Matter theory, 1, 2 Chinese

The interest in alchemy did not exclude philosophical or theoretical aspects of the study of matter, and a number of different systems of matter theory were developed in China. A four-element system based on earth, water, air (or wind), and fire can be traced back to Chinese creation stories, but a more popular system, based on five elements, was well established by the time of the introduction of Taoism, and its roots are lost in history. The five elements of... 

The related theory about extenics is founded by the Chinese scholars Cai wen to solve the problem of subjective and objective contradictions in 1983 (Cai, 1983), it bases on the matter-element theory and extension set theory and does research on the influence degree of the described problems about quantity and quality , so as to completely know the system features (Guo et al., 2009). Due to the complexity production conditions of underground working face, there are a variety of factors that affect gas emission, how to quickly and accurately judge the reasons that why the gas emission is abnormal is an important task of gas early-warning, the extension theory can calculate the abnormal gas emission level by using the normalized correlation function. Under the condition of correct identification of gas hazard in coal mine. 

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