A green pregelatinized glutinous rice flour biological admixture was developed in this paper.The cement hydration process,hydration products,pore structure,and strength of mortar with different quantities of glutinous...A green pregelatinized glutinous rice flour biological admixture was developed in this paper.The cement hydration process,hydration products,pore structure,and strength of mortar with different quantities of glutinous rice flour(GRF),and the macroscopic changes in concrete cracking resistance testing were investigated.Simultaneously,a fast cracking resistance evaluation method based on graphic recognition was proposed.The results indicated that pregelatinized glutinous rice flour(T-GRF)delayed the dissolution rate of anhydrous cement during the induction period,shifting the main exothermic peak of hydration backward.The compressive strength developed slowly in 7-28 d age and returned to normal in 28-56 d.The compressive strength of T-GRF-0.6% modified mortar at 56 d age is less than 10% different from that of control group.The 3.0%T-GRF decreased the total porosity by 3%,and the average pore size decreased from 31.2 to 21.3 nm measured by MIP,indicating that T-GRF could inhibit harmful pores and densify concrete.The crack resistance coefficient of T-GRF modified concrete was obtained by image recognition method,and the GRF could decrease the length,width,and damaged area of cracks in the early age of concrete.展开更多
Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activ...Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activation deficiency(OAD),in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis,commonly attributed to inadequate intracellular calcium(Ca^(2+))release following sperm injection.Patient concerns:The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles,raising suspicion of an underlying oocyte activation defect.Diagnosis:Based on the repeated absence of fertilization post-ICSI and clinical history,a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.Interventions:Artificial oocyte activation(AOA)using the calcium ionophore A23187 was performed.After ICSI,unfertilized oocytes were exposed to the ionophore to induce Ca^(2+)influx,simulating physiological calcium oscillations essential for oocyte activation.The efficacy of intervention was evaluated through subsequent embryonic development,morphological grading,and chromosomal integrity.Outcomes:Following AOA treatment,successful oocyte activation occurred,resulting in the formation of high-grade embryos with normal developmental progression.Chromosomal analysis revealed no detectable abnormalities,indicating genomic stability.Lessons:Calcium ionophore–mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD.This case highlights the importance of individualized therapeutic strategies in assisted reproduction;however,further research is needed to refine protocols,validate broader clinical efficacy,and assess long-term safety,including potential epigenetic risks.展开更多
Peroxymonosulfate(PMS)-assisted visible-light photocatalytic degradation of organic pollutants using graphitic carbon nitride(g-C_(3)N_(4))presents a promising and environmentally friendly approach.However,pristine g-...Peroxymonosulfate(PMS)-assisted visible-light photocatalytic degradation of organic pollutants using graphitic carbon nitride(g-C_(3)N_(4))presents a promising and environmentally friendly approach.However,pristine g-C_(3)N_(4) suffers from limited visible-light absorption and low charge-carrier mobility.In this study,a phosphorus-doped tubular carbon nitride(5P-TCN)was synthesized via a precursor self-assembly method using phosphoric acid and melamine as raw materials,eliminating the need for organic solvents or templates.The 5P-TCN catalyst demonstrated enhanced visible-light absorption,improved charge transfer capability,and a 5.25-fold increase in specific surface area(31.092 m^(2)/g),which provided abundant active sites to efficiently drive the PMS-assisted photocatalytic reaction.The 5P-TCN/vis/PMS system exhibited exceptional degradation performance for organic pollutants across a broad pH range(3–9),achieving over 92%degradation of Rhodamine B(RhB)within 15 min.Notably,the system retained>98%RhB degradation efficiency after three consecutive operational cycles,demonstrating robust operational stability and reusability.Moreover,key parameters influencing,active radi-cals,degradation pathways,and potential mechanisms for RhB degradation were systematically investigated.This work proposes a green and cost-effective strategy for developing high-efficiency photocatalysts,while demon-strating the exceptional capability of a PMS-assisted photocatalytic system for rapid degradation of RhB.展开更多
Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on lo...Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on low-toxicity tetravalent platinum(Pt(Ⅳ))com plexes holds substantial research value.Herein,we discovered that coumarin derivatives exhibit inherent antitumor efficacy and significantly enhance superoxide anion radicals(·O_(2)^(-))generation in aqueous solutions under ultrasound(US)irradiation.Given that·O_(2)^(-)is known to mediate the reduction of Pt(Ⅳ)to divalent platinum(Pt(Ⅱ)),we engineered an US-responsive dual-drug nanoprodrug(P-cisPt(Ⅳ)@5-MOP).This nanoprodrug was prepared by covalently conjugating Pt(Ⅳ)and methoxy polyethylene glycol hydroxyl(m PEG-OH)to a poly(_(L)-glutamic acid)(PLG)carrier,followed by encapsulating coumarin derivatives.Under low-intensity US irradiation(1.5 W/cm^(2),1 MHz,10 min),P-cisPt(Ⅳ)@5-MOP achieved a Pt(Ⅳ)reduction rate of 91.4%.Furthermore,upon US exposure,its half-maximal inhibitory concentration(IC_(50))against 4T1 breast cancer cells decreased dramatically from 25.7μmol/L to 0.1μmol/L.Remarkably,this system combined with US therapy yielded a tumor inhibition rate of 90.9%,with 40%of tumor-bea ring mice achieving com plete eradication of tumors,while exhibiting low systemic toxicity.Collectively,this work not only identifies a novel sonosensitizer capable of generating·O_(2)^(-)but also develops a new class of ultrasound-activatable Pt(Ⅳ)nanoprodrug.展开更多
Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt ...Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.展开更多
Cells of the central nervous system(CNS)are privileged in lying behind the blood-brain barrier(BBB).Unlike blood vessels in other organs,CNS blood vessels are unique in displaying high electrical resistance and low pe...Cells of the central nervous system(CNS)are privileged in lying behind the blood-brain barrier(BBB).Unlike blood vessels in other organs,CNS blood vessels are unique in displaying high electrical resistance and low permeability.With this unique structure and function,the BBB prevents potentially harmful blood components such as serum proteins,inflammatory cytokines,and inflammatory leukocytes from entering the hallowed space of the CNS and wreaking havoc.In addition to these“tightness”properties,the BBB has an array of specialized transporters designed to import essential nutrients.展开更多
The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ...The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.展开更多
As the second most important solid waste produced by coal-fired power plants,the improper management of coal-fired slag has the potential to result in environmental pollution.It is therefore imperative that high-value...As the second most important solid waste produced by coal-fired power plants,the improper management of coal-fired slag has the potential to result in environmental pollution.It is therefore imperative that high-value utilization pathways for coal-fired slag should be developed.In this study,modified magnesium slag(MMS),produced by a magnesium smelter,was selected as the alkali activator.The activated silica-aluminum solid wastes,namely coal-fired slag(CFS)and mineral powder(MP),were employed as pozzolanic materials in the preparation of alkali-activated cementitious materials.The alkali-activated cementitious materials prepared with 50 wt%MMS,40 wt%CFS and 10 wt%MP exhibited favorable mechanical properties,with a compressive strength of 32.804 MPa in the paste sample cured for 28 d.Then,the activated silica-aluminum solid waste consisting of CFS-MP generated a significant amount of C-S(A)-H gels,AFt,and other products,which were observed to occupy the pore structure of the specimen.In addition,the secondary hydration reaction of CFS-MP occurs in high alkalinity environments,resulting in the formation of a mutually stimulated and promoted reaction system between CFS-MP and MMS,this will subsequently accelerate the hydrolysis reaction of MMS.It is important to emphasize that the amount of MMS in alkali-activated cementitious materials must be strictly regulated to avert the potential issue of incomplete depolymerization-repolymerization of active silica-aluminum solid waste containing CFS-MP.This in turn could have a deleterious impact on the late strength of the cementitious materials.The aim of this work is to improve the joint disposal of MMS,CFS and MP and thereby provide a scientific basis for the development of environmentally friendly and low-carbon modified magnesium slag alkali-activated coal-fired slag based cementitious materials for mine backfilling.展开更多
This paper studied the hydration and strength influence factors ofSteel Slag Cement (SSC), such as the quantity of steel slag and slagand the dosage of additive. The results show that: (a) In the processof hydration o...This paper studied the hydration and strength influence factors ofSteel Slag Cement (SSC), such as the quantity of steel slag and slagand the dosage of additive. The results show that: (a) In the processof hydration of SSC, steel slag and slag activate each other; (b)Waterglass's structure forms the preliminary skeleton of SSC, and thehydration products of SSC link or fill in the skeleton; (c) Sodium inWaterglass is the catalytic and its concentration does not change inthe process of hydration. (d) Structure of activation is asignificant factor to the property of SSC.展开更多
Lime pretreated phosphogypsum（PG） was calcined at 500 ℃ to produce anhydrate gypsum cement. Due to the slow hydration of anhydrate gypsum, additives, K2SO4 and hemihydrate gypsum were selected to accelerate the hyd...Lime pretreated phosphogypsum（PG） was calcined at 500 ℃ to produce anhydrate gypsum cement. Due to the slow hydration of anhydrate gypsum, additives, K2SO4 and hemihydrate gypsum were selected to accelerate the hydration of anhydrate. The hydration characteristics, the resistance to hydrodynamic water, and the mineralogical studies were investigated. The experimental results suggest that activated by K2SO4 and hemihydrate, anhydrate PG hydrates much more rapidly than that in the presence of only K2SO4 or in the absence of additives. The binder has proper setting time, good strength development, and relatively better resistance to water. The hardened binder has hydrated products of rod or stick like shaped dihydrate gypsum crystals.展开更多
