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【Background and Objective】 Automation of water measurement is a crucial to developing water-saving agriculture and enhancing irrigation water utilization efficiency. Although water measurement technologies for large canals have reached a mature stage, there is a significant technology gap in the context of small channels. The objective of this paper is to address this gap by developing an automatic flow measurement system specifically designed for small rectangular channels. 【Method】 The proposed automatic flow measurement system for small rectangular channels utilizes an innovative design featuring an airfoil-shaped sluice gate. The system comprises an airfoil-shaped measuring flume and a flat gate, with the core functionality implemented using the STC89C51RC microcontroller. The system incorporates essential components such as flow measurement facilities, data processing and communication facilities, as well as power facilities. To assess its performance, extensive hydraulic performance tests were conducted, analyzing the system's behavior under various flow rates and gate openings. 【Result】 The threshold for determining the outflow of the airfoil gate pier was between 0.77 and 0.82. The flow formulae for gate outflow and weir flow were established based on the submerge of the gate at different gate openings. Based on water level and gate opening measured using the ultrasonic sensing technology, an automatic control and communication system was developed using the STC89C51RC microcontroller. The real-time outlet flow was collected by a built-in flow calculation module, and the system was powered by a photovoltaic facility. 【Conclusion】 The proposed automatic flow measurement system using airfoil gate pier is accurate. It has potential for automating flow measurement in small rectangular channels in irrigation districts.

【Objective】 Flow measurement through sluice gates in U-Shaped channels depends on a range of factors. We experimentally measured the characteristics of flow through the gates under different designs and working conditions, and then derived a formula using these data to estimate flow rates based on hydraulic characteristics of the gate and channel, as well as the working conditions. 【Method】 The experiments were conducted by controlling the flow rates from 10 to 50 L/s. The critical ratio of orifice flow to weir flow, as well as the flow capacity were analyzed utilizing hydraulic parameters, including water surface line, Froude number, and water head loss across the gate. These parameters were used in the orifice flow formula to calculate the flow rate. 【Result】 The critical ratio of orifice flow to weir flow was close to 1, the Froude number was uniformly distributed along the flow path, and the average relative head loss across the gate was 7%. Compared to the measured data, the error of the derived formula was less than 3.5%. 【Conclusion】 The sluice gate for the U-Shaped channel works well, and water head loss across it is minor. The derived formula for calculating flow rate is accurate. These results are helpful for designing U-shaped channels in irrigation areas and calculating flow rates through them.

A new type of indexing cam-planetary gear composite mechanism is designed and studied. The input shaft is coaxial with the output shaft， the input shaft is fixedly connected to the swing rod， the swing rod is hinged to the planetary gear shaft， and the planetary gear， the two swing arms and the planetary gear shaft are fixedly connected. The swinging rod rotates with the input shaft， and the rollers on the two swinging rods are kept in contact with the two cams respectively. The contact point changes continuously with the rotation of the swinging rod， and the swinging arm rotates relative to the swinging rod to drive the planetary wheel connected thereto to swing. Finally， the intermittent movement of the center wheel is realized， that is， the indexing movement. The working condition parameters of the mechanism motion are defined. According to the specific parameters， the actual contour equation of the cam is designed， and the 3D modeling and motion simulation of the mechanism are completed， which verifies the correctness of the design modeling process.

The time-varying cutting force in the process of gear hobbing will cause chatter and affect the quality and the precision of workpiece. To analyze the vibration characteristics of hob and workpiece system,according to the theory of metal cutting,a calculation method of the time-varying cutting force is proposed,by considering single tooth cutter and double-tooth cutter. At the same time,a dynamics model of gear hobbing vibration with four degrees-of-freedom is established,the effects of different rotational speed on the vibration characteristics are obtained. Also,a vibration experiment of gear hobbing is carried out,and the dynamics model is proved to be correct based on contrastively analyzing the experimental data and the results of theoretical calculation. The results of study show that the new calculation method can calculate the vibration characteristics of the hob and workpiece accurately,which can provide a basis for studying the mechanism of cutting chatter and monitoring the conditions of machining system.

Ceramsite substrate was prepared by crushing, screening, mixing, pelletizing, preheating and calcining using polyaluminium chloride residue (PACR) as the main raw materials. Through orthogonal design-range analysis, the best preparation condition of ceramsite substrate determined was: the ratio of PACR: bentonite was 14 g:6 g; amount of eggshell 0.6 g, calcination temperature 600 °C, and calcination time 60 min; and SEM-EDS and XRD were used to characterize the micromorphology, element changes and crystal structure of the ceramsite substrate before and after phosphorus adsorption. Furthermore, static adsorption experiment was conducted, which indicated that the prepared ceramsite substrate possessed good phosphorus adsorption characteristics, with the removal rate of 99.74% and the adsorption capacity of 4.12 mg/g; the adsorption process conformed to the quasi-second-order kinetic model and was controlled by physical and chemical processes; the adsorption isotherm fairly fit the Langmuir and Freundlich models, indicating that ceramsite substrate could provide homogeneous monolayer and heterogeneous multilayer active sites for phosphorus adsorption; and the speciation analysis for the adsorbed phosphorus revealed that the chemisorption by aluminum, calcium and iron in ceramsite substrate was the dominant adsorption mechanism. Finally, the laboratory dynamic column experiment conducted revealed that the Thomas and Yoon-Nelson models could used to well simulate the dynamic adsorption data of ceramsite substrate: the higher the phosphorus concentration in the influent, the shorter the penetration time of the adsorption column of ceramsite matrix. In general, the ceramsite made from PACR could be used in constructed wetland as a potential substrate for removing phosphorus in sewage; besides, the headache problems of solid waste such as PACR in Gongyi area of Henan Province would find a way to tackle. In summary, the aim of turning waste into treasure and green environmental protection could be expected to attain. [ABSTRACT FROM AUTHOR]

Shearing was a key part of the spent fuel reprocessing processes. Due to the strong irradiation constraints, there were few studies on the shearing processes. The parameters of shearing processes needed to be optimized by a large number of experiments. But the high cost, the long experimental cycle and complex shear mechanism made it unaccessible. The stainless steel tubes, the main support structures of spent fuel assemblies, were introduced as the research object and based on Johnson-Cook model the imte element numerical simulation method was used to analyze the shearing processes. The shear test was designed to verify the correctness of the previous model, and the effects of process parameters such as shear clearance, tool angle and tool edge width on shearing processes. The results show that the shear test and the simulation of model have good fitting performance, which proves the correctness of the model. The maximum shear forces and shear forces during fracturing are positively related with the augment of shear clearance and edge width, and the decreases of tool angle. The shear clearance has a great influence on the fracture morphology of the compression sections, and the tool angle and the edge width have a great influence on the opening width of the separation sections. [ABSTRACT FROM AUTHOR]