Warning: file_put_contents(): Only 0 of 4956 bytes written, possibly out of free disk space in /home/www/wwwroot/zidian/001308.com/index.php on line 55 国产精品久久久久久无码专区,v片在线看
1. N the analysis of a spectrum to determine the properties of its source, such as the analysis of the emission spectrum of a substance to determine the electron distribution in its molecules 光譜分析