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[Display omitted] • EDIPA greatly improves compressive strength and shortens setting time of SS paste. • Chelation of EDIPA promotes the formation of monocarboaluminate (C(A,F) C ¯ H) • The chelating ability of EDIPA to Al3+ and Fe3+ is stronger than that of Ca2+. • The chelation of EDIPA changes the crystal structure and morphology of Ca(OH) 2. The low cementitious activity of steel slag (SS) limits its application in cement-based materials. The effects of ethanol-diisopropanolamine (EDIPA) on the hydration and mechanical properties of pure basic oxygen furnace SS were investigated. The hydration kinetics and pore structure of SS pastes incorporated with EDIPA and the chelation of EDIPA were analyzed to reveal the working mechanism of EDIPA. The results show that EDIPA improves the compressive strength of the hardened SS paste and greatly shortens the setting time of SS paste, which is related to the chelation of EDIPA. EDIPA could chelate with Ca2+, Al3+, and Fe3+ to form metal chelates, and the chelating ability of EDIPA to Al3+ and Fe3+ is stronger than that of Ca2+. The chelation of EDIPA simultaneously promotes the hydration and carbonation of aluminate and ferrite phases (C 3 A, C 12 A 7 , and C 2 F), resulting in a large amount of monocarboaluminate (C(A,F) C ¯ H), thus improves the hydration degree of SS paste. EDIPA could refine the pore structure of hardened SS paste, which is mainly manifested as the decrease in the amount of macropores and pore size, and the increase in the amount of small pores. The chelation of EDIPA changes the crystal structure and morphology of Ca(OH) 2 , which is potentially helpful to weaken the negative effect of Ca(OH) 2 on strength. This study reveals the effect of chelation of EDIPA on the hydration of SS, which is a valuable guide for the resource utilization of SS. [ABSTRACT FROM AUTHOR]

This work aims to investigate the solubilizing ability of alkanolamines on steel slag (SS) and the chelating ability of alkanolamines with metal ions. In this paper, the chelation effect of four alkanolamines, including triethanolamine (TEA), triisopropanolamine (TIPA), diethanol-isopropanolamine (DEIPA), and methyl diethanolamine (MDEA), and metal ions on the dissolution of SS was investigated. The conductivity meter, pH meter, X-ray powder diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), total organic carbon (TOC) and isothermal calorimetry were used to investigate the solubilizing ability of SS impacted by alkanolamines. Additionally, the conductivity meter and chemical precipitation method (CPM) were used to investigate and explore the chelating ability of alkanolamines interacting with the metal ions. Finally, the nuclear magnetic resonance hydrogen (1HNMR) spectroscopy was adopted to investigate the chelating mechanism between alkanolamines and metal ions. The results showed that the alkanolamines increased the elemental concentrations of [Ca], [Al], [Fe] and [Si] in the liquid phase of SS through chelating and promoted the dissolution of the mineral phase of C 3 S, C 2 S and C 4 AF in SS. Among the different alkanolamines, DEIPA was present in the liquid phase for the longest time and possessed a more sustained ability to chelating metal ions. The result also shows that alkanolamines can chelate the Ca2+, Al3+ and Fe3+ in solution. The chelating ability of tertiary alkanolamines were stronger than the secondary alkanolamine. And the alkanolamine with asymmetric molecular structure have stronger chelating ability than those with symmetric molecular structure. Tertiary alkanolamines form ternary five-ring structure with metal ion through nitrogen and oxygen atoms. • Alkanolamines promoted the dissolution of the mineral phase in steel slag. • DEIPA possessed a more sustained ability to chelating metal ions. • Alkanolamine with asymmetric molecular structure have stronger chelating ability. • Ternary five-ring structure formed between the ternary alkanolamine and metal ion. [ABSTRACT FROM AUTHOR]

