High-strength glass is an important window material in the fields of aerospace, information electronics and equipment manufacturing. In order to ensure that the glass can be used normally under harsh environmental conditions, it is necessary to continuously improve the mechanical strength, hardness and impact resistance of the glass. Therefore, the research of high-strength glass has attracted much attention. The current research on high-strength glass mainly focuses on: (1) exploring the relationship among the components, structure, performance of high-strength glass materials in different systems, and the performance changes of doped glass; (2) developing new strengthening methods for high-strength glass. Research on physical strengthening and chemical strengthening processes applicable to different high-strength glass systems. This article reviews the effects of oxides on the network structure and mechanical strength of different glass systems, compares the evolution characteristics of the mechanical properties of doped glasses based on the analysis of different glass systems and chemical composition, summarizes the research progress of high-strength glass composition design at home and abroad, and provides reference for scientific research and development of high-strength glass materials.

This work employed XRD, SEM, TG-DSC, corrosion resistance, density, hardness, fracture toughness and other test methods to study the influences of different heat treatment systems and coal gangue content on the crystal structure, morphology, physical and chemical properties of glass-ceramics. The results show that the main crystal phase of coal gangue glass-ceramics is anorthite (CaAl2Si2O8), both the quantity and the size of main crystal phase become larger with increasing crystallization temperature during the heat treatment process, but the main crystal phase remains unchanged. Keeping nucleation temperature of 750 ℃ for 1 h and crystallization temperature of 1 000 ℃ for 1 h, the crystal size of main crystal phase is about 300~400 nm. With an optimal heat treatment schedule, when the content of coal gangue increases from 44% (mass fraction) to 70%, the physical and chemical properties of glass-ceramics with different content of coal gangue are similar. Comprehensively considering the utilization rate of coal gangue solid waste and the physical and chemical properties of the samples, the sample with coal gangue content of 70% has the best comprehensive performance. The coal gangue glass-ceramic system designed in this work has good tolerance and strong absorption of coal gangue solid waste. It can realize the high-volume and high-value utilization of coal gangue solid waste, and provide a theoretical basis and experimental basis for solving problems such as coal gangue solid waste accumulation and environmental pollution.

Using titanium slag as the main raw material, the CaO-MgO-Al2O3-SiO2 series glass-ceramics were prepared by the melting method. Through integrated thermal analyzer, X-ray diffractometer, and scanning electron microscopy, the effect of SiO2 content on the stability and crystallization behavior of the base glass of titanium slag glass-ceramics was analyzed. The results show that when the original slag is used to prepare glass-ceramics, the structure of the basic glass is unstable, and perovskite crystals are easy to precipitate. With the increase of SiO2 content, the basic glass tends to be stable, the crystallization temperature increases, and the degree of crystallization after heat treatment becomes higher, the microstructure is denser and therefore the strength is higher. The SiO2 content is adjusted by adding the auxiliary raw material quartz powder. When the SiO2 content is 40% (mass fraction), glass-ceramics with stable glass body, crystal phase only diopside, and bending strength of 82.1 MPa are prepared. The content of titanium slag is more than 80%(mass fraction), which has important economic and social effects.

The stress distribution characteristic of vacuum glazing due to atmospheric pressure difference, temperature difference and wind load were analyzed according to its typical structure characteristics, and the quantitative calculation formulas of the maximum bending tensile stress were given in this work. The bearing capacity design of vacuum glazing under synergetic effect of long-term and short-term stress was analyzed based on the structural resistance design method. The results show that under the condition of given substrate thickness, the maximum bending tensile stress of vacuum glazing basically increases linearly with the increase of the support spacing. With a given support spacing, the maximum bending tensile stress of vacuum glazing decreases exponentially with the increase of the substrate thickness. The maximum bending tensile stress due to temperature difference is not related to the thickness, length and width of the glass substrate, but related to the expansion coefficient.There is a linear relationship between the temperature difference and the maximum bending tensile stress of vacuum glazing. Under the same conditions, the wind pressure resistance of vacuum glazing is not as good as that of plate glass with equal thickness.Under the synergetic effect of long-term and short-term stress, the design value of vacuum glazing effect under different stress action time should be calculated separately for verification.

Vacuum glazing is a new type of green building material with great heat preservation, thermal insulation and noise reduction performance. COMSOL Multiphysics 5.6 was utilized to establish the physics models to explore the performance of vacuum glazing with different specifications and simulate the application of different glasses in energy-saving buildings in this study. The results show that the thermal insulation performance of vacuum glazing with size of 500 mm × 500 mm is better than that of 200 mm × 200 mm and 100 mm × 100 mm. With the size increasing, the area of the vacuum gap becomes larger, whereas the edge sealing layer occupies a smaller percentage of the surface area of the whole vacuum glazing. Therefore, the effect of the edge sealing layer on the heat transfer of the vacuum glazing is reduced, and the thermal insulation performance of vacuum glazing is enhanced. A better energy-saving effects can be achieved using vacuum glazing replacing ordinary flat glass and insulating glass in energy-saving buildings. The average indoor temperature of energy-saving buildings using vacuum glazing for 7 d in winter is 3.91 K higher than that of using flat glass, and 2.25 K higher than that of using insulating glass.

