Coordination Model Research Articles

Optimization of Water Hyacinth Stem-Based Oxygen-Functionalized Activated Carbon for Enhanced Supercapacitors.

In the current world, storing and converting energy without affecting the natural ecosystem are considered a sustainable and efficient green energy source production technology. Especially, using low-cost, environmentally friendly, and high-cycle stability activated carbon (AC) from the water hyacinth (Eichhornia crassipes) waste material for charge storage application is the current attractive strategy for renewable energy generation. In this study, preparation of AC from water hyacinth using a mixed chemical activation agent followed by activation time was optimized by the I-optimal coordinate exchange design model based on a 3-factor/3-level strategy under nine experimental runs. The optimum conditions to prepare AC were found to be potassium hydroxide (≈17 g) and potassium carbonate (≈11 g), and the carbonization time was approximately 1 h. Under these augmented conditions, the maximum specific capacitance suggested by the designed model was found to be ≈75.2 F/g. The regression coefficient (R 2 = 0.9979), adjusted (R 2 = 0.9917), predicted (R 2 = 0.8706), adequate precision (39.2795), and p-values (0.0062) proved the good correlation between actual and predicted values. The physicochemical and electrochemical properties of the final optimized AC were characterized by thermogravimetric/differential thermal analysis (TGA/DTA), X-ray diffractometry (XRD), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED), and potentiostat (CV and EIS) instruments. Finally, the optimized AC electrode after 100 cycles at a current density of 2 A g-1 retains an efficiency of 71.57%, indicating the good stability and sustainability of this material.

Study on the multifunctional spatial-temporal evolution and coupling coordination of cultivated land: A case study of Hebei Province, China.

The rational use of cultivated land can guarantee food security and thus is highly important for ensuring social stability, economic development and national security. The current study investigated the multifunctional temporal and spatial variation characteristics of cultivated land and explored the spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land throughout Hebei Province. Based on the administrative division data, statistical yearbook data and land use status data of the impacted areas, a multifunctional evaluation index system of cultivated land was established. The CRITIC weight method and entropy weight method were used to determine the weight of the index, the comprehensive index model was used to determine the production, social security, ecology and landscape functions of cultivated land of Hebei Province in different periods, the coupling coordination model was used to explore the multifunctional coupling coordination degree of cultivated land in each county, and spatial autocorrelation analysis was performed to determine the correlation of the multifunctional coupling coordination degrees. From 2000 to 2020, the production, social security and landscape function of cultivated land in Hebei Province trended upward; the ecological function trended slightly downward. The multifunctional coupling coordination degree of cultivated land in Hebei Province trended significantly upward and changed from limited coordination to intermediate coordination. Furthermore, it exhibited strong agglomeration and a significant positive spatial correlation, forming a 'V'-type change rule of first decreasing and then increasing. Hebei Province exhibited remarkable spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land. Regions could thus customize different cultivated land functions to maximize the benefits of cultivated land use. The findings of this study may provide a scientific basis and theoretical support for sustainably using and managing cultivated land resources in areas with similar human geographical environments.

Coupling and Coordination Development, Spatiotemporal Evolution, and Driving Factors of China’s Digital Countryside and Inclusive Green Growth in Rural Areas

Inclusive green growth is an effective strategy for achieving sustainable development in rural areas. In the digital economy era, it is crucial to examine whether rural digital development and inclusive green growth can be harmoniously integrated. This study investigates the spatial and temporal evolution of the coupled coordination between digital village construction and rural inclusive green growth in China. Utilizing panel data from 30 provinces from 2011 to 2022, we assess development levels using the entropy weighting method and analyze interdependencies with a coupling coordination model. The results indicate an upward trend in coupling coordination, with significant regional disparities, and it is slowly taking on the characteristics of spatial clustering. Economically advanced regions exhibit higher coordination levels, attributed to stronger economic foundations and better fiscal resources, enabling effective investments in digital infrastructure and green growth initiatives. Additionally, factors such as urbanization rate, innovation levels, reduction in natural disasters, increased financial support for agriculture, and improved large-scale operations positively contribute to this coordination. These findings offer insights for targeted regional development strategies, enhancing the synergy between digital transformation and sustainable rural development.