This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration pro...This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-evaporable water measurement,and X-ray diffraction analysis.The results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement blend.The pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate hydrates.These hydrates are similar to those found in pure Portland cement.The results show that if activated coal gangue is substituted for cement at up to 30%(w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a sup-plementary cementing material.The relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same equation.However,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.展开更多
Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2 content in the cement paste were tested, and t...Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2 content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2 and AFt. The cement with 30% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.展开更多
CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride(PVC) ...CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride(PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter(APD) and volume fraction of pore b 200 nm in diameter(VF200) in hydration activity of CaO from carbide slag(CS-CaO)were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model(D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature,the core–shell structure formed by the addition of graphite or Ca CO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79 ℃·min^-1 to27.19 ℃·min^-1 and to 29.27 ℃·min^-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.展开更多
This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process,pore structure variation,and compressive strength developm...This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend(ACGC) . Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing. To evaluate the specific effect of activated coal gangue(ACG) as a supplementary cementing material(SCM) ,a fly ash-cement blend(FAC) was used as a control. Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength. The effect of curing temperature on FAC is greater than that on ACGC. The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 °C,but when the curing temperature reaches 60 °C,the changing nature of the pore structure leads to a decrease in strength. The correlation between compressive strength and the degree of hydration and porosity is linear in nature.展开更多
Phosphogypsum（PG） calcined at 500 ℃ was activated by K2SO4 and salt lime with loose structure as seed crystal. To determine the effect of activation, hydration of the anhydrate PG activated was investigated by exam...Phosphogypsum（PG） calcined at 500 ℃ was activated by K2SO4 and salt lime with loose structure as seed crystal. To determine the effect of activation, hydration of the anhydrate PG activated was investigated by examination of the setting time, the proportion of hydrated anhydrate PG, the microstructure of the hardenite and the resistance to water. Results show that activated anhydrate PG hydrates much more rapidly than that in the absence of activators. The activated anhydrate PG has proper setting time and hydrated proportion. The resistance to water was greatly improved. SEM photos show that the set activated PG has hydrated products of rod-like and closely connected crystals. The different addition of activator leads to different compact structure.展开更多
Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much a...Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources.However,most existing NGH coring techniques cannot preserve the in-situ temperature of NGH,leading to distortion of the physical properties of the obtained core,which makes it difficult to effectively guide NGH exploration and development.To overcome this limitation,this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials(PCM).An active temperature-preserved corer(ATPC)is designed and developed,and an indoor experimental system is established to investigate the heat transfer during the coring process.Based on the experimental results under different environment temperatures,a heat transfer model for the entire ATPC coring process has been established.The indoor experimental results are consistent with the theoretical predictions of the heat transfer model,confirming its validity.This model has reconstructed the temperature changes of the NGH core during the coring process,demonstrating that compared to the traditional coring method with only passive temperature-preserved measures,ATPC can effectively reduce the core temperature by more than 5.25℃.With ATPC,at environment temperatures of 15,20,25,and 30℃,the duration of low-temperature state for the NGH core is 53.85,32.87,20.32,and 11.83 min,respectively.These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.展开更多
Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasm...Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasma optical emission spectroscopy, thermoluminescence and isothermal calorimetry. All the samples were stabilized as T1 form C_3S. Changes in the crystal structure of C_3S could mainly be monitored by changes in lattice parameters, which were closely correlated with the incorporation concentration and substitution types of alkalis. Although alkalis were incorporated at trace level in C_3S, the thermoluminescence and hydration behavior of C_3S were significantly influenced. Initial hydration activity was dramatically increased and highly related to the intensity of the irradiation-induced thermoluminescence peaks at low temperatures due to their direct correlation with defects. The oxygen vacancy sites resulting from the substitution of alkalis for Ca could readily account for the acceleration of the initial hydration of C_3S.展开更多
Coal fly ash is a typical secondary aluminum/silicon resource.The preparation of zeolite-type absorbent is a potential way for its value-added utilization,while the purity and adsorption property of zeolite are limite...Coal fly ash is a typical secondary aluminum/silicon resource.The preparation of zeolite-type absorbent is a potential way for its value-added utilization,while the purity and adsorption property of zeolite are limited due to the occurrence of side reactions in the synthesis process.In this study,a designated composite consisted of crystalline zeolites and amorphous calcium silicate hydrate was selected,which was direct synthesized from fly ash under conditions of a Ca/Si molar ratio of 0.8,an initial NaOH concentration of 0.5 mol/L,a hydrothermal temperature of 170℃and a liquid–solid ratio of 15 mL/g.The results indicated that this composite had superior adsorption property for a variety of heavy metals,which was based on the exchange of calcium and sodium ions in zeolites and calcium silicate hydrate.Its adsorption capacities for Pb^(2+),Ni^(2+),Cd^(2+),Zn^(2+),Cu^(2+)and Cr^(3+)attained 409.4,222.4,147.5,93.2,101.1 and 157.0 mg/g,respectively,in single solution with a pH of 4.5.After regulating the synthesis conditions,the transformation of amorphous calcium silicate hydrate into crystallized tobermorite weakened the adsorption capacity of the composite.Besides,due to the competitive adsorption in a multiple ions solution,the adsorption capacities for these heavy metals had a reduction.展开更多
This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the poro...This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.展开更多
This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly a...This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.展开更多
基金Funded by Hainan Provincial Natural Science Foundation(No.522QN279)State Key Laboratory of High Performance Civil Engineering Materials(No.2023CEM004)。
文摘A green pregelatinized glutinous rice flour biological admixture was developed in this paper.The cement hydration process,hydration products,pore structure,and strength of mortar with different quantities of glutinous rice flour(GRF),and the macroscopic changes in concrete cracking resistance testing were investigated.Simultaneously,a fast cracking resistance evaluation method based on graphic recognition was proposed.The results indicated that pregelatinized glutinous rice flour(T-GRF)delayed the dissolution rate of anhydrous cement during the induction period,shifting the main exothermic peak of hydration backward.The compressive strength developed slowly in 7-28 d age and returned to normal in 28-56 d.The compressive strength of T-GRF-0.6% modified mortar at 56 d age is less than 10% different from that of control group.The 3.0%T-GRF decreased the total porosity by 3%,and the average pore size decreased from 31.2 to 21.3 nm measured by MIP,indicating that T-GRF could inhibit harmful pores and densify concrete.The crack resistance coefficient of T-GRF modified concrete was obtained by image recognition method,and the GRF could decrease the length,width,and damaged area of cracks in the early age of concrete.
文摘Rationale:This case report describes a couple with recurrent fertilization failure despite undergoing multiple cycles of intracytoplasmic sperm injection(ICSI).The principal clinical concern was suspected oocyte activation deficiency(OAD),in which fertilization is impeded due to the oocyte’s inability to initiate embryogenesis,commonly attributed to inadequate intracellular calcium(Ca^(2+))release following sperm injection.Patient concerns:The couple repeatedly experienced complete or near-complete fertilization failure in previous ICSI cycles,raising suspicion of an underlying oocyte activation defect.Diagnosis:Based on the repeated absence of fertilization post-ICSI and clinical history,a diagnosis of suspected OAD leading to recurrent ICSI fertilization failure was considered.Interventions:Artificial oocyte activation(AOA)using the calcium ionophore A23187 was performed.After ICSI,unfertilized oocytes were exposed to the ionophore to induce Ca^(2+)influx,simulating physiological calcium oscillations essential for oocyte activation.The efficacy of intervention was evaluated through subsequent embryonic development,morphological grading,and chromosomal integrity.Outcomes:Following AOA treatment,successful oocyte activation occurred,resulting in the formation of high-grade embryos with normal developmental progression.Chromosomal analysis revealed no detectable abnormalities,indicating genomic stability.Lessons:Calcium ionophore–mediated AOA may serve as an effective adjunct in cases of recurrent ICSI failure attributed to OAD.This case highlights the importance of individualized therapeutic strategies in assisted reproduction;however,further research is needed to refine protocols,validate broader clinical efficacy,and assess long-term safety,including potential epigenetic risks.