The traditional vacuum glass support pillar is manually or mechanically arranged, which has the disadvantages of low production efficiency and high leakage rate. In this paper, a support pillar was prepared by printing sintering of low melting point glass slurry, the blending concentration and printed plate parameters of the support pillar printing slurry were optimized, and the effects of different sintering temperatures on the molding size and strength of the support pillar were analyzed. The results show that the optimized slurry blending concentration is 5 g/mL, the optimized pore size and thickness of the printed plate are 1.0 mm and 0.5 mm, the optimal sintering temperature of the support pillar is 380 ℃. The diameter of support pillar after molding is 1.25 mm, the height is 0.23 mm, the hardness is 549.92 HV, and the performance is good. This study has guiding significance for the vacuum glass manufacturing process.

High-strength ultrathin cover glass is an important part of electronic information products, and chemical strengthening (ion-exchange) is the main technological approach to improve the mechanical properties of ultrathin cover glass. During ion-exchange, stress relaxation (structural relaxation) can easily take place, making it difficult for chemically strengthened glasses to simultaneously achieve high compressive stress, large depth of layer, and high Vickers hardness. To overcome this issue, two-step ion-exchange was developed to strengthen aluminosilicate glasses. Effects of molten salts, ion-exchange temperature and duration on the distributions of stress layers and Vickers hardness were investigated. Results demonstrate that high compressive stress, large depth of layer, and high Vickers hardness can be simultaneously achieved via two-step ion-exchange. After ion-exchange, the compressive stress of the glass is over 900 MPa, the depth of layer is over 70 μm and Vickers hardness is over 7.2 GPa.

The resistivity of glass melt is one of the key parameters for designing glass electric melting furnace and electric boosting furnace. In order to test the resistivity of glass melt accurately, figuring out the influences of boundary conditions on the resistivity measurement of glass melt is very important. Based on Ohm’s law, a glass melt resistivity measuring device was constructed in this work, and the influences of feed-in voltage, frequency of alternating current, particle size of sample and filling rate on the resistivity of soda-lime glass melt at 900~1 450 ℃ were discussed. The results show that when the feed-in voltage is 2~10 V, the frequency of alternating current is 1 kHz, the sample particle size is 830~1 700 μm, the filling rate is 80%, and the cooling rate is 2 ℃/min, the errors of the measurement results of resistivity are all less than 1 in each temperature segment. This work provides a reference for the measurement of glass melt resistivity, which is essential to design the electric heating system of electric melting furnace and electric boosting furnace for refractory and volatile glasse production.

The transmittance of photochromic glass varies with the intensity of light radiation. Hence, photochromic glass is a smart glass with energy-saving effect, which can be used to regulate the sunlight into the building. However, there are few studies on the application of photochromic glass in buildings, and there is a lack of scientific methods to evaluate its energy-saving performance. In this paper, a simplified simulation method for energy-saving performance of the as-prepared photochromic glass was established. Focusing on the energy-saving effect, different types of buildings were modeled by the energy consumption software (DeST), and the cooling and heating load and lighting energy consumption of buildings with photochromic glass were calculated and compared. The results show that, photochromic glass has an annual energy-saving ratio up to more than 10% in public buildings with large building areas and window to wall ratio above 0.6. Furthermore, in buildings with smaller building areas and window wall ratio, its main role is to block ultraviolet light and prevent glare. The results and methods of this paper can provide a reference for the research of energy-saving performance of photochromic glass, and have significance to promote the practical application of photochromic glass.

For the float glass process, a simplified steady multiphase model was proposed for the simulation of glass melt forming process in the tin bath entrance area. The Ansys Fluent 2019 R3 software package was employed to simulate the glass melt flow and forming process for a tin bath with pull rate of 500 t/d. The flow behavior and layer thickness distribution of glass melt at spout lip and restrictor area were investigated with different pull rates and viscosities. According to the results, the glass melt layer becomes discontinuous with small pull rate or viscosity, and the uniformity of layer thickness in transverse direction gets worse with extreme large pull rate or viscosity. Finally, the optimized operation condition for float glass forming process of the sample tin bath is pull rate of 400~550 t/d and viscosity of 400~600 Pa·s.

AZS material is a key building material in the furnace of glass industry, the microstructure of material and the stability of zirconia phase have significant effects on the corrosion resistance to the molten soda-lime glass. The physical and chemical properties of fused-cast 41#AZS materials with a small addition of yttrium oxide were studied by means of chemical analysis, high temperature X-ray diffraction, glass corrosion resistance test and electron microscope. The results show that the microstructure of material is improved by adding a small amount of Y2O3 stabilizer, Y2O3 is mainly deposited in the ZrO2 crystals and dendrites, which firstly crystallize, resulting in the refinement of the particles of these crystalline phases. The temperature range of ZrO2 phase transition becomes smaller, the degree of transformation reduces, and the stability of ZrO2 crystal and eutectic improves, thus the corrosion resistance of material to glass melt is significantly improved.

Magnesium oxychloride cement (MOC) has many advantages, such as high strength, strong adhesion, wear resistance, impact resistance, low alkalinity and low corrosion, and so on. As a kind of inorganic adhesive and cementitious material, it has been widely used in many industries including wood processing. However, the poor water resistance of MOC seriously affects its large-scale application and industrialization. Therefore, how to improve the MOC water resistance under the condition of ensuring the mechanical property has become a hot topic in the MOC research field. In this paper, the recent progress on the improvements of MOC water resistance both at domestic and abroad was reviewed, and different modification methods of distinct admixtures were emphatically summarized, as well as its mechanism. Finally, the prospects of MOC in wood industry and other application fields were discussed, which would provide theoretical and technical guidance in the development of high-performance MOC.

