Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resi...Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.展开更多
According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae ...According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae of T.granarium fed on wheat seeds(25 gm)treated with different weights of silica as well as silica nanoparticles(20,40,60 and 80 mg)at different temperature(9℃,25℃,and 35℃).Study showed that using silica nanoparticles in cold temperature(9℃)was the most efficient treatment with the lowest LC_(50)(lethal concentration required to kill 50%of the population)value and caused the highest toxicity index.In contrast,the least efficient treatment(25℃)with the highest LC_(50) value and showed lowest toxicity index was using silica in normal temperature,when using silica nanoparticles,the cold temperature was the best condition followed by hot temperature(35℃)and finally the normal temperature.On the other hand,using silica in hot temperature was most effective followed by silica with cold temperature and finally silica with normal temperature.The biochemical assays revealed that the change in the experimental temperature had a nonsignificant effect on the total protein content of the larvae.The total lipids and total carbohydrates exhibited a significant increase due to hot treating.5th instar larvae of T.granarium treated with LC50 of silica at high temperature led to a nonsignificant(p≤0.05)decrease in Acetylcholinesterase(AchE)activity compared to treatment at normal temperature.In contrast,Glutathione S-transferase(GST)and Peroxidase activities were significantly(p≤0.05)raised due to the treatment conducted at high temperature.Additionally,treating larvae with LC50 of silica nanoparticles at low temperature caused a significant increase in both GST and peroxidase activities,while the increase in AChE was nonsignificantly(p≤0.05)compared to treatment at normal temperature.Using silica at low temperature could be used as an alternative to chemical insecticides to control T.granarium larvae.展开更多
A novel method for scandium recovery is proposed through high-surface area silanol-rich silica sorbents which were prepared with calcium silicate hydrate(C-S-H) as raw material.Two types of silanol-rich silica particl...A novel method for scandium recovery is proposed through high-surface area silanol-rich silica sorbents which were prepared with calcium silicate hydrate(C-S-H) as raw material.Two types of silanol-rich silica particles,i.e.,LAC-S(silica derived from acid leaching of amorphous C-S-H) and LLC-S(silica derived from acid leaching of low-crystallinity C-S-H) are obtained after calcium ions are removed from both amorphous and low-crystallinity forms of C-S-H through a facile acid leaching process(3 mol/L,25℃,24 h).(29)^Si NMR spectroscopy reveals that the proportion of silicon atoms carrying silanol groups increases from less than 43% to over 80% when silica particles are transferred from a dry state to an aqueous solution.Batch adsorption experiments were conducted to evaluate the sorption performance and selectivity of these silica sorbents toward Sc(Ⅲ).The scandium sorption capacities of LAC-S and LLC-S at an equilibrium pH of 4.2 are 174.45 and 129.57 mg/g,respectively.The separation factors(SFSc/Ln) of both silica particles exceed 1000 in the initial pH range of 3.5-5.The loaded scandium ions are recovered with 3 mol/L hydrochloric acid and the sorbents exhibit good reusability.This strategy provides an efficient and green method for recovering scandium from aqueous solutions.展开更多
Due to excellent thermal insulation performance at room temperature and ultralow density,silica aero-gels are candidates for thermal insulation.However,at high temperatures,the thermal insulation prop-erty of silica a...Due to excellent thermal insulation performance at room temperature and ultralow density,silica aero-gels are candidates for thermal insulation.However,at high temperatures,the thermal insulation prop-erty of silica aerogels decreased greatly caused by transparency to heat radiation.Opacifiers introduced into silica sol can block heat radiation yet destroy the uniformity of aerogels.Herein,we designed and prepared a silica aerogel composite with oriented and layered silica fibers(SFs),SiC nanowires(SiC_(NWs)),and silica aerogels,which were prepared by papermaking,chemical vapor infiltration(CVI),and sol-gel respectively.Firstly,oriented and layered SFs made still air a wall to block heat transfer by the solid phase.Secondly,SiC_(NWs) were grown in situ on the surface of SFs evenly to weave into the network,and the network reduced the gaseous thermal conductivity by dividing cracks in SFs/SiC_(NWs)/SA.Thirdly,SiC_(NWs) weakened the heat transfer by radiation at high temperatures.Therefore,SFs/SiC_(NWs)/SA presented remarkable thermal insulation(0.017 W(m K)^(-1) at 25℃,0.0287 W(m K)^(-1) at 500℃,and 0.094 W(m K)^(-1) at 1000℃).Besides,SFs/SiC_(NWs)/SA exhibited remarkable thermal stability(no size transform after being heat treated at 1000℃ for 1800 s)and tensile strength(0.75 MPa).These integrated properties made SFs/SiC_(NWs)/SA a promising candidate for highly efficient thermal insulators.展开更多
Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxy...Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxylum bungeanum,which promotes the management of obesity by triggering the browning of white adipose tissue(WAT)targeting the membrane receptor of transient receptor potential vanilloid 1(TRPV1).However,HAS easily undergoes configuration transformation and oxidative degradation.The short peptide CKGGRAKDC or adipose-targeting sequence(ATS)binds specifically to prohibitin on the surface of WAT cells and can be used as recognition assembly to enhance adipocyte targetability.Furthermore,mesoporous silica nanoparticles(MSNs)are widely used in drug delivery systems because of their large specific surface area and pore volume.Therefore,HAS-loaded adipose-targeted MSNs(MSNs-ATS)were developed to enhance the adipocyte targetability,safety,and efficacy of HAS,and tested on mature 3T3-L1 cells and obese mouse models.MSNs-ATS showed higher specificity for adipocyte targetability without obvious toxicity.HAS-loaded MSNs-ATS showed anti-obesity effects superior to those of HAS alone.In conclusion,we successfully developed adipocyte-targeted,HAS-loaded MSNs with good safety and anti-obesity effects.展开更多
Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles o...Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles of human alveolar type II epithelial cells(A549 cells)exposed directly to silica were characterized using non-targeted metabolomic approaches.A total of 84 differential metabolites(DMs)were identified in silica-treated A549 cells undergoing EMT,which were mainly enriched in metabolisms of amino acids(e.g.,glutamate,alanine,aspartate),purine metabolism,glycolysis,etc.The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica.Remarkably,glutamine catabolism was significantly promoted in the silica-treated A549 cells,and the levels of related metabolites(e.g.,succinate)and enzymes(e.g.,α-ketoglutarate(α-KG)dehydrogenase)were substantially up-regulated,with a preference toα-KG pathway.Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail(zinc finger transcription factor).Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.展开更多