文摘Peroxymonosulfate(PMS)-assisted visible-light photocatalytic degradation of organic pollutants using graphitic carbon nitride(g-C_(3)N_(4))presents a promising and environmentally friendly approach.However,pristine g-C_(3)N_(4) suffers from limited visible-light absorption and low charge-carrier mobility.In this study,a phosphorus-doped tubular carbon nitride(5P-TCN)was synthesized via a precursor self-assembly method using phosphoric acid and melamine as raw materials,eliminating the need for organic solvents or templates.The 5P-TCN catalyst demonstrated enhanced visible-light absorption,improved charge transfer capability,and a 5.25-fold increase in specific surface area(31.092 m^(2)/g),which provided abundant active sites to efficiently drive the PMS-assisted photocatalytic reaction.The 5P-TCN/vis/PMS system exhibited exceptional degradation performance for organic pollutants across a broad pH range(3–9),achieving over 92%degradation of Rhodamine B(RhB)within 15 min.Notably,the system retained>98%RhB degradation efficiency after three consecutive operational cycles,demonstrating robust operational stability and reusability.Moreover,key parameters influencing,active radi-cals,degradation pathways,and potential mechanisms for RhB degradation were systematically investigated.This work proposes a green and cost-effective strategy for developing high-efficiency photocatalysts,while demon-strating the exceptional capability of a PMS-assisted photocatalytic system for rapid degradation of RhB.
基金financially supported by the National Natural Science Foundation of China(Nos.52533015,52495013,52403211,52573183,52273157,52073279 and 52025035)Jilin Province,China(Nos.20250601009RC and 20230508102RC)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2022224)。
文摘Given that platinum-based drugs are widely used clinically as chemotherapeutic agents,their severe toxic side effects have attracted significant attention.Consequently,the development of novel nanoprodrugs based on low-toxicity tetravalent platinum(Pt(Ⅳ))com plexes holds substantial research value.Herein,we discovered that coumarin derivatives exhibit inherent antitumor efficacy and significantly enhance superoxide anion radicals(·O_(2)^(-))generation in aqueous solutions under ultrasound(US)irradiation.Given that·O_(2)^(-)is known to mediate the reduction of Pt(Ⅳ)to divalent platinum(Pt(Ⅱ)),we engineered an US-responsive dual-drug nanoprodrug(P-cisPt(Ⅳ)@5-MOP).This nanoprodrug was prepared by covalently conjugating Pt(Ⅳ)and methoxy polyethylene glycol hydroxyl(m PEG-OH)to a poly(_(L)-glutamic acid)(PLG)carrier,followed by encapsulating coumarin derivatives.Under low-intensity US irradiation(1.5 W/cm^(2),1 MHz,10 min),P-cisPt(Ⅳ)@5-MOP achieved a Pt(Ⅳ)reduction rate of 91.4%.Furthermore,upon US exposure,its half-maximal inhibitory concentration(IC_(50))against 4T1 breast cancer cells decreased dramatically from 25.7μmol/L to 0.1μmol/L.Remarkably,this system combined with US therapy yielded a tumor inhibition rate of 90.9%,with 40%of tumor-bea ring mice achieving com plete eradication of tumors,while exhibiting low systemic toxicity.Collectively,this work not only identifies a novel sonosensitizer capable of generating·O_(2)^(-)but also develops a new class of ultrasound-activatable Pt(Ⅳ)nanoprodrug.
