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Carbon sequestration refers to the technology of capturing carbon and storing it safely instead of directly discharging CO2 into the atmosphere. Rock salt is a promising CO2 reservoir, and the underground rock salt structure formed by salt cavern reservoirs in geological history has a natural sealing function. Storing carbon dioxide in salt caves can ensure that carbon dioxide is stably stored underground for a long time. However, at present, there are few studies on carbon sequestration in abandoned salt caves. This study analyses the characteristics of carbonate-evaporite strata in the high fold zone of eastern Sichuan and qualitatively evaluates Triassic carbonate-evaporite layers formed in the depth range of 800-3000 m in various sedimentary basins in Chongqing. A large set of carbonates-evaporites are developed in Chongqing, and the carbonate rocks near evaporites have low porosity and permeability, which can be used as CO2 storage caprock in salt cavities. Thick evaporated strata can also provide a good cover for CO2 storage in abandoned salt caves, which has great potential space resources.

Establish the piston ring-cylinder liner frictional model using the software of GT-Suite combine both of the frictional condition and lubrication, analyze and compute the thickness of oil film between piston ring and cylinder liner, the distribution of oil stress, and the force and power of the friction in rated condition. Then, mainly analyze the thickness of oil film and power of friction at the first piston ring under different temperatures of lubrication oil and different speeds. The results indicate that: The lubrication effect at first piston ring is poor, and the consumption of frictional power is high. The frictional power is significantly reduced with the oil temperature increases. However, the thickness of the oil film will decrease with the oil temperature increases, which is bad to the lubricational condition. Considering both of the lubrication condition and the frictional power, the frictional characteristics are better when the oil temperature is maintained at 80-90°C. With the increase of rotational speed, the oil film thickness and frictional power increase, but comparing with the influence on the frictional power, the change of rotational speed has less influence on the oil film.

A computationally sufficient technique is used to solve the 3-D cooperative re-entry guidance problem for hypersonic gliding vehicles. Due to the poor surrounding adaptive ability of the traditional cooperative guidance methods, a novel methodology, named as model predictive static programming (MPSP), is used to solve a class of finite-horizon optimal control problems with hard terminal constraints. The main feature of this guidance law is that it is capable of hitting the target with high accuracy for each one of the cooperative vehicles at the same time. In addition, it accurately satisfies variable constraints. Performance of the proposed MPSP-based guidance is demonstrated in 3-D nonlinear dynamics scenario. The numerical simulation results show that the proposed cooperative re-entry guidance methodology has the advantage of computational efficiency and better robustness against the perturbations.

China's government environmental protection-related departments attach great importance to the environmental pollution problems of petrochemical enterprises. The Environmental Protection Law as the core ecological regulation policy has been continuously improved to address the impact of macroenvironmental regulation on micro-individual petrochemical enterprises. The study subjects are 182 petrochemical companies from 2011-2021. The effect of different environmental regulations on the financial performance of petrochemical companies is studied empirically using a time-fixed effects model and a mediating effects model and using principal component analysis based on an agency cost perspective. The results show that environmental regulations significantly improve petrochemical firms' financial performance and suppress agency costs. Agency costs play a partial mediating role in the process of environmental regulations affecting financial performance.

In order to improve the restoration effect of soils in mining wasteland, based on site investigations for the mining wasteland, five different vegetation restoration models are used for soil restoration, and study on effect mechanism of different vegetation restoration models on physical and chemical properties as well as activity of enzyme in soil are conducted, providing a solid theoretical basis for guiding the subsequent management of the soil in the mining area.

Iron oxide and bismuth oxide powder are synthesized by the liquid phase precipitation method. Then a certain proportion of iron oxide, bismuth oxide and sodium chloride are mixed and ground to prepare the bismuth ferrite precursor by the molten salt method. The bismuth ferrite precursors are calcined at different temperatures to obtain bismuth ferrite photocatalyst. By studying the degradation performance of bismuth oxide, iron oxide and bismuth ferrite photocatalysts for methyl orange dyes, the best conditions for the degradation of methyl orange dyes by bismuth ferrite photocatalysts are found. The experimental results show that the bismuth ferrite prepared by calcining at 750°C has the best degradation. Compared with a single oxide, the photocatalytic performance of bismuth ferrite is better.

In order to reproduce the grand look of Hanqing Stadium and restore the most realistic Hanqing Stadium internal layout and structure, a simulation system based on the virtual reality technology for the internal structure layout design of the stadium was designed and developed. Based on the current development trend of virtual reality technology, a three-dimensional dynamic space model was established to restore the real conditions of Hanqing Stadium. By integrating emerging technologies such as panoramic images, panoramic views, and stereo vision into virtual reality technology, the sense of reality was enhanced. 3Dmaxs was used to establish the Hanqing Stadium scene design model, the surrounding and internal scene models were reconstructed, and the experiencers’ feelings about the real scene were restored 1:1. The use of technologies such as panoramic images and views enhances the realism and three-dimensionality of the picture.