Spatial relevance of synergistic effects between air pollutants and carbon dioxide emission reductions: A case study in the Bohai Rim region of China

Analyzing the spatial correlation of synergistic effect of reducing air pollutants and carbon dioxide (SERAC) between cities, which are spatial hubs characterized by dense populations, industries, and energy usage, provides a foundation for devising regional joint prevention and control policies tailored to local circumstances at this scale. The study analyzed 43 cities in the Bohai Rim region, assessing synergistic emission reduction effects from 2006 to 2020 using a coupled coordination model based on air pollutants (AP) and carbon dioxide (CO2) emission trends. Social network analysis is employed to investigate the structural characteristics and robustness of the spatial correlation network and to unveil the position and significance of each city within the network. The study found that: (1) AP emission equivalent peaked in 2011, while the growth rate of CO2 emission equivalent slowed down in the Bohai Rim region. (2) The low-value areas for the SERAC are spatially clustered in Beijing, Tianjin, and Tangshan, with 90% of the cities in a coordinated state. (3) The network showcasing the spatial correlation between the SERAC features both “local clustering” and “global correlation” coexisting, and its robustness needs improvement. (4) Membership within the plates is relatively stable. On this basis, it is proposed that the Bohai Rim region can enhance the SERAC by establishing a “lead-follow” inter-city mechanism, strengthen the stabilizing role of core entities, implement differentiated emission reduction measures in communities, and expand regional cooperation, ultimately reducing costs and increasing efficiency.

Optimizing zoning for ecological management in alpine region by combining ecosystem service supply and demand with ecosystem resilience

In order to enhance ecosystem stability and promote sustainable regional ecological, social, and economic development, it is crucial to explore the coupling relationship between ecosystem service supply and demand and the resilience of ecosystem, so as to propose scientific ecological management zones and strategies. Taking the vulnerable alpine ecosystem in Gannan Tibetan Autonomous Prefecture (Gannan Prefecture) as the study area, this paper comprehensively utilized multi-source data, grid analysis, ecosystem service supply and demand estimation model, and coupled coordination model to analyze the spatio-temporal differentiation and coordination pattern of ecosystem service supply and demand in the study area from 2000 to 2020. With the assistance of the Analytic Hierarchy Process (AHP), the ecosystem resilience index system was constructed to evaluate the regional ecological resilience. The results reveal the following: (1) In the past 20 years, the ecosystem service supply and resilience in Gannan Prefecture showed a fluctuating upward trend, and the demand continued to grow steadily. Their spatial differentiation were obvious, but the pattern remained stable. (2) There was a moderate incoordination indicated by the average coordination degree of the supply and demand coupling of ecosystem services, which rangeed between 0.3 and 0.4. (3) Gannan Prefecture was split into three ecological management zones, considering the spatial distribution of ecosystem service supply and demand, as well as resilience. Through system function monitoring and other measures, the ecological conservation zone will rely on its high resilience to support the restoration and self-sufficiency of the system, ensuring the stability and well-being of the ecosystem. The primary objectives of general protected zone includes environmental preservation, strict regulations, and the prevention of human intervention. To enhance their ecological background, key restoration zone must intensify the implementation of ecological restoration initiatives. To address the needs of the locals, strategies such as ecological compensation, optimizing the land use structure, and fostering the growth of environmentally friendly companies can be implemented simultaneously.

The realization logic of rural revitalization: Coupled coordination analysis of development and governance.

