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【Objective】 Many arid and semiarid regions in North and Northwest of China are poor in freshwater but have saline groundwater. Efficient utilization of these saline waters is crucial for agricultural sustainability. This study seeks to experimentally identify the optimal alternation of freshwater and saline water for irrigating arable crops in areas with shallow groundwater. 【Method】 The experiment was conducted at a maize field from May to October in 2022 at an experimental site in Darat Banner, Erdos. It compared four irrigations: irrigating with saline water only (T1), irrigating with saline water twice followed by a freshwater irrigation (T2), irrigating with saline water once followed by one freshwater irrigation (T3), irrigating with freshwater only (CK). In each treatment, we measured water and salt distribution in the soil, as well as yield of the maize. 【Result】 Alternate irrigation significantly influenced soil moisture and salinity. T3 considerably increased root water uptake during the critical growth stage of the crop, manifested by the 0.75% to 1.3% reduction in water content in the 0~40 cm soil layer, and 2.02% to 3.71% increase in water content in the 40~100 cm soil layer. During the irrigation period, there were 58.45% and 63.98% of soils salinized in T2 and T3, respectively. Compared to CK, alternate irrigation reduced crop yield by 10% to 13%, but saved 33% to 50% of freshwater. Grain yield and water use efficiency of T3 were 90.26% and 23.2% higher than that of T1, respectively, despite its 7.2% reduction in grain yield compared to CK. Groundwater recharge during the reproductive period accounted for 21.74% to 25.55% of the water consumed by the maize. 【Conclusion】 Considering the effect of alternate irrigation on distribution of water and salt in soil, as well as the growth and water consumption of the maize, the most suitable irrigation method for maize in the saline soil is alternating saline water and freshwater(T3).

Traditional machining is transforming to digital and intelligent machining, in which adaptive machining cyber-physical system (CPS) provides a useful approach to control the machining quality of large thin-walled parts. And the running of adaptive machining CPS is a complex multi-processes execution flow, which can be regarded as a continuous–discrete hybrid system. To realise adaptive controlling of machining quality and adaptive managing of process flow, a unified model for continuous–discrete hybrid adaptive machining CPS is constructed. Firstly, an architecture of adaptive machining CPS is proposed. Next, the cutting process in adaptive machining CPS is modelled as a continuous-variable system (CVS), while the process flow in adaptive machining CPS is modelled as a discrete-events system (DES). Then, the finite state machine is adopted to integrate the CVS and DES to form the unified model of adaptive machining CPS. Finally, an adaptive machining CPS is developed based on the unified model, and the machining results demonstrate that machining quality is efficiently controlled, as well as the process flow is orderly managed. The built unified model has four features, respectively universality, integrability, scalability, and reconfigurability, which can be reconstructed to form a new instancing model according to the different machining requirements. [ABSTRACT FROM AUTHOR]

The competition mechanisms between crop species for water and nutrients, especially nitrate (NO3-N), in intercropping ecosystems are still poorly understood. Therefore, an experiment involving high (300 kg ha-1 for corn and 250 kg ha-1 for tomato), medium (210 kg ha-1 for corn and 175 kg ha-1 for tomato), and low (150 kg ha-1 for corn and 125 kg ha-1 for tomato) N-fertilizer applications (HF, MF, LF, respectively) was conducted in the corn and tomato intercropping ecosystem during 2014 (a calibration period for modeling) and 2015 (a validation period for modeling). The modified HYDRUS-2D code was used to analyze soil NO3-N concentrations (SNC) in the middle between corn rows (Pc), between corn and tomato rows (Pb), and between tomato rows (Pt), NO3-N exchange in the horizontal direction between different regions, NO3-N leaching from the corn, the bare, and the tomato region, and N uptake by crops. Simulated SNCs were in good agreement with measurements, with RMSE, NSE, and MRE of 0.01-0.06 mg cm-3, 0.75-0.98, and 8.7-19.1%, respectively, during the validation period (2015). Average SNCs in the 0-40 cm soil layer were different between Pc, Pt, and Pb. Intensive NO3-N exchange in the horizontal direction occurred during the second stage (Day After Sowing [DAS] 37-113 in 2014; DAS 29-120 in 2015). NO3-N exchange between the corn and bare regions was lower than between the tomato and bare regions due to smaller concentration gradients. However, in the vertical direction, NO3-N leaching from the corn region in both years was 4.1 and 8.8 times larger, respectively, than from the tomato region under HF since NO3-N mainly moved from the tomato region to the corn region. Our results reveal the competition between corn and tomato for N and provide a rationale for formulating and optimizing different fertilizer regimes for different crops in the intercropping ecosystem.

