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The co-application of water, fertilizer, and air is a new water-saving irrigation method based on drip irrigation technology, which can effectively alleviate the phenomenon of soil rhizosphere hypoxia, improve water and fertilizer utilization efficiency, and inhibit the clogging of irrigation equipment in drip irrigation systems. The performance of drip irrigation systems is one of the important factors affecting the effectiveness of the co-application of water, fertilizer, and air. However, the impact of factors such as the aeration method, fertilization device, and working parameters on the performance of drip irrigation systems for the co-application of water, fertilizer, and air is still unclear. Therefore, based on two typical aeration methods, i.e., micro-nano and Venturi aeration, the performance of a drip irrigation system under the co-application of water, fertilizer, and air was studied by comparing and analyzing the effects of different aeration methods, working pressures of the drip irrigation system, and the pressure difference between the inlet and outlet of fertilizer irrigation on the spatial distribution uniformity of water, fertilizer, and air in the drip irrigation pipeline network. The results showed that the pressure difference between the inlet and outlet of fertilization irrigation had no significant impact on system performance, while the working pressure significantly affected system performance. Compared with the effective effect of Venturi aeration on system performance, micro-nano aeration can significantly affect drip irrigation system performance and effectively improve drip irrigation system performance. The micro-nano-aerated drip irrigation system with the co-application of water, fertilizer, and air under a working pressure of 0.1 MPa has better system performance. The research results are of great significance for revealing the mechanism underlying the impact of the co-application of water, fertilizer, and air on the performance of drip irrigation systems and constructing efficient drip irrigation technology for the co-application of water, fertilizer, and air.

Nanoparticles have been identified in numerous studies as effective antigen delivery systems that enhance immune responses. However, it remains unclear whether this enhancement is a result of increased antigen uptake when carried by nanoparticles or the adjuvanticity of the nanoparticle carriers. Consequently, it is important to quantify antigen uptake by dendritic cells in a manner that is free from artifacts in order to analyze the immune response when antigens are carried by nanoparticles. In this study, we demonstrated several scenarios (antigens on nanoparticles or inside cells) that are likely to contribute to the generation of artifacts in conventional fluorescence-based quantification. Furthermore, we developed the necessary assay for accurate uptake quantification. PLGA NPs were selected as the model carrier system to deliver EsxB protein (a Staphylococcus aureus antigen) in order to testify to the feasibility of the established method. The results showed that for the same antigen uptake amount, the antigen delivered by PLGA nanoparticles could elicit 3.6 times IL-2 secretion (representative of cellular immune response activation) and 1.5 times IL-12 secretion (representative of DC maturation level) compared with pure antigen feeding. The findings above give direct evidence of the extra adjuvanticity of PLGA nanoparticles, except for their delivery functions. The developed methodology allows for the evaluation of immune cell responses on an antigen uptake basis, thus providing a better understanding of the origin of the adjuvanticity of nanoparticle carriers. Ultimately, this research provides general guidelines for the formulation of nano-vaccines.

Highly sensitive staphylococcal enterotoxin B (SEB) assay is of great importance for the prevention of toxic diseases caused by SEB. In this study, we present a gold nanoparticle (AuNP)-linked immunosorbent assay (ALISA) for detecting SEB in a sandwich format using a pair of SEB specific monoclonal antibodies (mAbs) performed in microplates. First, the detection mAb was labeled with AuNPs of different particle sizes (15, 40 and 60 nm). Then the sandwich immunosorbent assay for SEB detection was performed routinely in a microplate except for using AuNPs-labeled detection mAb. Next, the AuNPs adsorbed on the microplate were dissolved with aqua regia and the content of gold atoms was determined by graphite furnace atomic absorption spectrometry (GFAAS). Finally, a standard curve was drawn of the gold atomic content against the corresponding SEB concentration. The detection time of ALISA was about 2.5 h. AuNPs at 60 nm showed the highest sensitivity with an actual measured limit of detection (LOD) of 0.125 pg/mL and a dynamic range of 0.125–32 pg/mL. AuNPs at 40 nm had an actual measured LOD of 0.5 pg/mL and a dynamic range of 0.5 to 128 pg/mL. AuNPs at 15 nm had an actual measured LOD of 5 pg/mL, with a dynamic range of 5–1280 pg/mL. With detection mAb labeled with AuNPs at 60 nm, ALISA’s intra- and interassay coefficient variations (CV) at three concentrations (2, 8, and 20 pg/mL) were all lower than 12% and the average recovery level was ranged from 92.7% to 95.0%, indicating a high precision and accuracy of the ALISA method. Moreover, the ALISA method could be successfully applied to the detection of various food, environmental, and biological samples. Therefore, the successful establishment of the ALISA method for SEB detection might provide a powerful tool for food hygiene supervision, environmental management, and anti-terrorism procedures and this method might achieve detection and high-throughput analysis automatically in the near future, even though GFAAS testing remains costly at present.