Socialism with Chinese characteristics has entered a new stage. The principal social contradiction is the uneven development of urban and rural areas. The rural revitalization strategy has emerged as time has required. The realization of rural revitalization not only requires development to lay the foundation of the countryside but also requires governance to lead the development of the countryside. Development and governance are two indispensable aspects of rural revitalization. However, China's rural areas have long been in a state of development without governance, and this situation must change. Therefore, systematically exploring the relationship between development and governance is the key to solving the current shortcomings in rural areas. Based on the data from the statistical yearbook, the study constructed a set of evaluation indicators for rural development governance and revitalization and verified the model's effectiveness.The entropy method and the assessment model were used to calculate the comprehensive score of rural development, governance, and revitalization. The relationship between rural development and governance was analyzed using a coupled coordination model. The regression analysis model was used to explore the relationship between the coupling results of rural development, governance, and rural revitalization. From the comprehensive results, both development and governance show an upward trend, but the upward trend of development is better. From the analysis of coupling coordination between development and governance, the C value is in good condition, the T value fluctuates wildly, and the D fluctuates with the fluctuation of T. Judging from the comprehensive score of rural revitalization, it also shows an upward trend year by year. Judging from the regression analysis results of coupling coordination degree and rural revitalization comprehensive score, coupling coordination degree will significantly impact the rural revitalization evaluation value. The study found that current rural development and governance present a spiral coupling coordination relationship, and the degree of coupling coordination significantly correlates with rural revitalization. Based on the research conclusions, the study further proposes three paths to promote the coupling and coordination of development and governance. The first is an organizational isomorphism, which builds a coupled coordination system for rural development and governance. The second is to tilt resources and improve the supply of connected and coordinated factors for rural development and governance. The third is the operating mechanism to optimize rural development and governance's coupling and coordination path.

Enhancing the Forming Accuracy of CFRP through a Global Compensation Method by Introducing an Optimal Profile.

Irreversible curing distortion represents a significant limiting factor in the application of high-performance composite structures. Curing distortion is the deviation of a component's profile from the theoretical profile after demolding. Introducing the optimal compensation profile into the traditional compensation algorithm represents an effective method to enhance CFRPs' forming accuracy. For this method, it is necessary to obtain the optimal compensating profile by establishing the coordinate model of the curing process parameter and mold profile compensation. The coordinated control model consists of four parameters: the mean value (Dav), root mean square value (Dmsr), minimum (Dmin), and maximum (Dmax) of curing distortion. Two sizes of composite structural parts are manufactured using the global compensation method. We investigate the influence mechanisms of heating, holding, and cooling times on curing distortion and residual stresses and develop a multi-field coupled finite element model. Strong agreement between the numerical and experimental findings serves as evidence for the effectiveness of the numerical model. The middle layer of the fabricated parts exhibit a reduction in residual stresses as the heating and holding times increase, while an opposite trend is noted with an increase in cooling time. Refining the design of curing process parameters can yield the minimum value of curing deformation within the specified resin system interval. Comparisons indicate that the distortion of the composite wall panel structure is reduced by 86.2% through the use of the global compensation method, demonstrating the validity of this approach for composite structures.

Regional patterns and factors analysis of the sustainable development of benefits in China's national-level marine ranching: Based on shellfish and algae

National-level marine ranching plays an important role in enhancing the marine ecological environment, fostering social and economic development, and bolstering human well-being. Quantitatively analyzing the level of coordinated development of its “ecological-economic-social” benefits and the factors influencing them is of great theoretical significance and practical value for refining the new round of development planning and guiding its construction and management. Therefore, on the basis of establishing a theoretical framework for the interaction of “ecological-economic-social” benefits, shellfish and algae were selected as research objects. We calculated the levels of ecological, economic, and social benefits, explored the interrelationships among the three using the coupled coordination model, and analyzed the influencing factors by using multivariate linear regression and geographically weighted regression. The results showed that: (1) In 2015 and 2021, the ecological and economic benefits of national-level marine ranching for shellfish and algae were better than the social benefits, in which the ecological and social benefits were stable, while the economic benefits were more variable; (2) The degree of coordination of the coupling between the three benefits in each province was mostly low, with most experiencing severe disorder; (3) The level of openness to the outside world and the standard of living of fishermen contributed positively to the coordination of benefit coupling between shellfish and algae. Conversely, the level of science and technology, innovation capacity, and the level of social development had a slightly negative impact. In conclusion, shellfish and algal aquaculture in China's national-level marine ranching significantly contributes to the ecological, economic, and social systems. However, the merits and demerits of natural, social, and economic factors must be comprehensively considered to promote the sustainable development of marine ranching.

