In order to study the mechanical properties of negative Poisson’s ratio(NPR) anchor cable under static tension and drop hammer impact load, the self-developed NPR anchor cable tension test system and NPR anchor cable drop hammer impact test system were used to conduct static tensile test and dynamic impact test for a certain batch of NPR anchor cables. Its resistance and absorption of slow deformation and instantaneous impact energy of surrounding rock were verified by the supporting force, elongation and expansion of anchor cable. Secondly, a 3D numerical model of NPR anchor cable was established, and relevant numerical parameters were calibrated according to laboratory test results. The static tensile test of NPR anchor cable and the drop hammer impact test were carried out. The results of the numerical test are in good agreement with those of the laboratory test, which verifies the reliability of the numerical model. The 3D numerical model of NPR anchor cable can be used as an auxiliary analysis tool for the improvement and upgrading of NPR anchor cable in the future.

In order to improve the efficiency of air transportation, reduce transportation costs and carbon emissions, the evolutionary game method was adopted to explore the influencing factors of the cargo alliance between the government and airlines. The system dynamics model (SD) was used to conduct simulation experiments on the game evolution process. The results indicate that the strategic choices between airlines are influenced by investment costs and alliance benefits, while the government’s strategic choices are influenced by factors such as the carbon emission penalty coefficient paid by airlines, carbon tax subsidy amounts, social benefits, and regulatory costs. In the long run, the government should establish a dynamic subsidy mechanism and increase the diversity of subsidies to enhance the innovation and core competitiveness of airlines.

To explore the effects of weak mineralized water and straw separation treatment on soil water and salt transport, through indoor soil column infiltration and evaporation test, the distribution of water and salt in soil under the irrigation condition of fresh water and slightly mineralized water with different salinity (1, 2, 3 g/L) at the buried depth of 0, 10 and 20 cm of straw interlayer was studied. The results show that there is a power function relationship between the wetting front and the infiltration time at the infiltration stage. The water infiltration rate increases with the increase of salinity, and the cumulative infiltration decreases with the increase of salinity. Kostiakov model and Philip model are used to fit the cumulative infiltration amount and infiltration time respectively, and the fitting results are good. During the evaporation stage, the straw interlayer has a significant water retention effect on the soil below the buried depth, and the vertical distribution of soil salinity shows a significant low desalination effect, and salt accumulates in the straw interlayer. When the salinity of irrigation water is 2 g/L and the depth of straw layer is 10 cm, it is conducive to soil bottom desalting, and has a better effect of promoting soil water infiltration and water retention. The research can provide basis and reference for weak mineralized water irrigation and the exploitation and utilization of straw resources.

The Box-Behnken experimental design and response surface methodology were employed to optimize the preparation of the aspirin micro-porous osmotic pump tablets. The core of the tablet was prepared with aspirin and β-CD inclusion, then osmotic pump tablets were obtained by coating a layer of cellulose acetate containing PEG 4000 as porogenic agent. The in vitro release test shows that the aspirin inclusion complex microporous osmotic pump tablets prepared by this process has a cumulative release rate of 1.5% and 1.6% within 0~2 h in artificial gastric juice compared to commercially available aspirin enteric coated tablets. After adjusting the release medium to pH 6.8, there is no significant difference in the cumulative drug release between the two formulations at 10 h. And the inclusion complex microporous osmotic pump tablet shows zero order release and complete release within 12 h(cumulative release rate > 90%), indicating the possibility of reducing drug damage to the gastric mucosa.

The current seismic toughness assessment is mainly aimed at the impact of a single earthquake on a single building, it is difficult to consider the seismic toughness assessment of different buildings in the same area. The research area was divided into grids according to 500 m×500 m, and seismic risk analysis was carried out. Six indexes, including the cost of building defense, damaged area of different degrees, direct economic loss of buildings, repair time, repair cost and casualties, were taken as the evaluation indexes of earthquake resilience. Analytic hierarchy process (AHP) was used to determine the weights of each index, and an earthquake resilience evaluation model based on grid and radar map was established and applied to Chengdu City. The results show that the earthquake toughness of Chengdu City is normal when the fortification is not upgraded. After upgrading the fortification, the cost of fortification increases by 45.95%, and the damaged area, the direct economic loss of the house, the repair time, the repair cost and the number of casualties decreases by 26.25%, 37.75%, 45.1%, 44.24% and 48.18%, respectively. Through comparative analysis of the model data, it is found that after upgrading the fortification, the comprehensive benefit of earthquake resilience of Chengdu City buildings is increased by 40.8%, the disaster loss is greatly reduced, and the improvement effect is obvious.

Gaseous detonation is a method to obtain nanomaterials in a short time by gas explosion, which has been successfully applied to the preparation of carbon nanomaterials and oxides. Compared with other nanomaterials preparation methods, gaseous detonation method has the advantages of high efficiency, convenience, high yield and green environmental protection. The instrumentation and operation procedures required for the preparation of nanomaterials by gaseous detonation were described. Secondly, the morphology, structure, and performance characteristics of carbonaceous nanomaterials and metal oxide nanomaterials prepared by gaseous detonation were presented. At the same time, the current status of the growth mechanism of nanomaterials was analysed and summarized. Moreover, the progress of the research on nanomaterials prepared by gaseous detonation in the areas of photocatalysis, electromagnetic wave absorption, and friction resistance was summarized. Finally, the application potential and technological prospect of the gaseous detonation method and the nanomaterials prepared by the method were discussed, which can provide a useful reference for the industrialised large-scale synthesis of nanomaterials by the gaseous detonation method.

