In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM’s durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca2+ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.

Porous basalt aggregate is commonly used in roadbed engineering, but its application in concrete has rarely been studied. This paper studies the application of porous basalt in concrete. Porous basalt aggregate is assessed for its effects on mechanical strength and durability of prepared C50 concrete; because it has a hole structure, porous basalt aggregate is known for its porosity, and porous basalt aggregates can be made full of water through changing the content of saturated basalt; after full-water condition is achieved in porous basalt aggregate mixture of C50 concrete, we discuss its mechanical properties and durability. The effects of C50 concrete prepared with basalt aggregate on the compressive strength, water absorption, and electric flux of concrete specimens of different ages were studied through experiments, and the effects of different replacement rates of saturated porous basalt aggregate on the properties of concrete were also studied. The results show that porous basalt aggregate can be prepared as C50 concrete. For early saturated porous basalt aggregate concrete, its compressive strength decreases with the increase of the replacement rate of saturated aggregate; this occurs up to concrete curing at 28 d, when the replacement rate of saturated basalt aggregate is greater than or equal to 40 %. The compressive strength of concrete increases with the increase of the replacement rate of saturated aggregate. The 28 d electric flux decreases with the increase of the replacement rate of saturated aggregate, indicating that saturated porous basalt aggregate can improve the chloride ion permeability resistance of concrete in later stages.

To solve the common problems of concrete preparation in low-temperature environments, calcium formate (C2H2O4Ca), anhydrous sodium sulfate (Na2SO4), triethanolamine (C6H15O3N), calcium bromide (CaBr2), and triisopropanolamine (C9H21NO3) are selected as early strength agents and mixed with C40 concrete in different dosages under low-temperature environments of 5 oC and 10 oC to develop a high-efficiency low-temperature compound early strength agent based on the effect of single-doped early strength agents. The effects of the compound early strength agent on the early strength of the concrete, the cement paste setting time, and cement fluidity at 5 oC and 10 oC are investigated, and the corresponding reaction mechanism is discussed from the perspective of micro-products. The best compound early strength agent ratio is found to be 2% of calcium formate + 0.08 % of TEA (C6H15O3N). The compound early strength agent effectively promotes the formation of hydration products, such as Ca(OH)2 and C-S-H gel. In comparison with the control group, the strength of the concrete cured for 18 h, 1 d, 3 d, and 7 d under simulated natural conditions at 5 oC increases by 700%, 540%, 11.4 % and 10 %, respectively, whereas at 10 oC, the corresponding values are 991%, 400%, 19.6 % and 11 %, respectively. The strength of the concrete at each age is close to the normal temperature standard of the curing strength. The addition of the compound early strength agent causes a reduction in cement fluidity and initial and final setting times, and also yields a good effect on the porosity of the early concrete.

In this paper, AgCl/Ag3PO4/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag3PO4/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag3PO4/diatomite composite under visible light are evaluated. In the AgCl/Ag3PO4/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag3PO4/diatomite remains at 95 % of the original level, much higher than that of pure Ag3PO4 (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag3PO4/diatomite composites can be attributed to the synergistic effect of Ag3PO4, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO2 and H2O. Even more remarkably, AgCl/Ag3PO4/diatomite can maintain above 95 % photo-degradation activity after five cycles.

In this article, poly methyl triethoxy silane was compounded with an inorganic waterproof admixture at a certain ratio to improve the performance of gypsum products; a new type of high-efficiency compound water-proofing additive was also investigated. Furthermore, the waterproof mechanism and the various properties on the hardened gypsum plaster were investigated in detail by XRD and SEM. The results show that the intenerate coefficient of gypsum plaster increased to more than 0.9; the water absorbing rate decreased to less than 10 %. Both the bending strength and the compressive strength of gypsum plaster increased by various degrees. The intenerate coefficient reached a maximum value of 0.73 and the strength of the samples showed almost no change when 5 % cement alone was added. In this new type of the high-efficiency compound with waterproof additive, the optimal technological parameters for formulas were obtained to be: 5 % cement, 18 % mineral powder, and 0.8 % poly methyl triethoxy silane, to compound gypsum plaster. Meanwhile, the production of high performance gypsum as a building material has become possible.

Three species: Anorthoa angustipennis (Matsumura), Harutaeographa stenoptera (Staudinger), and Cerastis pallescens (Butler), are recorded for the first time from China, and Nikara castanea (Moore) is newly added to the fauna of Northeast China. The image of adult, genitalic characteristics, and the distributions are given as necessary.

With the wave of digital economy sweeping the world, artificial intelligence, blockchain, cloud computing, 5G, ChatGPT and other information technologies are developing rapidly. All walks of life are undergoing changes, and people’s thinking, cognition, life, study, and work are changing accordingly. Both developed and developing countries are also facing new situations and challenges in politics, economy, science and technology, culture, and education. It can be said that digitalization itself and its impacts are related to the development of the future world and affect every citizen of the earth. Digital literacy and skills derived from digitalization have gradually become the focus of attention from all walks of life. In terms of college students’ digital literacy and digital literacy skills, it mainly refers to the digital ability that college students should have and use in study, employment, and future work under the background of informatization and digitalization. Although digital literacy and digital literacy skills have been paid more and more attention by the international community and schools, there is no unified definition of digital literacy and digital literacy skills by various countries and international organizations, and there are some differences in the use of this concept by countries and regions. From the perspective of enterprises’ demand for digital talents, this paper puts forward some suggestions on the training and improvement of college students’ digital literacy skills.