Abstract: An optical system includes: a stop; a first lens having a positive refractive power, an object side surface being convex at a paraxial area; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens having a positive refractive power, an image side surface being convex at a paraxial area; a seventh lens; and an eighth lens, an image side surface being concave a paraxial area. The optical system satisfies the condition: (MIN6*MAX8/MAX6*MIN8)?2. MIN6 is a minimum thickness of the sixth lens in a direction of an optical axis, MAX6 is a maximum thickness of the sixth lens in the direction of the optical axis, MIN8 is a minimum thickness of the eighth lens in the direction of the optical axis, and MAX8 is a maximum thickness of the eighth lens in the direction of the optical axis.

Abstract: An optical system includes: a stop; a first lens having a positive refractive power, an object side surface being convex at a paraxial area; a second lens; a third lens; a fourth lens; a fifth lens; a sixth lens having a positive refractive power, an image side surface being convex at a paraxial area; a seventh lens; and an eighth lens, an image side surface) being concave a paraxial area. The optical system satisfies the condition: (MIN6*MAX8/MAX6*MIN8)?2. MIN6 is a minimum thickness of the sixth lens in a direction of an optical axis, MAX6 is a maximum thickness of the sixth lens in the direction of the optical axis, MIN8 is a minimum thickness of the eighth lens in the direction of the optical axis, and MAX8 is a maximum thickness of the eighth lens in the direction of the optical axis.

Abstract: An optical system, sequentially comprising from an object side to an image side: a diaphragm; a first lens having positive refractive power; a second lens having negative refractive power, an object-side surface of the second lens being convex in a paraxial region; a third lens, a fourth lens, and a fifth lens which have refractive power; and a sixth lens having negative refractive power, an image-side surface of the sixth lens being concave in a paraxial region. The optical system satisfies the following relationship: (TTL-BFL)/f<0.92, TTL being a distance from an object-side surface of the first lens to an imaging surface of the optical system on an optical axis, BFL being the shortest distance from the image-side surfaceof the sixth lens to the imaging surface in a direction parallel to the optical axis, and f being an effective focal length of the optical system.

Abstract: An optical system, a lens module, and an electronic device are provide. The optical system includes a first lens having a positive refractive power, a second lens having a refractive power, a third lens having a refractive power, a fourth lens having a refractive power, a fifth lens having a refractive power, a sixth lens having a positive refractive power, a seventh lens having a negative refractive power which are sequentially arranged from an object side to an image side along an optical axis of the optical system. The first lens has an object-side surface which is convex near the optical axis. The seventh lens has an image-side surface which is concave near the optical axis. The optical system satisfies the following expression: 4?(Y72*TL)/(ET7*f)?10.

Abstract: The present invention provides a functional diene polymer, a preparation method thereof and a rubber composition comprising the functional diene polymer. The functional diene polymer comprises at least one type of conjugated diene structural units and silane coupler functional units represented by formula (I) in its molecular chain, and the number-average molecular weight of the functional diene polymer is 50,000˜1,000,000; R1-R4 are C1-C20 linear or branched alkyl or heteroatom-containing C1-C20 linear or branched alkyl, and the heteroatom is selected from one or more of halogen, oxygen, sulfur, silicon, and phosphorus. Not only the relationship between the wet slip resistance and the rolling resistance of the functional diene polymer is effectively improved, but also the offensive odor produced in the rubber mixing process owing to the addition of the silane coupler is reduced.

Abstract: Provided is a copolymer rubber, comprising a copolymer having a star-shaped block structure (SIB-PA)n-X, wherein SIB is a block comprising styrene, butadiene, and isoprene as constituent monomers; PA is a block comprising butadiene or isoprene as a constituent monomer; X is the residue of at least one coupling agent; and n=2-4. Also provided is a process for preparing the copolymer rubber and use thereof.

Abstract: The present invention provides a functional diene polymer, a preparation method thereof and a rubber composition comprising the functional diene polymer. The functional diene polymer comprises at least one type of conjugated diene structural units and silane coupler functional units represented by formula (I) in its molecular chain, and the number-average molecular weight of the functional diene polymer is 50,000˜1,000,000; R1-R4 are C1-C20 linear or branched alkyl or heteroatom-containing C1-C20 linear or branched alkyl, and the heteroatom is selected from one or more of halogen, oxygen, sulfur, silicon, and phosphorus. Not only the relationship between the wet slip resistance and the rolling resistance of the functional diene polymer is effectively improved, but also the offensive odor produced in the rubber mixing process owing to the addition of the silane coupler is reduced.

Abstract: Provided is a copolymer rubber, comprising a copolymer having a star-shaped block structure (SIB-PA)n-X, wherein SIB is a block comprising styrene, butadiene, and isoprene as constituent monomers; PA is a block comprising butadiene or isoprene as a constituent monomer; X is the residue of at least one coupling agent; and n=2?4. Also provided is a process for preparing the copolymer rubber and use thereof.