Drip irrigation under plastic film mulching with applications of the N-fertilizer is an excellent agricultural strategy, resulting in saving irrigation water, improving N use efficiency, and increasing crop yield. However, the film residue and nitrate-nitrogen (NO3-N) losses are the leading cause of non-point pollution in agricultural fields. To promote the development of sustainable agriculture, the HYDRUS (2D/3D) model was first calibrated and then validated using experimental data from 2016 and 2017, respectively, collected in the drip-irrigated sandy field with plastic film mulching (PFM), biodegradable film mulching (BFM), and no film mulching (NFM). Additionally, the NO3-N spatial and temporal distributions, uptake, leaching, and use efficiency (NUE) under PFM, BFM, and NFM with 280 kg ha−1 of the N-fertilizer (the local recommendation) were evaluated using both observed and simulated data. These factors were also assessed under BFM with 210 (75 % of the recommended value) and 140 kg ha-1 (50 % of the recommended value) of the N-fertilizer. The results of numerical simulations were in good agreement with observations, with the RMSE, R2, and NSE during verification being 0.01-0.08 mg cm-3, 0.62-0.87, and 0.68-0.94, respectively. When the same amount of the N-fertilizer (280 kg ha−1) was applied in each treatment, there were no apparent differences in NO3-N concentrations in the soil profile, cumulative NO3-N uptake by corn (CNU), and cumulative NO3-N leaching (CNL) in the 100-cm soil depth between the BFM280 and PFM280 scenarios (the subscript indicates the amount of the N-fertilizer) during the early growing season (Day After Sowing [DAS] of 0–78 in 2016 and DAS of 0–92 in 2017). However, CNU and CNL were higher, and the NO3-N concentrations in the upper soil layer (0−40 cm soil layer) lower in these two scenarios than in the NFM280 scenario. The NO3-N concentrations in the topsoil layer (the 0−20 cm soil layer) in the BFM280 scenario were 3.9 % higher than in the PFM280 scenario during DAS 93–154 in 2017 due to the disintegration of the biodegradable film and 26.3 % lower during DAS 79–155 in 2016 because of intensive rainfall. Additionally, the highest NUE (50.9 kg kg-1, the average value for two years) was found when 75 % of the recommended N-fertilizer (210 kg ha−1) was applied. Therefore, an application of 210 kg ha−1 of the N-fertilizer in the BFM scenario can be recommended for sandy farmland to avoid plastic pollution, increase NUE, and effectively promote the development of sustainable agriculture.

A series of ferroelectric thin films of Bi3.25Ce0.75Ti3O12 (BCTO) was deposited on a composite substrate of Pt/Ti/SiO2/Si through the sol-gel method, and the deposited films were irradiated with different doses of gamma rays. The crystal structure, surface morphology, ferroelectricity, leakage, and anti-fatigue properties of the deposited films before and after irradiation were compared by thermogravimetric differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and ferroelectric tester. The results showed that an increase in absorbed γ ray doses, didn't change the crystal structure of films. The ferroelectricity of the deposited films decreased significantly with the residual polarization 2Pr decreasing from 51.5 μC/cm2 to 23.7 μC/cm2. The leakage current density of the films increased slightly from 0.9×10-7 A/cm2 to 7.2×10-7 A/cm2. Some of the films showed fatigue performance after 1012 polarization switching cycles.