Based on the fractal geometry, a quantitative index describing the development degree of the internal corrosion expansion of reinforced concrete was proposed. This approach could describe the ...similarity and complexity of the development of corrosion-induced cracks in concrete simultaneously. Based on this approach, the influence of cracking pattern and coarse aggregate distribution on crack distribution was investigated. This study obtained the crack distribution of reinforced concrete by using the half-soaking galvanic accelerated corrosion method. The results showed that the cracking pattern was the main factor affecting the complexity of crack distribution. For cracks with the simplest cracking pattern, the presence of coarse aggregate and its surface irregularity greatly affected their development trend.
•We establish an improved model to represent the microstructure forming process of polyacrylate polymer modified mortars.•We specify the chemical reactions between PA polymer and cement hydrates.•We ...design a simulation test to identify the reactions products in polymer modified mortars.•The influence of PA polymer on the mechanical performance and pore structure was enlightened.
The microstructure forming process of polyacrylate (PA) latex modified cement-based materials was investigated from mixing to hardening. Owing to the chemical reaction between PA particles and calcium ions in the pore solution, PA polymer will not uniformly disperse in cement mortar due to its adsorption on cement particles or hydrates. As a result, PA polymer should exist in cement mortars through different morphologies. The early age mechanical properties of PA modified mortars are lower than those of unmodified mortars, while a rapid progress of the compressive strength and fracture energy can be recognized from the PA modified mortars. It was found that PA polymer addition will refine the small pores but induce big pores to cement mortar. SEM and EDX analysis proves that PA polymer is localized at some places within PA modified mortar which can be named as the localization of polymer modification. The physical and chemical influence of PA polymer on cement-based materials was integrated into an improved model.
In view of the existing phenolphthalein method cannot accurately detect the carbonation depth in laboratory study, based on the test principle of determining the existence of CaCO_3 in concrete ...samples by infrared spectroscopy which can detect C-O keys, use the infrared spectra to set up different water cement ratio under the same conditions as the raw materials and to do a concrete carbonation depth test under different ages, and to specify the operating procedure of the method. Comparing with the phenolphthalein method, the test results showed that the carbonation depth measured by infrared spectroscopy is 2-3 times of carbonation depth obtained by phenolphthalein method. The characteristic peak of the C-O functional group gradually decreases with the increase of the test depth. It indicates that the CaCO_3 content gradually decreases and plateaus at a certain depth. The test results of infrared spectroscopy are more accurate and reliable, and can be used to measure the carbonation depth of concrete effectively.
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•The multifunctional cellulose/silica hybrid microcapsules were prepared via one-step emulsion-solvent diffusion.•The multifunctional fabric coating system is water-based and ...environmental friendly.•The fabric coating exhibits excellent superhydrophobicity, ultraviolet resistant and thermal insulation.•These coatings demonstrate the self-healing ability of superhydrophobicity and ultraviolet protection after damaged.
Exploiting water-based fabric coatings outfitted with multiple protections (e.g., waterproofness, ultraviolet (UV) resistance and thermal insulation) are urgently demanded. Nevertheless, achieving the multifunction and durability poses the major challenge. In the present study, novel multifunctional cellulose/silica hybrid microcapsules were developed by one-step emulsion-solvent diffusion; these microcapsules were well dispersed into waterborne silicone resins to form waterborne multiple protective fabric coatings. Since the encapsulated phase change materials were in the core of capsules, and the hydrophobic coupling reagent and UV absorber were grafted onto the silicas in the shell of capsules, these fabric coatings exhibited high superhydrophobicity, UV protection and thermal insulation. Moreover, because hydrophobic coupling reagent and UV absorber in the shell-cellulose of capsules exhibited easy mobility, the fabric coatings displayed self-repairability of superhydrophobicity and UV protection even after being damaged chemically or mechanically. The fabric coating presented in this study could have a range of applications, covering special protective fabric, high-altitude garments as well as self-cleaning materials.
Natural ecology is the basis of social development. The destruction of natural ecological environment would limit the development of society. Environmental issues have become the commonly concerned ...problems internationally and globally. Promoting the public knowledge and awareness of environmental problems as well as understanding of the correlations among living environment, resources, and humans through education would absolutely be urgent for educators. Campus environment is the best place for students’ ecological education and learning; therefore, a campus with good ecological environment would to-some-degree assist in the overall campus ecology. To maintain the overall balance between campus ecological environment and biological conservation, build natural landscape, and create aquatic and terrestrial habitats, traditional ecological environment engineering should be regulated to suit the sustainable development of ecological campus environment with biological conservation and ecological restoration environment. With college students in Guangxi as the research objects, total 288 students from two classes each in universities, as the experimental research objects, are preceded the 16-week (3 hours per week for total 48 hours) experimental teaching research. The research results conclude that 1.campus ecological environment integrated art education would affect learning motivation, 2.campus ecological environment integrated art education would affect learning effectiveness, 3.learning motivation presents significantly positive effects on learning effect in learning effectiveness, and 4.learning motivation shows remarkably positive effects on learning gain in learning effectiveness. According to the results to propose suggestions, it is expected to establish students’ identification and the successive belongingness through environmental integrated art education to assist students in overcoming the personality development stage for the positive psychological development.