The use of new polymeric building block is one of the important routes to extend the layer-by-layer (LbL) assembly technique to fabricate novel nanofiltration (NF) membrane. In this work, the low cost sulfonated cyclohexanone–formaldehyde (SCF) condensation polymer is used as anionic building blocks to prepare a novel positively charged nanofiltration membrane by LbL self-assembly technique. The LbL assembly process was investigated by XRD, FTIR, SEM and AFM measurements. The separation performance of cationic ions and dyes was evaluated by pressure-driven nanofiltration tests. It is found that the multilayer surfaces exhibited periodic variations in positive charges. And the prepared membrane showed an effective rejection of both cationic ions and dyes. The multilayer membrane of 4.5 bilayers exhibited rejections of 92.8% and 90.6% to Ni 2 + and Ca 2 + , along with flux of 40.8 and 44.9 L/(m 2 ·h·MPa) and pure water flux of 49.3 L/(m 2 ·h·MPa), respectively. Simultaneously, this membrane also showed rejection of 93.7% and 90.8% to RdB and EbT, along with flux of 24.3 and 20.5 L/(m 2 ·h·MPa), respectively. Moreover, the long-term performance stability of the membrane was improved through cross-linking the multilayer membrane. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous SiO 2 @PDMS protective layer has been constructed on the top of FAS-modified ceramic membranes. • The presence of cavities within the layer helps to reduce the vapor transport resistance through membranes. • The layer shows robust hydrophobicity. • The desalination stability of FAS-modified ceramic membranes has been significantly enhanced. The production of freshwater by desalination has great significance. Membrane distillation (MD) is considered as a promising technique for desalination. As a popular candidate for MD desalination, FAS (fluoroalkylsilane)-modified ceramic membrane suffers from insufficient stability, such as membrane wetting and decline of salt rejection during long-term operation, because of the degradation of hydrophobicity. In the present work, a novel strategy is proposed to enhance the long-term desalination stability of FAS-modified cordierite ceramic membranes by constructing a porous SiO 2 @PDMS (polydimethylsiloxane) protective layer on their tops to obtain a robust hydrophobic property. The results show that such a layer can be successfully fabricated by a two-step spraying method with hydrosoluble NaCl particles as templates. The incorporation of SiO 2 nanoparticles into PDMS generates a loose and porous structure in the layer and renders an enhanced hydrophobicity. At a SiO 2 /PDMS mass ratio of 0.30, the membranes exhibit a notable resistance to both mechanical abrasion and chemical corrosion. The dissolution of NaCl templates leaves behind cavities within the layer, which prevents the SiO 2 /PDMS species from blocking the membrane pores and thereby helps to reduce the vapor transport resistance. These membranes are highly stable upon long-term desalination (>300 h) and can preserve a stable water flux of 8.10 kg/m2h and a salt rejection close to 100% under the following conditions: a feed temperature of 80 °C, a NaCl concentration of 3.5 wt% and a feed flow rate of 300 mL/min. The SiO 2 @PDMS layer is responsible for the outstanding desalination stability since it prevents membrane wetting by reducing the direct contact of the reflux feed solution to the underlying cordierite ceramic membranes. [ABSTRACT FROM AUTHOR]

[Display omitted] • PU-UF MPCMs with binary esters as core and double-layered shell are synthesized. • The performance of PU-UF MPCMs in cement composites is investigated. • PU-UF MPCMs exhibit potential for enhancing energy savings and thermal comfort of buildings. In this study, novel microencapsulated phase change materials (PU-UF MPCMs) with methyl palmitate and methyl stearate as core and double-layered shell structure were designed for building energy conservations. Their composition, microstructure and thermal performances were determined by techniques including optical microscope (OM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Effects of PU-UF MPCMs on the thermal performance of cementitious composites were also investigated. Results show that PU-UF MPCMs with spherical shape and double-layered shell structure were successfully prepared. DSC results show that the latent heat of PU-UF MPCMs is 137.6 J/g and the melt temperature of cores in PU-UF MPCMs is 24.2 °C. 5%-15% PU-UF MPCMs addition increases the thermal storage capacity of cement pastes through a phase transition process, among which 15% PU-UF MPCMs leads to the highest thermal storage capacity. Those results suggest that PU-UF MPCMs exhibit the potential for enhancing energy savings and thermal comfort of buildings. [ABSTRACT FROM AUTHOR]

