As we all know, the properties of ring are determined by its right unital modules category. Sometimes we only want to know the properties of a certain module. S
Ⅰ. INTRODUCTIONWhittaker first studied the relation between the first integral and integral invariant, and proved that an integral invariant can be determined
We have already known that many risk factors have an effect on the spread of the AIDS. A macroscopic analysis is done by the statistical data reported to WHO. T
Orbicular rocks refer to a group of rocks having orbicular structure named by von Buch in 1802. They have been found in more than one hundred localities in thir
Most cosmic dusts possess distinctive surfacial textures. The investigation on these textures greatly contributes to the research of ablation for meteorite and
(2′-5′) oligoadenylate (2-5 A) synthetase is a key enzyme in the establishment of the antiviral and antieetlular states caused by interferon. 2-5 A synthesize