1. The shelf life is generally 0 days. The effective irradiation distance is not more than 1 m, and the irradiation time is not less than 30min? If the aseptic package is contaminated
2. It depends on whether it is a spot produced by parallel light.
Parallel light 20cm.
3. 10
Set object distance u
U & gt2f, the real image of reverse reduction.
U=2f, inverted equal real image.
2f>u> Inverted Magnification of Real Image
U=f does not image
U<f vertical magnification virtual image
4. The effective irradiation distance shall not exceed 1m, and the irradiation time shall not be less than 30min? If the aseptic packaging is contaminated, the shelf life is generally 0 days, and if it is just opened, it seems to be 4 hours.
5. Is the LED of the floodlight single or multiple? If it is single. If the spotlight is good, it can shine as far as 100 meter, and the brightness can reach 4000 lumens to 4500 lumens. If high-power LED wants to maintain high brightness and long life, heat dissipation must be good!
6. This belongs to the scope of the environmental and resource protection law. I suggest you go to the bookstore to browse this kind of books. If you have encountered such a problem, you can consult a law firm. Generally speaking, some toxic and harmful enterprises should stay away from the city center. 1The Environmental Protection Law of People's Republic of China (PRC) promulgated in February 1989 belongs to China. ...
7. 10 sets the object distance u u >；; 2f, reverse the reduced real image u=2f, and reverse the size of the real image 2f >；; U>f inverts and magnifies the real image, u=f does not image u.
8. Light pollution is generally divided into three categories in the world, namely white light pollution, artificial sunlight pollution and colored light pollution. /view/2 1865.htm
9. Under normal circumstances, the temperature decreases with the elevation, with an average increase of 100 m and a temperature decrease of about 0.6 degrees, which makes the temperature of the lower atmosphere high and the air density low; The upper temperature is low and the air density is relatively high, resulting in the phenomenon of "top-heavy". The atmospheric stratification is unstable, and it is easy to roll up and down to form convection, which will make the lower layer particularly tight. ...
10. If it is within15m, it will have a serious impact on human health and livestock. But if it is too high, it will cause the destruction of the ozone layer. Polluted gases will fall to the ground through wet deposition. In a word, air pollution at different heights will have different consequences.