The ionic transport in sub-nanochannels plays a key role in energy storage,yet suffers from a high energy barrier.Wetting sub-nanochannels is crucial to accelerate ionic transport,but the introduction of water is chal...The ionic transport in sub-nanochannels plays a key role in energy storage,yet suffers from a high energy barrier.Wetting sub-nanochannels is crucial to accelerate ionic transport,but the introduction of water is challenging because of the hydrophobic extreme confinement.We propose wetting the channels by the exothermic hydration process of pre-intercalated ions,the effect of which varies distinctly with different ionic hydration structures and energies.Compared to the failed pre-intercalation of SO_(4)^(2-),HSO_(4)^(-) with weak hydration energy results in a marginal effect on the HOMO(Highest Occupied Molecular Orbital)level of water to avoid water splitting during the electrochemical intercalation.Meanwhile,the ability of water introduction is reserved by the initial incomplete dissociation state of HSO_(4)^(-),so the consequent exothermic reionization and hydration processes of the intercalated HSO_(4)^(-) promote the water introduction into sub-nanochannels,finally forming the stable confined water through hydrogen bonding with functional groups.The wetted channels exhibit a significantly enhanced ionic diffusion coef-ficient by~9.4 times.展开更多
Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–gly...Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–glycerol system.Longer whiskers were obtained from crystal seeds prepared via hydration of DH for 30 s than via ball milling for 5 min followed by hydration for 20 s.The attachment of cetyltrimethyl ammonium bromide and glycerol additives to the whisker tops promoted whisker growth.The whisker sponges exhibited good thermal barrier properties and compression cycle stability.展开更多
A ternary system comprising Ca_(20)Al_(26)Mg_(3)Si_(3)O_(68)(Q-phase),limestone,and metakaolin is proposed,and its hydration behavior,hydration product phases,microstructure,and mechanical properties are investigated ...A ternary system comprising Ca_(20)Al_(26)Mg_(3)Si_(3)O_(68)(Q-phase),limestone,and metakaolin is proposed,and its hydration behavior,hydration product phases,microstructure,and mechanical properties are investigated and compared with pure Q-phase cement.The results indicate that the ternary system exhibits exceptional and sustained compressive strength even under a 40℃environment,significantly outperforming pure Q-phase.The mechanism lies in that metakaolin effectively inhibits the transformation of metastable phase.Meanwhile,the interactions among Q-phase,limestone,and metakaolin further enhance the cementitious performance.The ternary system effectively addresses potential issues of strength loss in Q-phase cement application,and as a low-carbon cementitious material system,it holds promising potential applications.展开更多
It was found that silica fume can reduce the maximum hydration heat release rate of cement by microcalorimetry,inhibit CAH_(10),promote the generation of C_(3)AH_(6)and strätlingite C_(2)ASH_(8),or promote the co...It was found that silica fume can reduce the maximum hydration heat release rate of cement by microcalorimetry,inhibit CAH_(10),promote the generation of C_(3)AH_(6)and strätlingite C_(2)ASH_(8),or promote the conversion of CAH_(10)to C_(3)AH_(6).Sodium tripolyphosphate can retard the early hydration of cement,have a slight effect on 1 d hydration products of cement and inhibit the generation hydration products.Sodium tripolyphosphate and silica fume can promote the early hydration of cement,advance the formation of C_(2)ASH_(8)or the conversion from CAH_(10)to C_(3)AH_(6)at 1 d.展开更多
The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic calorimetry.The specimens were prepared with water-cement ratios of 0.31,0.38,and...The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic calorimetry.The specimens were prepared with water-cement ratios of 0.31,0.38,and 0.45,and the molding temperature was specified at 10 and 20℃.The experimental results show that,as the water-binder ratio increases,the value of the second temperature peak on the temperature curve of the cement paste decreases,and the age at which the peak appears is delayed.The higher the water-cement ratio,the higher the hydration heat release in the early period of cement hydration,but this trend reverses in the late period.There are intersection points of the total hydration heat curve of the cement pastes under the influence of the water-cement ratio,and this law can be observed at both molding temperatures.With the increase in the molding temperature,the age of the second temperature peak on the temperature curve of the cement paste will advance,but the temperature peak will decrease.The higher the molding temperature,the earlier the acceleration period of the cement hydration began,and the larger the hydration heat of the cement in the early stage,but the smaller the total heat in the late period.A subsection function calculation model of the hydration heat,which was based on the existing models,was proposed in order to predict the heat of the hydration of the concrete.展开更多
The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementi...The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive strength.The results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.展开更多