Investigating the mechanism of early-strength polycarboxylate superplasticizer (ES-PCE) on cement hydration is helpful to the development, design and application of ES-PCE. In this paper, the influence mechanisms of ES-PCE and regular polycarboxylate superplasticizer (PCE) on early hydration of reference cement were analyzed by characterizing the hydration process, dissolution rate, hydration product growth, setting time and compressive strength of cement. The results show that both PCE and ES-PCE reduce the dissolution rate of cement suspension. The addition of PCE delays the induction and acceleration of cement hydration and reduces the heat release of hydration. ES-PCE only slightly delays the induction period of cement hydration, but shortens the acceleration period and hydration heat release is basically unchanged. Compared with reference cement, ES-PCE advances the initial setting time of cement by 10 min and the final setting time by 85 min. The incorporation of ES-PCE improves the early and late strength of cement. The 7 d compressive strength of cement with 0.2% ES-PCE (mass fraction) increases by 14% in comparison with reference group, while the strength of cement with PCE increases by only half of the former. The addition of PCE and ES-PCE releases the water in the granular flocculation structure of cement, which is beneficial to cement hydration, but their effects on hydration are opposite. A large number of carboxyl groups in the molecular structure of PCE complexes Ca2+ in the solution, inhibits the formation of crystal nuclei on the surface of cement particles, and plays a certain role of retarding coagulation. However, the carboxyl content of ES-PCE molecular structure is low, the complex effect of Ca2+ is weak, and the retarding effect is not obvious. When the effective water content in the system increases, the hydration of cement is promoted, which has the effect of early strength. In cement mortar with water cement ratio of 0.4, the mixing amount of ES-PCE is suitable to be controlled below 0.3%, which not only ensures the water reduction rate, but also enhances the early and late strength of cement.

In order to broaden the application range of magnesium oxychloride cement (MOC), the effects of three retarders including citric acid, boric acid and sodium gluconate on the setting time, compressive strength, electrical resistivity, heat of hydration and water resistance of magnesium oxychloride cement were investigated. Meanwhile, X-ray diffractometer was used to analyze the hydration products of modified MOC. The results show that retarders prolong the setting time. When the content of retarders is 0.75% (mass fraction, the same below), the 28 d compressive strength of samples compared with the control group decreases by 19.3%, 16.7% and 20.2%, respectively. The addition of retarders reduces the peak value of electrical resistivity rate curves and internal temperature curves, delays the second peak of hydration heat rate curves, that is, retarders reduce the hydration rate of magnesium oxychloride cement so that the heat is liberated slowly. Retarders can improve the water resistance of magnesium oxychloride cement. When the content of boric acid is 0.75%, the softening coefficient reaches 0.79.

Extreme environment and complex load conditions put forward higher requirements for the material properties of concrete. The method of improving concrete performance by modifying cement-based material with polymer has been widely used. To reveal the hardening mechanism of the hydration process of epoxy latexes-modified cementitious materials, the influence of epoxy latexes on the hydration process of cement hydration was studied by isothermal calorimetry, and the phase evolution of the cement clinker minerals and hydration products was tracked by in-situ XRD. The results show that the retardation effect of epoxy latexes on cement hydration is related to the interaction among epoxy particles, cement clinker minerals and hydration products, and the interaction effect becomes more obvious with time-dependent. When epoxy latexes are added into the cement paste, the heat-generation rate slows down, and the heat flow peak and cumulative heat generation reduce. Epoxy latexes can delay silicate reaction and aluminate reaction by inhibiting the dissolution of cement minerals (C3S, C3A and gypsum) and the precipitation of hydration products (ettringite and portlandite). The effect of epoxy latexes on cement hydration increases with the increase of its content.

The compressive strength at early and late age is relatively low for low-alkalinity cement prepared by ordinary Portland cement, silica fume and fly ash for the solidification of radioactive incineration ash. In this study, polyaluminum sulfate was used as additive to stimulate the reactivity of pozzolanic materials in the low-alkalinity cement. The effect and mechanism of polyaluminum sulfate on the early age hydration of low-alkalinity cement were characterized by evaluating the compressive strength, porosity, pH value, phase assemblage and microstructure of low-alkalinity cement after addition of polyaluminum sulfate. The results indicate that the incorporation of polyaluminum sulfate significantly improves the early age compressive strength of the low-alkalinity cement. The exothermic peak of early age hydration is advanced and the pozzolanic reaction is promoted. The amount of hydration products increases, and the microstructure is densified. The early age alkalinity effectively reduces, which is beneficial to inhibit the corrosion reaction of metal aluminum in the incineration ash waste form.