Coupling coordination degree measurement and spatial characteristics analysis of green finance and technological innovation -Empirical analysis based on China

The coordinated development of green finance and technological innovation is a key driver of China's high-quality economic growth and therefore deserves close attention. But are green finance and technological innovation really coordinated? This study establishes a coordinating coupling system to link green finance and technological innovation. 2010–2021 is chosen as the observation period, and 31 provinces in China are selected for study. This paper uses the coupling coordination model to investigate the development of the coupling coordination of technological innovation and green finance, and discusses its spatial distribution by the Moran index. The results show that, overall, the degree of coupling coordination between green finance and technological innovation shows a consistent upward trend. The trend is particularly strong in the East. Moreover, the coordination coupling between green finance and technological innovation has the spatial effect. And it shows a binary characteristic, with a decreasing trend observed from coastal to inland regions. These results remained valid after replacing weight matrix and sample size.The above findings have important policy implications for optimising the synergistic development of green finance and technological innovation and achieving high-quality economic development.

Collaborative optimization of intersection signals and speed guidance for buses run on overlapping route segments under connected environment

AbstractIn order to reduce bus bunching in overlapping route segments and improve the efficiency of bus operation, a dynamic scheduling model is proposed to adjust bus operation states by adopting a cooperative strategy involving multi‐line bus timetable optimization, arterial signal control, and speed guidance. Based on mixed integer linear programming, an arterial signal coordination model with autonomous public transport vehicles (APTVs) dedicated lanes is developed, which enables APTVs to pass through intersections without stopping under conditions that almost have no effect on regular vehicles (RVs). Based on this, a speed guidance strategy of APTVs under connected environment is proposed. After guiding APTVs into the overlapping route segments at a reasonable interval, the optimization goal of maintaining the independent running headway of each bus line to the maximum extent is realized. The simulation verification based on three actual overlapping lines in Hangzhou shows that only the combination of signal coordination considering the characteristics of APTVs and speed guidance can realize the full benefits of bus operation based on dedicated APTVs lane.

Spatio-Temporal Evolution and Driving Mechanism of Coupling Coordination of Pseudo Human Settlements in Central China’s Urban Agglomerations

The construction of pseudo human settlements in the context of “digital-real integration” in the information age is crucial for the high-quality development of human settlements in the new era. This study aimed to investigate the spatio-temporal evolution of the pseudo human settlements and its mechanism to provide new ideas for scientific breakthroughs in cross-disciplinary fields, such as human settlements, and to provide a strong basis for promoting the overall improvement of the quality of the human settlements in the central China’s urban agglomerations in the new era. Employing the theoretical framework of “three states” in human settlements, this study utilizes big data, including tourism, shopping, work, and socialization, to investigate the dynamic patterns and driving mechanisms of pseudo human settlements within Central China’s urban agglomerations from 2011 to 2021, employing methodologies such as the coupling coordination model, standard deviation ellipse, kernel density, and gray correlation degree. The results show the following: (1) the overall pseudo human settlements in central China’s urban agglomerations exhibit a pattern of “high coupling and low coordination”. (2) The overall coupling degree exhibits a fluctuating upward trend and has been at a high coupling-state level. (3) The degree of coupling coordination has obvious spatial differentiation characteristics, such as the core circle, “tower”, and “two main and one secondary” core structure. (4) The overall level of pseudo human settlements is influenced by the combination of time, space, and the multidimensionality of systems and indicators. This study conducted research on pseudo human settlements to enrich the theory of the human–land interaction relationship in geography and reflect the decision-making needs in the strategy of network power.