Skin care products with carbonic acid(H_(2)CO_(3))have gained extensive attention worldwide.However,the conversion of CO_(2) to H_(2)CO_(3) is not stable,and the mechanism of the effect of H_(2)CO_(3) on skin care has...Skin care products with carbonic acid(H_(2)CO_(3))have gained extensive attention worldwide.However,the conversion of CO_(2) to H_(2)CO_(3) is not stable,and the mechanism of the effect of H_(2)CO_(3) on skin care has not been clearly proved.The hydration-dissolution behaviors of CO_(2) were investigated under different temperature,pH,and pressure conditions.Moreover,based on the phenomenon of CO_(2) hydration transformation,the inflammatory effect of CO_(2) hydrate on macrophages(RAW 264.7)was investigated.The result shows that the increase in temperature weakened the hydration of CO_(2),and the increase in pH and pressure both promoted the water-phase transformation of CO_(2).When pH<6,CO_(2) reacts with water to generate H_(2)CO_(3).When pH was between 6-7,the prompt solution was a mixture of H_(2)CO_(3) and HCO_(3)^(-).When the pH was between 7-9,they mainly generated HCO_(3)^(-).And when pH>9,CO_(2) solubility mainly converts to CO_(3)^(2-).Besides,CO_(2) can inhibit the secretion of inflammatory factors by RAW 264.7 cells by inhibiting the phosphorylation of the p38 protein.CO_(2) hydrate inhibited the expression of pro-inflammatory factors IL-6,TNF-α,and up-regulated the expression of anti-inflammatory factor IL-10.Furthermore,the anti-inflammatory molecular mechanism of CO_(2) hydration inhibited the MAPK signaling pathway by inhibiting the phosphorylation of p38.The hydration-dissolution behavior of CO_(2) was investigated.This work revealed the anti-inflammatory bioeffect of CO_(2) hydrate,providing a theoretical basis and application support for CO_(2) skin care products.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
Magnesia-calcium materials have stable hot performance,good resistance to the erosion and corrosion of liquid steel and steel slag,and a special role in purifying liquid steel,so they are widely used in iron and steel...Magnesia-calcium materials have stable hot performance,good resistance to the erosion and corrosion of liquid steel and steel slag,and a special role in purifying liquid steel,so they are widely used in iron and steel industry.However,hydration of magnesia-calcium materials seriously restricts their use,so researches have been done to improve their hydration resistance,obtaining a series of achievements.In this paper,the improvements on the hydration resistance of magnesia-calcium materials by additives in recent 20 years were presented,and their mechanisms were summarized.展开更多
PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula...PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.展开更多
In recent decades,MgSO_(4)·7H_(2)O(epsomite)has attracted significant attention as a promising thermochemical-based thermal energy storage material due to its high theoretical energy density,wide availability,and...In recent decades,MgSO_(4)·7H_(2)O(epsomite)has attracted significant attention as a promising thermochemical-based thermal energy storage material due to its high theoretical energy density,wide availability,and affordability.Despite extensive research efforts,progress in achieving high-energy density has been limited,primarily due to inadequate understanding of its reaction mechanisms and unfavorable dehydration/hydration kinetics.This study systematically investigated the hydration/dehydration kinetics and cyclability of MgSO_(4)·7H_(2)O.The results reveal that the dehydration process is influenced by the heating rate,with an optimal rate of 5℃/min,resulting in a seven-step MgSO_(4)·7H_(2)O dehydration process with a dehydration heat close to the theoretical value.The reaction kinetic analysis indicated that the rate of hydration was approximately 50%lower than that of dehydration.In addition,thermal cycling tests of MgSO4·7H_(2)O under the conditions of this study(small sample size)indicated good cyclability,with hydration rates increasing with increasing cycling numbers up to approximately 10 cycles where level-off occurs.These results are consistent with scanning electron microscopy analyses,which revealed the formation of cracks and channels in the salt hydrate particles,facilitating mass transfer and improved kinetics.展开更多
The lamellar hydrates of CAC were designed with the introduction of nano CaCO_(3)or Mg-Al hydrotalcite(M-A-H),and the effects on the green strength,pore structures,and high-temperature fracture behavior of alumina-spi...The lamellar hydrates of CAC were designed with the introduction of nano CaCO_(3)or Mg-Al hydrotalcite(M-A-H),and the effects on the green strength,pore structures,and high-temperature fracture behavior of alumina-spinel castables were investigated.The results show that nano CaCO_(3)or M-A-H stimulates rapidly the hydration of CAC and the formation of lamellar C_(4)AcH_(11)or coexistence of C_(2)AH_(8)and C_(4)AcH_(11)at 25℃.The formation of lamellar hydrates can contribute to a more complicated pore structure,especially in the range of 400-2000 nm.Meanwhile,the incorporation of well-distributed CaO or MgO sources from nano CaCO_(3)or M-A-H also regulates the distribution of CA_(6)and spinel(pre-formed and in-situ).Consequently,the optimized microstructure and complicated pore structure can induce the deflection and bridging of cracks,thus facilitating the consumption of fracture energy and enhancing the resistance to thermal stress damage.展开更多
Contrast-induced acute kidney injury(CI-AKI)is a major concern in clinical practice,particularly among high-risk patients with preexisting renal and cardiovascular conditions.Although periprocedural hydration has long...Contrast-induced acute kidney injury(CI-AKI)is a major concern in clinical practice,particularly among high-risk patients with preexisting renal and cardiovascular conditions.Although periprocedural hydration has long been the primary approach for CI-AKI prevention,recent advancements have led to the development of novel approaches such as RenalGuard and contrast removal systems.This editorial explores these emerging approaches and highlights their potential for enhancing CI-AKI prevention.By incorporating the latest evidence into clinical practice,health-care professionals can more effectively maintain renal function and improve outcomes for patients undergoing contrast-enhanced procedures.展开更多