Intercooled cycle gas turbine has great potential in improving the output power because of the low energy consumption of high-pressure compressor. In order to more efficiently recovery and utilize the waste heat of the intercooled system, an organic Rankine cycle power generation system is developed to replace the traditional intercooled system in this study. Considering the effects of different kinds of organic working fluids, the thermodynamic performance of organic Rankine cycle power generation system is investigated in detail. On this basis, the sensitivity analyses of some key parameters are conducted to study the operating improvements of organic Rankine cycle power generation system. The results indicate that the integration of organic Rankine cycle and intercooled cycle gas turbine not only can be used for waste heat power generation but also increases the output power and efficiency of intercooled cycle gas turbine by selecting the organic working fluids of n -butane (R600), n -pentane (R601), toluene, and n -heptane. And compared to the others, organic Rankine cycle power generation system with toluene exhibits the best performance. The maximum enhancements of output power and thermal efficiency are 6.08% and 2.14%, respectively. Moreover, it is also concluded that both ambient temperatures and intercooled cycle gas turbine operating conditions are very important factors affecting the operating performances of organic Rankine cycle power generation system.

The alfalfa-loess composite, obtained by artificial planting in PVC tubes, was selected as the research object. Through triaxial compression tests, the time effect of shear strength change of alfalfa-loess composite was analyzed, and the effects of confining stress and water content on the shear strength of alfalfa-loess composite were compared. The results shown that the shear strength of alfalfa-loess complex was significantly enhanced compared to the plain loess. The cohesion of the alfalfa-loess composite significantly increased with increasing growth period of alfalfa (60 days, 90 days, 120 days and 150 days). Under a lower confining stress, the cohesion of alfalfa-loess composite with different growth periods in unconsolidated and undrained (UU) test increased by 7.02%, 18.81%, 26.09% and 36.41%, respectively, compared with that of plain loess, while that in the unconsolidated and undrained (CU) test increased by 27.62%, 50.87%, 77.62% and 158.11%, respectively. Under a higher confining stress, the cohesion of alfalfa-loess composite in unconsolidated and undrained (UU) test was significantly higher than that of plain loess, and increased with the growth period, but there was no obvious pattern in consolidated and undrained (CU) test. In addition, the case of herbaceous plants with shallow root growth was more practical to conduct triaxial test in a lower confining stress. The shear strength index of alfalfa-loess composite in the saturated water content was significantly lower than that in the natural water content in the same growth period. As the growth period of alfalfa increased, the decrease in cohesion in the saturated water content was more obvious than that in natural water content. Artificial planting of alfalfa-loess composite using PVC tubes was more conductive to modeling the interaction between roots and soil.

[Objective] The factors influencing landslide potential of loess terraces and the associated landslide formation mechanisms were studied in order to provide a scientific basis for the prevention and control of loess terrace landslides. [Methods] With data from the Google Earth Engine cloud computing platform for Pengyang County, Ningxia Hui Autonomous Region, we used the random forest algorithm to extract terrace distribution information in the study area. Based on the overlay analysis method, the high and extremely high susceptibility zones of potential loess terrace landslides in the study area were determined. Eight influencing factors were selected, and the certainty factor method was used for analysis. [Results] ① The terrace area in the study area accounted for 47.28% of the total area of the county. There were 86 potentially unstable slopes, and there were no deforming areas within the influence range of terraces. ② The high and extremely high susceptibility zones for potential landslides of loess terraces accounted for 46.68% of the total area of high and extremely high susceptibility zones in the study area (27.64% of the total area of terraces in the study area). ③ Rainfall, stratum lithology, gully density, and slope direction had strong controlling effects on the spatial distribution of potential landslides of loess terraces in the study area. [Conclusion] The main controlling factors for potential landslides of loess terraces in the study area were rainfall and stratum lithology, especially in the area where the annual rainfall was more than 450 mm and there were Quaternary stone loess with paleosol strata.

The Yellow River Basin has active geological structure, rapid geomorphic evolution and significant regional differentiation of climate, resulting in many types of major disasters in the basin, wide distribution and strong paroxysm. Taking the Loess Hilly Region in the south of Ningxia as the research area, this paper introduces the concept of loess potential landslide of terrace. By combining historical data collection, remote sensing image interpretation, field investigation and mathematical statistics, it analyzes the development characteristics and distribution rules of loess potential landslide of terrace, and analyzes its formation reasons. The results show that: （1）There are 26 loess potential landslide of terrace in the study area, which are mainly distributed in the Quaternary loess, with a larger number of medium and long slopes, mainly loess potential landslide of terrace of shallow and middle-level, and the scale is mainly small. （2）The loess potential landslide of terrace are mainly distributed in loess hilly areas and large undulating mountain areas, the elevation interval of 1 800~2 000 m, and the slope direction is southeast, South and southwest in space; It is mainly distributed in rainy season or seismicity period in time. （3）Topography, stratum lithologic, rainfall, surface water and human engineering activities are the main factors for the loess potential landslide of terrace. The research results have guiding and reference significance for the risk identification and risk management of loess potential landslide of terrace in the Loess Hilly Region in Southern Ningxia and the Yellow River Basin.

