PAN-based carbon fiber was surface-modified with silane coating, and a composite material was prepared using a PI resin as a matrix. The structure and surface properties of carbon fibers were studied by means of X-ray photoelectron spectroscopy (XPS) and SEM. The tensile strength of the composite was measured by a tensile tester, and the friction properties of the composite were measured by a micro-nano mechanics comprehensive test system. The results show that treatment with silane coating can improve the surface roughness and chemical activity of carbon fiber, improve the interface between carbon fiber and PI resin matrix, and improve the tensile strength and wear rate of the composite.

The surface treatment of carbon fiber is carried out by electrophoretic deposition of p-aminobenzenesulfonamide grafted carbon nanotube (CNT), and it is used as a reinforcement of polyamide 6. The monofilament tensile test and XPS were used to study the effect of p-aminobenzenesulfonamide concentration on the tensile strength and surface functional groups of carbon fiber monofilaments. The results show that the higher the p-aminobenzenesulfonamide concentration, the greater the decrease in the mechanical properties of carbon fibers, and the greater the content of oxygen-containing functional groups on the surface. It is preferred that carbon fiber and thermoplastic polyamide 6 with higher retention rate of monofilament tensile strength and rich oxygen-containing functional group content are made into composite materials, and the interlaminar shear strength (ILSS) is evaluated.

Salination poses serious hazards to farmland soil. For the purpose of solving soil salination, desalination of water sources, and other problems faced by arid areas, a separation and desalination process for farmland saline-alkaline water is proposed; a separation and desalination device based on this process is also presented and tested. Results indicate that water associated with the pretreatment device satisfied the working conditions of the composite nanofiltration (NF)-reverse osmosis (RO) membrane system. The composite NF-RO membrane system produced a better filtering effect than either the NF membrane or the RO membrane. When used for filtering saline-alkaline water, the composite NF-RO membrane system achieved a desalination rate of 96.06%, a total hardness removal rate of 98.93%, and a Cl- removal rate of 99.32%, adhering to the standard for irrigation water quality. The flashing-condensation process realized a fresh water recovery rate greater than 70%. During brine evaporation using solar salt making processes, the primary compound of crystals precipitated was NaCl (with a relative content of 93%), suggesting that the precipitates have the potential values of industrial salts. These findings offer new technical references for solving the problem of farmland irrigation water faced by saline-alkaline areas worldwide.

The farmland in Xinjiang of China is mainly sandy loam soil, on which the crops are subject to flat planting with mulched film. Before planting, the soil should go through deep ploughing in a short operation period, thus there is high demand on the high-speed plow and it is necessary to optimize the plow based on tillage resistivity to improve its working performance. In view of optimal design of the surface of high-speed reversible plow, simulation test was adopted to optimize the resistivity model, then finite element method was used to test the force condition of the plow. At last, the tillage resistivity of the plow after optimization was tested by soil bin test. Test results showed that, at tilling depth of 300 mm, tilling speed of 12 km/hm, and when the plow height was 250 mm with cutting angle of 37° and dozer angle of 84°, the plow achieved the optimal tillage resistivity and the optimal combination was 2.85 N/cm2; at tilling depth of 300 mm, soil moisture content of 17%, and soil compactness of 220 N/cm2, the maximum tensile stress on the surface of the plow was 115.61 MPa and total deformation was 2.869 mm; the maximum flexible strain of the plow was 9.38×10-4. Soil bin test showed that, at tilling depth of 300 mm, dozer angle of 84°, the optimized high-speed reversible plow reduced the tillage resistance by 17.9% compared with common high-speed reversible plow made in China, and can provide reference to the design of high-horsepower tractors.

This study designed two levels of quantitative fertilizer distribution to investigate precision fertilization applications in orchards in South Xinjiang, China, which have vast rows and narrow plant spaces. The machine comprised a base frame, a ditching device, a fertilizing apparatus and an earth-covering device. The design parameters of the flow stabilization screw, conveyor screw and single-ring fertilizer quantity were summarised using theoretical analysis. The single-ring fertilizer quantity of the conveyor screw was verified via an experiment by combining EDEM software. Three-factor and three-level Box–Behnken tests were conducted using the spiral rotation speed of the conveyor, advancing of the speed and the opening degree of fertilizer outlet as the test factors and using the coefficient of variation (CV) of uniformity as the test index—thus obtaining the optimal working parameters. The simulation test results revealed that the single-ring fertilizer quantity of the fertilizing apparatus was 145.6 g, fulfilling the design requirements. The prototype testing results showed that the CV of uniformity was 6.521% when the spiral rotation speed of the conveyor, the opening degree of the fertilizer outlet and the advancing speed were 66 RPM, 42% and 2.7 km/h—thus meeting the needs of precision fertilization operations. The two designed levels of the quantitative fertilizer distributors were applied to fertilization processes in orchards with wide-row spaces and narrow plant spaces in South Xinjiang, China and were able to effectively carry out the precision fertilization applications. These data could also provide references for the optimization of spiral quantitative fertilizer distributors.