Abstract: Provided are a positive electrode material, a preparation method thereof and a lithium-ion battery. The positive electrode material has a composition as represented by formula (I): NixCoyMn1-x-yDkLizO2 (I); where value ranges of x, y, z and k in the positive electrode material are respectively as follows: 0.6<x<1,0<y<0.2, and x+y<1; 1?z?1.05, 0?k?0.05; D is a modifying element including at least one of S, P, F, B, Al, Ti, Mg, Cr, Zr, V, Nb, Y, W, Ta, Co, Ce and Zn. A three-electrode battery cell is prepared with the positive electrode material of the present disclosure, and a change rate of an electrochemical active surface area of the positive electrode material is less than 5% during charge and discharge cycles of the three-electrode battery cell.

Abstract: The present disclosure provides a kit for identifying tumor tissue-of-origin, including an adapter and PCR amplification primers, where the adapter includes nucleotide sequences of A01-T, A01-B, A02-T, A02-B, A03-T, A03-B, A04-T, A04-B, A05-T, A05-B, A06-T, and A06-B; and the PCR amplification primers include nucleotide sequences of R01-F, R01-R, R02-F, and R02-R. In the present disclosure, new adapter nucleotide sequences and PCR amplification primers are designed, with higher accuracy and effectiveness. The present disclosure further provides a data analysis method for a kit for identifying tumor tissue-of-origin, including data preprocessing, alignment, methylation information statistics, quality control, and analysis. In the present disclosure, the analysis of a Beta value-based methylation index further improves a recognition ratio.