With the continuous development of industrial technology, the safety and efficiency of thermal equipment work in related industries and industrial fields are facing many problems. First, with the improvement of integrated level, the size of electronic components is getting smaller and smaller, and the heat load per unit area is increasing, which makes the traditional heat dissipation method difficult to meet the requirements; second, with the increase of energy-saving pressure, the temperature difference of low-temperature waste heat recovery is reduced, and the traditional heat exchange equipment is difficult to meet the working requirements. The pulsating heat pipe has the characteristics of small volume and excellent heat transfer performance. In view of the heat transfer performance of the pulsating heat pipe, we designed the gas-liquid pulsating heat pipe heat exchanger and studied its heat transfer performance, which has been verified to be effective.

The change of plant dynamics results in mismatch between the current model and the model used for design, which may have significant impacts on the performance of control system. A method to monitor the influence of the mismatch is proposed, including the estimation of mismatched model and the evaluation of control performance. The estimation method is based on back-propagation (BP) neural network and provide more accurate and reliable estimation effect. Serious mismatch can be alarmed according to evaluation method presented. Simulation results demonstrate the effectiveness of the proposed method.

The Poyang Lake basin in the Jiangxi province of China has been exposed to nitrate pollution caused by irrigation practices, leading to high groundwater nitrate concentration. Eight groundwater samples were collected from shallow wells for hydrochemical, bacterial diversity, and community structure analysis in November 2017. Shallow groundwaters of the basin are weakly acid and in an oxidizing state, with EC ranging from 87.6 to 279.5 µS/cm and TDS varying between 53 to 344 mg/L and averaging of 164 mg/L. The NO3-N form is the dominant nitrogen species in groundwater, with сoncentrations of NO3-N, NO2-N and NH4-N ranging between 2.5 to 164 mg/L, 0.01 to 0.10 mg/L,

The research is devoted to the analysis of the changes in the chemical composition of shallow groundwater within the agricultural landscapes of the Poyang Lake area taking into account the peculiarities of soil composition. The analysis is based on field data collected during 2011–2017 by the sampling of the shallow groundwater from the private and public wells and adjoining soils. Correlations between the content of the N-compounds and the Eh values in autumn as well as a relationship of the NH4+ concentration with the DOC content reflect the processes of the organic matter transformation in the aquifer. Correlations between the N content in the upper soil horizon and the concentrations of the N-compounds in the shallow groundwater indicate a strong connection of the origin of the groundwater chemical composition with the soil composition.

In order to study the effect of mutual intercropping tomato on soil enzyme activity and available selenium content in selenium-containing soil, cherry tomatoes of red, yellow and purple varieties were selected for pairwise and three intercrops in this experiment respectively. The results showed that the activities of sucrase, phosphatase and urease in soil were increased after the three kinds of tomato were intercropped with each other, and the highest soil enzyme activity was found when red and purple tomatoes were mixed. Soil pH reached the maximum when three tomatoes were mixed. The content of available selenium in soil after intercropping tomato was higher than monoculture, and the content of available selenium was the highest when red and yellow tomatoes were mixed. Therefore, intercropping could improve the soil microecological environment, increase soil enzyme activity and increase available selenium content in tomato rhizosphere soil.

Dynamic programming algorithm is the classic method in distribution of plant loads. The traditional calculation method of dynamic programming is easy to make the calculation take too long time. This paper proposes two modiefied methods of dynamic programming, namely, dynamic programming in progressive structure and dynamic programming in progressive step-size. What is more, these two methods are combined to a new hybrid method. And these three methods and conventional dynamic programming are applied to the distribution of thermal power plant load to verify. The results of modiefied methods contrast with the conventional method show the modiefied methods reduce the calculation time and alleviate the curse of dimensionality effectively, ensuring the accuracy of calculation.

In order to save the energy of the trigeneration system based on gas-steam combined cycle, this paper proposes to explore optimal operation modes related to primary energy saving (PES) and operating costing saving (OCS) respectively, by considering the parallel operation of the gas turbine and the steam turbine valve. By taking the summer load of an office building group as the research object, the variations of controllable parameters and indexes are analysed in the trigeneration system with the traditional operation mode and the optimal operation modes. The results suggest that the proposed two operation modes over energy saving and economic aspects are more appropriate than the traditional modes.

The hydrochemical and stable hydrogen and oxygen isotope compositional characteristics of surface and shallow groundwaters in the vicinity of HK nuclear power plant in Jiangxi Province of China. Dissolved oxygen (DO) contents of shallow groundwaters range between 1.75 to 19.40 mg/L, with variations related to well depth, groundwater level, and oxidation-reduction potential. Respective ranges of δD and δ18O (‰ VSMOW) in shallow groundwaters are -40.7 to -24.9 and -6.71 to -5.40, with average values of -31.8 and -5.87. The δD-δ18O relationship for the study area is δD = 8.3δ18O +16.8, indicating that atmospheric precipitation is the major recharge source of shallow groundwaters.