Coupling Coordination Analysis of Green Tourism - Regional Economy - Regional Logistics

By using the panel data of 30 provinces and cities in China from 2011 to 2021, the entropy weight method, coupled coordination model and obstacle degree model are used to construct the coupled coordination index system of green tourism, regional economy and regional logistics, and explore the spatio-temporal evolution, coupled coordination evolution characteristics and impact factors of different regions. The results showed that: (1) Green tourism and regional economic system showed an overall upward trend, while regional logistics system showed a trend of first increase and then decrease. (2) The coupling coordination degree showed an upward trend, from moderate imbalance to mild imbalance, but the overall coupling coordination degree in the country was not high enough. (3) Total investment of foreign-invested enterprises, express delivery volume, total import and export volume of business units, and total postal business are the main obstacle factors. They are the main obstacle factors of economic development module, regional logistics scale module, economic development scale and logistics infrastructure module respectively.

A Study on the Coupling Coordination of Urban Resilience and the Tourism Economy in the Beijing–Tianjin–Hebei Region

The high-quality economic growth of tourism is intimately related to a city’s overall strength, and urban resilience is an important index to measure the comprehensive strength of a city. Therefore, determining how to enhance the construction of urban resilience, improve the quality of tourism development, and promote the coupling coordination of these two systems has attracted academic attention in recent years. Based on the panel data of 13 cities in the Beijing–Tianjin–Hebei region from 2010 to 2021, an entropy weight method, coupling coordination model, and obstacle degree model were used to analyze the coupling coordination degree, spatiotemporal evolution characteristics, and obstacle factors between urban resilience and the tourism economy. The results show the following: (1) Urban resilience and tourist economic development levels in the Beijing–Tianjin–Hebei region show an overall upward trend, and both of them show obvious spatial differences. (2) The coupling coordination degree of urban resilience and the tourism economy shows a trend of first rising and then declining in the temporal dimension, while it shows a spatial differentiation pattern of “high in the middle and low in the surrounding area” in the spatial dimension. (3) The obstacle degree structure of the coupling coordination of urban resilience and the tourism economy in the Beijing–Tianjin–Hebei region is relatively stable, with economic resilience as the leading obstacle in the urban resilience system and tourist economic development benefits as the leading obstacle in the tourism economy system. In the future, the Beijing–Tianjin–Hebei region needs to strengthen regional cooperation, enhance the driving role of central cities, continuously improve urban resilience, and promote the high-quality development of the tourism economy.

The Digital Economy and Agricultural Modernization in China: Measurement, Mechanisms, and Implications

Promoting the progression of agricultural modernization and digital economy integration has introduced new opportunities and challenges for the advancement of China’s agriculture towards high-quality development. Based on panel data from 31 provinces in China from 2011 to 2020, we use the entropy method, coupling coordination model, spatial auto-correlation model, and obstacle model to explore the degree of coupling coordination and influencing factors of China’s digital economy and agricultural modernization. The results show the following. (1) China’s digital economy and agricultural modernization are underdeveloped on the whole, but they show a positive upward trajectory. The digital economy is outpacing the development of agricultural modernization, but the gap between the two is gradually narrowing. (2) The degree of coupling coordination between China’s digital economy and agricultural modernization shows an upward trend. Additionally, there is regional heterogeneity and uneven development of the coupling coordination, i.e., it is high in the eastern region and low in the western region, accompanied by strong spatial agglomeration and correlation. (3) The main obstacle to the progression of the digital economy is digital infrastructure, while the main obstacle to the progression of agricultural modernization is agricultural production capacity. Based on China’s national conditions, we should fully promote the role of the digital economy, explore plans and strategies for promoting the digital economy in differentiated areas, mitigate any imbalanced development, promote the coordinated development of the digital economy and agricultural modernization, and provide decision-making references for the implementation of a digitized China, as well as rural revitalization strategies.

Analysis of the coupling coordination between traditional Chinese medicine medical services and economy and its influencing factors in China.

