607 papers published in CNKI database and 308 documents published in WOS database from 2014 to 2024 were selected to conduct in-depth analysis and research from the perspectives of the number of publications, high-frequency authors and keywords by adopting CiteSpace visualization research method. The result shows that the number of publications in the field of carbon performance research is on the rise, but a closely cooperating author network has not yet been formed. The hot spots of carbon performance research are mainly focused on low carbon economy and carbon performance, carbon performance evaluation, and the influencing factors and economic effects of carbon performance, and so on. In the future, it is necessary to continue to expand the research perspectives of carbon performance, focus on the research of digital transformation, technological innovation and carbon performance, and strengthen the interdisciplinary cooperation mechanism.

In order to solve the problem that the dynamic control performance of permanent magnet synchronous motor is poor when PI(proportional-integral) control strategy is used in vector control, and the motor parameters are easily affected by changes in external temperature and load, which leads to poor precision and responsiveness of the control motor, a model predictive control method is proposed to control the motor. This strategy uses the system model to predict the future input and state of the system, and directly calculates the control input by optimizing the objective function, which significantly improves the dynamic performance and steady-state accuracy. Moreover, with its strong ability to deal with nonlinearity and parameter changes, it can control the nonlinear system of permanent magnet synchronous motor well. According to the waveform diagram obtained by simulation, model predictive control is superior to PI control in dynamic response, anti-interference ability, low speed performance and robustness. Therefore, using model predictive control can effectively improve the control performance of permanent magnet synchronous motor.

In the construction of underground line reconstruction, pavement deformation has characteristics such as uncertainty and complexity. Therefore, the grey model was used to establish a prediction model for pavement deformation, and engineering examples were combined to verify its good accuracy. Given that the grey model can only predict the overall trend in deformation prediction and cannot reflect the volatility of prediction errors, prediction errors were processed to determine the upper and lower limit values of grey prediction, endowing the model with a certain prediction interval and changing the point prediction form. According to the intersection position of the deformation control line and the upper and lower limit curves of grey, the safety state of pavement deformation was divided to more reasonably judge the construction safety and provide reference for related projects.

In view of the centralized construction of pile foundation or large-scale excavation of foundation pit in rainstorm and typhoon weather, a technology for purification, treatment and recycling of construction sludge and wastewater is proposed. An integrated purification treatment device was used to form a sludge and wastewater treatment system that integrates sedimentation, purification and recycling. Flocculants, polyacrylamide, polyaluminum chloride were used to mix, mix and react with the sewage after three-stage sedimentation, so that the sewage solid-liquid can be separated into mud and clean water. Clear water can be recycled for on-site construction, car washing, watering and dust reduction, etc., achieving the effect of green economy, high efficiency and environmental protection, greatly improving the image of on-site civilized construction, and obtaining significant benefits.

According to the risk assessment guidelines of DNV, an internationally recognized risk assessment agency, there is a 50% risk of injury and death from sustained exposure within 15 minutes at a CO₂ concentration of 10%. Carbon dioxide is a “non-flammable and non-toxic gas”, which belongs to Class 2.2 dangerous goods and is an asphyxiating gas. For safety reasons, such as CO₂ pumps and compressors, special care should be taken to avoid a two-phase flow zone between the suction section and the compression/pumping section. Based on the uniqueness of CO₂ medium and its pipeline, the safety technology system of supercritical CO₂ pipeline and its related engineering solutions in foreign countries were studied, the characteristics and technical status of CO₂ pipeline transportation in foreign countries from two aspects of operation and guarantee were summarized, in order to provide guidance for the safe operation of domestic supercritical CO₂ pipeline.

