTG plan was not launched until 2019. As for the Japanese sunflower 9, we won't discuss it much, because the core instruments on it were sold to them by Americans

in fact, the radiometer is easy to understand. It is a camera that takes pictures of the earth, that is, a high-precision sensor. After all, the distance is too far. The radiometer is offset by an angle. The attitude of oil viscosity on the earth will also affect the equipment. If the equipment fails to reach the rated load, it will be offset by ten kilometers. The maximum temperature of the track is 150 ℃ and the minimum temperature is minus 130 ℃. Such a huge temperature difference is a great consideration for the stability of the material. As one of the most used substrates in aerospace, ceramic materials are no exception this time, and have gained a position of core application

ceramic circuit board

the development of China's special ceramics is the fastest in military industry and aerospace. China Bizhong aluminum materials Institute immediately organized scientific researchers to set up a project team to start the trial production. It has a vast territory, rich material elements and sufficient supplies, which is also the reason why China can quickly catch up in the aerospace industry

the high-tech enterprises such as slyton, which produce ceramic circuit boards, are also under the strong support of the state. They can quickly implement the laboratory technology into products that can truly benefit the public. I want to achieve the goal of made in China 2025 and take the lead in the era of industry 4.0. It also needs the emergence of more such high-tech enterprises to benefit the public while developing high-tech products

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