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•Ethyl cellulose/silica hybrid capsule was prepared via one-step solvent diffusion method.•Waterborne multifunctional fabric coating was fabricated by a facile and green way.•The ...as-obtained fabric coatings exhibited controlling aromatic-release performance.•The coated fabric showed excellent durable UV resistant property with high UPF value.
The synthesis of multifunctional microcapsules using natural polymers has contributed to a broad range of practical applications on fabric coatings. This paper presents a facile and environment-friendly approach for waterborne multifunctional fabric coatings by using cellulose/silica hybrid microcapsules. In this method, lavender fragrance oil-loaded cellulose/silica hybrid microcapsules were one-step synthesized via emulsion solvent diffusion. This microcapsule is core-shell structure with UV absorbers and methacrylic acid grafted silica in the shell and then added into the waterborne polysiloxane resins to form multifunctional fabric coatings. The as-obtained fabric coatings not only exhibited controlled lavender fragrance oil-releasing performance, and it can keep above 30 % fragrance after ninety days due to the slow releasing of lavender fragrance oil in the capsules, but also showed excellent UV resistant property with 159 UPF value.
Land surface temperature (LST) is crucial for the energy balance between the Earth's surface and the atmosphere. Thermal Infrared (TIR) and Passive Microwave (PMW) remote sensing are key methods for ...acquiring surface temperature globally and regionally. TIR observations have certain limitations due to their inability to penetrate cloud cover. Conversely, PMW measurements partially overcome this drawback to some extent, but their lower retrieval accuracy and coarse resolution limit its wider application. This study developed an artificial intelligence (AI) framework for precise and high-resolution LST estimation from PMW measurements, comprising PMW LST retrieval and downscaling components. Within this framework, high-resolution LST products have been obtained from AMSR2, and the station-based validations and sensitivity analysis have also been conducted on the algorithm. The results were as follows: (1) The GeoFusionNet algorithm achieved higher LST retrieval accuracy than empirical or physical models. The Mean Absolute Error (MAE) was 2.37 K (1.60 K) during daytime (nighttime). (2) The downscaled PMW LST retained high accuracy, with a daytime (nighttime) MAE increase of 0.28 K (0.14 K) compared to the MODIS 1 km product. Station-based validations showed that the coefficient of determination R 2 was above 0.9, with an average RMSE of 3.4 K (2.4 K) for daytime (nighttime) and MAE of 2.80 K (1.98 K). (3) Sensitivity analysis demonstrated the algorithm's stable performance, especially in summer and autumn. Spatially, the accuracy remained within 3 K for various land types, including cropland, evergreen forests, and deciduous forests. These results indicate that PMW LST retrieved by this framework has sufficient accuracy and fine-spatial resolution for monitoring dynamic changes in large-scale hydrological, climatic, and agricultural fields.
To enhance the tribological properties of TC4 alloy, the plasma electrolytic oxidation (PEO) method was utilized to prepare the coating incorporated various contents of Al2O3 nanoparticles (0, 3, 6, ...9, 12 and 15 g/L) on TC4 alloy. The phase composition, chemical compositions, elemental distribution and microstructure of the coatings were investigated by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray computer tomography (XCT). The results revealed that the introduction of Al2O3 nanoparticles into the electrolyte promoted the formation of Al2TiO5 phase in the PEO coatings, and most of the nanoparticles were embedded into the coatings which reduced porosity of the coatings, but increased surface roughness. Also, the increase in the addition of Al2O3 nanoparticles enhanced the microhardness of the PEO coatings due to the formation of Al2TiO5. The tribological behavior of the PEO coatings was improved significantly owing to the high microhardness and porous structure of the coatings. The primary wear mechanism of the coating with 12 g/L Al2O3 nanoparticles was abrasive wear as this coating formed a lubrication zone during the wear process. Besides, the friction coefficient and wear loss mass of the PEO coating prepared with 12 g/L Al2O3 nanoparticles additive exhibited the excellent wear resistance compared to its counterparts.
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