To alleviate the quality deterioration and extend the shelf life of crucian carp fillets,a bio-based active composite film integrating eugenol(EG)-loaded mesoporous silica nanoparticles(MSNs)modified with caffeic acid...To alleviate the quality deterioration and extend the shelf life of crucian carp fillets,a bio-based active composite film integrating eugenol(EG)-loaded mesoporous silica nanoparticles(MSNs)modified with caffeic acid(CA)within the zein matrix(EG/CA-MSN/Zein)was developed.This study compared the effects of EG/CA-MSN/Zein,polyethylene(PE),and zein films on the quality of fish fillets during refrigerated storage.The results showed that the EG/CA-MSN/Zein film significantly retarded the increase in pH and microbial growth.Moreover,the film had higher water-holding capacity(WHC),better texture,and color stability,as indicated by low-field nuclear magnetic resonance(LF-NMR),magnetic resonance imaging(MRI),and sensory evaluation.The EG/CA-MSN/Zein composite film extended the shelf life of crucian carp fillets by 3-4 days,highlighting its potential as an environmentally friendly and efficient packaging material for aquatic products.展开更多
The micro-dispersion structure of silica fillers exerts significant infiuences on the performance characteristics of rubber-based products. How to monitor this parameter is an important issue in the rubber industry, b...The micro-dispersion structure of silica fillers exerts significant infiuences on the performance characteristics of rubber-based products. How to monitor this parameter is an important issue in the rubber industry, but there is currently no suitable technical solution for numerical monitoring that can be applied in automatic production line. The labeling of silica in rubber is a challenge that bottlenecks the development of numerical quality monitoring technology. In this work, we employed the organometallic europium to modify silica endowing the fiuorescence properties for characterization. It provides more feasible solutions for visually studying the relationship between the submicroscopic structure and macroscopic properties of inorganic-filled polymers, and is the key foundation for achieving numerical monitoring of rubber filler qualities in industry.展开更多
Ordered porous silica nanospheres with pores vertical to the walls were prepared by using 1,3,5-trimethyl-benzen(TMB)and hexadecitrile trimethyl ammonium bromide(CTAB)as templates.After removing the templates,porous s...Ordered porous silica nanospheres with pores vertical to the walls were prepared by using 1,3,5-trimethyl-benzen(TMB)and hexadecitrile trimethyl ammonium bromide(CTAB)as templates.After removing the templates,porous structures were obtained.The porous silica nanosperes were further modified with amino and amino acid functionalization to obtain L-Glutamic acid-functionalized mesoporous silica nanospheres,which were used as chiral selective agents for amino acid enantioseparation such as PheCOOH,PhgCOOH,and TrpCOOH enantiomers.The experimental results show that the functionalized nanospheres have good adsorption selectivity for D-PheCOOH and L-PhgCOOH,especially showing high adsorption selectivity for the L-TrpCOOH enantiomers compared with L-PheCOOH and D-PhgCOOH and D-TrpCOOH enantiomers.展开更多
The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insuffici...The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insufficient mass diffusion and unsatisfactory durability due to the lack of interconnected and regulatable porosity.Developing catalytic architectures with engineered active sites and prominent stability through rational synthesis strategies has become one of the core projects in solar-driven applications.The unique properties of mesoporous silicas render them among the most valuable functional materials for industrial applications,such as high specific surface area,regulatable porosity,adjustable surface properties,tunable particle sizes,and great thermal and mechanical stability.Mesoporous silicas serve as structural templates or catalytic supports to enhance light harvesting via the scattering effect and provide large surface areas for active site generation.These advantages have been widely utilized in solar applications,including hydrogen production,CO_(2)conversion,photovoltaics,biomass utilization,and pollutant degradation.To achieve the specific functionalities and desired activity,various types of mesoporous silicas from different synthesis methods have been customized and synthesized.Moreover,morphology regulation and component modification strategies have also been performed to endow mesoporous silica-based materials with unprecedented efficiency for solar energy storage and utilization.Nevertheless,reviews about synthesis,morphology regulation,and component modification strategies for mesoporous silica-based catalyst design in solar-driven applications are still limited.Herein,the latest progress concerning mesoporous silica-based catalysis in solar-driven applications is comprehensively reviewed.Synthesis principles,formation mechanisms,and rational functionalities of mesoporous silica are systematically summarized.Some typical catalysts with impressive activities in different solar-driven applications are highlighted.Furthermore,challenges and future potential opportunities in this study field are also discussed and proposed.This present review guides the design of mesoporous silica catalysts for efficient solar energy management for solar energy storage and conversion applications.展开更多
Metal nanoparticles used in high‐temperature catalytic reactions,such as dry reforming of methane,are prone to sintering,leading to particle growth,loss of active surface area,and eventual catalyst deactivation.This ...Metal nanoparticles used in high‐temperature catalytic reactions,such as dry reforming of methane,are prone to sintering,leading to particle growth,loss of active surface area,and eventual catalyst deactivation.This is particularly true for nickelbased catalysts,which,despite their high activity and low cost,often suffer from severe agglomeration and carbon deposition under harsh reforming conditions.Therefore,effectively preventing metal particle growth is crucial for achieving long‐term catalytic stability.In this work,we present a robust strategy to stabilize monodispersed Ni nanoclusters(NCs,1 wt.%)by anchoring them onto a silica‐coated silicon carbide support(SiC@SiO_(2)).The resulting Ni/SiC@SiO_(2) catalyst exhibited outstanding performance at 800℃,with 90%conversion for both CH_(4) and CO_(2).The Ni NCs maintained a uniform size(~1.8 nm)after stability testing,in contrast to the severe sintering(~9.3 nm)and low activity(<10%conversion)observed for Ni on unmodified SiC.The silica layers played a key role in chemically confining the Ni NCs,enhancing their dispersion and thermal stability.Furthermore,the formation of Ni‒O‒Si interfacial structures improved metal‐support interactions,effectively suppressing the reverse water–gas shift(RWGS)reaction and facilitating carbon oxidation via CO_(2) activation.This interfacial engineering strategy significantly enhanced the catalyst's resistance to both sintering and coking,offering a generalizable approach to designing durable metal catalysts for high‐temperature reactions.展开更多
