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The conflict between rice production and water scarcity is becoming more pronounced. Therefore, the advancement of water‐saving rice cultivation is crucial in guaranteeing both food and ecological security. This study provides a summary of the development and characteristics of various water‐saving cultivation techniques for rice, including alternate wetting and drying irrigation, wet irrigation, controlled irrigation, the system of rice intensification, direct seeding rice, and dry cultivation of rice (DCR). We also introduce the varietal characteristics of upland rice, aerobic rice, water‐saving and drought‐resistant rice, and DCR. We summarize the impact of different water‐saving cultivation models on yield and quality and regulatory measures, and propose challenges and strategies for the development of water‐saving cultivation of rice in the future. We hope to provide a reference for promoting the development of rice water‐saving cultivation and dry farming agriculture. Core Ideas: This review summarizes the development of water‐saving cultivation techniques for rice.This review presents the challenges and strategies for developing water‐saving rice cultivation.This review provides technical and theoretical support for the development of rice water‐saving cultivation. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Metal organic frameworks have been employed as high‐performance layered double hydroxide (LDH) composite supercapacitor electrode materials but have shown unsatisfactory redox ability and stability. Herein, a host‐guest CuMo‐based polyoxometalate‐based metal organic framework (POMOF) with copious electrochemically active sites and strong electrochemical redox activities has been effectively coupled with POM‐incorporated CoNi‐LDH to develop a nanocomposite (NENU‐5@CoNi‐LDH) by a simple solvothermal method. The designed electrode shows a high specific capacity of 333.61 mAh·g–1 at 1 A·g–1. In addition, the novel hybrid symmetric supercapacitor NENU‐5@CoNi‐LDH/active carbon (AC) demonstrated a high energy density of 80.8 Wh·kg–1 at a power density of 750.7 W·kg–1. Interestingly, the nanocomposite of NENU‐5@CoNi‐LDH exhibits an outstanding capacitance retention of 79% after 5000 charge‐discharge cycles at 10 A·g–1. This work provides a new strategy and will be the backbone for future energy storage research. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Metal organic frameworks have been employed as high‐performance layered double hydroxide (LDH) composite supercapacitor electrode materials but have shown unsatisfactory redox ability and stability. Herein, a host‐guest CuMo‐based polyoxometalate‐based metal organic framework (POMOF) with copious electrochemically active sites and strong electrochemical redox activities has been effectively coupled with POM‐incorporated CoNi‐LDH to develop a nanocomposite (NENU‐5@CoNi‐LDH) by a simple solvothermal method. The designed electrode shows a high specific capacity of 333.61 mAh·g–1 at 1 A·g–1. In addition, the novel hybrid symmetric supercapacitor NENU‐5@CoNi‐LDH/active carbon (AC) demonstrated a high energy density of 80.8 Wh·kg–1 at a power density of 750.7 W·kg–1. Interestingly, the nanocomposite of NENU‐5@CoNi‐LDH exhibits an outstanding capacitance retention of 79% after 5000 charge‐discharge cycles at 10 A·g–1. This work provides a new strategy and will be the backbone for future energy storage research. [ABSTRACT FROM AUTHOR]

This study proposes a sensorless flux adaption direct torque and flux control (DTFC) for an interior permanent magnet synchronous motor (IPMSM), in which an maximum torque per ampere (MTPA) based on active flux and an adaptive second-order sliding mode observer (SOSMO) are adopted. Flux adaption DTFC is proposed based on the existing active flux concept. Thus, the stator current amplitude can be minimised in both steady state and transient state. Furthermore, to realise the sensorless control of the IPMSM, an adaptive SOSMO is proposed. Compared with constant gains SOSMO, the gains of the adaptive SOSMO can be adjusted adaptively with the motor speed changing. Then, the precision of position estimation is enhanced effectively in a wide speed range. Numerical simulations and experiments with a 60 kW IPMSM are implemented. In addition, the results validate the capability of the proposed sensorless flux adaption DTFC scheme. [ABSTRACT FROM AUTHOR]

In this study, the permanent-magnet synchronous motor sensorless control systems realised by sliding-mode observers in stationary aß and estimated γδ coordinates are systematically studied and compared. First, based on the sufficient condition of sliding-mode stability, a more reasonable selection method of boundary layer width and sliding-mode gain is derived, effectively reducing the system chattering. Furthermore, in extracting estimated extended electromotive force, the advantages and disadvantages of the backforward method in the aß-axis and the influence of filter cut-off frequency on estimation error in the γδ-axis are analysed. Finally, the estimation error, speed range, stability, and the effect of speed error of these two sensorless control systems are analysed and compared. The results indicate that these two systems have equivalent position error above a certain speed, and the γδ-axis estimation system has a larger position error in low-speed range, but still operating well. Moreover, the γδ-axis estimation algorithm has better stability and wider-speed range. Owing to the fast track of phase-locked loop, the effect of speed error on estimation accuracy of the γδ-axis system can be neglected. Simulation and experiment verified the theoretical analysis and comparison. [ABSTRACT FROM AUTHOR]