Abstract: Disclosed is a nonlinear optimization method for parameters of ocean ecological dynamics model, comprising the following steps: acquiring a state variable set and a parameter set to be optimized; building an ocean ecological dynamics model; acquiring a final cost function equation group; solving the ocean ecological dynamics model to obtain numerical solutions of each state variable; acquiring a Hamilton function of the cost function equation group under a constraint condition, and acquiring an adjoint equation based on the Hamilton function; adjusting the parameter set to be optimized based on the adjoint equation to obtain an optimal parameter set.

Abstract: Embodiments of this application disclose a camera assembly and a terminal device. The camera assembly includes a transmission mechanism, a base, a rear housing, and a guide ring. A first end of the base is connected to the transmission mechanism, and a second end of the base is hinged to the rear housing. The rear housing has space for accommodating a camera, and at least two guide slots are disposed on the rear housing. A fixing part and a guide post are disposed on the guide ring, the fixing part is configured to fasten the guide ring to the terminal device, and the guide post adapts to the at least two guide slots. In a process in which the rear housing protrudes out of the terminal device, the guide post of the guide ring moves on the at least two guide slots of the rear housing, so that a movement direction of the rear housing is offset by a preset included angle. Therefore, a shooting angle of the camera disposed in the rear housing also changes, and the shooting angle of the camera is adjusted.

Abstract: A light guiding apparatus, a light emitting device, an electronic device, and a key are provided. The light guiding apparatus includes a light guiding body, where a prism structure is disposed in the light guiding body, and the prism structure is configured to reflect light that enters the light guiding body; and the light guiding body has a light incident surface and a light emitting surface, where the light incident surface is an irregular surface matched with the prism structure and is configured to reflect light, which is reflected back from the prism structure, to the light emitting surface. The light guiding apparatus provided in the embodiments of the present invention can effectively scatter incident beams emitted by a light source, so that uniform emergent light can be obtained.