An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,includ...An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,including Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and elemental analysis,etc.,confirmed the successful prepared of this innovative stationary phase.The unique combination of amide,long alkyl chain,and imidazole ring in the hydrogel coating enables the stationary phase to function effectively in hydrophilic/reversed-phase/ion exchange liquid chromatography.Notably,the stationary phase exhibited superior separation performance owing to the synergistic effect of the ionic liquid and hydrogel.This was particularly evident when analyzing various analytes such as organic acids,nucleosides/bases,polycyclic aromatic hydrocarbons(PAHs)and anions.Furthermore,under our operating conditions,an excellent column efficiency of 53,642.9 plates/m was achieved for theobromine.In summary,we have proposed a straightforward strategy to enhance the separation performance of hydrogel coatings in liquid chromatography,thereby broadening the potential applications of hydrogels in the field of separation.展开更多
Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resul...Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.展开更多
Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations a...Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.展开更多
Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification ...Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification and good biocompatibility.However,as a result of the poor biodegradability of MsNs,their biomedical applications are limited.To break the bottleneck of limited biomedical applications of MSNs,more and more researchers tend to design biodegradable MSNs(b-MSNs)nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers.In this review,we focused on sum-marizing strategies to improve the degradability of MsNs and innovatively proposed a series of advan-tages of b-MsNs,including controlled cargo release behavior,multifunctional frameworks,nano-catalysis,bio-imaging capabilities and enhanced therapeutic effects.Based on these advantages,we have inno-vatively summarized the applications of b-MsNs for enhanced tumor theranostics,including enhanced chemotherapy,delivery of nanosensitizers,gas molecules and biomacromolecules,initiation of immune response,synergistic therapies and image-guided tumor diagnostics.Finally,the challenges and further clinical translation potential of nanosystems based on b-MsNs are fully discussed and prospected.We believe that such b-MsNs delivery carriers will provide a timely reference for further applications in tu-mor theranostics.展开更多
Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shape...Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.展开更多
Gliomas are the most common primary tumors of the central nervous system;among them,glioblastoma multiforme stands out as the most aggressive and lethal subtype,characterized by high therapeutic resistance and frequen...Gliomas are the most common primary tumors of the central nervous system;among them,glioblastoma multiforme stands out as the most aggressive and lethal subtype,characterized by high therapeutic resistance and frequent recurrences.Glioblastoma’s complex pathology is driven by biological and molecular factors that compromise conventional therapies,including blood-brain and bloodtumor barriers,angiogenesis,immune evasion,and aberrant signaling pathways,along with genetic drivers of drug resistance.In cancer therapy,mesoporous silica nanoparticles(MSNs)have shown promise as nanocarriers thanks to the unique attributes of their mesostructure,including large surfaces,uniform pore sizes,high loading efficiency,and flexibility of chemical modifications.Several studies have proposed MSNs to address a number of challenges facing drug delivery in gliomas,including limited penetration across the blood-brain barrier,non-specific biodistribution,and systemic adverse reactions.Moreover,MSNs can be functionalized with tumor-targeting ligands so that cancer cells are selectively taken up,while they can also release therapeutic agents in response to internal and external stimuli,enabling controlled drug delivery within tumor microenvironments.Herein,we review the integration of the MSN-based delivery approach with advances in molecular oncology to improve clinical outcomes for glioma therapeutics,while highlighting the concerns around their limited clinical translation and potential toxicity.展开更多
Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies betw...Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies between theoretical and experimental studies remain,particularly regarding strain rate effects during compression.Here,we examine strain rate influences on the shock-induced amorphous–amorphous phase transitions in fused silica by measuring its Hugoniot equation of state and longitudinal sound velocity(CL)up to 7 GPa at strain rates of 10^(6)–10^(7)s^(-1)using a one-stage light-gas gun.A discontinuity in the relationship between shock velocity(US)and particle velocity(UP)and a significant softening in C_(L)of fused silica were observed near~5 GPa under shock loading.Our results indicate that high strain rates restrict Si–O–Si rotation in fused silica,modifying their bonds and increasing silicon coordination.The transition pressure by shock compression is significantly higher than that under static high-pressure conditions(2–3 GPa),which agrees with some recent theoretical predictions with high compression rates,reflecting the greater pressure needed to overcome energy barriers with the strain rate increase.These findings offer insights into strain rate-dependent phase transitions in fused silica and other silicate minerals(e.g.,quartz,olivine,and forsterite),bridging gaps between theoretical simulations and experiments.展开更多
Soil cement bentonite(SCB)is a common material for constructing vertical cutoff walls to prevent groundwater migration at contaminated industrial sites.However,site contaminants can degrade the durability of the cutof...Soil cement bentonite(SCB)is a common material for constructing vertical cutoff walls to prevent groundwater migration at contaminated industrial sites.However,site contaminants can degrade the durability of the cutoff wall.To enhance its performance,this study developed a silica fume-SCB(SSCB).The macroscopic and microscopic properties of SSCB were assessed by unconfined compressive strength test,variable head permeability test,X-ray diffraction(XRD),scanning electron microscopy(SEM)and nuclear magnetic resonance(NMR)spectroscopy.The correlation between its multi-scale properties was analyzed based on pore characteristics.The results indicate that increasing the silica fume substitution ratio improved SSCB strength,especially in the middle and late curing stages.Moreover,increasing the substitution ratio decreased SSCB permeability coefficient,with a more pronounced effect in earlier curing stages.Silica fume addition also refined SSCB pore structure and reduced its porosity.The fractal dimension was used to quantify SSCB pore structure complexity.Increasing silica fume content reduced small pore fractal dimension in SSCB.Concurrently,SSCB strength increased and SSCB permeability coefficient decreased.The findings of this research will demonstrate the great potential of SSCB backfill for practical applications.展开更多