The coordinative relationship between medical treatment and the economy is an important part of promoting the sustainable and healthy development of a social economy, and it is conducive to promoting the coordinated development of the two systems. Based on constructing a comprehensive evaluation index system for the relationship between traditional Chinese medicine medical services and economic development, the entropy method, coupling coordination model, and Tobit model are used to calculate the comprehensive development level, coupling coordination degree, and influencing factors of the two systems in 31 provinces of China from 2015 to 2021. Suggestions are proposed for the coordinated development of traditional Chinese medicine medical services, and economy. The results showed that the development level of traditional Chinese medicine was higher than that of social and economic development, the relative development gap between the two systems was gradually narrowed, and the coupling coordination degree increased steadily; however, the regional differences were large. The relative development level and coupling coordination degree of each region show a development pattern of eastern > central > western > northeast; the coupling coordination degree of the two systems in the spatial region was positively correlated and was enhanced year by year. From the perspective of influencing factors, the level of economic development is the decisive factor in the coupling and coordination between traditional Chinese medicine medical treatment and the social economy. Factors such as human capital and health level in traditional Chinese medicine have an inhibitory effect on the coordinated development of the two systems. So, China should focus on optimizing the regional allocation of traditional Chinese medicine medical personnel, improving the quality of medical services, and enhancing the health level of medical personnel.

A Conceptual Model for the Development of Tornadoes in the Complex Orography of the Po Valley

Abstract The Po Valley in northern Italy is a hotspot for tornadoes in Europe in spite of being surrounded by two mountain ridges: the Alps in the north and the Apennines in the southwest. The research focuses on the case study of 19 September 2021, when seven tornadoes (four of them rated as F2) developed in the Po Valley in a few hours. The event was analyzed using observations and numerical simulations with the convection-permitting Modello Locale in Hybrid Coordinates (MOLOCH) model. Observations show that during the event in the Po Valley, there were two surface boundaries that created a triple point: an outflow boundary generated by convection triggered in the Alpine foothills and a dryline generated by downslope winds from the Apennines, while warm and moist air advected westward from the Adriatic Sea east (ahead) of the boundaries. Tornadoes developed about 20 km northeast of the triple point. Numerical simulations with 500-m grid spacing suggest that the development of supercells and drylines in the Po Valley was sensitive to the elevation of the Apennines. Simulated vertical profiles show that the best combination of instability and wind shear for the development of tornadoes was attained within a narrow area located ahead of the dryline. A conceptual model for the development of tornadoes in the Po Valley is proposed, and the differences between tornado environments over a flat terrain and over a region with complex terrain are discussed. Significance Statement The Po Valley is a highly populated area where some of the most violent tornadoes in Europe have developed. We investigated a tornado outbreak that occurred on 19 September 2021 in this region, in order to identify its main environmental characteristics. High-resolution numerical simulations revealed that values of instability and wind shear were compatible with the development of several tornadoes only in a narrow area close to the intersection of two surface boundaries (a triple point). Moreover, the atmospheric environment during the tornado outbreak was strongly influenced by the presence of mountain ridges surrounding the plain. We have summarized our results in a conceptual model that can potentially be used for forecasting applications.

Spatiotemporal dynamics of human ecosystems in the context of protected areas as a policy tool: Insights from Sanjiangyuan National Park, China

As one of the most critical ecological functional areas in China and even the world, Sanjiangyuan National Park’s sustainable development has attracted attention. The integrated evaluation method, the coupling coordination model, and the grey correlation model were employed to uncover the coupling coordination relationship among sub-systems in the human ecosystem of Sangjiangyuan National Park. The results are as follows. First, the sustainable development capacity of the human ecosystem in Sanjiangyuan National Park fluctuated and declined during the study period, with insufficient momentum for sustainable development. Second, from 2005 to 2020, Sanjiangyuan National Park experienced a process of optimization and adjustment from moderately uncoordinated to nearly uncoordinated. At the county scale, the coupling coordination state of the sub-system was consistent with the overall national park. Third, among the four dimensions, the correlation degree of openness to the human ecosystem of Sanjiangyuan National Park was far ahead, followed by harmony, independence, and vulnerability. Our research can provide a reference for the coordinated development of the human ecosystem in other national parks with similar ecological functions around the world.