In this paper, the effects of sea water and mineral admixture on the mechanical properties and apparent porosity of sulphoaluminate cement (SAC) mortar, the properties such as setting time, chemical shrinkage, pH value of pore solution and chloride ion binding capacity of paste were studied. Furthermore, the hydration products and the microstructure of SAC were analyzed by XRD, SEM and EDS. The results show that sea water accelerates the early hydration of SAC and improves its early strength, while there is no significant difference in the long-term strength of cement mortar between sea water and fresh water. Both fly ash and silica fume prolong the setting time of SAC, which is disadvantageous to the early compressive strength. 28 d compressive strength of SAC mortar improves with the silica fume mass fraction of 5.0% and 7.5%. As the silica fume content increases, the water consumption, chemical shrinkage and apparent porosity of SAC increase. However, the fluidity, the pH value and the chloride ion binding amount of cement paste reduce with the increase of silica fume content. Meanwhile, Fly ash improves the fluidity of mortar and reduces the chemical shrinkage of cement paste. But the adverse effect on the compressive strength and flexural strength of SAC mortar is more obvious with the increase of fly ash content. When 10% (mass fraction) fly ash is added, the chloride ion binding amount increases and the apparent porosity reduces slightly.

High temperature not only reduces the mechanical properties of mortar, but also has a great impact on its durability. The fire test was simulated by heating the mortar to 400 ℃, 500 ℃ and 600 ℃ by high temperature muffle furnace at three different heating rates (5 ℃/min, 10 ℃/min and 15 ℃/min). Throuth a new experimental technique allowing simultaneous measurement of gas permeability and porosity changes under confining pressure, the changes of gas permeability, porosity and mechanical properties of mortar damaged at different temperatures were studied.The main results show that the gas permeability and porosity of mortar increase gradually with the acceleration of heating rate and temperature. Compared with no heating, when heated to 600 ℃ at 15 ℃/min, the gas permeability of mortar increases by 2 orders of magnitude and the porosity increases by 1.77 times. In the process of loading and unloading confining pressure, the gas permeability and porosity of mortar decrease irreversibly. When the heating rate is faster and the heating temperature is higher, the gas permeability and porosity of mortar are more sensitive to confining pressure. The sensitivity of porosity to confining pressure is smaller than that of gas permeability, but the sensitivity of porosity to confining pressure confirms the irreversible closure of cracks and irreversible fracture of pores during loading and unloading confining pressure. When the mortar is heated to 400 ℃, 500 ℃ and 600 ℃ at three heating rates, the compressive strength of the mortar decreases gradually with the acceleration of heating rate and the increase of temperature.

Based on the center pull-out test of basalt fiber reinforced polymer bars/engineering cementitious composites (BFRP bars/ECC), the effects of graded particle size of ECC, surface treatment and diameter of BFRP bars on bond performance and bond-slip curve of BFRP bars/ECC were analyzed. The results show that the failure modes of the specimens are BFRP bar pull-out failure and BFRP bar rupture failure. The BFRP bars/ECC bond-slip curve is wave type. The peak point of each wave is selected and an absolute value of linear slope |k| is fitted to characterize the wear degree of ECC and tear degree of BFRP transverse rib. If the |k| ≥ 0.144, transverse rib of BFRP bar is deemed to wear completely, and if the |k| < 0.144, the transverse rib of BFRP bar is deemed to worn and flush with the ECC. The average bond strength of BFRP bars/ECC does not change significantly with the particle size. The graded particle size of ECC increases the average bond strength of BFRP bars/ECC by 3.2%~9.6%. The BFRP bars/ECC with the aggregate particle size of 0.15~0.3 mm has the best bond strength. The larger the diameter of BFRP bars is, the smaller the average bond strength of BFRP bars/ECC is. The average bond strength of BFRP bars/ECC with the diameter of 12 mm is about 8.2% and 4.4% lower than that of BFRP bars/ECC with the diameter of 8 mm and 10 mm. The average bond strength of BFRP bars/ECC with shallow thread BFRP bars decreases by 83.7%, but the overall bond stress changes stably, and the failure degree to both ECC and BFRP bars is minimal. Reducing the diameter of BFRP bars, ECC aggregate particle size, or the rib depth of BFRP bars at the free end of BFRP bars/ECC can improve the bond performance and stability of BFRP bars/ECC.

The macroscopic mechanical behaviors of concrete depend on the material composition and its properties. In this paper, a mesoscale numerical model of concrete with multiphase heterogeneity based on the band-based peridynamic theory was established to study the macroscopic mechanical properties and fracture processes of concrete under uniaxial tension. The rationality of the model was verified by varying the content of coarse aggregate, the strength of mortar, the strength of coarse aggregate and the strength of interface transition zone (ITZ). The results show that the stress-strain curves before the softening section can be reproduced well, and the mechanical properties and fracture process of concrete under uniaxial tension can be accurately described. In addition, the fracture process of different types of concrete under uniaxial tension can be reasonably simulated by adjusting the mechanical parameters of each phase materials in the numerical model.

Basic magnesium sulfate cement concrete (BMSC) has many advantages, such as quick setting, early strength, high tensile strength, resistance to corrosion, and so on. However, the failure of diagonal-tension of BMSC beams has not been studied. In order to explore the differences in mechanical performance between BMSC beams and Portland cement concrete (PC) beams, a comparative test of diagonal-tension failure of the BMSC and PC beams were conducted. The experimental results show that the BMSC beams have advantages in the cracking load and the ultimate bearing capacity compared with the PC beams under diagonal-tension failure. There are some differences in the failure mode between the BMSC and PC beams. The cracking load and the bearing capacity of the BMSC beams are 20% higher than that of the PC beams with the same reinforcement and the same concrete strength grade. So the calculation formulas for cracking load and bearing capacity of the PC beams have been modified. This paper has significance to the application of BMSC in civil engineering.