Balancing the NH 3 selective catalytic reduction (NH 3 -SCR) and catalytic oxidation performance is difficult but necessary for the synergistic elimination of NO x and chlorine-containing volatile organic compounds (CVOCs). We herein unveiled that electronic structure tailoring of the applied catalyst was an efficient pathway for balancing the catalytic behaviors in the NH 3 -SCR of NO and chlorobenzene catalytic oxidation (CBCO). Specifically, environmentally friendly CeO 2 substituted by low valent Al3+ exhibited better NH 3 -SCR of NO and CBCO activity in comparison with the CeO 2 sample without doping. Detailed characterizations and theoretical simulations revealed that the strong dopant-oxide pairs in the CeO 2 with Al3+ doping significantly tailored the electronic structure of O 2p states, enhancing the amount of Lewis acid sites and promoting the ability of lattice oxygen to act as an oxidizing agent, thereby leading to superior performance for the synergistic elimination of NO/CB. The counterpart with substitution of high valent Ta5+ showed an opposite trend, due to that Ta5+ donated more electrons to the coordination oxygen than Ce4+ inhibiting lattice oxygen separating from the surface of the catalyst, and Lewis base sites were formed. [Display omitted] • Electronic structure tailoring could be achieved via metal doping. • Al-doped CeO 2 tailored the electronic structure of O 2p states. • Lewis acid sites and lattice oxygen ability of Al-doped CeO 2 was enhanced. • Al-doped CeO 2 exhibited better NH 3 -SCR of NO and chlorobenzene catalytic oxidation activity. [ABSTRACT FROM AUTHOR]

Abstract: In this work, aragonite CaCO3 with complex morphologies was synthesized through homogeneous precipitation, in which calcium acetate and urea precipitated at 90°C in the presence of PVP. The effect of the concentration of urea and PVP on the CaCO3 crystalline was investigated. The morphology and structure of the CaCO3 particles were characterized by SEM, XRD, and FT-IR. It was found that the concentrations of urea and PVP in the mixed aqueous solution were turned out to be important parameters for the morphology of CaCO3 particles. All CaCO3 particles were mainly aragonite with morphology from bundles of rods, bouquet-like and dumbbell-like. And there was no phase transition under the research conditions. Moreover, the possible process for the formation of the morphology of aragonite was discussed. [Copyright &y& Elsevier]

• The accelerated self-healing of cracks in cement mortars containing TEA was investigated. • The size of portlandite are greatly decreased by the addition of TEA in cement mortars. • The accelerated formation of CaCO 3 is responsible for the accelerated crack healing in TEA containing mortars. Mechanism of accelerated self-healing behavior of cement mortars incorporating triethanolamine (TEA) was investigated. The crack width in cement mortar specimens and the healing efficiency of cracks during immersion in water were quantitatively measured according to the Poiseuille's law. To reveal the working mechanism of TEA in the accelerated self-healing of cracks in cement mortars during water immersion, multi-techniques including X-ray diffraction (XRD), thermogravimetry (TG), nitrogen sorption isotherm and scanning electron microscopy (SEM) were employed to determine the changes in composition and microstructure of hydration products in the presence of TEA before and after water immersion. In addition, carbonation process of synthesized CH powder was studied. Results show that self-healing of the cracks in cement mortars during water penetration is a result of the continuous formation of CaCO 3 on the fractured surfaces. TEA addition visibly enhances the self-healing performance of cement mortars and a higher dosage of TEA leads to a higher self-healing efficiency, because of the accelerated precipitation of CaCO 3 on the fractured surface in mortars. TEA addition results in great morphological changes and increasing the surface area of portlandite as the second major hydration product of cement. Thus the carbonation process is notably accelerated in the mortars containing TEA. Moreover, the TEA-Ca2+complexation may promote the decalcification of C-S-H. [ABSTRACT FROM AUTHOR]

