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Self-ignition coal gangue (SCG) used as one of precursors to fabricate autoclaved aerated concrete (AAC). Aiming at studying water absorptivity and frost resistance performance of SCG-based AAC (SCGAAC), three-period water absorption tests and freeze-thaw tests were carried out and the corresponding results were recorded and analyzed. In order to modify the water absorptivity of SCGAAC, foam stabilizer was applied to adjust pore structure while calcium stearate was expected to change hydrophilic feature of SCG. It was demonstrated that the compressive strength of SCGAAC containing foam stabilizer or calcium stearate declined at different levels. For water absorption, foam stabilizer failed to decrease the water content and even increased water absorption rates. Calcium stearate controlled water absorption rate successfully although the ultimate water content hardly reduced. All of the SCGAAC samples exhibited intact appearance after 50 freeze-thaw cycles and showed excellent frost resistance performance. Three models were proposed to predict water absorptivity and frost resistance performance of SCGAAC and the corresponding prediction results matched test resulted well.

Because of its priority to remove anions, nano-layered double hydroxide (LDH) was incorporated to improve the sulfate attack corrosion resistance of cement-based materials. Herein, the synthesis of high-efficiency LDH for removal of SO 4 2 − {\text{SO}}_{4}^{2-} is necessary. In this study, LDH with different Mg/Al ratios was synthesized under different dual solvent systems (water and ethylene glycol/ethanol/tetrapropylammonium hydroxide). Based on the adsorption experimental results, the LDH synthesized with n(Mg:Al) = 2:1 under water and ethanol solvent systems (ET2.0) exhibits the best adsorption capacity. The d (003) of LDH synthesized with n(Mg:Al) = 2:1 under different dual solvent systems are 0.7844, 0.7830, and 0.7946 nm, respectively. Three LDH belong to LDH- NO 3 − {\text{NO}}_{3}^{-} . The results indicated that their surface charges show obvious difference synthesized under different dual solvent systems, which leads to differences in adsorption performance. The adsorption experimental results show that ET2.0 followed pseudo second-order kinetics and Langmuir model. The ET2.0 removed SO 4 2 − {\text{SO}}_{4}^{2-} through anion substitution and electrostatic interaction and exhibited excellent adsorption rate with the maximum adsorption capacity of 95.639 mg/g. The effects of pore solution anion (OH−, Cl−, and CO 3 2 − {\text{CO}}_{3}^{2-} ) on the removal of SO 4 2 − {\text{SO}}_{4}^{2-} by the ET2.0 are limited.

In this study, Ni nanoparticles supported on renewable porous carbon were prepared using hydrochar as a carbon precursor via in situ formation and self-reduction. The structure properties of the prepared nanocatalysts were characterized by multiple techniques, including XRD, SEM, and HR-TEM, and the dry reforming of methane (DRM) performance of the nanocatalysts in terms of conversion efficiency and reactivity stability was evaluated. The results revealed that the Ni2+ was uniformly anchored on the surface of the hydrochar, and subsequently the Ni nanoparticles were well dispersed in the composite with a diameter of less than 8 nm and had a narrow particle size distribution at a temperature lower than 800 &deg, C. With an increased temperature from 800 to 900 &deg, C, the significant sintering and agglomeration of nickel particles and the transformation from amorphous carbon to graphitic structure were observed in the composite. The nanocatalysts prepared at a temperature of 700 &deg, C (Ni@C-700) and 800 &deg, C (Ni@C-800) exhibited a high reforming conversion rate and catalytic stability of CH4 by CO2 (around 52% for Ni@C-700 and 70% for Ni@C-800 after 800 min of run-time, respectively). As for the composite obtained at 900 (Ni@C-900), the highly graphitic degree was coupled with the significantly increased nickel particle size, and this resulted in a remarkably decreased conversion efficiency. The present study offers a valuable application of the hydrochar and a facile and green approach to prepare highly active and cost-efficient Ni nanoparticles on porous carbons towards the dry reforming of methane.

