Abstract: A flat tube, a multi-channel heat exchanger, and an air conditioning and refrigeration system. The flat tube has n groups of flow channels extending in a length direction of the flat tube, and the n groups of flow channels are distributed to be spaced apart in a width direction of the flat tube; and a flow cross-sectional area of a first group of the flow channels is A1, . . . , a flow cross-sectional area of kth group of the flow channels is Ak, . . . , a flow cross-sectional area of an nth group of the flow channels is An, 1<k?n, Ak?1.2Ak?1, and k is an integer greater than 1.

Abstract: The present disclosure discloses a control method for an air conditioning system. The air conditioning system at least includes a compressor, a heat exchanger and a throttle device. The operation phase of the air conditioning system at least includes a start-up phase and a stable phase. The control method includes an action that in the start-up phase, the operating time of the compressor is set as t, when t is greater than 0 and less than 60s, an operating frequency F of the compressor is controlled to be less than 75 Hz, and a frequency rise speed per second Vf of the compressor is controlled to be less than 1.25 Hz/s.

Abstract: The present disclosure discloses a control method for an air conditioning system. The air conditioning system at least includes a compressor, a heat exchanger and a throttle device. The operation phase of the air conditioning system at least includes a start-up phase and a stable phase. The control method includes an action that in the start-up phase, the operating time of the compressor is set as t, when t is greater than 0 and less than 60s, an operating frequency F of the compressor is controlled to be less than 75 Hz, and a frequency rise speed per second Vf of the compressor is controlled to be less than 1.25 Hz/s.

Abstract: An in situ phase change gel sustained-release preparation for a small molecule drug and a preparation method thereof. The in situ phase change gel sustained-release preparation comprises a small molecule drug comprising an active pharmaceutical ingredient, a phospholipid, Span, and an ethanol solution. The in situ phase change gel sustained-release preparation has a high concentration of phospholipids combined with Span, and is thus able to reduce the immediate-release of the small molecule drug and extend the release time, and is suitable for various administration routes, such as subcutaneous injection and external administration.