Background: Natural moisturizing factors (NMFs) are filaggrin-derived components in the cornified layer that are critical for maintaining healthy skin moisturization and barrier function. However, studies have reporte...Background: Natural moisturizing factors (NMFs) are filaggrin-derived components in the cornified layer that are critical for maintaining healthy skin moisturization and barrier function. However, studies have reported conflicting findings on the relationship between NMF levels and aging, while few studies have investigated this relationship clinically. To fill this research gap, we determined the levels of major NMF components such as free amino acids, pyrrolidone carboxylic acid, and urocanic acids, and individually verified their relationships with skin hydration, barrier function, age, and skin aging. Purpose: The objective of this study was to clinically investigate the relationship between NMF components levels and skin aging in facial skin. The main NMF components were obtained from facial skin and quantified. We then selected NMF components showing strong relationships to skin hydration, and analyzed the relationships of the levels of these selected NMF components with signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). We also examined the efficacy of treatment with a skin care formula (SK-II Facial Treatment Essence, called SK-II FTE hereafter) including Galactomyces ferment filtrate (GFF, PiteraTM) on the selected NMF component levels associated with skin hydration and barrier function, and the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Method: We conducted two clinical trials in this research. In Study 1, we measured 23 NMF components using tape-stripped cornified layer to quantify them via an HPLC method in 196 Asian females aged 20 to 59 (mean S.D., 38.6 9.4). Facial visual aging parameters [texture, pores, wrinkles, and dullness (L-value)], as well as elasticity (R7), skin hydration, and TEWL, were quantified using facial skin imaging and skin physical property measurement devices. Study 2 was performed to evaluate whether the facial application of SK-II FTE affects the NMF levels and skin aging parameters in 63 Asian female volunteers aged 20 to 55 (38.4 9.03). During the course of Study 2, 0.6 mL of SK-II FTE was applied to the face twice daily in the morning and afternoon. Skin measurements were performed at the start of the day (baseline) and at week 8. Results: In Study 1, we examined the stratum corneum levels of 23 NMF components comparing to the skin hydration status in 196 female subjects. The subjects were divided into two groups using the median of each measured NMF component. Skin hydration values were compared between the two groups defined for each NMF component. The results showed that subjects with higher levels of six amino acids, alanine, arginine, asparagine, glutamine, glycine, and histidine, exhibited significantly higher skin hydration than those with lower amino acid levels. No significant differences in skin hydration values were found for the other 17 NMF components. We then analyzed whether the sum of these six amino acid NMF components (called 6-AA-NMFs, hereafter) is affected by aging. The 6-AA-NMF level peaked in the subjects aged 25-29, and then gradually and significantly decreased with age. Interestingly, the 6-AA-NMF level was significantly correlated with the skin hydration value, but not with TEWL. In addition, the 6-AA-NMF level demonstrated significant correlations with the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Then, in Study 2, we examined whether the daily application of SK-II FTE affects the 6-AA-NMF level and visual aging parameters in 63 females. SK-II FTE demonstrated significant increases of the levels of 6-AA-NMFs and each of its components associated with hydration and barrier function, and improvements of skin texture, pores, wrinkles, and dullness (L-value) during the 8 weeks of treatment of facial skin. Conclusion: These clinical studies with large numbers of subjects across a wide age range revealed that six amino acids as NMF components were highly correlated with facial skin hydration in the stratum corneum. The levels of these six NMF components were also found to decrease at ages after the 30 s and were significantly correlated with major signs of skin aging. Notably, these six NMF components (6-AA-NMFs) were increased by SK-II FTE treatment associated with improvements of skin hydration and signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). These studies were limited by the lack of investigation of why some NMF components were not associated with skin hydration. More clinical trials examining various NMF components and their relationship with aging are anticipated.展开更多
This study introduces a handheld terahertz(THz)scanner designed to quantitatively evaluate human skin hydration levels and thickness.This device,through the incorporation of force sensors,demonstrates enhanced repeata...This study introduces a handheld terahertz(THz)scanner designed to quantitatively evaluate human skin hydration levels and thickness.This device,through the incorporation of force sensors,demonstrates enhanced repeatability and accuracy over traditional fixed THz systems.The scanner was evaluated in the largest THz skin study to date,assessing 314 volunteers,successfully differentiating between individuals with dry skin and hydrated skin using a numerical stratified skin model.The scanner measures and displays skin hydration dynamics within a quarter of a second,indicating its potential for real-time,noninvasive examinations,opening up opportunities for in vivo and ex vivo diagnosis during patient consultations.Furthermore,the portability and ease of use of our scanner enable its widespread application for in vivo and ex vivo diagnosis during patient consultations,potentially allowing in situ biopsy evaluation and elimination of histopathology processing wait times,thereby improving patient outcomes by facilitating simultaneous tumor diagnosis and removal.展开更多