Most of the conventional topographic map drawing methods adopt the principle of tilt photography real scene 3D model, which is more suitable for land area survey and drawing. The application effect in the water area topographic map drawing is poor, the plane error of the topographic map is large, and the drawing accuracy is low. Based on this, a new rendering method was proposed by introducing the principle of digital aerial photogrammetry. Firstly, digital aerial photography parameters was designed, including ground sampling distance(GSD), altitude, and image overlap. Then, image control points was set up and global navigation satellite system real time kinematic(GNSS-RTK) technology was used to measure the coordinates of the image control points. On this basis, the digital aerial photogrammetry technology was used to obtain the plane and elevation elements of the topographic map respectively, and then the topographic map was drawn. The experimental results show that the new method is highly feasible, its plane mean square error is small, the maximum is not more than 0.091 m, and the accuracy of topographic map drawing is high.

Aiming at the complex geographical conditions of the mountainous rivers flowing through the region, which leads to the difficulty of the control measurement of waterway improvement, combined with the implementation of the control measurement of waterway improvement in Zigong section of Tuo River, the layout of control points analysis, selection of coordinate systems, and selection of methods for plane and elevation control measurement were conducted. Based on the characteristics of mountainous waterways, the optimal method for layout and measurement of plane coordinate systems is proposed. The research results can provide important references and inspirations for the subsequent control measurement of long river channel regulation in mountainous areas, which will promote the smooth implementation of long river channel regulation in mountainous areas.

In order to accurately evaluate the operation safety level of civil aviation transportation airport apron, the evaluation index system was established based on “man-machine-environment-management”, the evaluation index system was verified by using the structural equation model, and the entropy weight method was used to carry out subject-objective assignment. The combination of assignment was conducted based on the game theory, so as to put forward the transportation airport apron safety evaluation model based on the SEM(structural equation model)-entropy weight method and the extension cloud model. Chengdu Shuangliu Airport was used as an example for verification, and the results show that the apron operation safety level of this transportation airport is good, which is in line with the actual operation situation, and the evaluation model can provide a scientific and feasible reference method for the evaluation of the apron operation safety of civil aviation transportation airports.

In order to improve the accuracy and efficiency of land and resources mapping, a rapid land and resources image mosaic method based on UAV remote sensing information was proposed. Firstly, by estimating the height and angle of aerial photography, the land and resources mapping images with high accuracy were obtained. Then, the corresponding feature detection algorithm combined with BRIEF (binary robust independent elementary features)algorithm was used to describe the feature rotation invariance. Next, KNN (K-nearest neighbor) algorithm was used to match feature points to achieve precise extraction. Finally, the SPHP (shape-preserving half-projective warps for image stitching)algorithm was used for image fusion, and the image mosaic is completed. The experimental results show that the designed land and resources image rapid splicing method can realize accurate mapping of land and resources, ensure the mapping efficiency, and has certain application value.

The causes and future trends of water level variations in Qinghai Lake against the backdrop of climate warming was discussed. Drawing upon meteorological observation data spanning from 1960 to 2023, the impacts of climate warming on key factors within the Qinghai Lake basin was analyzed, including evaporation, runoff, precipitation, and maximum soil frost depth. Employing Bigaussian nonlinear fitting, the water level trends of Qinghai Lake from 2025 to 2035 is predicted. Key findings reveal that as climate warming intensifies, the soil evaporation near Qinghai Lake has increased significantly, and it is the most significantly affected by climate warming (with a Pearson correlation coefficient of 0.860). Meanwhile, both runoff and precipitation have shown a slow upward trend, while the maximum soil freezing depth has declined. For now, the volume of water consumed by evaporation is less than the total volume of water injected into Qinghai Lake by runoff, precipitation, and permafrost melting. Consequently, this has led to a continuous rise in the water level of Qinghai Lake. Through Bigaussian nonlinear fitting, it is predicted that the water level of Qinghai Lake will continue to rise slowly from 2025 to 2035, reaching 3 198.133 meters by 2035. This research provides a scientific basis for ensuring the safe operation of trains on the Qinghai-Tibet Railway’s section surrounding the lake.