In our previous study,the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization(MDA)reaction.It has been confirmed that the physically mixed NiO n...In our previous study,the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization(MDA)reaction.It has been confirmed that the physically mixed NiO not only promoted the dispersion of MoC_(x)active sites but also reduced the coke formation on the MoC_(x)owing to the CNTs growth on Ni.However,the promotional effect of NiO was limited when the particle size was reduced,due to the excessive interaction with MoOx(forming NiMoO_(4))which is detrimental to the MoC_(x)dispersion.In this study,to overcome the limitation,silica shell on NiO particles with various sizes(5,15,110 nm)was introduced.The catalyst with silica shell coated NiO with the size of 15 nm exhibited a significant improvement in both BTX yield and stability,and the catalyst with silica shell coated NiO with the size of 5 nm achieved the highest maximum BTX yield,about 7.2%.This study demonstrates that the catalytic performance improved as the NiO particle size decreased with the introduction of the silica shell.Combined transmission electron microscopy-energy dispersive spectroscopy,X-ray diffraction,temperature-programmed surface reaction of methane,CO chemisorption,visible Raman,and thermogravimetric analysis allowed us to confirm that a thin silica shell further enhances the MoC_(x)dispersion while preventing the formation of Ni-Mo complexes.However,when the size of NiO decreased to 5 nm,CNT growth on Ni was limited during the reaction,which is crucial for reducing coke formation on Mo active sites,thereby resulting in the decreased catalyst stabilization ability of Ni.Overall,this study indicates that the introduction of a silica shell in a controlled way can significantly enhance the promotional effect of physically mixed NiO on MDA.展开更多
基金Funded by the Natural Science Foundation of Hubei Province(No.2024AFB833)。
文摘Silica fibers were modified by a specific ratio of SiB6 mixed with silica sol through vacuum impregnation method.The modified fibers were then incorporated into a phenolic resin matrix to prepare fiber-reinforced resin composites.The influences of the SiB_(6)/SiO_(2)mixed modification on silica fiber properties were analyzed through thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM),and X-ray diffraction(XRD),respectively.Additionally,the influence of the SiB_(6)/SiO_(2)mixed modification on the mechanical properties of phenolic resin matrix composites was evaluated through mechanical testing.The experimeatal results indicate that the SiB_(6)/SiO_(2)mixed surface modification shows significant improvement in strength at room temperature and high temperatures,and crystallization temperature of silica fiber increases.The SiB_(6)/Silica sol co-modified silica fiber shows potential for future application in thermal protection and other high-temperature conditions.
文摘According the importance of the stored grains and other products,it is an essential to keep them from khapra beetle,Trogoderma granarium infestation.This study determined the mortality percentage of 5th instar larvae of T.granarium fed on wheat seeds(25 gm)treated with different weights of silica as well as silica nanoparticles(20,40,60 and 80 mg)at different temperature(9℃,25℃,and 35℃).Study showed that using silica nanoparticles in cold temperature(9℃)was the most efficient treatment with the lowest LC_(50)(lethal concentration required to kill 50%of the population)value and caused the highest toxicity index.In contrast,the least efficient treatment(25℃)with the highest LC_(50) value and showed lowest toxicity index was using silica in normal temperature,when using silica nanoparticles,the cold temperature was the best condition followed by hot temperature(35℃)and finally the normal temperature.On the other hand,using silica in hot temperature was most effective followed by silica with cold temperature and finally silica with normal temperature.The biochemical assays revealed that the change in the experimental temperature had a nonsignificant effect on the total protein content of the larvae.The total lipids and total carbohydrates exhibited a significant increase due to hot treating.5th instar larvae of T.granarium treated with LC50 of silica at high temperature led to a nonsignificant(p≤0.05)decrease in Acetylcholinesterase(AchE)activity compared to treatment at normal temperature.In contrast,Glutathione S-transferase(GST)and Peroxidase activities were significantly(p≤0.05)raised due to the treatment conducted at high temperature.Additionally,treating larvae with LC50 of silica nanoparticles at low temperature caused a significant increase in both GST and peroxidase activities,while the increase in AChE was nonsignificantly(p≤0.05)compared to treatment at normal temperature.Using silica at low temperature could be used as an alternative to chemical insecticides to control T.granarium larvae.
基金Project supported by the National Natural Science Foundation of China (52064002)Guangxi Science and Technology Major Project(AA23073018)。
文摘A novel method for scandium recovery is proposed through high-surface area silanol-rich silica sorbents which were prepared with calcium silicate hydrate(C-S-H) as raw material.Two types of silanol-rich silica particles,i.e.,LAC-S(silica derived from acid leaching of amorphous C-S-H) and LLC-S(silica derived from acid leaching of low-crystallinity C-S-H) are obtained after calcium ions are removed from both amorphous and low-crystallinity forms of C-S-H through a facile acid leaching process(3 mol/L,25℃,24 h).(29)^Si NMR spectroscopy reveals that the proportion of silicon atoms carrying silanol groups increases from less than 43% to over 80% when silica particles are transferred from a dry state to an aqueous solution.Batch adsorption experiments were conducted to evaluate the sorption performance and selectivity of these silica sorbents toward Sc(Ⅲ).The scandium sorption capacities of LAC-S and LLC-S at an equilibrium pH of 4.2 are 174.45 and 129.57 mg/g,respectively.The separation factors(SFSc/Ln) of both silica particles exceed 1000 in the initial pH range of 3.5-5.The loaded scandium ions are recovered with 3 mol/L hydrochloric acid and the sorbents exhibit good reusability.This strategy provides an efficient and green method for recovering scandium from aqueous solutions.