The fluidity of fresh cemented tailings backfill(CTB) slurry depends on its rheological properties. Hence, it is crucial to understand the rheology of fresh CTB slurry, which is related to the cement hydration progr...The fluidity of fresh cemented tailings backfill(CTB) slurry depends on its rheological properties. Hence, it is crucial to understand the rheology of fresh CTB slurry, which is related to the cement hydration progress and temperature evolution within CTB mixtures. For this reason, a numerical model was developed to predict the evolution of the rheological properties of fresh CTB slurry under the coupled effect of cement hydration and temperature. Experiments were conducted to investigate the rheological behaviours of the fresh CTB slurry. By comparing the simulated results with the experimental ones, the availability of this developed model was validated. Thereafter, the model was used to demonstrate the coupled effect of cement hydration and temperature on the evolution of fresh CTB slurry's rheological properties, under various conditions(initial CTB temperature, cement to tailings ratio, and water to cement ratio). The obtained results are helpful to better understanding the rheology of CTB slurry.展开更多
The feasibility of sulphoaluminate cement (SAC) utilization in support mortar was studied. Setting time and strength of as-received sulphoaluminate cement (SAC) paste were examined, hydration kinetics behavior was...The feasibility of sulphoaluminate cement (SAC) utilization in support mortar was studied. Setting time and strength of as-received sulphoaluminate cement (SAC) paste were examined, hydration kinetics behavior was determined through Isothermal Calorimeter, and hydration mechanism was investigated by X-Ray diffraction analysis (XRD) and field emission scanning electron microscopy analysis (FSEM). Results showed that as-received SAC contained 61% of anhydrous calcium sulfate (3CA'CaSO4) and dicalcium silicate (C2S). The strength after 1 day or 3 days grew to 68.6% or 85.7% of that after 28 days respectively, while most of hydration heat was released within 1 day. The emergency of three exothermic peaks at acceleration stage was found and hydration kinetics model was established choosing the terminal time of the first exothermic peak at accelerating stage as the beginning of accelerating stage. XRD analysis suggested that large amount of ettringite (AFt) was produced at early age and FSEM observation revealed that ettringite (AFt) formed in sulphoaluminate cement (SAC) paste was characterized of different morphology which was proved to be caused by different ion concentrations.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
Physical and mechanical properties variations of lithium slag were systematically investigated by three different ways such as physical, chemical activation, physical-chemical combined activation. Mechanisms of the ce...Physical and mechanical properties variations of lithium slag were systematically investigated by three different ways such as physical, chemical activation, physical-chemical combined activation. Mechanisms of the cementitious properties and hydration process of lithium slag composite cement were studied by XRD and SEM. The results showed that specific surface area increased from 254 to 700 m2/kg while median particle size decreased from 14.97 to 8.45 urn with the increase of grinding time. Physical, chemical activation and combined activation improved the strength and hydration degree of lithium slag composite cement. Compared with original lithium slag, the flexural strength and compressive strength of mortars were improved significantly with the increase of grinding time. A higher strength of the cement with the lithium slag was attained; The sample with 10% lithium slag got the highest strength when the grinding time was 10 min; the compressive strength was higher than OPC at 28 days, which increased by 12.3%. When the Na2SO4 content was 0.6%, the compressive strength increased by 1.4%; when the Al2(SO4)3·18H2O content was 0.4%, the compressive strength increased by 5.8% at 28 days. Compared with the late strength, the improving degree of early strength was larger with the incorporation of activator. The results of XRD and SEM were consistent with the results of mechanical properties; it is also evident that lithium slag composite cement hydration products were mainly AFt, Ca(OH)2, CaSO4·2H2O, and C-S-H gel.展开更多
To study the relationship between material composition, curing conditions and strength development, the study simulated high-strength precast concrete pile production, and a high-strength mortar up to 90 MPa was desig...To study the relationship between material composition, curing conditions and strength development, the study simulated high-strength precast concrete pile production, and a high-strength mortar up to 90 MPa was designed and a hot-water pool was built for concrete curing. The major point of the study was to achieve a high early strength by using cement/metakaolin systems without autoclave curing with high-pressure steam. By means of XRD and thermal analysis, the progress of the hydration of the cement pastes blended with metakaolin was characterized. The main results indicate that high strength can be obtained at early age by the use of metakaolin and thermal treatment (hot-water curing). The improvement in strength of mortars with metakaolin can be explained by an increase in the amount of C-S-H and C-S-A-H hydrated phases and a decrease in the amount of calcium hydration(CH). Further more, a decrease in Ca/Si ratio of the matrix was observed from the results of EDX analysis, which also leaded to an improvement of the compressive strength. These results are of great importance for the high-strength precast concrete manufacturing industry.展开更多
基金supported by the National Key Research and Development Program of China(2021YFA1101300)the National Natural Science Foundation of China(Grant No.22225801,21776197,22078214,and 21905206)Special Fund for Science and Technology Innovation Team of Shanxi Province(No.202204051001009).
