Abstract: Embodiments of the present application provide a positive electrode plate, a secondary battery and an electrical apparatus. The positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one side of the positive electrode current collector, where the positive electrode film layer includes a first film layer and a second film layer in a thickness direction of the positive electrode plate; the first film layer includes a lithium transition metal phosphate and a carbon coating applied on at least part of the surface of the lithium transition metal phosphate, and the second film layer includes a lithium transition metal oxide and a conductive agent; and a resistivity difference between the second film layer and the first film layer is 10-200 ?·cm.

Abstract: A positive electrode plate includes: a positive electrode current collector, a first film layer, a second film layer, and a third film layer, where the third film layer is located between the first film layer and the second film layer, the first film layer is located on a surface of at least one side of the positive electrode current collector and is closer to the positive electrode current collector than the second film layer; the first film layer includes a first active material, and the first active material includes a layered structure material; the second film layer includes a second active material, and the second active material includes at least one of an olivine structure material and a spinel structure material; and the third film layer is used for isolating the first active material from the second active material.

Abstract: A positive electrode plate includes a current collector, a conductive coating, a first active material layer and a second active material layer, where the conductive coating is formed on a surface of the current collector, the first active material layer is formed on a surface of the conductive coating, and the second active material layer is formed on a surface of the first active material layer; the first active material layer includes a first active material; the second active material layer includes a second active material; the first active material does not catch fire in a nail penetration test; and the second active material has a gram capacity greater than or equal to 165 mAh/g.

Abstract: A positive electrode plate and a preparation method therefor, a battery cell, a battery, and an electric device are described. The positive electrode plate includes: an active material layer, where the active material layer includes a first active material, a conductive agent, and a binder. The first active material includes a layered transition metal oxide, and the binder includes a flexible binder, configured to bind the first active material and the conductive agent. Performance of a battery including the positive electrode plate is improved.

Abstract: A positive electrode plate and a preparation method thereof, a battery cell, a battery, and an electric apparatus are described. The positive electrode plate includes: a positive electrode current collector and a first film layer and a second film layer disposed on the same side of at least one surface of the positive electrode current collector; where the first film layer includes a first active material, and the first active material includes at least one of a material with an olivine structure and a material with a spinel structure; the second film layer includes a second active material, and the second active material includes a material with a layered structure; a resistivity R1 of the first active material and a resistivity R2 of the second active material satisfy: 20?R2/R1?500. The technical solution of the embodiment of this application enhances the performance of the battery cell.

Abstract: The present application provides a negative electrode plate for a secondary battery, a method for preparing the same, and a secondary battery including the negative electrode plate, a battery module, a battery pack, and an electrical device. The negative electrode plate in the present application includes a current collector and an active material layer disposed on at least one surface of the current collector, wherein the active material layer includes: a first graphite layer disposed on at least one surface of the current collector, a lithium titanate layer disposed on the surface of the first graphite layer, and a second graphite layer disposed on the surface of the lithium titanate layer; and the first graphite layer has an OI value of greater than or equal to 20.0, and the second graphite layer has an OI value of less than or equal to 15.0.

Abstract: The present invention relates to the field of noninvasive prenatal gene testing by high-through sequencing technologies. Particularly, the present application relates to a method for determining the content of cell-free fetal DNA in maternal peripheral blood.

Abstract: An intelligent terminal, and a computer-readable storage medium is provided. The detection method includes: obtaining a column set, a page set, and a block set, and presetting a bad column set, a bad page set, an error threshold, and an initial bad block template; alternately obtaining bad page elements and bad column elements from the block set in sequence based on the error threshold, and alternately updating the bad page set and the bad column set in sequence; based on the bad column sets and the bad page sets corresponding to different error thresholds, updating the error threshold, obtaining a final column set from the bad column sets, and obtaining a final page set from the bad page sets; and obtaining a final bad block template. The present invention can reduce the impact of a bad page on a subsequent operation of selecting a bad column element.

Abstract: Provided herein is a method of constructing a high throughput sequencing library for use in detecting chromosome copy number variation comprising mainly the following steps: (1) subjecting DNAs to be tested to random fragmentation by a double-strand DNA fragmentation enzyme; (2) end-filling and adding poly-adenine at the 3?end of the fragmented DNAs; (3) connecting the end-filled DNAs having a 3?end poly-adenine with sequencing linkers to obtain connected products; (4) purifying the connected products to obtain the sequencing library; wherein steps (1)-(3) are performed in a single reaction tube. Also provided is a kit for constructing a sequencing library for use in detecting chromosome copy number variation.

Abstract: The present invention relates to the field of noninvasive prenatal gene testing by high-through sequencing technologies. Particularly, the present application relates to a method for determining the content of cell-free fetal DNA in maternal peripheral blood.