Analysis of the dynamic mechanism of trans-boundary pollution collaborative control in the Yangtze River Economic Belt

Climate change mitigation requires simultaneous reduction of carbon emissions and air pollution. This study examines the synergy between pollution reduction and carbon reduction, identifying key variables and strategies to achieve this goal. Using a Geographical Detector model and a Coupling Degree of Coordination model, 108 cities in the Yangtze River Economic Belt (YREB) are investigated. Results show that while controlling PM2.5 has been more successful than managing carbon emissions in the YREB, synergy between pollution reduction and carbon emissions increased by an average of 7.2% from 2006 to 2019. Spatial analysis reveals higher synergy in upstream areas, indicating significant spatial diversity. The impact of pollution and emission reduction synergies is influenced by societal and environmental variables, including industry structure, technological innovation, energy structure, human capital quality, and economic basis. Synergy is amplified when natural limits align with high-quality development drivers such as technical innovation and the digital economy. Recommendations include enhancing city-to-city contact, improving energy and industrial structures, and fostering technological innovation to address regional variations in synergy levels.

Catalytic ozonation of reverse osmosis membrane concentrates by catalytic ozonation: Properties and mechanisms.

Ni-Mn@KL ozone catalyst was prepared for the efficient treatment of reverse osmosis membrane concentrates. The working conditions and reaction mechanism of the ozone-catalyzed oxidation by Ni-Mn@KL were systematically studied. Then, a comprehensive CRITIC weighting-coupling coordination evaluation model was established. Ni-Mn@KL was characterized by scanning electron microscopy, BET, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive spectrometry, and X-ray fluorescence spectrometry and found to have large specific surface area and homogeneous surface dispersion of striped particles. Under the optimum working conditions with an initial pH of 7.9 (raw water), a reaction height-to-diameter ratio of 10:1, an ozone-aeration intensity of 0.3L/min, and a catalyst filling rate of 10%, the maximum COD removal rate was 60.5%. Free-radical quenching experiments showed that OH oxidation played a dominant role in the Ni-Mn@KL-catalyzed ozone-oxidation system, and the reaction system conformed to the second-order reaction kinetics law. Ni-Mn@KL catalysts were further confirmed to have good catalytic performance and mechanical performance after repeated utilization. PRACTITIONER POINTS: Ni-Mn@KL catalyst can achieve effective treatment of RO film concentrated liquid. High COD removal rate of RO membrane concentrated liquid was obtained at low cost. Ni-Mn@KL catalyst promotes ozone decomposition to produce ·OH and O2 -· oxidized organic matter. The Ni-Mn@KL catalyst can maintain good stability after repeated use. A CRITIC weight-coupling coordination model was established to evaluate the catalytic ozonation.

Towards sustainability: How does the digital-real integration affect regional green development efficiency?

Integrating the digital economy into the real economy (thereafter referred to as digital-real integration) is one of the important ways to promote the efficiency improvement of green development. We adopt the panel data of 30 provinces and cities in China (excluding Tibet, Hong Kong, Macao, and Taiwan) from 2011 to 2021 as the basis of our study. We also use the coupled coordination model to measure the level of digital-real integration in each region. Then, we set up a spatio-temporal geographically weighted regression model to examine the spatio-temporal distribution pattern and the specific mechanism of its impact on the efficiency of regional green development. Our study finds that the vast majority of provinces in the country are in the coupling and coordination state on the verge of dysfunction and mild dysfunction. Moreover, coordinating with the development speed of the digital economy to reach the state of dynamic interconnection and constraints is difficult for the real economy. Second, the level of digital-real integration can contribute to the improvement of green development efficiency, and that in Xinjiang and Qinghai is lower than in other provinces. Further in terms of spatial distribution, the digital-real integration in the Yangtze River Delta region (Shanghai, Jiangsu, Zhejiang, Anhui) and Fujian Provinces during the 11-year period obviously promotes the efficiency of green development. Finally, through the mechanism analysis, the digital-real integration development can be found to promote the improvement of green development efficiency via three channels: industrial structure rationalization, factor market development degree, and government intervention. Findings of this paper provide some basis and reference for better promoting the digital-real integration and then realizing the long-term sustainable development of the region.