With the rapid development of the construction industry, it is necessary to synthesize environment-friendly functional polymers, especially when developing "green" construction industry types. Herein a novel solid-state polycarboxylate superplasticizer (PCE) with low energy-consumption was designed and synthesized. In industrial application, solid-state PCE has exhibited better cement paste fluidity and concrete slump compared to liquid-state PCE. A life cycle assessment (LCA) of the PCE synthesis, the packaging materials used, and the transportation of the PCE were conducted based on the ReCiPe method. The results indicated that liquid-state PCE has a far greater environmental impact at >60% than solid-state PCE, which is less significant at <40%. The inventory data that are associated with the production of the new polymer are disclosed for the first time to enrich the related database in this field. This study demonstrates the optimization of the state and synthesis technique of a functional polymer, improving the performance and lowering the environmental impacts involved in producing the polymer, while reducing the risks to human health and protecting the ecosystem at the same time. [Display omitted] • A green chemistry and green technical processes for PCE are established. • Solvent-free system is a potential technique to achieve sustainability goals. • Low temperature synthesis of solid-state PCE show better application performance. • Normalization done to recommend best process options and lowest environmental impact. • A cradle-to-gate LCA of the synthesized PCE has been carried out. [ABSTRACT FROM AUTHOR]

• Amine molecular structures play a key role on the aggregation behaviors in C–S–H gel. • Penetration depth and residence time reflect bonding property and molecular mobility. • High concentrated hydroxyl groups in TEAs form strong hydrogen bonds in a remarkable stability. • Breakage of hydrogen bonds in water leads to the failure of C–S–H gel and its nanocomposites. Determining the amine molecules behaviors in the nanochannels enables the interpretation of the microstructure and macroscopic properties of amines modified cement based materials. In this study, quantitative analysis were performed on the behaviors of amine molecules (TEPAs, PAMs and TEAs) by molecular dynamics (MD) simulation in the nanochannels of C–S–H gel. According to the interaction of amine molecules with C–S–H gel substrates or water molecules, research works revealed that amine molecules with special spatial structures illustrate different aggregation behaviors. TEPAs with linear structures tend to aggregate in a regular sequence at the center of the C–S–H gel nanochannels. Instead, PAMs and TEAs with branched structures prefer dispersing in the aqueous solution in the C–S–H gel nanochannels. Such different aggregation behaviors allow amine molecules to have various penetration depth and residence time in the interfacial regions. It was found that oxygen atoms and active hydrogen atoms in PAMs and TEAs can form stable interaction with calcium ions and oxygen atoms of C–S–H gel substrates, respectively. The oxygen involved bonds are stronger than nitrogen involved ones for all the molecules due to great electronegativity. There is no formation of hydrogen bonds in TEPAs, but polar atoms in PAMs and TEAs can interact through hydrogen bonding. Moreover, TEPAs cannot form strong hydrogen bonding with water molecules due to their aggregation behavior, whereas PAMs and TEAs formed strong hydrogen bonding with surrounding water molecules. In addition, formation of more hydrogen bonding with amine molecules leads to a lower diffusion coefficient of water molecules. Breakage of hydrogen bonds of water molecules causes the final failure of C–S–H/amine molecules nanocomposites subjected to tensile loads. [ABSTRACT FROM AUTHOR]

The application of self-healing property to cement-based materials promoted a long-term service time in engineering. In this study, dimethyl thio-toluene diamine (DMTDA) microcapsules were synthesized successfully through melting-dispersion-condensation techniques, and enabled crack closure thus recovering the mechanical property. The as-fabricated DMTDA microcapsules showed a core-shell structure and well-dispersed properties with a tailorable core fraction and diameter, (e.g., a diameter of 312.7 ± 97.6 μm and a shell thickness of 15.2 ± 2.6 μm under agitation rate of 300 RPM). It was found that DMTDA microcapsules had a high core fraction and good thermal stability. The introduction of microcapsules decreased the flowability of cement paste but remained integral structures during the mechanical agitation. The increase of microcapsule concentrations led to a significant drop in porosity but a slight decrease in compressive strength of cement paste. Most importantly, the addition of DMTDA microcapsules and isocyanates microcapsules in the cement paste could repair the early hydration cracks with a size less than 100 μm, thereafter achieving a satisfying recovery of the compressive strength. [ABSTRACT FROM AUTHOR]