文摘Triclosan(TCS) poses harmful risks to ecosystems and human health owing to its endocrine-disrupting effects.Therefore,developing an efficient and sustainable technology to degrade TCS is urgently needed.Herein,cobalt oxyhydroxide @covalent organic frameworks(CoOOH@COFs) S-scheme heterojunction was synthesized,which combined the visible-light-driven photocatalysis and peroxymonosulfate(PMS) activation to synergistically generate abundant reactive oxygen species(ROSs) for TCS degradation.The degradation efficiency of TCS reached 100 % within 8 min in the Vis-CoOOH@COFs/PMS system,and the reaction rate constant was 0.456 min^(-1),which was nearly 1.90 and 2.85 times that of single Co OOH and COFs,and2.36 times that under dark condition,respectively.The density functional theory(DFT) calculations confirmed the energy band bending of CoOOH@COFs and S-scheme charge transport from COFs to Co OOH.Both experimental and theoretical analyses indicated that Co OOH@COFs in photocatalytic-PMS activation systems synergistically facilitated photo-generated carrier separation,enhanced interfacial electron transfer,accelerated PMS activation,and generated multiple ROSs.In particular,photogenerated electrons(e^(-))accelerated the Co(Ⅲ)/Co(Ⅱ) redox cycle,while the PMS captured the e-,which significantly decreased the charge combination of Co OOH@COFs.Radicals(O_(2)^(·-),^(·)OH,and SO_(4)^(·-)) and non-radicals(such as ^(1)O_(2),h^(+),and e^(-)) were both presented in the Vis-CoOOH@COFs/PMS system,with O_(2)^(-) playing a dominant role in TCS degradation.Furthermore,the pathway of TCS degradation and toxicity of intermediates were explored by DFT calculation and transformation product identification.Importantly,the environmentally friendly CoOOH@COFs S-scheme heterojunction exhibited excellent stability and reusability.In conclusion,this study innovatively designed an S-scheme heterojunction in the photocatalytic-PMS activation system,providing guidance and theoretical support for efficient and eco-friendly wastewater treatment.
基金supported by the NIH RF1 grant NS119477 jointly funded by NINDS and NIA(to RM).
文摘Cells of the central nervous system(CNS)are privileged in lying behind the blood-brain barrier(BBB).Unlike blood vessels in other organs,CNS blood vessels are unique in displaying high electrical resistance and low permeability.With this unique structure and function,the BBB prevents potentially harmful blood components such as serum proteins,inflammatory cytokines,and inflammatory leukocytes from entering the hallowed space of the CNS and wreaking havoc.In addition to these“tightness”properties,the BBB has an array of specialized transporters designed to import essential nutrients.
基金supported by the National Natural Science Foundation of China (Grant Nos.T2325004 and 52161160330)the National Natural Science Foundation of China (Grants No.12504233)+2 种基金Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0606900)the Talent Hub for “AI+New Materials” Basic Researchthe Key Research and Development Program of Ningbo (Grant No.2025Z088)。
文摘The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.
基金Projects(52222404,52074212)supported by the National Natural Science Foundation of ChinaProject(2023-LL-QY-07)supported by the Two-chain Integration Key Projects in Shaanxi Province,China。
文摘As the second most important solid waste produced by coal-fired power plants,the improper management of coal-fired slag has the potential to result in environmental pollution.It is therefore imperative that high-value utilization pathways for coal-fired slag should be developed.In this study,modified magnesium slag(MMS),produced by a magnesium smelter,was selected as the alkali activator.The activated silica-aluminum solid wastes,namely coal-fired slag(CFS)and mineral powder(MP),were employed as pozzolanic materials in the preparation of alkali-activated cementitious materials.The alkali-activated cementitious materials prepared with 50 wt%MMS,40 wt%CFS and 10 wt%MP exhibited favorable mechanical properties,with a compressive strength of 32.804 MPa in the paste sample cured for 28 d.Then,the activated silica-aluminum solid waste consisting of CFS-MP generated a significant amount of C-S(A)-H gels,AFt,and other products,which were observed to occupy the pore structure of the specimen.In addition,the secondary hydration reaction of CFS-MP occurs in high alkalinity environments,resulting in the formation of a mutually stimulated and promoted reaction system between CFS-MP and MMS,this will subsequently accelerate the hydrolysis reaction of MMS.It is important to emphasize that the amount of MMS in alkali-activated cementitious materials must be strictly regulated to avert the potential issue of incomplete depolymerization-repolymerization of active silica-aluminum solid waste containing CFS-MP.This in turn could have a deleterious impact on the late strength of the cementitious materials.The aim of this work is to improve the joint disposal of MMS,CFS and MP and thereby provide a scientific basis for the development of environmentally friendly and low-carbon modified magnesium slag alkali-activated coal-fired slag based cementitious materials for mine backfilling.