The Lhasa to Nyingchi Expressway in Xizang made efforts to protect the ecological environment during its construction, but it still caused varying degrees of damage to the fragile ecosystems along the route. Accurately assessing the process of change in the ecological environment quality in this region holds significant research value. This study selected the Linzhi-to-Gongbo’gyamda section of the Lhasa-to-Nyingchi Expressway as the research area. Firstly, based on the remote sensing ecological index (RSEI), this study constructed an ecological environmental quality evaluation system for the Xizang region. Subsequently, using the Google Earth Engine (GEE) platform, sub-indicators were extracted, and the combination weighting method of game theory was employed to determine indicator weights. This process resulted in the calculation of the MRSEI for the study area from 2012 to 2020. Finally, by utilizing the spatial distribution of the MRSEI, monitoring the level of MRSEI changes, and employing the transition matrix, this study analyzed the changing trend of the ecological environmental quality from 2012 to 2020. The results indicate that the MRSEI are 0.5885, 0.5951, 0.5296, 0.6202, 0.59, 0.5777, 0.5898, 0.5703, and 0.5987, showing a gradual increasing trend with an initial decrease followed by an ascent. This trend is mainly attributed to concentrated road construction and subsequent ecological restoration, leading to an improvement in the restoration effect. Simultaneously, the ecological environmental quality remains relatively stable, with 69.5% of the region showing no change, and the remaining 30.5% experiencing improvement exceeding degradation. Specifically, there were significant improvements in the land with ecological quality levels categorized as poor, fair, moderate, and good. The types of degradation primarily involved lands originally classified as excellent and good degrading to good and moderate levels, respectively. The above results serve as a theoretical reference for the ecological restoration project of the Lhasa-to-Nyingchi Expressway.

In this paper, the formation mechanism of a slightly inclined bedding mudstone landslide in the overlying mountain of the coal mining subsidence area of the Tanshan Coal Mine in Ningxia, China, is studied. By means of geotechnical investigation, indoor geotechnical tests, theoretical analysis and other technical means, we find the geological environment background of the study area and obtain the physical and mechanical property indexes of the mining landslide in the Tanshan Coal Mine. By combining the numerical simulation of discrete elements and finite elements, the macro deformation and failure law of the mining mudstone landslide and the displacement and stress nephogram of the failure process are discussed. The results show that the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is 850 m long from east to west, 500 m wide from north to south and 10,875,000 m3 in volume. It is composed of Jurassic mudstone and is a traction landslide caused by the coal mining subsidence area. The formation of the landslide is affected by internal factors and inducing factors. The internal factors are mainly geotechnical types and engineering geological properties, and the inducing factors are mainly coal mining activities and rainfall. By analyzing and summarizing the calculation process of the slope model prior to the landslide in 2D-Block and GeoStudio numerical simulation software, the sliding process of the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is divided into four stages: slope creep, slope deformation, landslide movement and landslide accumulation. GeoStudio software is used to calculate the stability of the Tanshan Coal Mine landslide under natural and rainfall conditions. The landslide is in a stable state under natural conditions and is basically stable under rainfall conditions. By comparing the calculation results of the limit equilibrium method and the finite element limit equilibrium method, we find that the calculated stability coefficient is more accurate when the appropriate constitutive model is selected. The research results have important reference significance for the prevention and control of the gently inclined bedding mudstone landslide of the overlying mountain in the coal mining subsidence area of the Loess Plateau.

When the traditional one-dimensional consolidator is used to study the creep characteristics of loess, due to the hoop effect of the ring cutter, only the attenuation creep stage and stable creep stage of loess can be studied, but the accelerated creep stage cannot be presented. In order to avoid the influence of drilling on the creep characteristics of loess, the paper improves the consolidation instrument by drilling holes along the diameter direction in the center of the sample to provide artificial space for soil failure. At the same time, the sample size is increased to ensure that the diameter of the sample is greater than five times of the diameter of the borehole, so as to avoid the influence of drilling on the creep characteristics of loess. The creep characteristics of loess are studied by step loading (vertical pressure at all levels is 125 kPa, 175 Pa, 225 kPa, and 275 kPa), and the whole creep process characteristic curves of loess under different stress conditions are obtained. An endoscope was placed in the hole to observe the deformation and failure characteristics of loess in different stages of creep. This method makes up for the defect that the traditional one-dimensional consolidator cannot obtain the whole process characteristics of loess creep. At the same time, it has the advantages of simple operation, less external influence factors, stronger data reliability, and can directly observe the changes of loess creep soil. It has a beneficial role in promoting the experimental research of loess creep characteristics.