文摘The ionic transport in sub-nanochannels plays a key role in energy storage,yet suffers from a high energy barrier.Wetting sub-nanochannels is crucial to accelerate ionic transport,but the introduction of water is challenging because of the hydrophobic extreme confinement.We propose wetting the channels by the exothermic hydration process of pre-intercalated ions,the effect of which varies distinctly with different ionic hydration structures and energies.Compared to the failed pre-intercalation of SO_(4)^(2-),HSO_(4)^(-) with weak hydration energy results in a marginal effect on the HOMO(Highest Occupied Molecular Orbital)level of water to avoid water splitting during the electrochemical intercalation.Meanwhile,the ability of water introduction is reserved by the initial incomplete dissociation state of HSO_(4)^(-),so the consequent exothermic reionization and hydration processes of the intercalated HSO_(4)^(-) promote the water introduction into sub-nanochannels,finally forming the stable confined water through hydrogen bonding with functional groups.The wetted channels exhibit a significantly enhanced ionic diffusion coef-ficient by~9.4 times.
基金supported by the Degradable Plastics Engineering Research Center of Yunnan Provincial Education Department(KKPU202205001).
文摘Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is imperative.Herein,crystal seeds and whiskers were prepared from DH in a water–glycerol system.Longer whiskers were obtained from crystal seeds prepared via hydration of DH for 30 s than via ball milling for 5 min followed by hydration for 20 s.The attachment of cetyltrimethyl ammonium bromide and glycerol additives to the whisker tops promoted whisker growth.The whisker sponges exhibited good thermal barrier properties and compression cycle stability.
基金Funded by the National Natural Science Foundation of China(No.52172026)the Science and Technology Development Project of China Railway Design Corporation(Nos.2023A0226407 and 2023B03040003)。
文摘A ternary system comprising Ca_(20)Al_(26)Mg_(3)Si_(3)O_(68)(Q-phase),limestone,and metakaolin is proposed,and its hydration behavior,hydration product phases,microstructure,and mechanical properties are investigated and compared with pure Q-phase cement.The results indicate that the ternary system exhibits exceptional and sustained compressive strength even under a 40℃environment,significantly outperforming pure Q-phase.The mechanism lies in that metakaolin effectively inhibits the transformation of metastable phase.Meanwhile,the interactions among Q-phase,limestone,and metakaolin further enhance the cementitious performance.The ternary system effectively addresses potential issues of strength loss in Q-phase cement application,and as a low-carbon cementitious material system,it holds promising potential applications.
基金Funded by the National Natural Science Foundation of China(No.51802235)Hubei Science and Technology Innovation Talent Project,China(No.2023DJC087)。
文摘It was found that silica fume can reduce the maximum hydration heat release rate of cement by microcalorimetry,inhibit CAH_(10),promote the generation of C_(3)AH_(6)and strätlingite C_(2)ASH_(8),or promote the conversion of CAH_(10)to C_(3)AH_(6).Sodium tripolyphosphate can retard the early hydration of cement,have a slight effect on 1 d hydration products of cement and inhibit the generation hydration products.Sodium tripolyphosphate and silica fume can promote the early hydration of cement,advance the formation of C_(2)ASH_(8)or the conversion from CAH_(10)to C_(3)AH_(6)at 1 d.
基金the National Natural Science Foundation of China(Nos.52368032 and 51808272)the China Postdoctoral Science Foundation(No.2023M741455)+1 种基金the Tianyou Youth Talent Lift Program of Lanzhou Jiaotong UniversityGansu Province Youth Talent Support Project(No.GXH20210611-10)。
文摘The effects of the water-cement ratio and the molding temperature on the hydration heat of cement were investigated with semi-adiabatic calorimetry.The specimens were prepared with water-cement ratios of 0.31,0.38,and 0.45,and the molding temperature was specified at 10 and 20℃.The experimental results show that,as the water-binder ratio increases,the value of the second temperature peak on the temperature curve of the cement paste decreases,and the age at which the peak appears is delayed.The higher the water-cement ratio,the higher the hydration heat release in the early period of cement hydration,but this trend reverses in the late period.There are intersection points of the total hydration heat curve of the cement pastes under the influence of the water-cement ratio,and this law can be observed at both molding temperatures.With the increase in the molding temperature,the age of the second temperature peak on the temperature curve of the cement paste will advance,but the temperature peak will decrease.The higher the molding temperature,the earlier the acceleration period of the cement hydration began,and the larger the hydration heat of the cement in the early stage,but the smaller the total heat in the late period.A subsection function calculation model of the hydration heat,which was based on the existing models,was proposed in order to predict the heat of the hydration of the concrete.
