The coupling dynamic effect of government environmental attention, green efficiency, and air quality

Abstract There exists a significant interactive coupling relationship between the government’s environmental attention, green efficiency, and air quality. Studying the dynamic coupling effects among these variables is crucial for promoting the sustainable development of China’s economy and society. This paper clarifies the coupling mechanism of government environmental attention, green efficiency, and air quality by analyzing 270 prefecture-level cities in China using the coupling coordination model and PVAR model. The results indicate that while government environmental attention, green efficiency, and air quality all show an upward trend, their temporal and spatial performances differ. The degree of coupling and coordination among these variables also exhibits significant fluctuations, indicating a dynamic relationship. Government environmental attention as a fundamental driving force in the dynamic coupling of these variables, promoting high-level development through factors like economic growth, technological progress, and socio-cultural influences. Finally, this paper proposes five key policy recommendations. The study provides valuable insights into promoting local governments’ environmental initiatives, advancing China’s ecological civilization, and addressing international environmental pollution in developing countries

Study on the Surface Morphology of Micro-Particles and the Oxide Layer on Silicon Carbide Crystal Using Nanosecond Green Laser Cleaning Assisted with Airflow

With a focus on the particle pollutants on the surface of silicon carbide crystal materials, this paper establishes a laser cleaning model for the fine particles found in silicon carbide crystal materials and proposes a new nanosecond green laser cleaning method assisted by airflow, which can effectively remove microparticles and the oxide layer on the substrate surface. Abaqus software and ANSYS Fluent software were used to simulate changes in the cleaning temperature field and the distribution of particles and dust during cleaning simulation, respectively. Based on the experimental research, and by using a nanosecond green laser to produce a wavelength of 532 nm, the direct irradiation of a nanosecond green laser on the surface of the element, and the particle contaminants on the surface of the silicon carbide material, optimized the process parameters to achieve a better cleaning efficiency. A green laser was used as a light source to conduct experiments to control the wind force of the gas chamber. The influence of the laser energy, scanning speed, and other parameters on the final cleaning efficiency was studied. The parameters of the silicon carbide before and after cleaning were characterized. The research shows that laser cleaning assisted with airflow is an efficient cleaning method that can be used to clean microparticles without damaging silicon carbide crystal substrate and to reduce the surface roughness of silicon carbide material from 1.63 to 0.34 μm, with an airflow of 0.2 Mpa

Study on the Surface Morphology of Micro-Particles and the Oxide Layer on Silicon Carbide Crystal Using Nanosecond Green Laser Cleaning Assisted with Airflow

With a focus on the particle pollutants on the surface of silicon carbide crystal materials, this paper establishes a laser cleaning model for the fine particles found in silicon carbide crystal materials and proposes a new nanosecond green laser cleaning method assisted by airflow, which can effectively remove microparticles and the oxide layer on the substrate surface. Abaqus software and ANSYS Fluent software were used to simulate changes in the cleaning temperature field and the distribution of particles and dust during cleaning simulation, respectively. Based on the experimental research, and by using a nanosecond green laser to produce a wavelength of 532 nm, the direct irradiation of a nanosecond green laser on the surface of the element, and the particle contaminants on the surface of the silicon carbide material, optimized the process parameters to achieve a better cleaning efficiency. A green laser was used as a light source to conduct experiments to control the wind force of the gas chamber. The influence of the laser energy, scanning speed, and other parameters on the final cleaning efficiency was studied. The parameters of the silicon carbide before and after cleaning were characterized. The research shows that laser cleaning assisted with airflow is an efficient cleaning method that can be used to clean microparticles without damaging silicon carbide crystal substrate and to reduce the surface roughness of silicon carbide material from 1.63 to 0.34 μm, with an airflow of 0.2 Mpa