Abstract: The present disclosure relates to a negative electrode material and a preparation method thereof and a lithium ion battery, wherein the negative electrode material includes an active material, the active material includes a skeleton structure and a silicon oxygen material embedded on the skeleton structure; the skeleton structure includes a skeleton of lithium silicate located inside the active material and a skeleton of water-insoluble silicate located on a surface layer of the active material, and the skeleton of water-insoluble silicate is linked with the skeleton of lithium silicate, wherein in an XRD pattern of the negative electrode material, an intensity of a strongest diffraction characteristic peak of the lithium silicate is IA, and an intensity of a strongest diffraction characteristic peak of the water-insoluble silicate is IB, and 0.03?IB/IA?0.2.

Abstract: Disclosed are a method, device, computer system for obtaining respiratory signal. The method includes: filtering aliasing vital signs signals obtained by piezoelectric sensor to obtain target vital signs signals; performing a Fourier transform to obtain first frequency response, and generating an upper envelope according to each frequency point of the first frequency response; determining main peak frequency point and main peak amplitude according to the frequency point corresponding to the maximum value of flat tops; identifying the flat top corresponding to the main peak amplitude as main peak flat top; determining minimum value frequency point according to the minimum value between the main peak flat top and an adjacent flat top or flat bottom; and determining respiratory spectrum principal component interval according to the minimum value frequency point; reconstructing the respiratory spectrum principal component interval through an empirical wavelet function to obtain reconstructed respiratory signal.

Abstract: Provided are a composite material and a preparation method thereof, a negative electrode material, and a lithium ion battery. The negative electrode material includes at least one composite material, and the lithium ion battery includes at least one composite material. The composite material has a core-shell structure composed of an inner core and a hydrophobic coating layer, with the inner core including at least one lithium-containing silicon oxide, and the hydrophobic coating layer being used to cover the inner-core material.