Mn-based catalysts are expected to be applied for removing NO x due to its excellent low-temperature activity. However, the practical use of these catalysts is extremely restricted with the co-poisoning of alkali metal and SO 2 in the flue gas. Here the MnO 2 /TiO 2 catalyst was employed to elucidate the co-poisoning mechanisms of K and SO 2 for the low temperature selective catalytic reduction (SCR) of NO. The physicochemical properties of catalysts under different toxicity conditions were studied by experiments. The adsorption of NH 3 , SO 2 , NO, and K on active component (MnO 2) and support (TiO 2) was studied by density functional theory. This work unravels a promotion effect of support on the alkali and sulfur resistance. The SO 2 &K co-poisoning catalyst had higher SCR activity than the SO 2 -poisoned and K-poisoned catalyst alone. For a single toxic condition: (1) SO 2 was preferentially bonded with the terminated O site of MnO 2 inhibiting the dehydrogenation of NH 3 and redox cycle. (2) The presence of Lewis base (K atom) on the catalyst decreased the binding energy of a Lewis base (NH 3) and hindered the adsorption of NH 3. For the synergistic effect of K and SO 2 , the majority of K adsorbed on the support (TiO 2) lead to increase alkalinity, which could promote the adsorption of SO 2 on the TiO 2 and reduce the toxicity of the active component (MnO 2). [Display omitted] • The SO 2 &K co-poisoning MnO 2/ TiO 2 catalyst has higher SCR activity. • The synergistic poisoning mechanism of SO 2 and K+ over MnO 2/ TiO 2 is revealed. • The support promotion effect on the resistance to the co-poisoning is illustrated. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2) is widely used in membrane separation because of its outstanding chemical and structural stability. In this study, MoS 2 nanosheets were in-situ grown on a tubular ceramic substrate through one-step hydrothermal synthesis with the graphene quantum dots (GQDs) incorporated in the precursor solution. The growth of the MoS 2 nanosheets was inhibited due to the combination with GQDs through the Mo-O bond. Therefore, the number of transport channels in the MoS 2 /GQDs composite membrane were increased to improve the permeability. The results indicated that the MoS 2 /GQDs composite membrane have excellent permeances for both the aqueous solution and organic solvent. Moreover, the MoS 2 /GQDs composite membrane can be continuously operated in cross-flow filtration device for 100 h because the in-situ hydrothermal method has greatly improved the stability of membrane. The results indicated that the MoS 2 /GQDs composite membrane exhibits great potential in nanofiltration. [Display omitted] • MoS 2 /GQDs composite membrane was prepared by in-situ hydrothermal method. • The structure of MoS 2 was regulated by adding GQDs. • MoS 2 /GQDs composite membrane achieves high water and methanol flux. [ABSTRACT FROM AUTHOR]

• A novel comb-structural PMA-g-PVA was synthesized and used as a promising dispersant. • Functionalization of PVA can greatly enhance its thermal stability and dispersibility. • Good plasticizing and retention capacities were shown for wide potential applications. • Established a guiding equation for regulating the side chain length of comb polymer. • Innovative design on molecular topological transformation helped PVA performances. A novel dispersant for cement slurries or other suspensions was synthesized by graft copolymerization between maleic anhydride (MA) and end-functionalized poly(vinyl alcohol) (PVA) to produce comb polymer, i.e. PMA-g-PVA. The chemical structure was characterized by 1H Nuclear Magnetic Resonance (1H NMR), Infrared Spectroscopy (IR), Gel Permeation Chromatography (GPC), alcoholysis degree and element analysis. This functionalization of PVA can significantly enhance its thermal stability and dispersibility. The evaluations of PMA-g-PVA and PVA in cement slurries were comparatively discussed in detail. The results showed that PMA-g-PVA performed well in dispersing and dispersing retention capacities, presenting more excellent fluidities of cement slurry (~200 mm) with maintenance of >85% within 3 h, due to its strong ability of breaking large flocculated structures of cement particles to fine size and homogeneous dispersion. This new type of functionalized PVA may be introduced as a promising candidate for the rheology modifying superplasticizer in slurry or colloid materials. [ABSTRACT FROM AUTHOR]

