After decades of rapid development, there exists insufficient and contradictory land use in the world, and social, economic and ecological sustainable development is facing severe challenges. Balanced land use functions (LUFs) can promote sustainable land use and reduces land pressures from limited land resources. In this study, we propose a new conceptual index system using the entropy weight method, regional center of gravity theory, coupling coordination degree model and obstacle factor identification model for LUFs assessment and spatial-temporal analysis. This framework was applied to 17 cities in central China’s Hubei Province using 39 indicators in terms of production–living–ecology analysis during 1996–2016. The result shows that (1) LUFs showed an overall upward trend during the study period, while the way of promotion varied with different dimensions. Production function (PF) experienced a continuous enhancement during the study period. Living function (LF) was similar in this aspect, but showed a faster rising tendency. EF continued to increase during 1996–2011, but declined during 2011–2016. LUFs were higher in the east than in the west, and slightly higher in the south than in the north. The spatial coordination was enhanced during the study period. (2) The overall level of coupling coordination degree continued to increase during 1996–2016, while regional difference declined obviously, indicating a good developing trend. However, the absolute level was still not satisfactory. (3) The obstacle degree of PF was always dominant, and LF showed a downward trend, while EF showed an increasing trend. Benefit index (A2), Comfort index (B2) and Green index (C1) constituted the primary obstacle factor for each dimension. Added-value of high and new technology industry (A2-3) and land use intensity (A3-2) were key factors restricting PF. Number of medical practitioner (B1-4) and internet penetration rate (B2-3) were key factors restricting LF. Air quality rate (C3-1) and wetland coverage rate (C1-4) were key factors restricting EF. This study can help to give a more detailed understanding of sustainable land use for the particularity of China from a land function perspective and provide lessons and suggestions for other developing countries in the world.

The feasibility of enhancing oil recovery in Qinghai oilfield with hypersalinity was studied. The results showed that main microbial populations in the reservoir were saprophytic, hydrocarbon-oxidizing, fermentative, nitrate-reducing bacteria and methanogens. The indigenous microorganisms preferentially used nitrogen sources for emulsification, the gas–liquid ratio was 0.20, pressure reached 0.27 MPa; saturated hydrocarbon was catalyzed selectivity. The species isolated were confirmed as Oceanobacillus sp. and Staphylococcus sp.; the oil recovery was 8.42%, which shows great potential to enhance oil recovery.

Scientifically characterizing the spatial-temporal distribution characteristics of agricultural land use intensity and analyzing its driving factors are of great significance to the formulation of relevant agricultural land use intensity management policies, the realization of food safety and health, and the achievement of sustainable development goals. Taking Hubei Province as an example, and taking counties as the basic evaluation unit, this paper establishes an agricultural land use intensity evaluation system, explores the spatial autocorrelation of agricultural land use intensity in each county and analyzes the driving factors of agricultural land use intensity. The results show that the agricultural land use intensity in Hubei Province increased as a whole from 2000 to 2016, and the spatial agglomeration about the agricultural land use intensity in Hubei Province experienced a process of continuous growth and a fluctuating decline; the maximum of the Global Moran’s I was 0.430174 (in 2007) and the minimum was 0.148651 (in 2001). In terms of Local Moran’s I, H-H agglomeration units were mainly concentrated in two regions: One comprising the cities of Huanggang, Huangshi and Ezhou, and the other the cities of Xiangyang and Suizhou; the phenomenon is particularly obvious after 2005. On the other hand, factors such as the multiple cropping index (MCI) that reflect farmers’ willingness to engage in agricultural production have a great impact on agricultural land use intensity, the influence of the structure of the industry on agricultural land use intensity varies with the degree of influence of different industries on farmers’ income, and agricultural fiscal expenditure (AFE) has not effectively promoted the intensification of agricultural land use. The present research has important significance for enhancing insights into the sustainable improvement of agricultural land use intensity and for realizing risk control of agricultural land use and development.

The building sector is responsible for significant carbon emissions and energy consumption, making it a critical field for global energy-saving and emission reduction efforts to combat climate change. This study calculated the building carbon emissions (BCE) of 30 provinces in the Chinese Mainland from 2010 to 2020 using the IPCC carbon emission factor method based on the statistical data of energy consumption and building materials, and then the decoupling relationship between BCE and the construction land area (CLA) was analyzed. The results are as follows: (1) BCE exhibited an overall increase from 2010 to 2020, yet at a descending rate, with a prominent decrease in indirect BCE (IBCE); (2) BCE and direct BCE (DBCE) were higher in the north but lower in the south, while IBCE was higher along the eastern coast; (3) the provinces in North China and Northeast China possess the largest areas of construction land, but the growth of CLA was the slowest or even declined in the later stage of the study; (4) the decoupling relationship between BCE and CLA is dominated by expansive negative decoupling or strong negative decoupling. The growth of BCE is generally much faster than the expansion of construction land. The findings will have important reference for achieving energy-saving and “dual carbon” strategic development goals in China.

Fixed monitoring networks characterize urban PM_2.5 trends but cannot resolve variation among individual roads and transport corridors. This study developed and evaluated a two-stage framework integrating long-term mobile measurements with satellite-assisted geospatial modeling to estimate on-road PM_2.5 at 30 m resolution in Hong Kong during 2018–2025. The first-stage TOA-LUR-GTWR model used regulatory observations, Landsat 8/9 and Sentinel-2 top-of-atmosphere (TOA) reflectance, meteorology, and geographic predictors. Quality-controlled AirCasting measurements were matched to roads and aggregated into 1184 road-segment-date observations. Mobile-minus-base residuals were modeled using a Light Gradient Boosting Machine (LightGBM) and evaluated on held-out roads and against independent roadside regulatory observations. The mobile-informed estimates, defined as base estimates adjusted using residuals learned from mobile observations, increased R² from 0.73 to 0.85 and reduced RMSE from 12.31 to 9.02 µg/m³ and MAE from 8.68 to 6.42 µg/m³. Major road density, sky view factor, wind speed, Green View Index, and built-up density were the leading residual predictors. Annual concentrations generally declined after 2018, although road-level contrasts persisted. These results indicate that long-term mobile measurements can capture road-scale PM₂.₅ variation not resolved by satellite-assisted base estimates alone and extend fine-scale estimation beyond directly sampled routes.

Megacities represent an advanced stage of urban development where expansion-induced carbon debt increases environmental pressure. This study examined the spatial response of carbon stock change to urban expansion in megacities. Based on 2000–2020 land use/land cover data for 11 Chinese megacities, concentric ring analysis and spatial exploratory methods were employed to quantify urban expansion intensity and carbon stock change and to infer stage transition characteristics. The results indicate that: (1) urban expansion intensity declined over time as growth shifted from rapid edge or infill expansion toward smart-growth-oriented development; (2) carbon budget fluctuations weakened, and emission patterns evolved toward improved carbon balances and enhanced sink effects, with Beijing and Tianjin emerging as local carbon sinks; (3) the carbon effects of LUCC showed a stage transition from rapid expansion–intensive emission to slow expansion–moderate emission, and policy intervention reshaped this relationship. The carbon effects of megacity expansion are stage-dependent rather than linear, and policy intervention can shift this relationship before economic maturity, offering guidance for low-carbon planning in developing-country contexts.