It is of great significance to separate hazardous methyl tert-butyl ether (MTBE) from water in terms of environmental protection and human health. In the present work, &alpha, Al2O3-suppotred silica membranes were prepared by the sol-gel and dip-coating technique. Two fluorinated alkylsilanes (1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) and trifluoropropyltriethoxysilane (TFPTES)) and two non-fluorinated alkylsilanes (octyltriethoxysilane (OTES) and propyltriethoxysilane (PTES)) were adopted to silylate the silica membrane by the post-grafting method which is used for the separation of MTBE from water by pervaporation. The results show that silylation enhances the hydrophobicity of silica membranes. The silylated silica membranes are selective towards MTBE, and the MTBE/water separation factor varies with grafting agents in the order: PFOTES &gt, TFPTES &gt, OTES &gt, PTES. Membranes silylated with fluorinated carbon chains seem to be more selective towards MTBE than those with non-fluorinated carbon chains. The total flux is proportional to the pore volume of silica membranes, which depends on grafting agents in the order: PTES &gt, PFOTES &gt, TFPTES. Considering both total flux and selectivity, the PFOTES-SiO2 membrane is most effective in separation, with a MTBE/water separation factor of 24.6 and a total flux of 0.35 kg m&minus, 2 h&minus, 1 under a MTBE concentration of 3.0% and a feed temperature of 30 &deg, C.

This paper aims at investigating the long-term mechanical strengths and drying shrinkage, as well as pore structure of cement mortars with hydroxyethyl methyl cellulose (HEMC). The results show that the 3-d flexural strength and compressive strength of cement mortars tend to decrease with the HEMC content increasing. At 28 d to 360 d, the strengths keep decreasing with the HEMC content increasing at 0–1%, and then increase from the minimum value with the HEMC content increasing at 1–3%, still being much lower than those of the control (0% HEMC). Throughout the curing age, both the tensile bond strength and the drying shrinkage value gradually increase with the HEMC content, to be nearly twice at 3% HEMC than those of the control. HEMC significantly delays the 3-d hydration of cement pastes, but has negligible retardation effect on the hydration after 28 d, to bring the similar late hydration degree of cement pastes with HEMC or not. With the HEMC content increasing in the range of 0–1%, incorporating HEMC brings the sharp increase of macro pores, large capillary pores and porosity, and decreases the interconnected pores to bring many more closed pores. Further increasing the HEMC content to 3%, macro pores and porosity decrease, large capillary pores slightly increase and interconnected pores have a negligible change. Obviously, the understanding on the performance development of cement mortars with HEMC is conducive to the better application of HEMC in dry-mix mortars to meet different requirements.

It is always a challenge to prepare multifunctional epoxy resins (EP) composites with excellent flame retardance, mechanical property and high transparency. In this work, a reactive flame-retardant (BDO) was synthesized from DOPO, 3,5-diamino-triazolz and thiophene-2-formaldehyde, and taken to prepare EP/BDO composites. Surprisingly, benefitting from the synergy of efficient flame retardant unit (DOPO structure), catalytic curing unit (triazole structure) and optical functional structure (thiophene-2-formaldehyde), the EP composites with excellent comprehensive performance was obtained. In detailed, after adding only 5 wt% BDO, the EP composites passed the UL-94 V-0 level, and the limiting oxygen index was increased to 33% from 22.5% of neat EP. At the same time, EP/BDO-5 showed obvious heat suppression and smoke suppression effects. Besides, EP/BDO-5 presented excellent mechanical strength, that the tensile strength and bending strength were increased by 25% and 30% compared with neat EP. Moreover, EP/BDO composites maintained the same good light transmittance as neat EP, and also presented enhanced Tg and dielectric property. In addition, the dual phase flame-retardant mechanism was revealed through systematically analyzing residues after combustion and the gaseous phase products of flame retardant. The above results indicated EP/BDO composites with excellent comprehensive performance possessed a great potential application in high-performance composites fields.

As one of the special curing regimes, low temperature environment is considered to be crucial to the development of various properties of cementitious materials. This work focuses on the long-term performance and hydration of cement mortars with hydroxyethyl methyl cellulose (HEMC) cured at 5℃. The results show that the mid-late flexural and compressive strengths decrease with the HEMC content increasing, to get the lowest values at 1% HEMC. Afterwards, with the HEMC content increasing to 3%, the above strengths gradually increase, still being lower than those of the control. The tensile bond strength increases with the HEMC content increasing, to reach the maximum value at 0.3–0.5% HEMC, and then decreases with the HEMC content increasing to 3%, which is still much higher than that of the control. The drying shrinkage presents a significant increase with the HEMC content increasing. Moreover, HEMC significantly retards the early hydration of cement pastes. But the final hydration degree of cement pastes with HEMC tends to be close to that of the control. In addition, macro pores and the total porosity increase with the HEMC content increasing at 0–1%, and then decrease to some extent at 3% HEMC. Obviously, due to its better long-term properties at 5℃, the cement mortars with HEMC are still applicable at low temperatures.