Collaborative disposal of sludge has been applied extensively in cement industry kilns, but the influence of organic components in sludge on the selective non-catalytic reduction (SNCR) denitrification is still in highly demanding. This paper focuses the influence of ethanol, n-octane, benzene, and acetone on the SNCR denitrification, and the influence of ethanol are analyzed on SNCR denitrification under different flue gas condition. The result showed that the presence of organic components reduces the reaction temperature of SNCR. When the temperature of SNCR reaction is at 750 ~ 800 ℃, the denitrification rate of four organic components is ethanol > benzene > n-octane > acetone. The optimum denitrification rate on SNCR can reach as high as 90.377% when the reaction condition is the NH 3 /NO is 1; the ethanol concentration is 1000 ppm; O 2 concentration is 2%; and temperature is 750 ℃. The presence of carbon dioxide inhibits the denitrification reaction. With the increase of temperature, the influence of SO 2 on the denitrification reaction first increases and then decreases. In this paper, the influence of organic components in sludge on SNCR denitrification will be analyzed, which provides a theoretical basis for the selection of sludge dosing method for cement kiln collaborative disposal., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, two types of liquid alkali-free accelerators were prepared by aluminum sulfate (AF 1 ) and aluminum mud wastes (AF 2 ), and the life cycle assessment (LCA) in the preparation of AF 1 and AF 2 was compared. The LCA was considered from cradle to gate including raw materials used, transportation, and accelerator preparation based on the method ReCiPe2016. The results indicated that AF 1 had a higher environmental impact in all midpoint impact categories and endpoint indicators than that of AF 2 , and AF 2 reduced 43.59% emission of CO 2 , 59.09% emission of SO 2 , 71% consumption of mineral resources, and 46.67% consumption of fossil resources than that of AF 1 respectively. As an environment-friendly accelerator, AF 2 had a better application performance than traditional accelerator AF 1. When the dosage of accelerators was 7%, the initial setting times of cement pastes containing AF 1 and AF 2 were 4 min 57 s and 4 min 04 s respectively, the final setting times of cement pastes containing AF 1 and AF 2 were 11 min 49 s and 9 min 53 s respectively, and the compressive strengths at 1 d of mortars containing AF 1 and AF 2 were 7.35 MPa and 8.33 MPa respectively. This study aims to provide technical feasibility and environmental impact assessment for exploring new avenues of preparing environment-friendly liquid alkali-free accelerators with aluminum mud solid wastes. It has great potential in reducing carbon and pollution emissions and has a greater competitive advantage due to great application performance., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Contamination of leafy vegetables grown in heavy metal(loid)-polluted mining areas pose serious health risks. This study aimed to explore the heavy metal(loid) contamination of leafy vegetables near two mining areas, by collecting samples from 14 different leafy vegetable species in Yunnan Province, China. The lead (Pb), cadmium (Cd), arsenic (As), and copper (Cu) contents of the samples were determined, and risks to human health were calculated using the hazard quotient and hazard index (HI). Moreover, Malabar spinach was identified as a leafy vegetable that exhibits low accumulation of heavy metal(loid)s. The accumulation capacity of different Malabar spinach varieties was verified, and a Cd soil safety threshold was determined using a pot experiment. Overall, Pb and Cd were the main soil and vegetable contaminants found in both study sites. The HI values for all leafy vegetables, apart from Malabar spinach, were greater than 1, indicating the presence of risks to human health; moreover, the health risks were greater for children than adults. The Malabar spinach pot experiment results showed that only some Cd forms exceeded China's maximum permissible standards. Furthermore, Malabar spinach varieties A (instant Malabar spinach), C (extra-large leaf green vine Malabar spinach), and F (large leaf Malabar spinach) displayed the lowest Cd accumulation. We calculated Cd total and bioavailable soil safety thresholds of 4.75 and 0.77 mg kg -1 , respectively. However, further research is required to validate soil heavy metal safety thresholds for different vegetables. Ultimately, the heavy metal(loid) contamination of leafy vegetables described here was more serious than anticipated. Finally, the results of this study can inform residents living near these mining areas of a low-risk leafy vegetable, which will reduce the harm caused by heavy metal(loid) contamination in the area., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Flame retardant modification of leaf fibers was carried out to solve the technical problem of poor fire resistance of plant fibers and improve the utilization rate of urban fallen leaves in building materials. The modification scheme adopts three flame retardants, i.e., ammonium polyphosphate (APP), magnesium hydroxide (MH), and aluminum hydroxide (ATH), and two covering layers, i.e., pure acrylic polymer lotion and water glass (Na 2 O · nSiO 2 ) solution. The modified leaf fiber's combustion behavior and pyrolysis properties were tested and analyzed. The physical and mechanical characteristics, as well as the thermal insulation qualities, of leaf fiber cement-based composites (LFCC) were studied at high temperatures. The findings revealed that the three flame retardants had an effect on the chemical structure of leaf fibers. In comparison to leaf fibers without flame-retardant modification, flame-retardant-modified leaf fibers have a much greater thermal stability. and its LOI is greater than 27.0%, which is a fire-retardant material. Except for the sample with water glass as the modified cover layer, at high temperatures, the composite flame-retardant fiber LFCC's mass-loss rate is lower compared with fibers without flame-retardant modification or fibers modified with only one kind of flame-retardant. In the composite flame-retardant modified fiber LFCC, the samples with better strength at high temperature are those with ATH replacing 30% and 50% MH. The thermal conductivity of LFCC is negatively correlated with the range of temperature change., Competing Interests: The authors declare no conflict of interest., (© 2022 The Author(s).)