Due to environmental erosion, concrete structures are easy to crack and damage, and appropriate additives can reduce damage and deterioration. In this paper, the influence of different content of magnesium oxide expansive agent on the corrosion resistance of concrete was studied, the mass loss and strength change of concrete which soaked in MgSO4 solution were tested. Combined with the microstructure changes, the sulfate corrosion resistance of the concrete mixed with magnesium oxide expansive agent was evaluated. The results show that the mass and mechanical properties of concrete specimens increase first and then decrease in the long-term sulfate immersion environment, and the sulfate damage rate can be reduced by adding magnesium oxide expansive agent and reducing the concentration of sulfate solution. Among them, on the one hand, the addition of magnesium oxide expansive agent refines the internal pore structure of concrete, reduces the rate of sulfate corrosion damage, and delays the damage cracking of specimens to form microcracks; on the other hand, magnesium oxide expansive agent fills the microcracks after cracking, blocking or reducing the sulfate continuous transmission channel, thus hindering the crack propagation.

In this paper, the bonding strength and chloride ion concentration of coatings were tested on the surface-coated concrete specimens exposed for 10 years and the solid structure of Qingdao Jiaozhou Bay Bridge. The long-term protective effect of the coatings applied to the concrete structure was studied. The results show that after 10 years exposure to the frozen seawater environment, the bonding strength of the coatings on the concrete in the atmospheric zone, the splash zone and the tidal zone all exceed 1.5 MPa, which still meets the requirements of current specifications. Compared with the tidal zone, the coatings on the marine concrete exposed in the splash zone and the atmospheric zone show better long-term protection. In the tidal zone, the apparent chloride ion diffusion coefficient of the coated concrete specimens is not significantly different from that of uncoated concrete. The surface chloride ion concentration of the coated concrete in the structure of the bridge is 2.3 to 3.9 times lower than that of the uncoated concrete, and the long-term chloride ion corrosion resistance of the coatings on the bridge is slightly weaker than that of the small-sized concrete specimens.

In view of the characteristics of high requirements for grouting material performance in large pore asphalt mixture pavement, this paper develops an early strength cement-based grouting material for semi-flexible pavement. The basic ratio of cement system was determined by mixing fast hardening sulphoaluminate cement with ordinary Portland cement in different proportions. Through the orthogonal test, the optimum ratio of mineral admixtures such as fly ash, silica fume and red mud was determined. By adding water reducing agent, rubber powder, retarder and early strength additive into the grouting material system, the working performance of grouting material was optimized and controlled, and finally, the cement-based grouting material for semi-flexible pavement meeting the performance requirements was obtained. The results show that the optimal proportion of grouting material system is m(fast hardening sulphoaluminate cement)∶m(ordinary portland cement)=7∶3, the amounts of fly ash, silica fume and red mud are 9%, 6% and 3% of the mass of sulphoaluminate-ordinary silicate composite cement, respectively, the water-binder ratio is 0.40, the sand-binder ratio is 0.25. The admixtures of early strength agent, rubber powder, water reducer and retarder are 0.08%, 2.5%, 0.35% and 0.20% (mass fraction) respectively. The initial fluidity and 20 min fluidity are 13 s and 19 s. The initial and final setting time are 62 min and 65 min, respectively, and the compressive strength is 1708 MPa, 1813 MPa, 2459 MPa and 26.19 MPa at 3 h, 1 d, 7 d and 28 d, respectively, and the drying shrinkage rate at 7 d is 0.18%.

Activated carbon has an extremely important application in the field of industrial flue gas purification due to its unique pore structure and surface properties. However, the small pore volume, wide distribution of micropores and small specific surface area of ordinary activated carbon made its adsorptive property cannot meet the needs of deep purification. The modification of activated carbon optimize its pore volume and aperture, improve its porosity and surface acidity and alkalinity, and therefore improve the adsorption performance of activated carbon. In this paper, the research progress of modified activated carbon under acidic, alkaline and neutral conditions over recent years has been summarized. And based on the existing shortcomings and bottlenecks of activated carbon modification. The research focus on activated carbon modification in the future is suggested.

Vermiculite is widely used in the field of wastewater treatment due to its good adsorption and ion exchange properties. A large number of hydrophilic inorganic cations are filled between the layers of natural vermiculite, which produce a thin water film on the mineral surface and reduce its organic wastewater adsorption capacity. To improve the adsorption ability of vermiculite for naphthalene sulfonic acid, natural vermiculite was pretreated using acid activation, and then modified by trioctylamine (TOA) to prepare TOA modified acid-activated vermiculite (TOA-Hts), which possessed the vermiculite with adsorption and extraction properties. The prepared samples were characterized by XRD, FT-IR and BET methods. The influence of solution pH value and TOA-Hts dosage on the adsorption performance was studied, and the adsorption mechanism of TOA-Hts was analyzed. The results show that, the R′SO-3 ions in wastewater are majority adsorbed on TOA-Hts by complex extraction reaction with TOA. Compared with natural vermiculite, the naphthalene sulfonic acid removal rate of TOA-Hts is increased by 90.63%, and the adsorption quantity reaches 78.98 mg·g-1. The adsorption process can be described by the Freundlich model and pseudo-second-order kinetics model.