基金Funded by the National Natural Science Foundation of China (Nos.51772033, 52002040)the National Key Research and Development Program of China (No. 2023YFB3711400)。
文摘The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive strength.The results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement.
文摘Skin care products with carbonic acid(H_(2)CO_(3))have gained extensive attention worldwide.However,the conversion of CO_(2) to H_(2)CO_(3) is not stable,and the mechanism of the effect of H_(2)CO_(3) on skin care has not been clearly proved.The hydration-dissolution behaviors of CO_(2) were investigated under different temperature,pH,and pressure conditions.Moreover,based on the phenomenon of CO_(2) hydration transformation,the inflammatory effect of CO_(2) hydrate on macrophages(RAW 264.7)was investigated.The result shows that the increase in temperature weakened the hydration of CO_(2),and the increase in pH and pressure both promoted the water-phase transformation of CO_(2).When pH<6,CO_(2) reacts with water to generate H_(2)CO_(3).When pH was between 6-7,the prompt solution was a mixture of H_(2)CO_(3) and HCO_(3)^(-).When the pH was between 7-9,they mainly generated HCO_(3)^(-).And when pH>9,CO_(2) solubility mainly converts to CO_(3)^(2-).Besides,CO_(2) can inhibit the secretion of inflammatory factors by RAW 264.7 cells by inhibiting the phosphorylation of the p38 protein.CO_(2) hydrate inhibited the expression of pro-inflammatory factors IL-6,TNF-α,and up-regulated the expression of anti-inflammatory factor IL-10.Furthermore,the anti-inflammatory molecular mechanism of CO_(2) hydration inhibited the MAPK signaling pathway by inhibiting the phosphorylation of p38.The hydration-dissolution behavior of CO_(2) was investigated.This work revealed the anti-inflammatory bioeffect of CO_(2) hydrate,providing a theoretical basis and application support for CO_(2) skin care products.
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.
文摘Magnesia-calcium materials have stable hot performance,good resistance to the erosion and corrosion of liquid steel and steel slag,and a special role in purifying liquid steel,so they are widely used in iron and steel industry.However,hydration of magnesia-calcium materials seriously restricts their use,so researches have been done to improve their hydration resistance,obtaining a series of achievements.In this paper,the improvements on the hydration resistance of magnesia-calcium materials by additives in recent 20 years were presented,and their mechanisms were summarized.
基金supported by the National Research Foundation (NRF) grant funded by the Korea government (NRF2022R1C1C1007619, NRF-2021M3H4A1A01002921, NRF2021M3I3A1084292)supported by the KIST Institutional Program (Project No. 2E32592-23-069)。
文摘PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.
文摘In recent decades,MgSO_(4)·7H_(2)O(epsomite)has attracted significant attention as a promising thermochemical-based thermal energy storage material due to its high theoretical energy density,wide availability,and affordability.Despite extensive research efforts,progress in achieving high-energy density has been limited,primarily due to inadequate understanding of its reaction mechanisms and unfavorable dehydration/hydration kinetics.This study systematically investigated the hydration/dehydration kinetics and cyclability of MgSO_(4)·7H_(2)O.The results reveal that the dehydration process is influenced by the heating rate,with an optimal rate of 5℃/min,resulting in a seven-step MgSO_(4)·7H_(2)O dehydration process with a dehydration heat close to the theoretical value.The reaction kinetic analysis indicated that the rate of hydration was approximately 50%lower than that of dehydration.In addition,thermal cycling tests of MgSO4·7H_(2)O under the conditions of this study(small sample size)indicated good cyclability,with hydration rates increasing with increasing cycling numbers up to approximately 10 cycles where level-off occurs.These results are consistent with scanning electron microscopy analyses,which revealed the formation of cracks and channels in the salt hydrate particles,facilitating mass transfer and improved kinetics.
基金supported financially by the Natural Science Foundation of Qinghai(2022-ZJ-928)the Special Project for Transformation of Scientific and Technological Achievements of Qinghai Province(2023-GX-102).
文摘The lamellar hydrates of CAC were designed with the introduction of nano CaCO_(3)or Mg-Al hydrotalcite(M-A-H),and the effects on the green strength,pore structures,and high-temperature fracture behavior of alumina-spinel castables were investigated.The results show that nano CaCO_(3)or M-A-H stimulates rapidly the hydration of CAC and the formation of lamellar C_(4)AcH_(11)or coexistence of C_(2)AH_(8)and C_(4)AcH_(11)at 25℃.The formation of lamellar hydrates can contribute to a more complicated pore structure,especially in the range of 400-2000 nm.Meanwhile,the incorporation of well-distributed CaO or MgO sources from nano CaCO_(3)or M-A-H also regulates the distribution of CA_(6)and spinel(pre-formed and in-situ).Consequently,the optimized microstructure and complicated pore structure can induce the deflection and bridging of cracks,thus facilitating the consumption of fracture energy and enhancing the resistance to thermal stress damage.
