Acceleration urbanization and industrialization has resulted in challenges such as river ecosystem degradation and water scarcity that have hindered sustainable development in China. Healthy rivers provide ecosystem services that improve human well-being. The Happy River Index (HRI) integrates trends in river health and human well-being. This study aimed to establish an HRI assessment framework. The assessment framework was applied to the Yellow River, China at three spatial scales in which the analytic hierarchy process (AHP)-entropy weight and single index quantification-multiple indices syntheses-poly-criteria integration (SMI-P) methods were utilized. Limiting factors were diagnosed by the obstacle degree model and approaches to improve the HRI in regions along the Yellow River are suggested. The results showed that: (1) the overall HRI of the Yellow River was relatively low, with some differences among different regions; (2) the HRI for the upper, middle, and lower reaches of the Yellow River showed a decreasing trend from 0.77 to 0.65; (3) Sichuan had the highest HRI at the regional scale, followed by Gansu and Qinghai, whereas Inner Mongolia had the lowest; (4) scarcity of water resources and the fragility of the ecological environment were the two dominant factors restricting the improvement of the HRI in regions along the Yellow River. The results of this study can provide a valuable reference for protection of river health and improvement of human well-being in China.

Water resources management (WRM) is a global strategic issue. Effectively evaluating WRM performance and analyzing its influencing factors have strong practical significance for improving regional WRM performance. Data envelopment analysis (DEA) is one of the most popular models to measure the efficiency of decision-making units (DMUs). Taking regional WRM performance as efficiency DMUs, this paper proposes the indicator system to quantify WRM performance from the perspectives of resource endowments, economic and technological development, and ecosystem protection. The WRM performance of 31 provincial administrative regions in mainland China from 2013 to 2019 are measured, and the temporal and spatial changes are explored using the window DEA model and the Malmquist index model. Finally, the Tobit model is used to quantitatively analyze the affecting factors. The results indicate that: (1) in 2015 and 2019, WRM performance of Sichuan, Shaanxi, Xinjiang, Inner Mongolia, and Guangxi were slightly higher than that in other years, and the areas with more room for WRM performance improvements were areas with abundant water resources; (2) from 2013 to 2019, China’s overall WRM performance showed a slow rise, and there were obvious fluctuations in 2018; (3) the improvement in WRM performance was primarily the result of an improvement to comprehensive technical efficiency changes (EC), whereas technological progress changes (TC) have largely restricted China’s WRM performance; (4) the main influencing factors of WRM performance in China were as follows: industrial development level, water resources utilization rate, and urban sewage discharge per capita.

To achieve the global temperature control target under the background of climate warming, it is necessary to establish a systematic carbon dioxide (CO₂) emission accounting method system in the field of water resources as soon as possible. In this study, the carbon dioxide emission equivalent analysis (CEEA) method for different water resource behaviors (WRBs) is proposed from four dimensions of development, allocation, utilization, and protection, and a function table of CEEA (FT-CEEA) for WRBs is constructed. The FT-CEEA includes CEEA formulae for 16 aspects in four categories of water resource development, allocation, utilization, and protection. The CEEA method is applied to 31 provinces in China. The results reveal that: (1) There are significant spatial differences in the carbon dioxide emission equivalent (CEE) of WRBs in different provinces of China under the influence of various factors such as water supply structure and natural conditions. (2) Reservoir storage, tap water allocation, and wastewater treatment are the main contributors to CEE in the categories of water resource development, allocation, and protection behaviors, respectively. (3) The water resource utilization behavior category has the most significant CO₂ emission and absorption effects, and industrial and domestic water utilization behaviors are the main sources of emission effects. (4) The overall CO₂ emission effect of WRBs is greater than the absorption effect. Measures such as increasing the proportion of hydroelectric power generation, improving ecological water security capacity, and strengthening the level of wastewater treatment and reclaimed water reuse are effective ways to promote the goal of carbon neutrality in the field of water resources.

The human–water relationship in the Yellow River Basin is extremely complex, and the human–water relationship discipline is a powerful tool to solve difficult problems caused by the complexity. This study firstly analyzes the historical evolution of the human–water relationship in the Yellow River Basin. Secondly, we summarize some representative problems in dealing with the human–water relationship. Then, on the basis of discussing the main contents of the human–water relationship discipline, the possible solutions to the difficult problems are discussed. Taking the Yellow River water distribution dilemma as an example, we carry out a detailed application. Finally, the possibility of applying human–water relationship discipline to complex basin research is analyzed, and the future research prospects of the discipline are put forward. Results reveal that: (1) River diversion and unreasonable human activities are the main driving factors for the ecological evolution of the Yellow River Basin. In addition, the basin is currently in the “Protective coordination stage”. (2) The complexity of the human–water relationship is the root of many difficult problems, and forming a sound disciplinary system of human–water relationship discipline is the key to breaking through these difficult problems. (3) The Yellow River water distribution scheme based on human–water relationship discipline is consistent with the current water use pattern of the basin. (4) The theory and method system of human–water relationship discipline is also feasible and universal for other complex basins.

This paper proposes a new structure of module suspension system of Electromagnetic System (EMS) maglev train, and presents an active fault-tolerant control method via control law reconfiguration. Being different with conventional module suspension system, the new structure has four controllers which increase the redundancy degree of the system. And CAN network is adopted to transmit signals from sensors. Thus, each controller could obtain adequate information about the system states. Then, current loop is designed for each electromagnet based on cascade control theory. After that, the mathematical model of systems with different control channel failures are constructed and optimal controller is designed for each model. Though simulation, the new structure and its active fault-tolerant control method are proved to be more effective than the conventional method and worthy of using for reference to improve the reliability of suspension system of maglev train.

Enhancing the level of water use and alleviating the constraints of water shortage on economic and social development are powerful supports to realize the harmonious balance of water and economic society. In this study, the data envelopment analysis (DEA) window analysis method is applied to the study of water use level, and the SBM-DEA model (slack based measure, SBM) is combined to explore the spatial and temporal evolution characteristics of composite water use index (CWUI) in nine provinces from 2012 to 2018. The Malmquist index model is used to decompose the intrinsic causes of total factor productivity (TFP) changes, and the spatial matching degree calculation method is applied to study the matching degree between CWUI and economic and social development levels (E-SDL). The results showed that: (1) the overall trend of CWUI in the nine provinces from 2012 to 2018 was increasing, with significant spatial variability in water use levels; (2) the improvement of TFP of water in the nine provinces was mainly driven by technological change (TC), and the main factor limiting the improvement of TFP of water was technical efficiency change (EC); (3) E-SDL of the nine provinces showed an increasing trend, with the spatial distribution characteristics of decreasing E-SDL of the downstream, midstream and upstream provinces in sequence; (4) the degree of matching between CWUI and E-SDL shows strong regional differences, with different types of matching.