基金supported by the National Natural Science Foun-dation of China(Grant No.U2167214).
文摘Due to excellent thermal insulation performance at room temperature and ultralow density,silica aero-gels are candidates for thermal insulation.However,at high temperatures,the thermal insulation prop-erty of silica aerogels decreased greatly caused by transparency to heat radiation.Opacifiers introduced into silica sol can block heat radiation yet destroy the uniformity of aerogels.Herein,we designed and prepared a silica aerogel composite with oriented and layered silica fibers(SFs),SiC nanowires(SiC_(NWs)),and silica aerogels,which were prepared by papermaking,chemical vapor infiltration(CVI),and sol-gel respectively.Firstly,oriented and layered SFs made still air a wall to block heat transfer by the solid phase.Secondly,SiC_(NWs) were grown in situ on the surface of SFs evenly to weave into the network,and the network reduced the gaseous thermal conductivity by dividing cracks in SFs/SiC_(NWs)/SA.Thirdly,SiC_(NWs) weakened the heat transfer by radiation at high temperatures.Therefore,SFs/SiC_(NWs)/SA presented remarkable thermal insulation(0.017 W(m K)^(-1) at 25℃,0.0287 W(m K)^(-1) at 500℃,and 0.094 W(m K)^(-1) at 1000℃).Besides,SFs/SiC_(NWs)/SA exhibited remarkable thermal stability(no size transform after being heat treated at 1000℃ for 1800 s)and tensile strength(0.75 MPa).These integrated properties made SFs/SiC_(NWs)/SA a promising candidate for highly efficient thermal insulators.
基金supported by the Natural Science Foundation of Sichuan Province(No.2022NSFSC0720)Research Center for the Development of the Comprehensive Health Industry and Rural Revitalization of Sichuan TCM(No.DJKYB202306)State Administration of Traditional Chinese Medicine of Sichuan Province of China(No.2020HJZX001).
文摘Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxylum bungeanum,which promotes the management of obesity by triggering the browning of white adipose tissue(WAT)targeting the membrane receptor of transient receptor potential vanilloid 1(TRPV1).However,HAS easily undergoes configuration transformation and oxidative degradation.The short peptide CKGGRAKDC or adipose-targeting sequence(ATS)binds specifically to prohibitin on the surface of WAT cells and can be used as recognition assembly to enhance adipocyte targetability.Furthermore,mesoporous silica nanoparticles(MSNs)are widely used in drug delivery systems because of their large specific surface area and pore volume.Therefore,HAS-loaded adipose-targeted MSNs(MSNs-ATS)were developed to enhance the adipocyte targetability,safety,and efficacy of HAS,and tested on mature 3T3-L1 cells and obese mouse models.MSNs-ATS showed higher specificity for adipocyte targetability without obvious toxicity.HAS-loaded MSNs-ATS showed anti-obesity effects superior to those of HAS alone.In conclusion,we successfully developed adipocyte-targeted,HAS-loaded MSNs with good safety and anti-obesity effects.
基金supported by the National Natural Science Foundation of China(Nos.22206207,22127810,and 22276224)the Natural Science Foundation of Guangdong Province(Nos.2021A1515011546 and 2023A1515010085)the Science and Technology Planning Project of Guangzhou(No.202102080005)。
文摘Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles of human alveolar type II epithelial cells(A549 cells)exposed directly to silica were characterized using non-targeted metabolomic approaches.A total of 84 differential metabolites(DMs)were identified in silica-treated A549 cells undergoing EMT,which were mainly enriched in metabolisms of amino acids(e.g.,glutamate,alanine,aspartate),purine metabolism,glycolysis,etc.The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica.Remarkably,glutamine catabolism was significantly promoted in the silica-treated A549 cells,and the levels of related metabolites(e.g.,succinate)and enzymes(e.g.,α-ketoglutarate(α-KG)dehydrogenase)were substantially up-regulated,with a preference toα-KG pathway.Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail(zinc finger transcription factor).Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.
文摘To alleviate the quality deterioration and extend the shelf life of crucian carp fillets,a bio-based active composite film integrating eugenol(EG)-loaded mesoporous silica nanoparticles(MSNs)modified with caffeic acid(CA)within the zein matrix(EG/CA-MSN/Zein)was developed.This study compared the effects of EG/CA-MSN/Zein,polyethylene(PE),and zein films on the quality of fish fillets during refrigerated storage.The results showed that the EG/CA-MSN/Zein film significantly retarded the increase in pH and microbial growth.Moreover,the film had higher water-holding capacity(WHC),better texture,and color stability,as indicated by low-field nuclear magnetic resonance(LF-NMR),magnetic resonance imaging(MRI),and sensory evaluation.The EG/CA-MSN/Zein composite film extended the shelf life of crucian carp fillets by 3-4 days,highlighting its potential as an environmentally friendly and efficient packaging material for aquatic products.
基金financially supported by the Yangzhou Key Research and Development Program: Industry Foresight and Key Core Technology (No. YZ2023019)Cooperation Project of Yangzhou City with Yangzhou University (No. YZ2023209)+2 种基金Jiangsu Provincial Six Talent Peaks Project (No. XCL-090)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)Yangzhou Bangjie New Materials Co., Ltd. for support。
文摘The micro-dispersion structure of silica fillers exerts significant infiuences on the performance characteristics of rubber-based products. How to monitor this parameter is an important issue in the rubber industry, but there is currently no suitable technical solution for numerical monitoring that can be applied in automatic production line. The labeling of silica in rubber is a challenge that bottlenecks the development of numerical quality monitoring technology. In this work, we employed the organometallic europium to modify silica endowing the fiuorescence properties for characterization. It provides more feasible solutions for visually studying the relationship between the submicroscopic structure and macroscopic properties of inorganic-filled polymers, and is the key foundation for achieving numerical monitoring of rubber filler qualities in industry.