文摘This paper studied the hydration and strength influence factors ofSteel Slag Cement (SSC), such as the quantity of steel slag and slagand the dosage of additive. The results show that: (a) In the processof hydration of SSC, steel slag and slag activate each other; (b)Waterglass's structure forms the preliminary skeleton of SSC, and thehydration products of SSC link or fill in the skeleton; (c) Sodium inWaterglass is the catalytic and its concentration does not change inthe process of hydration. (d) Structure of activation is asignificant factor to the property of SSC.
基金Funded by the National Natural Science Foundation of China (No. 50802019)
文摘Lime pretreated phosphogypsum（PG） was calcined at 500 ℃ to produce anhydrate gypsum cement. Due to the slow hydration of anhydrate gypsum, additives, K2SO4 and hemihydrate gypsum were selected to accelerate the hydration of anhydrate. The hydration characteristics, the resistance to hydrodynamic water, and the mineralogical studies were investigated. The experimental results suggest that activated by K2SO4 and hemihydrate, anhydrate PG hydrates much more rapidly than that in the presence of only K2SO4 or in the absence of additives. The binder has proper setting time, good strength development, and relatively better resistance to water. The hardened binder has hydrated products of rod or stick like shaped dihydrate gypsum crystals.
基金Project supported by the National Basic Research Program (973) of China (Nos. 2001CB610704 and 2009CB623104)the Youth Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Ministry of Education, Chinathe Foundation of State Key Laboratory of High Performance Civil Engineering Materials (No. 2010CEM015), China
文摘This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-evaporable water measurement,and X-ray diffraction analysis.The results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement blend.The pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate hydrates.These hydrates are similar to those found in pure Portland cement.The results show that if activated coal gangue is substituted for cement at up to 30%(w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a sup-plementary cementing material.The relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same equation.However,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.
基金Funded by the Key Laboratory Foundation of Ecological-Environment Materials (Yancheng Institute of Technology) of Jiangsu Province (No.XKY2009033)the Natural Science Foundation of Jiangsu Provincial Edu-cation Department (No. 07KJB430123)
文摘Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2 content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2 and AFt. The cement with 30% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.
基金Supported by the National Natural Science Foundation of China(U1610101,51422405).
文摘CaO needs to show high activity to be used as Ca-sorbent and slagging agent. Hydration activity is an important characteristic to evaluate the activity of CaO. In this study, carbide slag from polyvinyl chloride(PVC) industry was utilized as precursor for preparing high activity CaO. The roles of crystallite grain, average pore diameter(APD) and volume fraction of pore b 200 nm in diameter(VF200) in hydration activity of CaO from carbide slag(CS-CaO)were respectively investigated. The hydrolysis kinetics model of CaO shows a three-dimensional spherically symmetric diffusion model(D4), which suggests that hydration activity was mainly associated with APD and VF200 of CS-CaO with limited correlation to the crystal size. Specifically, the hydration activity of CS-CaO is increased with increasing VF200, while decreased with increasing APD. Under the invariable calcination temperature,the core–shell structure formed by the addition of graphite or Ca CO3 to CS effectively inhibits the sintering of CS-CaO and improves VF200. Consequently, the hydration activity of CS-CaO increased from 22.79 ℃·min^-1 to27.19 ℃·min^-1 and to 29.27 ℃·min^-1, with addition of 5% graphite or 5% CaCO3 into carbide slag, respectively.
基金Project supported by the National Basic Research Program of China (Nos. 2001CB610704 and 2009CB623104)the Youth Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education,China
文摘This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 °C on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend(ACGC) . Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing. To evaluate the specific effect of activated coal gangue(ACG) as a supplementary cementing material(SCM) ,a fly ash-cement blend(FAC) was used as a control. Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength. The effect of curing temperature on FAC is greater than that on ACGC. The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 °C,but when the curing temperature reaches 60 °C,the changing nature of the pore structure leads to a decrease in strength. The correlation between compressive strength and the degree of hydration and porosity is linear in nature.
基金Funded by the National Natural Science Foundation of China(No.50802019)
文摘Phosphogypsum（PG） calcined at 500 ℃ was activated by K2SO4 and salt lime with loose structure as seed crystal. To determine the effect of activation, hydration of the anhydrate PG activated was investigated by examination of the setting time, the proportion of hydrated anhydrate PG, the microstructure of the hardenite and the resistance to water. Results show that activated anhydrate PG hydrates much more rapidly than that in the absence of activators. The activated anhydrate PG has proper setting time and hydrated proportion. The resistance to water was greatly improved. SEM photos show that the set activated PG has hydrated products of rod-like and closely connected crystals. The different addition of activator leads to different compact structure.