Natural hydraulic lime (NHL) is obtained from calcination and digestion of calcined calc-silicate raw materials. Its main components are dicalcium silicate (Ca2SiO4, C2S) and calcium hydroxide (Ca(OH)2, CH). It fits ancient lithology buildings well, and the durability is in line with the requirements of people for the restoration of ancient buildings. Using X ray diffraction and free calcium oxide (f-CaO) test methods, this paper evaluated the NHL calcination process by investigating the mineral phase composition and conversion rate of the products obtained under different cooling methods (fast cooling speed which is about 500 ℃/min compared with cooling in the closed furnace for the cooling speed of nearly 60 ℃/min), firing time (0 min to 180 min) and calcination temperatures (1 000 ℃ to 1 200 ℃) and with calcite power and silicate power. The results show that, when the calcination temperature is lower than 1 150 ℃, changing the cooling method will not cause the crystal phase transformation of C2S during the cooling process. At the same temperature, the content of C2S in the NHL calcined product increases with the increase of the constant temperature time, and its content reaches the maximum value at this temperature in 30 min to 45 min, and the increase of the calcination temperature increases the maximum value. C2S first exists in β-lattice, and gradually changes to γ-C2S over time. With a rapid cooling speed, the calcination temperature of β-C2S is lower than that of γ-C2S. To prepare NHL, the calcination process could be firing at 1 150 ℃ for 45 min, and with the rapid cooling system.

The influence of ground granulated blast furnace slag (GGBFS) on the early hydration of calcium aluminate cement (CAC) at 20 ℃, 35 ℃ and 50 ℃ were investigated in this study. The test on setting time, compressive strength, electrical resistivity, internal temperature of cement pastes and hydration products were employed. The results indicate that the addition of GGBFS reduces chemical shrinkage at 72 h and decreases the peak value of the rate of chemical shrinkage. The electrical resistivity curves and the chemical shrinkage curves show an obvious phase transformation stage and induction stage respectively at 20 ℃. At 35 ℃, the setting time of cement pastes is prolonged, the development of electrical resistivity is inhibited after the addition of GGBFS. At 50 ℃, the electrical resistivity decreases significantly near 24 h and the setting time of cement pastes are shortened obviously. However, the reduction of electrical resistivity at 24 h is undermined with GGBFS. Besides, the hydration products and compressive strength of CAC and GGBFS composites are affected significantly by the curing temperature. At 20 ℃, the incorporation of 40% (mass fraction) GGBFS reduces the amount of CAH10, decreases the compressive strength of cement pastes. At 35 ℃ and 50 ℃, the hydration products at 1 d are major C2AH8 and minor C3AH6, the reduction of compressive strength are weakened with GGBFS. At 28 d, the addition of GGBFS can promote the formation of C2ASH8 at different curing temperatures.

The difference of physical and chemical properties of slag has a great effect on the performance of new gypsum slag sulphoaluminate cement (SAC-GS). Therefore, three typical slags for production were selected to try to construct the relationship between the composition, structure of slag and the macroscopic properties of SAC-GS in multiple dimensions. The mineral composition, element composition and the existence state of each slag were compared and analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The hydration process of each hardened cement paste sample was analyzed by Scanning electron microscope (SEM), XRD and other methods, and the compressive and flexural strength of each sample at different hydration ages were tested, and the early hydration heat release evolution and pore size distribution were compared. The results show that the slag with higher aluminum content and higher reactivity has faster strength development, higher hydration degree and denser pore structure of cement sample. Slag with high aluminum content should be selected for the preparation of SAC-GS.

The discharge and storage of carbide slag are increasing year by year, so the utilization of ferrosilicon derived from carbide slag has also become a problem to be solved urgently. For the high-value application of carbide slag ferrosilicon, the heavy medium suspension was prepared using magnetic ferrosilicon separated from dry-process carbide slag, and the effects of suspension density, clay content and ferrosilicon particle size on viscosity and sedimentation characteristics of suspensions were studied. The results show that increasing suspension density or clay dosage and reduces ferrosilicon size increases the viscosity of suspension to reduce the sedimentation velocity of medium solids, and the stability of the suspension is improved. Furthermore, in order to verify the feasibility of using this suspension system for practical separation, the suspensions with different densities are tested in float and sink experiments to separate coal samples. Under the suspension density of 1.30 g/cm3 or 1.40 g/cm3, the floating coal reveal relatively high yield and its ash content significantly decrease compared to initial coal sample, which reflect the great separation performance of this suspension system.

This study aim to develop the carbon storage potential of γ-C2S stainless steel slag, and to maximize the comprehensive utilization rate of stainless steel slag. The impacts of several key parameters, such as molding pressure, liquid-solid ratio, CO2 partial pressure on the carbonation performance were studied, and the CO2 storage capacity of stainless steel slag was evaluated, so that a better carbonation process of the stainless steel slag could be offered. The composition and microstructure of the carbide products of stainless steel slag were characterized by XRD, SEM/EDS, DSC/TG to explore the carbonation mechanism. The results show that the optimal carbonation parameters are as follows: liquid-solid ratio 10%, molding pressure of 250 MPa, and CO2 partial pressure of 03 MPa. In above mentioned conditions, about 123.6 g of CO2 is stored in every kilogram of stainless steel slag. The γ-C2S carbonation is main reaction during the carbonation progress. Flake and granular CaCO3 are first observed, and then they gradually grow into clusters over time. Therefore, the storage and preparation of carbonized products using stainless steel slag are practicable.