基金Funded by the Opening Funding of the Provincial and Ministerial Joint Construction of the State Key Laboratory of New Textile Materials and Advanced Processing Technology(No.FZ2020003)the Science and Technology Innovation Program of Wuhan Textile University(No.233060)。
文摘Ordered porous silica nanospheres with pores vertical to the walls were prepared by using 1,3,5-trimethyl-benzen(TMB)and hexadecitrile trimethyl ammonium bromide(CTAB)as templates.After removing the templates,porous structures were obtained.The porous silica nanosperes were further modified with amino and amino acid functionalization to obtain L-Glutamic acid-functionalized mesoporous silica nanospheres,which were used as chiral selective agents for amino acid enantioseparation such as PheCOOH,PhgCOOH,and TrpCOOH enantiomers.The experimental results show that the functionalized nanospheres have good adsorption selectivity for D-PheCOOH and L-PhgCOOH,especially showing high adsorption selectivity for the L-TrpCOOH enantiomers compared with L-PheCOOH and D-PhgCOOH and D-TrpCOOH enantiomers.
基金financially supported by the Ningbo Institute of Digital Twin,Eastern Institute of Technology,Ningbo.We also acknowledge supportfrom the Young Innovative Talent of Yongjiang Talent Project(2023A‐387‐G).
文摘The efficient storage and application of sustainable solar energy has drawn significant attention from both academic and industrial points of view.However,most developed catalytic materials still suffer from insufficient mass diffusion and unsatisfactory durability due to the lack of interconnected and regulatable porosity.Developing catalytic architectures with engineered active sites and prominent stability through rational synthesis strategies has become one of the core projects in solar-driven applications.The unique properties of mesoporous silicas render them among the most valuable functional materials for industrial applications,such as high specific surface area,regulatable porosity,adjustable surface properties,tunable particle sizes,and great thermal and mechanical stability.Mesoporous silicas serve as structural templates or catalytic supports to enhance light harvesting via the scattering effect and provide large surface areas for active site generation.These advantages have been widely utilized in solar applications,including hydrogen production,CO_(2)conversion,photovoltaics,biomass utilization,and pollutant degradation.To achieve the specific functionalities and desired activity,various types of mesoporous silicas from different synthesis methods have been customized and synthesized.Moreover,morphology regulation and component modification strategies have also been performed to endow mesoporous silica-based materials with unprecedented efficiency for solar energy storage and utilization.Nevertheless,reviews about synthesis,morphology regulation,and component modification strategies for mesoporous silica-based catalyst design in solar-driven applications are still limited.Herein,the latest progress concerning mesoporous silica-based catalysis in solar-driven applications is comprehensively reviewed.Synthesis principles,formation mechanisms,and rational functionalities of mesoporous silica are systematically summarized.Some typical catalysts with impressive activities in different solar-driven applications are highlighted.Furthermore,challenges and future potential opportunities in this study field are also discussed and proposed.This present review guides the design of mesoporous silica catalysts for efficient solar energy management for solar energy storage and conversion applications.
基金supported by National Key Research and Development Program of China(Grant No.2022YFB4101200)the National Natural Science Foundation of China(Grant Nos.22072184 and 22372199)the Young Top‐notch Talent Cultivation Program of Hubei Province.
文摘Metal nanoparticles used in high‐temperature catalytic reactions,such as dry reforming of methane,are prone to sintering,leading to particle growth,loss of active surface area,and eventual catalyst deactivation.This is particularly true for nickelbased catalysts,which,despite their high activity and low cost,often suffer from severe agglomeration and carbon deposition under harsh reforming conditions.Therefore,effectively preventing metal particle growth is crucial for achieving long‐term catalytic stability.In this work,we present a robust strategy to stabilize monodispersed Ni nanoclusters(NCs,1 wt.%)by anchoring them onto a silica‐coated silicon carbide support(SiC@SiO_(2)).The resulting Ni/SiC@SiO_(2) catalyst exhibited outstanding performance at 800℃,with 90%conversion for both CH_(4) and CO_(2).The Ni NCs maintained a uniform size(~1.8 nm)after stability testing,in contrast to the severe sintering(~9.3 nm)and low activity(<10%conversion)observed for Ni on unmodified SiC.The silica layers played a key role in chemically confining the Ni NCs,enhancing their dispersion and thermal stability.Furthermore,the formation of Ni‒O‒Si interfacial structures improved metal‐support interactions,effectively suppressing the reverse water–gas shift(RWGS)reaction and facilitating carbon oxidation via CO_(2) activation.This interfacial engineering strategy significantly enhanced the catalyst's resistance to both sintering and coking,offering a generalizable approach to designing durable metal catalysts for high‐temperature reactions.
基金Innovation Groups of Basic Research in Gansu Province(No.23JRRA570)。
文摘An ionic liquid assisted hydrogel modified silica was synthesized using a one-pot polymerization and physical coating technique and subsequently applied to mixed-mode liquid chromatography.Analytical techniques,including Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and elemental analysis,etc.,confirmed the successful prepared of this innovative stationary phase.The unique combination of amide,long alkyl chain,and imidazole ring in the hydrogel coating enables the stationary phase to function effectively in hydrophilic/reversed-phase/ion exchange liquid chromatography.Notably,the stationary phase exhibited superior separation performance owing to the synergistic effect of the ionic liquid and hydrogel.This was particularly evident when analyzing various analytes such as organic acids,nucleosides/bases,polycyclic aromatic hydrocarbons(PAHs)and anions.Furthermore,under our operating conditions,an excellent column efficiency of 53,642.9 plates/m was achieved for theobromine.In summary,we have proposed a straightforward strategy to enhance the separation performance of hydrogel coatings in liquid chromatography,thereby broadening the potential applications of hydrogels in the field of separation.
