Abstract: The present invention relates to a variable-flow-path air valve for water hammer prevention and a design method. The variable-flow-path air valve includes a valve body with a top provided with an air intake-exhaust port. A ball valve seat and a floating ball are arranged below the air intake-exhaust port. The valve body is provided with at least one swing check valve configured to be opened inward. The swing check valve includes: a swing valve disc connected to a valve body hinge, a variable-flow-path air inlet controlled by the swing valve disc to open and close, a device for limiting the opening degree of the swing valve disc, and a sealing device. In the present invention, the air valve takes in air through the air intake-exhaust port and the variable flow path, and discharges air only through the air intake-exhaust port.

Abstract: The present invention relates to a variable-flow-path air valve for water hammer prevention and a design method. The variable-flow-path air valve includes a valve body with a top provided with an air intake-exhaust port. A ball valve seat and a floating ball are arranged below the air intake-exhaust port. The valve body is provided with at least one swing check valve configured to be opened inward. The swing check valve includes: a swing valve disc connected to a valve body hinge, a variable-flow-path air inlet controlled by the swing valve disc to open and close, a device for limiting the opening degree of the swing valve disc, and a sealing device. In the present invention, the air valve takes in air through the air intake-exhaust port and the variable flow path, and discharges air only through the air intake-exhaust port.

Abstract: The invention provides a MEMS micropump testing method and system. The method includes building a control model based on a least-square support vector; determining the magnitude of the pressure in a reservoir component relative to a preset first and second threshold in combination with a pressure value index to obtain a determination result; reading the determination result and controlling accordingly the reservoir component to be in or out of communication with the replenish component and the meter; and obtaining testing data for the under-test micropump based on variation in the liquid in the meter. The replenish component and the reservoir component assist in MEMS micropump testing so that a small volume and flow rate of the output liquid can be tested. The volumes and flow rates of the output liquid from the MEMS micropump at different pressures can be tested by controlling the pressure in the reservoir component.

Abstract: The invention relates to a device and method for laboratory ice jam and ice dam radar measurement tests, the device includes a non-metal water tank, a truss spans the top of the non-metal water tank, the truss is connected with a radar plate parallel to a surface of water through a lifting mechanism, a measuring radar is provided on the radar plate, a permeable measuring barrel soaked in the water is provided below the radar plate, a barrel bottom of the permeable measuring barrel is a permeable plate capable of rising and falling, model ice blocks are provided in the permeable measuring barrel, and a handle capable of shaking the truss upwards, downwards, leftwards and rightwards is provided on the truss.

Abstract: The invention relates to a device and method for laboratory ice jam and ice dam radar measurement tests, the device includes a non-metal water tank, a truss spans the top of the non-metal water tank, the truss is connected with a radar plate parallel to a surface of water through a lifting mechanism, a measuring radar is provided on the radar plate, a permeable measuring barrel soaked in the water is provided below the radar plate, a barrel bottom of the permeable measuring barrel is a permeable plate capable of rising and falling, model ice blocks are provided in the permeable measuring barrel, and a handle capable of shaking the truss upwards, downwards, leftwards and rightwards is provided on the truss.

Abstract: A multiple frequency band antenna is disclosed involving a first resonant portion tuned to a low frequency band; a second resonant portion tuned to a first high frequency band at frequencies higher than the low frequency band; a third resonant portion tuned to a second high frequency band at frequencies higher than the low frequency band and substantially different from the first high frequency band; and a first conductor portion forming part of the first resonant portion and the second resonant portion, the first conductor portion having a grounding point, a feeding point for providing an input signal to at least one of the first resonant portion and the second resonant portion and for receiving an output signal from at least one of the first resonant portion and the second resonant portion, and a second conductor portion electrically connected to the feeding point wherein the third resonant portion is electrically connected to the second conductor portion.

Abstract: A multiple frequency band antenna is disclosed involving a first resonant portion tuned to a low frequency band; a second resonant portion tuned to a first high frequency band at frequencies higher than the low frequency band; a third resonant portion tuned to a second high frequency band at frequencies higher than the low frequency band and substantially different from the first high frequency band; and a first conductor portion forming part of the first resonant portion and the second resonant portion, the first conductor portion having a grounding point, a feeding point for providing an input signal to at least one of the first resonant portion and the second resonant portion and for receiving an output signal from at least one of the first resonant portion and the second resonant portion, and a second conductor portion electrically connected to the feeding point wherein the third resonant portion is electrically connected to the second conductor portion.