In order to improve the cementing and filling effects of the upper part of shale oil horizontal wells, the settlement stability evaluation method was used to design the particle ratio scheme with equal particle size, which can simulate the actual temperature and pressure conditions underground. And a new hydration activator that is suitable for the normal and low temperature environment was developed with alkali lime and magnesium sulfate. In conclusion, a ternary low density filling cement slurry composed of fly ash, micro silicon, and cement was created by the 29Si NMR quantitative analysis, and it was carried out in 5 shale oil horizontal wells of Yanchang oilfield. The results show that the cement slurry is the most stable when the optimum dosage of fly ash and micro silicon is 40% and 35% (mass fraction), and the activator works best when the mass ratio of alkali lime to magnesium sulfate is 3∶1. All the above reduce the residual amount of cement by 29.59% and fly ash by 68.61%, and increase the 3 d and 7 d compressive strength of low density cement slurry at room temperature by 129% and 92%, respectively. In addition, the water loss, water precipitation and thickening time of the ternary composite system totally meet the needs of cementing and filling. The application of 5 wells shows that the qualified sections account for more than 90%, and the cement slurry has good application prospect and large-scale popularization potential.

Fineness modulus is an important index to measure the fineness of sand. The current national standard fineness modulus formula does not involve particles with particle size below 0.15 mm. In this paper, the particles with particle size below 0.15 mm were further subdivided into 0.075~0.15 mm and smaller than 0.075 mm, and three new fineness modulus formulas were formed by incorporating these two grades into the fineness mode formula. Four different fineness modulus tests were randomly generated by rand function in MATLAB software, combined with the screening test of granite manufactured sand, tuff manufactured sand and nature sand, the advantages and disadvantages of different fineness modulus formulas were further verified. The approximate stone powder content of manufactured sand measured at the same time of screening. The empirical formula between the approximate stone powder content and the stone powder content measured by the standard method fitted by linear regression. Research shows that the addition of particles with particle size of 0.075~0.15 mm screening content to the numerator of the original fineness modulus formula is more conducive to characterize the fineness of sand. The difference between the content of approximate stone powder and standard stone powder is 1.346 6%.The surface of different sand samples is magnified by 100 times by SEM. It is found that the coarser the surface of sand samples, the greater the adsorption of stone powder, and the greater the volatility of the difference between approximate stone powder content and standard stone powder content.

Polymer-derived ceramics technology has become one of the main preparation technologies for ceramics and ceramic composite materials due to the advantages of flexible designability of polymer molecules, easy molding and low preparation temperature. Pyrolysis is a key step for the preceramic polymer to transform from organic to inorganic, and plays a decisive role on the composition, structure and properties of the target ceramics. By adding transition metals to the preceramic polymers for catalytical pyrolysis, the pyrolysis behavior was tailored to regulate and expand the structure and performance of the pyrolyzates. The catalytical pyrolysis effects of different transition metals on preceramic polymers were reviewed, the research status was summarized, the catalytical mechanism was discussed, and the development suggestions for the subsequent research and application were proposed.

Silicon nitride ceramics not only have high mechanical properties, but also have strong wave-transmitting properties, high thermal conductivity and biocompatibility, which are regarded as the most excellent ceramic materials. Dense silicon nitride ceramics as bearing balls are widely used in the fields of the engineering industry; porous silicon nitride ceramics as wave-transmitting materials are extensively applied in the fields of the aerospace industry. With the continuous in-depth research on silicon nitride ceramic materials, their excellent properties of high thermal conductivity and biocompatibility have been gradually developed by researchers and their application fields are broadened. This article describes in detail the preparation methods of silicon nitride powder, and reviews the research progress of silicon nitride ceramics as structural ceramics in the areas of machinery, military, and aerospace industries. In addition, it also introduces the application of silicon nitride ceramics as functional ceramics in the fields of semiconductors and biopharmaceuticals. Finally, the future development of silicon nitride ceramics has prospected.

In this paper, the resin-based diatomite slurries for stereo lithography apparatus were successfully developed. The effects of dispersant types, content and solid content on the rheological properties of diatomite slurries were systematically discussed, and the mechanism of dispersant was analyzed. The diatomite slurries with high solid content and low viscosity for stereo lithography apparatus were obtained, and diatomite porous ceramics with complex structure were prepared by 3D ceramic stereo lithography equipment. Results show that BYK2009 is the best dispersant for diatomite slurries, and the viscosity is the lowest when the dispersant is 3% relative to the powder mass. Diatomite slurries with 40% (volume fraction) powder are prepared, and the viscosity of diatomite slurry is 17.30 Pa·s at the shear rate of 30 s-1. Diatomite porous ceramics sintered at 900 ℃ have apparent porosity of 51.30% and bending strength of (46.28±2.63) MPa. This study provides a reference for preparing diatomite carriers with complex porous structure based on stereo lithography apparatus.

High thermal conductivity Si3N4 ceramics with excellent mechanical properties were prepared by using ternary composite sintering agent Er2O3-Mg2Si-Yb2O3. The effects of Er2O3-Mg2Si-Yb2O3 system on densification, microstructure, mechanical properties and thermal conductivity of Si3N4 ceramics were studied. The results show that when the sintering agent is 5% (mass fraction, the same below) Er2O3+2%Mg2Si+4%Yb2O3, the effect of sintering agent on the balance between density and the content of grain boundary phase of Si3N4 ceramics is the best. At the moment, Si3N4 ceramics have the best properties, such as bending strength of 765 MPa, fracture toughness of 7.2 MPa·m1/2, and thermal conductivity of 67 W/(m·K). In the sintering process, adding only 5%Er2O3+2%Mg2Si produces less liquid phase with high viscosity, which cannot densify the Si3N4 ceramics. When the content of Yb2O3 exceeds 4%, the sintering agent produces a large amount of grain boundary phase, which reduces the properties of Si3N4 ceramics.

