In order to solve the seal failure and string safety problems caused by unreasonable application of prestress on the positioning seal of the injection pipe string in Q Oilfield of Bohai Sea, the wellbore string model of the injection well was established by using Landmark software to simulate and analyze the string expansion during the injection process of well X1 and the mechanical behavior changes of the pipe string after different prestress was applied to the positioning seal. The results show that the scientific application of positioning sealing prestress according to different well inclines can reduce the risk of pipe seal failure. The research results can provide theoretical support for the rational application of positioning sealing prestress to the waterflood string in Q oilfield.

Green development and low-carbon transformation is the only way to develop the new quality of productive forces, and it is a profound systematic change, which is bound to have a profound and wide-ranging impact on China’s economy and society. The impact of the performance of listed companies in the low-carbon economy from the dual perspectives of game perspective and quasi-natural experiment of “low-carbon city pilot” policy was explored. The pilot policy promotes performance improvement through three ways, such as mitigating inefficient investment, improving financial status and alleviating financing constraints. Meanwhile, the impact of the pilot policy on corporate performance is heterogeneous across industries and business-age enterprises. Policy insights in the development of low-carbon economy to continue are provided to cultivate and promote new quality productivity, stimulate enterprise innovation, and improve the information disclosure mechanism.

Based on the survey data of 1 457 farmers in Sichuan Province, the influence of social capital on farmers’ technical fertilization behavior was empirically examined, and the influence of green cognition on farmers’ willingness was analyzed to improve production and their influence on the decision of technical fertilization behavior. The results show that channel trust, social responsibility consciousness and green agricultural technology cognition have a significant influence on the willingness to improve production behavior. Social network, environmental pollution cognition, green agricultural technology cognition and production behavior improvement willingness have a positive influence on technical fertilization behavior, and a significant positive influence on technical fertilization behavior. Therefore, it is necessary to improve the channel trust of farmers, expand the social network of farmers, increase the quality and quantity of information acquisition, improve the social capital of farmers in multiple dimensions, strengthen the green cognition and technical production behavior willingness, and promote the adoption of farmers’ technical fertilization behavior.

Erosion wear of movable elbow is an important problem that cannot be ignored in fracturing field. In view of the phenomenon that particles carried in fracturing fluid are prone to erosion and wear of movable elbow pipes, a flow channel model was established. Orthogonal tests were designed according to the fluid parameters and pipeline structural parameters of movable elbow, and the influence of the erosion rate was analyzed by CFD numerical simulation. The test results show that the influence degree of each working parameter on the erosion rate of movable elbow is particle mass flow rate > particle diameter >2# bend Angle > flow rate. According to the orthogonal test results can guide the actual work, when the movable elbow is placed in U-shape, the erosion wear is the largest, and the position is in the bending surface of the elbow, so the movable elbow should be avoided in the U-shape state to reduce the erosion. At the same time, the erosion resistance design of the bend of the movable elbow is carried out, and the triangle erosion resistance groove is added. The maximum erosion wear rate of the original structure and the improved structure is compared with that of the original structure. The erosion wear of the improved structure is reduced by 39.01%, which proves that the improvement can effectively reduce the erosion wear of the movable elbow during work, and provides a solution for the erosion resistance of the movable elbow.

The spatial Durbin model was used to analyze the effect of green finance on high-quality economic development in 31 provinces(due to the lack of data, the statistical data mentioned here do not include the Tibet Autonomous Region, the Hong Kong Special Administrative Region, the Macao Special Administrative Region and Taiwan Province), municipalities and autonomous regions in China, and also to explore the role of green technology innovation in the influence of green finance on high-quality economic development. The results show that the effect of green financial development on economic high-quality development is positive. Green finance can promote high-quality economic development and has spatial spillover effects. Green technological innovation plays a partly intermediary role, and green finance can promote economic high-quality development through promoting green technological innovation. Finally, it is proposed to expand the green financial product system, make use of the spatial spillover characteristics of green finance, strengthen provincial and regional cooperation and enhance green R&D investment and patent protection.

With the rapid development of the digital economy, digital assets, as a new type of asset category, are showing an exponential growth trend. A comprehensive and systematic classification and summary of the types of digital assets was firstly conducted, and the valuation systems and operation mechanisms of various digital assets were deeply analyzed. The risks and challenges currently faced by the digital asset field were also examined and the regulatory measures at the regulatory level were discussed. Through in-depth and detailed sorting and analysis, scientific basis and guidance are provided for the future development of the digital asset field.

To address the lack of emphasis on carbon emissions in traditional airline network and fleet planning, an integrated optimization approach that incorporates carbon emissions into the planning process was proposed. The model was based on a multi-allocation hub-and-spoke network structure, taking into account route selection, demand distribution, capacity constraints and fleet size. Emissions were calculated using Environmental Protection Agency (EPA) standards, cruise phases, and a carbon tax mechanism was applied to convert emissions into cost elements, resulting in a joint optimization mathematical model aimed at minimizing airline operating costs. The model was solved using the Gurobi commercial solver. Results indicate that airlines should prioritize low-emission short-haul flights to meet market demand, and policymakers should consider gradually raising carbon tax levels to foster sustainable development in the aviation industry.

With the development of market economy and the enhancement of environmental awareness, market-based environmental regulation will play an increasingly important role. Based on the panel data of 300 prefecture-level cities in China from 2008 to 2022, taking carbon emission trading policies as a quasi-natural experiment, the multi-time-point differential method was adopted to empirically study the impact of market-based environmental regulations on regional green innovation. It is found that the carbon emission trading policy significantly promotes urban green innovation, and this conclusion remains valid in the robustness test. Mechanism analysis shows that talent gathering, public awareness of environmental protection and government investment in science and technology play an important role in promoting green innovation. In addition, there is regional heterogeneity in the policy effect, which has a more significant promoting effect on green innovation in East China, Central China and non-central cities. The research conclusions of this paper have important implications for the government to strengthen the construction of carbon trading market, increase personnel training, enhance public awareness of environmental protection, and strengthen regional collaborative management, so as to promote the construction of a green and low-carbon society and the realization of sustainable development goals.

Improving the ecological resilience of the Yellow River Basin is an important aspect of ecological protection and high-quality development.A spatial econometric model was used to analyze the impact of digital economy on ecological resilience in 66 cities in the Yellow River Basin from 2011 to 2020.The results indicate that the overall level of ecological resilience in the Yellow River Basin is relatively low, with slow development and further widening regional disparities. The role of digital economy in ecological resilience has obvious nonlinear characteristics, with a more significant impact on the entire watershed and upstream, while the impact on the midstream is less significant. The impact of the digital economy on ecological resilience has a significant spatial spillover effect, with direct and indirect benefits across the entire watershed. The direct effect is dominant in the middle and lower reaches, while the spatial spillover effect in the upstream is not significant. The main reasons for the non-linear effect of digital economy on ecological resilience are the differences in economic development, government intervention, and foreign investment.

To study the optimal excavation method for shallow-buried soft rock large-section tunnels, detailed numerical models were established for the step method, the cross-middle wall method and the double side wall guiding pit method. The research focused on the time-space evolution of the ground displacement field during the construction process and the stress distribution of the supporting structure. The results show than the excavation using the double side wall guiding pit method induces smaller crown settlement displacements. The ground settlement caused by the three excavation methods is characterized by a U-shaped curve, with the double side wall guiding pit method resulting in the smallest surface settlement displacement. The initial support stress calculated for the double side wall guiding pit method is higher, but remains within a safe range.