Abstract: This application discloses a protection circuit associated with a battery management system (BMS). The protection circuit includes a first protection module and a freewheeling module. The first protection module is connected in parallel to a first switch module of the BMS, and the freewheeling module is connected in parallel to a load module of the BMS. The first protection module switches to a charging state when the first switch module is turned off to stabilize a voltage between a first terminal of the first switch module and a second terminal of the first switch module. The freewheeling module is turned on when the first switch module is turned off to stabilize a voltage between the first switch module and the second switch module. The protection circuit mitigates risks of breakdown of the first switch module, and prevents a parasitic inductance from limiting a switching frequency of the first switch module.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing conversion path performance measures and reports. In one aspect, user interaction data are obtained, were the user interaction data specify user interactions for a plurality of conversions. User interactions that are associated with each conversion are selected from the user interaction data, where the associated user interactions for each conversion are user interactions with a converting user during the conversion cycle for the conversion. Using the user interaction data for the selected user interactions, a quantity of user interactions that are associated with each conversion and occurred during the conversion cycle for the conversion are determined. In turn, conversion path performance measures are computed and reports specifying the conversion path performance measures are generated.

Abstract: The refractive index of a fiber core of a few mode optical fiber is n1. A cladding layer surrounding the fiber core includes: a downward-concave cladding layer surrounding the fiber core, the refractive index thereof is n2; a first upward-convex cladding layer surrounding the downward-concave cladding layer, the refractive index thereof is n3; a second upward-convex cladding layer surrounding the first upward-convex cladding layer, the refractive index thereof is n4; an outer layer surrounding the second upward-convex cladding layer, the refractive index thereof is n5. The refractive indexes of the fiber core, the downward-concave cladding layer, the first upward-convex cladding layer, the second upward-convex cladding layer, the outer layer satisfy: n1>n3>n4>n5>n2. The fiber is a non-single mode in a direct waveguide state, and equivalent single-mode transmission can be achieved when the optical fiber is bent at a specific bending radius.

Abstract: Provided is a few-mode optical fiber. The optical fiber includes: a core and a cladding enclosing the core. The cladding includes: a first inner cladding surrounding the core; a first high-refractive-index mode filter layer surrounding the first inner cladding; a second inner cladding surrounding the first high-refractive-index mode filter layer; a second high-refractive-index mode filter layer surrounding the second inner cladding; and an outer cladding surrounding the second high-refractive-index mode filter layer.

Abstract: Provided is a few-mode optical fiber. The optical fiber includes: a core and a cladding enclosing the core. The cladding includes: a first inner cladding surrounding the core; a first high-refractive-index mode filter layer surrounding the first inner cladding; a second inner cladding surrounding the first high-refractive-index mode filter layer; a second high-refractive-index mode filter layer surrounding the second inner cladding; and an outer cladding surrounding the second high-refractive-index mode filter layer.

Abstract: The refractive index of a fiber core of a few mode optical fiber is n1. A cladding layer surrounding the fiber core includes: a downward-concave cladding layer surrounding the fiber core, the refractive index thereof is n2; a first upward-convex cladding layer surrounding the downward-concave cladding layer, the refractive index thereof is n3; a second upward-convex cladding layer surrounding the first upward-convex cladding layer, the refractive index thereof is n4; an outer layer surrounding the second upward-convex cladding layer, the refractive index thereof is n5. The refractive indexes of the fiber core, the downward-concave cladding layer, the first upward-convex cladding layer, the second upward-convex cladding layer, the outer layer satisfy: n1>n3>n4>n5>n2. The fiber is a non-single mode in a direct waveguide state, and equivalent single-mode transmission can be achieved when the optical fiber is bent at a specific bending radius.