In this paper, the Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3(PMN-PZT) piezoelectric ceramics were prepared by one-step synthesis method. The effect of Sm-doping on the structure and electrical properties of PMN-PZT ceramics were investigated. High piezoelectric performances are achieved in 2.0% (mole fraction) Sm-PMN-PZT ceramics, which are piezoelectric constant d33=611 pC/N, electromechanical coupling coefficient kp=0.68, dielectric loss tan δ=1.65%, relative dielectric constant εr=2 650, along with a high Curie temperature TC=283 ℃. Furthermore, a large unipolar strain of 2.0%Sm-PMN-PZT ceramics is attained to be 0.20% at the electric field of 3 kV/mm, which shows the characteristic of large strain material. These results suggest that the Sm-doped PMN-PZT ceramics with outstanding comprehensive properties are promising in the field of transducers, sensors, actuators, etc.

Semiconductor photocatalysts can be used to solve energy and environmental problems due to their high efficiency, ecological friendliness and low cost. Layered double hydroxides (LDHs) are a class of metal hydroxides composed of two or more metal cations, with main laminates and interlayer anions and water molecules overlapping each other. LDHs nanomaterials have the advantages of adjustable band gap, large specific surface area, various types, low cost and easy to composite with other materials to realize functionalization, therefore LDHs nanomaterials show good application prospects in the field of photocatalysis. This article systematically reviewed the recent developments in the preparation of photocatalytic LDHs nanomaterials and their photocatalytic application of the decomposition water to produce hydrogen, the adsorption and degradation of organic dyes, and the photocatalytic reduction of carbon dioxide. It provides a certain reference for the preparation and regulation of catalytic performance of high-performance LDHs based nano-catalytic materials in the future.

Bone defects caused by trauma, tumors, infections and other reasons are usually large in size, which exceed the self-healing range of bone and cannot be repaired by itself. Therefore, it is necessary to use bone cement to fill and repair bone defects. Calcium phosphate cement (CPC) is a kind of bone cement commonly used in clinical practice. Due to its plasticity, good bioactivity and biocompatibility, CPC has been widely studied by scholars at home and abroad in recent decades. However, in view of the perspective of clinical practice, the application scope of CPC is limited so that the performances of CPC need to be improved. This paper is mainly divided into two parts: in the part of physical and chemical properties, the modification methods of CPC in mechanical strength, injectability, anti-collapsibility and radiation opacity are summarized; in terms of biological properties, the modification of CPC in osteogenic activity, biodegradability and drug loading property are discussed.

Biochar is a solid product with high aromatization, high carbon and high stability produced by special treatment of raw materials under partial hypoxia or complete deoxygenation. Because the performance of biochar was prepared from different parts of the same plant often different, in this paper, hemp was taken as the research target, KOH and H3PO4 were used as activators, to activate the different parts (stem, skin and root) of hemp. Biochar materials from different sources were prepared by hydrothermal carbonization method, activation method and carbonization-activation method. The as-prepared products were used to adsorb rhodamine B (RhB) and methylene blue (MB) solutions, and their adsorption activities were evaluated. XRD, SEM, TG-DSC, N2-BET, UV-Vis and other characterization methods were used to analyze the properties of the products in order to explore the effects of carbonization temperature, activation temperature and activator type on the properties of biochar. Using flax rod as raw material, phosphoric acid as activator, carbonization temperature 200 ℃, activation temperature 820 ℃, the biochar pores were prepared with uniform distribution, a large number of cross sections in tubular shape. The specific surface area of the biochar is as high as 1 247.63 m2/g. It is also displayed great adsorption capacity for RhB and MB. After nearly 1 h, the 10 mg/L RhB solution has all faded, and the adsorption rate is as high as 100%.

BiMnO3 has attracted plenty of attention due to the coexistence of ferromagnetism and ferroelectricity properties simultaneously. However, the composition evolution of BiMnO3 nanoparticles with heating treatment is not clear. Here, the co-precipitation method was adopted to synthesize BiMnO3 nanoparticles at moderate temperature to investigate the heating treatment induced surface composition evolution. The as-prepared nanoparticles were heated at different temperatures from 300 ℃ to 600 ℃ in the air for 20 min. The influence of heating temperature on crystalline structure and composition was systematically studied using transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. The TEM images demonstrate that the diameter of BiMnO3 nanoparticles increases gradually as increasing heating temperature. The XRD results indicate that the structure of BiMnO3 nanoparticles changes from monoclinic to orthorhombic Pnma symmetry phase when the heating temperature is above 500 ℃. The XPS result suggests that the oxygen defects decrease as increasing heating temperature. Besides that, both XRD and XPS results affirm that BiMnO3 nanoparticles begin to decompose, presenting the unstable property of BiMnO3 nanoparticles in the air at a temperature above 600 ℃. The results are valuable in understanding the evolution of the composition of BiMnO3 nanoparticles with heating treatment.