Municipal solid waste incineration (MSWI) fly ash contains chlorides, heavy metals, and organic pollutants, which requires appropriate disposal to eliminate this risk. In this study, the effects of agents on heavy metals removal from MSWI fly ash by electric field-enhanced washing were systematically studied. The results show that when these fly ashes were washed at a current density of 35 mA/cm2, polarity switching frequency of 40 Hz, Ethylenediaminetetraacetic acid (EDTA) dosage of 0.5 mol/L, and a pH of 2 for 4 h, almost all of the Cd and Ni could be were removed, with a removal efficiency of 100.00% and 99.59%, respectively. Meanwhile, it also shows a significant effect on Cu and Zn, with a removal efficiency higher than 85%. After washing, the results of the sequential extraction procedure showed that the residual forms of Pb, Cu, Zn, Cd, Ni, and As increased obviously. According to GB5085.3-2007, the toxicity of the treated MSWI fly ash were below their thresholds of 5 and 1 mg/L for Pb and Cd, respectively. Thus, a novel technology for heavy metals removal from MSWI fly ash is proposed.

To explore the mechanism to water retention of cellulose ether (CE) in calcium sulfoaluminate (CSA) cement-based materials, three cellulose ethers (CEs) with similar viscosity but different substitution groups were selected in this paper, namely hydroxyethyl cellulose (HEC) and hydroxyethyl methyl cellulose (HEMC) with high and low degree of substitution (DS). Water retention of CE modified CSA cement mortar with different CE dosages was characterized by filter paper method. The water state and content in CE modified CSA cement paste were determined by low field nuclear magnetic resonance (1H NMR). The adsorption and dispersion characteristics of CE in CSA cement paste were analyzed by measuring the organic carbon content in the pore solution. Combined with the measurement of dynamic viscosity and surface tension of pore solution, the mechanism to water retention of CEs in CSA cement-based materials was comprehensively analyzed. The results show that the addition of CE can significantly improve the water retention of CSA cement mortar. At the same dosage, the water retention effect of HEMC is better than HEC, and DS has little effect on the water retention capacity of HEMC. The mechanism to water retention of HEC and HEMC added less than 0.1% dosage in system is governed by water sorption effect of CE. While more than 0.1% dosage, HEC and HEMC in CSA cement-based materials achieve water retention respectively through the adsorption of CE on cement and the formation of three-dimensional polymer network in pore solution.

Aims The mechanisms of atrial fibrillation (AF) in diabetes mellitus (DM) involve a complex interplay between increased oxidative stress, mitochondrial dysfunction and atrial remodeling. In this study, we examined the effects of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation on mitochondrial oxidative stress and atrial remodeling in a rabbit model of diabetes mellitus (DM). Main methods Healthy rabbits were selected and randomly divided into control, diabetic and apocynin administration group. Parameters of echocardiography, atrial electrophysiology, oxidative stress and mitochondrial function were compared between the different groups. Key findings Compared to the control group, the DM group showed higher activity of NADPH oxidase, increased oxidative stress, larger left atrial diameter, a reduction in atrial mean conduction velocity. These findings were associated with increased interstitial fibrosis of the atria and higher atrial fibrillation (AF) inducibility. Moreover, atrial ultrastructure and mitochondrial function such as the mitochondrial respiratory control rate (RCR) were impaired. NADPH oxidase inhibition using the pharmacological agent apocynin improved these changes. Significance NADPH oxidase activity plays an important role in mitochondrial oxidative stress, which is associated with AF inducibility by promoting adverse atrial remodeling. The NADPH oxidase inhibitor apocynin can prevent these pathological changes and may be a potential drug for AF treatment.

Tetrodotoxin (TTX), a blocker of sodium channels, exists in the pufferfish, amphibians, and octopus, and originated in endosymbiont-vibrio. Researches have confirmed that TTX affected the action potential through the regulation of voltage-gated sodium channels (VGSCs) and the ingestion of TTX inhibits the nerve signal’s transmission, showing symptoms like rapid weakening and paralysis of the muscles. Recent research shows that TTX’s medical value as the analgesic is mainly focused. The comparison on efficacy among placebo, TTX, and opioids manifests that TTX is healthy and effective in treating neuropathic pain. Moreover, since the drug is synthesized by TTX, it can block specific neurons to alleviate the pain on different parts of the body accurately. Currently speaking, TTX has been widely used as medicine for the alleviation of cancer pain. The mechanism, symptoms, application, and treatment are thoroughly discussed to popularize TTX and pass the “torch” to the new generation because there is still a long way to go—the unsolved mysteries of TTX awaiting humans.