文摘Contrast-induced acute kidney injury(CI-AKI)is a major concern in clinical practice,particularly among high-risk patients with preexisting renal and cardiovascular conditions.Although periprocedural hydration has long been the primary approach for CI-AKI prevention,recent advancements have led to the development of novel approaches such as RenalGuard and contrast removal systems.This editorial explores these emerging approaches and highlights their potential for enhancing CI-AKI prevention.By incorporating the latest evidence into clinical practice,health-care professionals can more effectively maintain renal function and improve outcomes for patients undergoing contrast-enhanced procedures.
文摘Background: Natural moisturizing factors (NMFs) are filaggrin-derived components in the cornified layer that are critical for maintaining healthy skin moisturization and barrier function. However, studies have reported conflicting findings on the relationship between NMF levels and aging, while few studies have investigated this relationship clinically. To fill this research gap, we determined the levels of major NMF components such as free amino acids, pyrrolidone carboxylic acid, and urocanic acids, and individually verified their relationships with skin hydration, barrier function, age, and skin aging. Purpose: The objective of this study was to clinically investigate the relationship between NMF components levels and skin aging in facial skin. The main NMF components were obtained from facial skin and quantified. We then selected NMF components showing strong relationships to skin hydration, and analyzed the relationships of the levels of these selected NMF components with signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). We also examined the efficacy of treatment with a skin care formula (SK-II Facial Treatment Essence, called SK-II FTE hereafter) including Galactomyces ferment filtrate (GFF, PiteraTM) on the selected NMF component levels associated with skin hydration and barrier function, and the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Method: We conducted two clinical trials in this research. In Study 1, we measured 23 NMF components using tape-stripped cornified layer to quantify them via an HPLC method in 196 Asian females aged 20 to 59 (mean S.D., 38.6 9.4). Facial visual aging parameters [texture, pores, wrinkles, and dullness (L-value)], as well as elasticity (R7), skin hydration, and TEWL, were quantified using facial skin imaging and skin physical property measurement devices. Study 2 was performed to evaluate whether the facial application of SK-II FTE affects the NMF levels and skin aging parameters in 63 Asian female volunteers aged 20 to 55 (38.4 9.03). During the course of Study 2, 0.6 mL of SK-II FTE was applied to the face twice daily in the morning and afternoon. Skin measurements were performed at the start of the day (baseline) and at week 8. Results: In Study 1, we examined the stratum corneum levels of 23 NMF components comparing to the skin hydration status in 196 female subjects. The subjects were divided into two groups using the median of each measured NMF component. Skin hydration values were compared between the two groups defined for each NMF component. The results showed that subjects with higher levels of six amino acids, alanine, arginine, asparagine, glutamine, glycine, and histidine, exhibited significantly higher skin hydration than those with lower amino acid levels. No significant differences in skin hydration values were found for the other 17 NMF components. We then analyzed whether the sum of these six amino acid NMF components (called 6-AA-NMFs, hereafter) is affected by aging. The 6-AA-NMF level peaked in the subjects aged 25-29, and then gradually and significantly decreased with age. Interestingly, the 6-AA-NMF level was significantly correlated with the skin hydration value, but not with TEWL. In addition, the 6-AA-NMF level demonstrated significant correlations with the signs of skin aging of texture, pores, wrinkles, and dullness (L-value). Then, in Study 2, we examined whether the daily application of SK-II FTE affects the 6-AA-NMF level and visual aging parameters in 63 females. SK-II FTE demonstrated significant increases of the levels of 6-AA-NMFs and each of its components associated with hydration and barrier function, and improvements of skin texture, pores, wrinkles, and dullness (L-value) during the 8 weeks of treatment of facial skin. Conclusion: These clinical studies with large numbers of subjects across a wide age range revealed that six amino acids as NMF components were highly correlated with facial skin hydration in the stratum corneum. The levels of these six NMF components were also found to decrease at ages after the 30 s and were significantly correlated with major signs of skin aging. Notably, these six NMF components (6-AA-NMFs) were increased by SK-II FTE treatment associated with improvements of skin hydration and signs of skin aging, namely, texture, pores, wrinkles, and dullness (L-value). These studies were limited by the lack of investigation of why some NMF components were not associated with skin hydration. More clinical trials examining various NMF components and their relationship with aging are anticipated.
基金support from the Engineering and Physical Sciences Research Council (EPSRC) (Grant Nos.EP/S021442/1 and EP/V047914/1)Cancer Research UK,the Royal Society (Wolfson Merit Award-EPM)the Health GRP at Warwick University.