Sulphoaluminate cement has the advantage of low-temperature application performance, but its hydration mechanism at low temperatures is not yet clear. Anhydrous calcium sulfoaluminate (C 4 A 3 S) is the main mineral in the composition of sulfoaluminate cement clinkers. In this paper, C 4 A 3 S mixed with gypsum (CaSO 4 ∙2H 2 O) to form a C 4 A 3 S-CSH 2 cement system; X-ray diffraction (XRD), thermogravimetric analysis (TG-DTG), scanning electron microscopy (SEM) and mercury intrusion analysis (MIP) to clarify the effect of temperatures on the hydration properties of C 4 A 3 S-CSH 2 cement system. The results showed that hydration of the C 4 A 3 S-CSH 2 cement system could carry on at low temperatures, even at -15 °C. The main hydration product was ettringite. Low temperatures did not change the types of the hydration products, but the low temperature of 0 °C was more favorable for the formation of ettringite. The early hydration of the C 4 A 3 S-CSH 2 cement system was inhibited by the decrease in temperature. However, hydration of the cement at 0 °C continued at a high rate after one day. Morphologies of the ettringite for the C 4 A 3 S-CSH 2 cement system at -15 °C were needle-like structures, while they were of columnar structure at 0 °C. The compressive strength of samples at 0 °C reached 82 MPa, which is significantly higher than that at 20 °C.

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO 2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO 2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO 2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 °C, and NO decomposition rate could approach 100% at high temperatures above 750 °C. Structure analysis indicates that the prepared Cu-Al/SiO 2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet-visible spectrophotometry (UV-Vis) results of the denitrification product show that the Cu-Al/SiO 2 material mainly decomposed to Cu 2 O and Si 2 O, and the CuO decomposed to Cu 2 O and O 2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO 2 porous material.

A series of MCM-41 molecular sieves with different molar ratio of template to silicon were synthesized through hydrothermal synthesis method by using cetyltrimethylammonium bromide (CTAB) as the template, diatomite as the silicon source. By using impregnation method, the Mn-Ce/MCM-41 SCR molecular sieve-based catalysts were prepared. The results observed that when the molar ratio of template to silicon was 0.2:1, the MCM-41 as catalyst carrier has the highest surface area and largest pore volume, it also presented typically ordered hexagonal arrays of uniform channels. The denitration catalytic material based on this carrier has a high number of Lewis acidic sites, and the denitration efficiency can reach more than 93%.

Objective: To study the effect of radionuclide lymphoscintigraphy, a new method of localization diagnosis of chyluria., Methods: Radionuclide lymphoscintigraphy was used to examine 34 patients with chyluria and the results of radionuclide lymphoscintigraphy was compared with those of cystoscopy and lymphangiography., Results: Among the 34 patients 85.3% of unilateral localization diagnosis by radionuclide lymphoscintigraphy was coincident with that by cystoscopy. The positive rate of bilateral localization diagnosis was higher than that by cystoscopy., Conclusion: A less invasive technique, radionuclide lymphoscintigraphy can be used as a new option for the localization diagnosis of chyluria.