An experiment was conducted to study the effect of peach seedlings (Prunus davidiana) grown in nutrient solution with different selenium concentration. The results showed that selenium concentration were 0.05 and 0.10 mg/L which caused a marked increase of roots and shoorts biomass, and the root/shoot ratio were relatively low (0.180 and 0.170) compared with control, and other selenium treatments decreased significantly the biomass. Consequently, 0.05 and 0.10 mg/L selenium treatments were conducive to peach seedlings growth, while the peach seedlings was inhibited significantly by the increasing concentration of selenium (≥ 0.10 mg/L). Selenium content of peach seedlings increased remarkably with the increase of selenium concentration that indicated the accumulation of selenium in peach seedlings had a linear relation with the dose of selenium. Above all, when selenium concentration in the range of 0-0.10 mg/ L, which not only promotes peach seedlings growth, but also increases peach seedlings selenium content.

Because of water shortages, the Xiaodian area in northern China had a long history of sewage irrigation. To study the distribution of antibiotics in the vadose zone, a sewage sample and 5 soil profiles were collected and analyzed. Macrolides and Fluoroquinolones were the main antibiotics observed in the shallow vadose zone. The contents of antibiotics in the soil profile nearby the sewage irrigation area were 2-3 times greater than in the groundwater irrigation area, indicating that sewage irrigation has had a significant impact on the contents of antibiotics in the soil. The elevation of antibiotic contents during the wet season is likely related to the fluctuating water level within the shallow vadose zone. The distribution of antibiotics is influenced by the flow direction of irrigation water. Moreover, the possibility of introducing antibiotics into the soil of the shallow vadose via the lateral recharge of sewage in the Beizhang Drainage Canal can not be excluded. Approximately 50 % of Fluoroquinolones were reduced in the upper 50 cm of the soil zone and 70 % at 80 cm depth. Tetracyclines may have experienced significant lateral migration. Macrolides and Sulfonamides (SMs) have similar soil profile distributions, with a concentration decrease down to 20 cm depth.

The operation reliability of spacecraft in orbitis affected by the interaction with space plasma, research on the space enviroment by advanced testing method is important. It is costly to carry out research and analysis with space flight. Therefore, tests using ground vacuum environment simulation system are of significance. This paper proposed the structure design, simulation analysis and numerical calculation methods for the three subsystems of plasma environment simulation system, including vacuum vessel, vacuum acquisition and vacuum measurement and control. The simulation results show that the maximum stress of the vacuum vessel is 113.2MPa , and the maximum deformation is 0.59mm , at the same time, vacuum technology index, structural stability and human-machine interaction performance of the system can meet the experimental research requirement.

UML is a standard modeling language, which is easy to express, powerful and universal. At the same time, it can support the software development process from the demand analysis. Using UML modeling mechanism, which can be visual representation and construction of system model for all the development process of the application software system based on UML. We design the use case diagram, class diagram, timing diagram, etc.

A novel method for synthesizing Au@Pd core-shell nanoparticles was proposed based on photochemistry. By irradiating the mixture of Au (III) and Pd (II) ions using ultraviolet light, the Au@Pd core-shell nanoparticles were prepared. The size of the nanoparticles and the thickness of the Pd shell could be efficiently adjusted by changing the molar ratio of Au (III) to Pd (II) ion. In this way, nanoparticles with diameter in the range of 5.6~4.6 nm were obtained. The core-shell structure of the synthesized nanoparticles was showed by the characterization using UV-Vis, TEM/HR-TEM and XPS. The paper investigated the electrocatalysis performance of Au@Pd nanoparticles in the methanol catalytic oxidation reaction, as well as the electron donating effect of Au core to Pd shell and the promotion of this effect on the catalytic activity of Pd shell. The experimental results provided reference for the development of non-platinum catalysts of low-temperature fuel cell anode.

A series of Pd@Pt nanoparticles were synthesized based on electrochemical seed growth method and co-reduction method in polyethylene-glycol and acetone solution system. The TEM/HR-TEM and XPS characterization proved that the prepared composite nanoparticles present core-shell structure and analyzed the chemical state of the particles. The electrocatalytic performance of Pd@Pt particles was studied by using the electrochemical workstation. The results showed that the Pd@Pt/C catalyst of different molar ratios of Pd to Pt exhibited preferable catalytic activity and stability for the methanol catalytic oxidation reaction. Among which, the Pd@Pt nanoparticles (Pd:Pt=1:1) prepared by co-reduction method, presented highest catalytic activity, which is 2 times higher than that of Pt/C catalyst. The high catalytic activity produced by the core-shell structure was briefly discussed.