基金the Youth Innovation Promotion Association of Chinese Academy of Science(No.2021160)the National Natural Science Foundation of China(No.51802319)the Technology and Engineering Center for Space(No.CSU-QZKT-2019-04)。
文摘Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades.Previous research on ceramic core molding was primarily conducted using vertical printing techniques,which not only resulted in lengthy molding durations but also compromised the mechanical strength.In this work,silica(SiO--_2)ceramic cores,with fine complex geometric shapes,were fabricated using 65vol.%ceramic slurry by digital light processing(DLP)with different printing angles.Printing angles significantly impact the surface accuracy,shrinkage,printing efficiency of green bodies,as well as the microstructure and mechanical properties of sintered ceramic core samples.As the printing angle in the green body increases,the bonding area decreases,surface roughness on the XY plane worsens,shrinkage in the Z direction becomes more pronounced,and the printing efficiency declines.Similarly,an increase in the printing angle in the sintered body leads to a reduction in bending strength.At a printing angle of 30°,the printing time is reduced to half of that at 90°,which improves the molding efficiency.Meanwhile,the obtained bulk density of 1.71 g·cm~(-3),open porosity of 24%,and fiexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores.Therefore,designing and optimizing the printing angles can achieve the balance between shrinkage,printing efficiency,and fiexural strength.
文摘Laminated elastomeric bearings used in seismic isolation rely on the mechanical properties of their constituent elastomers to ensure effective performance.However,despite their resistance to temperature fluctuations and environmental aggressors,silicone elastomers exhibit relatively low stiffness,limiting their direct applicability in seismic isolation.This study investigates the effect of fumed silica as a reinforcing filler to enhance the mechanical properties of laminated silicone elastomeric bearings.Elastomeric samples were fabricated with varying fumed silica proportions and subjected to Shore A hardness,uniaxial tensile,and lap shear tests to assess the influence of filler content.Additionally,quasi-static tests were conducted on reduced-scale bearing prototypes under combined vertical compression and cyclic horizontal shear to evaluate their seismic isolation performance.The results demonstrate that fumed silica reinforcement significantly increases stiffness,as evidenced by higher Shore A hardness values.However,a trade-off was observed in tensile properties,with reductions in tensile strength and elongation at break.Despite this,the equivalent elastic modulus did not show substantial variation up to large deformations,indicating that stiffness is preserved under most working conditions.Lap shear tests showed that fumed silica improves shear resistance,while quasi-static tests revealed inelastic behavior with small increases in equivalent shear coefficients but no substantial loss in damping ratios.These findings suggest that fumed silica reinforcement enhances silicone elastomers’stiffness and shear resistance while maintaining moderate damping properties,making it a promising approach for improving the mechanical performance of elastomeric bearings in seismic isolation applications.
基金from"XingLiao Talent Program"of Liaoning Province(No.XLYC2203156)Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program(No.RC220397)are greatly acknowledged。
文摘Mesoporous silica nanoparticles(MsNs)are thought to be an attractive drug delivery material because of their advantages including high specific surface area,tunable pore size and morphology,easy sur-face modification and good biocompatibility.However,as a result of the poor biodegradability of MsNs,their biomedical applications are limited.To break the bottleneck of limited biomedical applications of MSNs,more and more researchers tend to design biodegradable MSNs(b-MSNs)nanosystems to obtain biodegradable as well as safe and reliable drug delivery carriers.In this review,we focused on sum-marizing strategies to improve the degradability of MsNs and innovatively proposed a series of advan-tages of b-MsNs,including controlled cargo release behavior,multifunctional frameworks,nano-catalysis,bio-imaging capabilities and enhanced therapeutic effects.Based on these advantages,we have inno-vatively summarized the applications of b-MsNs for enhanced tumor theranostics,including enhanced chemotherapy,delivery of nanosensitizers,gas molecules and biomacromolecules,initiation of immune response,synergistic therapies and image-guided tumor diagnostics.Finally,the challenges and further clinical translation potential of nanosystems based on b-MsNs are fully discussed and prospected.We believe that such b-MsNs delivery carriers will provide a timely reference for further applications in tu-mor theranostics.
基金financially supported by the Liaoning Province Science and Technology Plan Joint Program(2023JH2/101700037).
文摘Ceramic cores are key to forming a cooling structure within the hollow blade cavities.The use of stereolithography(SL)3D printing technology eliminates the need for moulds,facilitating the preparation of complex-shaped ceramic cores.In this study,silica-based ceramic cores incorporating nano-3YSZ(3mol.% yttria stabilised zirconia)and micron-sized Y_(2)O_(3) were prepared via SL 3D printing ceramic technology to promote the formation of cristobalite and ZrSiO_(4),thereby improving the high-temperature properties.The flexural strength at 25℃ and 1,500℃,deflection at 1,500℃,shrinkage rate,and porosity of the core samples sintered at different temperatures(1,170℃,1,185℃,1,200℃,1,215℃,and 1,230℃)were tested and investigated.The mechanism underlying the high temperature performance of the cores was elucidated through analysis of cross-sectional morphology,element distribution,and phase constitution of the samples.As the sintering temperature increases,the shrinkage and flexural strength at 25℃ of the core rise,while the open porosity and deflection at 1,500℃ decrease.When the sintering temperature reaches 1,200℃ or higher,the 1,500℃ flexural strength can be measured,which increases as the sintering temperature rises.The core exhibits excellent creep resistance when sintered at temperatures of 1,200℃ and above.Considering the comprehensive performance requirements for the core,the sintering temperature of 1,200℃ was selected.At the sintering temperature of 1,200℃,the core exhibits shrinkage rates of 3.76%(X),3.38%(Y),and 3.95%(Z),alongside a flexural strength of 9.01 MPa at 25℃ and 32.15 MPa at 1,500℃,and an open porosity of 26.39%.The deflection of the core at 1,500℃ is 0.15 mm,which helps to maintain the dimensional stability of the ceramic core during casting.XRD results indicate that samples fractured after 25℃ flexural strength test still contain amorphous quartz glass,alongside substantial quantities of yttria stabilized zirconia and Y_(2)O_(3).Samples fractured after 1,500℃ flexural strength test exhibit significant crystallisation of amorphous quartz glass into cristobalite,with silica and 3YSZ combining to form ZrSiO_(4).Y_(2)O_(3) as a network modifier of the glass network destroys the bridging oxygen in the silica-oxygen bond,thereby reducing the energy required for glass crystallisation and promoting the crystallisation reaction of quartz glass to form cristobalite.In addition,nano-3YSZ combines with SiO_(2) at high temperatures to form ZrSiO_(4).Since cristobalite and ZrSiO_(4) are crystals,both of them have strong creep resistance,thus improving the high temperature flexural strength and deformation resistance of the ceramic cores.