基金financially supported by Shenzhen Science and Technology Program(Nos.JSGG20220831105002005 and KJZD20231025152759002)the National Natural Science Foundation of China(Nos.52274133 and 523B2101).
文摘Natural gas hydrate(NGH)has a bright future as a clean energy source with huge reserves.Coring is one of the most direct methods for NGH exploration and research.Preserving the in-situ properties of the core as much as possible during the coring process is crucial for the assessment of NGH resources.However,most existing NGH coring techniques cannot preserve the in-situ temperature of NGH,leading to distortion of the physical properties of the obtained core,which makes it difficult to effectively guide NGH exploration and development.To overcome this limitation,this study introduces an innovative active temperature-preserved coring method for NGH utilizing phase change materials(PCM).An active temperature-preserved corer(ATPC)is designed and developed,and an indoor experimental system is established to investigate the heat transfer during the coring process.Based on the experimental results under different environment temperatures,a heat transfer model for the entire ATPC coring process has been established.The indoor experimental results are consistent with the theoretical predictions of the heat transfer model,confirming its validity.This model has reconstructed the temperature changes of the NGH core during the coring process,demonstrating that compared to the traditional coring method with only passive temperature-preserved measures,ATPC can effectively reduce the core temperature by more than 5.25℃.With ATPC,at environment temperatures of 15,20,25,and 30℃,the duration of low-temperature state for the NGH core is 53.85,32.87,20.32,and 11.83 min,respectively.These findings provide new perspectives on temperature-preserving core sampling in NGH and provide technical support for exploration and development in NGH.
基金Funded by the National Natural Science Foundation of China(Nos.51302256 and 51672260)the Synergetic Innovation Center for Advanced Materials and State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)
文摘Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasma optical emission spectroscopy, thermoluminescence and isothermal calorimetry. All the samples were stabilized as T1 form C_3S. Changes in the crystal structure of C_3S could mainly be monitored by changes in lattice parameters, which were closely correlated with the incorporation concentration and substitution types of alkalis. Although alkalis were incorporated at trace level in C_3S, the thermoluminescence and hydration behavior of C_3S were significantly influenced. Initial hydration activity was dramatically increased and highly related to the intensity of the irradiation-induced thermoluminescence peaks at low temperatures due to their direct correlation with defects. The oxygen vacancy sites resulting from the substitution of alkalis for Ca could readily account for the acceleration of the initial hydration of C_3S.
基金This work was supported by the National Natural Science Foun-dation of China(No.52174273)the Basic Science Center Project for National Natural Science Foundation of China(No.72088101)+1 种基金the Postdoctoral Science Foundation of China(No.2021TQ0370)the Science and Technology Innovation Program of Hunan Pro-vince(No.2021RC2003).
文摘Coal fly ash is a typical secondary aluminum/silicon resource.The preparation of zeolite-type absorbent is a potential way for its value-added utilization,while the purity and adsorption property of zeolite are limited due to the occurrence of side reactions in the synthesis process.In this study,a designated composite consisted of crystalline zeolites and amorphous calcium silicate hydrate was selected,which was direct synthesized from fly ash under conditions of a Ca/Si molar ratio of 0.8,an initial NaOH concentration of 0.5 mol/L,a hydrothermal temperature of 170℃and a liquid–solid ratio of 15 mL/g.The results indicated that this composite had superior adsorption property for a variety of heavy metals,which was based on the exchange of calcium and sodium ions in zeolites and calcium silicate hydrate.Its adsorption capacities for Pb^(2+),Ni^(2+),Cd^(2+),Zn^(2+),Cu^(2+)and Cr^(3+)attained 409.4,222.4,147.5,93.2,101.1 and 157.0 mg/g,respectively,in single solution with a pH of 4.5.After regulating the synthesis conditions,the transformation of amorphous calcium silicate hydrate into crystallized tobermorite weakened the adsorption capacity of the composite.Besides,due to the competitive adsorption in a multiple ions solution,the adsorption capacities for these heavy metals had a reduction.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(No.2022R1A2C1006743).
文摘This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.
基金Funded by Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education(No.JLJZHDKF202204)。
文摘This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.