文摘This study introduces a handheld terahertz(THz)scanner designed to quantitatively evaluate human skin hydration levels and thickness.This device,through the incorporation of force sensors,demonstrates enhanced repeatability and accuracy over traditional fixed THz systems.The scanner was evaluated in the largest THz skin study to date,assessing 314 volunteers,successfully differentiating between individuals with dry skin and hydrated skin using a numerical stratified skin model.The scanner measures and displays skin hydration dynamics within a quarter of a second,indicating its potential for real-time,noninvasive examinations,opening up opportunities for in vivo and ex vivo diagnosis during patient consultations.Furthermore,the portability and ease of use of our scanner enable its widespread application for in vivo and ex vivo diagnosis during patient consultations,potentially allowing in situ biopsy evaluation and elimination of histopathology processing wait times,thereby improving patient outcomes by facilitating simultaneous tumor diagnosis and removal.
基金Project(SKLCRSM13KFB05)supported by State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(Beijing)
文摘The fluidity of fresh cemented tailings backfill(CTB) slurry depends on its rheological properties. Hence, it is crucial to understand the rheology of fresh CTB slurry, which is related to the cement hydration progress and temperature evolution within CTB mixtures. For this reason, a numerical model was developed to predict the evolution of the rheological properties of fresh CTB slurry under the coupled effect of cement hydration and temperature. Experiments were conducted to investigate the rheological behaviours of the fresh CTB slurry. By comparing the simulated results with the experimental ones, the availability of this developed model was validated. Thereafter, the model was used to demonstrate the coupled effect of cement hydration and temperature on the evolution of fresh CTB slurry's rheological properties, under various conditions(initial CTB temperature, cement to tailings ratio, and water to cement ratio). The obtained results are helpful to better understanding the rheology of CTB slurry.
基金Funded by the National Natural Science Foundation of China(Nos.51379163 and 51109170)the National Key Research Program(973 Program)(No.2013CB035901)
文摘The feasibility of sulphoaluminate cement (SAC) utilization in support mortar was studied. Setting time and strength of as-received sulphoaluminate cement (SAC) paste were examined, hydration kinetics behavior was determined through Isothermal Calorimeter, and hydration mechanism was investigated by X-Ray diffraction analysis (XRD) and field emission scanning electron microscopy analysis (FSEM). Results showed that as-received SAC contained 61% of anhydrous calcium sulfate (3CA'CaSO4) and dicalcium silicate (C2S). The strength after 1 day or 3 days grew to 68.6% or 85.7% of that after 28 days respectively, while most of hydration heat was released within 1 day. The emergency of three exothermic peaks at acceleration stage was found and hydration kinetics model was established choosing the terminal time of the first exothermic peak at accelerating stage as the beginning of accelerating stage. XRD analysis suggested that large amount of ettringite (AFt) was produced at early age and FSEM observation revealed that ettringite (AFt) formed in sulphoaluminate cement (SAC) paste was characterized of different morphology which was proved to be caused by different ion concentrations.
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Funded partly by the National Natural Science Foundation of China(Nos.51378408,51408448)State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2013-07)
文摘Physical and mechanical properties variations of lithium slag were systematically investigated by three different ways such as physical, chemical activation, physical-chemical combined activation. Mechanisms of the cementitious properties and hydration process of lithium slag composite cement were studied by XRD and SEM. The results showed that specific surface area increased from 254 to 700 m2/kg while median particle size decreased from 14.97 to 8.45 urn with the increase of grinding time. Physical, chemical activation and combined activation improved the strength and hydration degree of lithium slag composite cement. Compared with original lithium slag, the flexural strength and compressive strength of mortars were improved significantly with the increase of grinding time. A higher strength of the cement with the lithium slag was attained; The sample with 10% lithium slag got the highest strength when the grinding time was 10 min; the compressive strength was higher than OPC at 28 days, which increased by 12.3%. When the Na2SO4 content was 0.6%, the compressive strength increased by 1.4%; when the Al2(SO4)3·18H2O content was 0.4%, the compressive strength increased by 5.8% at 28 days. Compared with the late strength, the improving degree of early strength was larger with the incorporation of activator. The results of XRD and SEM were consistent with the results of mechanical properties; it is also evident that lithium slag composite cement hydration products were mainly AFt, Ca(OH)2, CaSO4·2H2O, and C-S-H gel.
基金Funded by the National Fundamental Scientific Research Project of China(2009CB623201)
文摘To study the relationship between material composition, curing conditions and strength development, the study simulated high-strength precast concrete pile production, and a high-strength mortar up to 90 MPa was designed and a hot-water pool was built for concrete curing. The major point of the study was to achieve a high early strength by using cement/metakaolin systems without autoclave curing with high-pressure steam. By means of XRD and thermal analysis, the progress of the hydration of the cement pastes blended with metakaolin was characterized. The main results indicate that high strength can be obtained at early age by the use of metakaolin and thermal treatment (hot-water curing). The improvement in strength of mortars with metakaolin can be explained by an increase in the amount of C-S-H and C-S-A-H hydrated phases and a decrease in the amount of calcium hydration(CH). Further more, a decrease in Ca/Si ratio of the matrix was observed from the results of EDX analysis, which also leaded to an improvement of the compressive strength. These results are of great importance for the high-strength precast concrete manufacturing industry.