文摘Gliomas are the most common primary tumors of the central nervous system;among them,glioblastoma multiforme stands out as the most aggressive and lethal subtype,characterized by high therapeutic resistance and frequent recurrences.Glioblastoma’s complex pathology is driven by biological and molecular factors that compromise conventional therapies,including blood-brain and bloodtumor barriers,angiogenesis,immune evasion,and aberrant signaling pathways,along with genetic drivers of drug resistance.In cancer therapy,mesoporous silica nanoparticles(MSNs)have shown promise as nanocarriers thanks to the unique attributes of their mesostructure,including large surfaces,uniform pore sizes,high loading efficiency,and flexibility of chemical modifications.Several studies have proposed MSNs to address a number of challenges facing drug delivery in gliomas,including limited penetration across the blood-brain barrier,non-specific biodistribution,and systemic adverse reactions.Moreover,MSNs can be functionalized with tumor-targeting ligands so that cancer cells are selectively taken up,while they can also release therapeutic agents in response to internal and external stimuli,enabling controlled drug delivery within tumor microenvironments.Herein,we review the integration of the MSN-based delivery approach with advances in molecular oncology to improve clinical outcomes for glioma therapeutics,while highlighting the concerns around their limited clinical translation and potential toxicity.
基金supported by the National Natural Science Foundation of China(Grant Nos.42422201,12175211,and 12350710177)the Sichuan Science and Technology Program(Grant No.2023NSFSC1910).
文摘Fused silica(SiO_(2)glass),a key amorphous component of Earth’s silicate minerals,undergoes coordination and phase transformations under high pressure.Although extensive studies have been conducted,discrepancies between theoretical and experimental studies remain,particularly regarding strain rate effects during compression.Here,we examine strain rate influences on the shock-induced amorphous–amorphous phase transitions in fused silica by measuring its Hugoniot equation of state and longitudinal sound velocity(CL)up to 7 GPa at strain rates of 10^(6)–10^(7)s^(-1)using a one-stage light-gas gun.A discontinuity in the relationship between shock velocity(US)and particle velocity(UP)and a significant softening in C_(L)of fused silica were observed near~5 GPa under shock loading.Our results indicate that high strain rates restrict Si–O–Si rotation in fused silica,modifying their bonds and increasing silicon coordination.The transition pressure by shock compression is significantly higher than that under static high-pressure conditions(2–3 GPa),which agrees with some recent theoretical predictions with high compression rates,reflecting the greater pressure needed to overcome energy barriers with the strain rate increase.These findings offer insights into strain rate-dependent phase transitions in fused silica and other silicate minerals(e.g.,quartz,olivine,and forsterite),bridging gaps between theoretical simulations and experiments.
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(52274182)supported by the National Natural Science Foundation of China+1 种基金Project(2021zzts0274)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(CX20210295)supported by the Postgraduate Scientific Research Innovation Project of Hunan Province,China。
文摘Soil cement bentonite(SCB)is a common material for constructing vertical cutoff walls to prevent groundwater migration at contaminated industrial sites.However,site contaminants can degrade the durability of the cutoff wall.To enhance its performance,this study developed a silica fume-SCB(SSCB).The macroscopic and microscopic properties of SSCB were assessed by unconfined compressive strength test,variable head permeability test,X-ray diffraction(XRD),scanning electron microscopy(SEM)and nuclear magnetic resonance(NMR)spectroscopy.The correlation between its multi-scale properties was analyzed based on pore characteristics.The results indicate that increasing the silica fume substitution ratio improved SSCB strength,especially in the middle and late curing stages.Moreover,increasing the substitution ratio decreased SSCB permeability coefficient,with a more pronounced effect in earlier curing stages.Silica fume addition also refined SSCB pore structure and reduced its porosity.The fractal dimension was used to quantify SSCB pore structure complexity.Increasing silica fume content reduced small pore fractal dimension in SSCB.Concurrently,SSCB strength increased and SSCB permeability coefficient decreased.The findings of this research will demonstrate the great potential of SSCB backfill for practical applications.
文摘In our previous study,the activity and stability of the Mo/HZSM-5 catalyst were enhanced by mixing physically with NiO in methane dehydroaromatization(MDA)reaction.It has been confirmed that the physically mixed NiO not only promoted the dispersion of MoC_(x)active sites but also reduced the coke formation on the MoC_(x)owing to the CNTs growth on Ni.However,the promotional effect of NiO was limited when the particle size was reduced,due to the excessive interaction with MoOx(forming NiMoO_(4))which is detrimental to the MoC_(x)dispersion.In this study,to overcome the limitation,silica shell on NiO particles with various sizes(5,15,110 nm)was introduced.The catalyst with silica shell coated NiO with the size of 15 nm exhibited a significant improvement in both BTX yield and stability,and the catalyst with silica shell coated NiO with the size of 5 nm achieved the highest maximum BTX yield,about 7.2%.This study demonstrates that the catalytic performance improved as the NiO particle size decreased with the introduction of the silica shell.Combined transmission electron microscopy-energy dispersive spectroscopy,X-ray diffraction,temperature-programmed surface reaction of methane,CO chemisorption,visible Raman,and thermogravimetric analysis allowed us to confirm that a thin silica shell further enhances the MoC_(x)dispersion while preventing the formation of Ni-Mo complexes.However,when the size of NiO decreased to 5 nm,CNT growth on Ni was limited during the reaction,which is crucial for reducing coke formation on Mo active sites,thereby resulting in the decreased catalyst stabilization ability of Ni.Overall,this study indicates that the introduction of a silica shell in a controlled way can significantly enhance the promotional effect of physically mixed NiO on MDA.