In order to study the molecular weight and molecular structure changes of asphalt under ultraviolet aging and the mechanism of their effects on macro properties, gel permeation chromatography and nuclear magnetic resonance tests were carried out on four commonly used asphalt, respectively. The molecular weight composition changes, such as molecular weight and molecular relative mass distribution, and the molecular structure composition changes, such as hydrogen spectrum, carbon spectrum, hydrogen atom content and molecular structure parameters were studied. On the basis of macroscopic rheological tests, the molecular composition of asphalt rheological properties was characterized by correlation analysis, and the molecular mechanism of ultraviolet aging macroscopic properties was analyzed. The results show that ultraviolet aging causes the agglomeration of molecules in asphalt, small molecules decreases and aggregates into large molecules, and the molecular weight distribution boundary narrows gradually. From the changes of hydrogen atoms and molecular structure parameters, it can be seen that the alkyl substituents on the aromatic ring in the asphalt increase after ultraviolet aging, resulting in the increase of the volume and stability of the aromatic ring, and the increase of molecular backbone stiffness. On the macro level, the elastic properties of asphalt increase. The phase angle, rutting factor, irrecoverable compliance and recovery rate of asphalt before and after ultraviolet aging were obtained by macroscopic rheological tests. The correlation analysis shows that the rheological properties are most affected by condensation degree parameters, substitution rate of peripheral hydrogen, average molecular weight and branched degree of alkyl chain.

In order to study the effect of basalt fiber on the porosity of recycled concrete under salt erosion, the internal variation of concrete was analyzed by scanning electron microscopy, and a linear regression model was established between the porosity of concrete and the number of dry and wet cycles, the height of penetration, the compressive strength and the splitting tensile strength. A fully connected neural network (FCNN) model was established for the penetration height under different soaking ages and fiber content for predicting the corrosion resistance life of basalt fiber regenerated concrete under salt erosion conditions. The results show that the porosity of concrete increases gradually with the erosion age increasing, and the appropriate addition of basalt fiber can significantly reduce the porosity of concrete, and the improvement effect is most significant when the fiber content is 1.0%. With fiber content increasing, the salt permeability resistance of recycled concrete increases, and permeability height decreases. When the fiber content is 1.0%, the best compressive strength and splitting tensile strength are obtained. The fully connected neural network model has a good effect and provides a reliable reference for the life prediction of basalt fiber recycled concrete.

With the increasingly serious problem of climate change, green and low-carbon operations have become an important principle for the sustainable development of the air transportation industry. Taking a single runway transport airport as the research object and green and low-carbon and passenger walking distance as the optimization objective, a green and low-carbon gate assignment model under multiple scenarios was constructed, and a genetic-tabu search combined optimization algorithm was designed to solve it. Finally, a transport airport in northeast China was taken as an example for simulation experiment. The experimental results are shown as follows. In the optimal assignment scheme, if considering green and low-carbon, the fuel consumption can be reduced by 3.1%, the taxiing distance of the aircraft by 3.1%, HC emission by 4.2%, CO emission by 3.6%, NO_X emission by 3.1%, and CO₂ emission by 3.1% comparatively. But passenger walking distance can be increased by 5.3% at the same time. If considering green and low-carbon as well as the interests of the passengers, the fuel consumption can be decreased by 2.1%, the taxiing distance of the aircraft by 2.2%, HC emission by 3.8%, CO emission by 2.7%, NO_X emission by 2.0%, CO₂ emission by 2.1%, and passenger walking distance by 2.1% comparatively. Thus, it is possible to strike a balance between green and low-carbon development and the interests of travelers.

The tension string system with concentrated viscous damping belongs to a hybrid dynamic system in mechanical models. Approximate methods are typically used to solve its inherent problems for engineering applications. In order to further clarify the vibration characteristics of the system, two centrally damped symmetrical damping string systems were taken as the basic research object, and their complex eigenvalues were solved analytically. The complex frequency equation and the eigenvalue expression of the system were derived, and the transformation of the complex frequency equation beyond the function form was treated as algebraic form, and the explicit solution of the complex eigenvalue of the system was given by the algebraic equation. The structure and properties of the complex eigenvalues of the system were analyzed, and the variation of vibration characteristics with damping coefficient was discussed. The results show that the eigenvalue solution of the system can be divided into three branches, in which the real part of the eigenvalue(the inverse is the decay rate) does not change with the order of the system motion, but the imaginary part of the eigenvalue(the frequency) increases with the order of the motion. The decay rate curves corresponding to each solution branch increase first and then decrease with the damping coefficient, and in the damping range of the decay rate curve, the frequencies of each order of the system are equal.