Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbona...Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbonate.The morphology,thermal properties and microstructure of the calcium carbonate micro-to-nanoscale crystals were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG） and X-ray diffraction（XRD） analysis.The results show that the volume fraction of egg white protein has great influence on the shape,size and morphology of calcium carbonate crystals.The calcium carbonate crystals were the mixtures of calcite-vaterite-like crystals including spherical and rough surface,which are different from that formed in pure water.With the increase of egg white protein concentration,the diameter of calcium carbonate crystals changed,the amount of formed spherical calcium carbonate particles decreased and that of vaterite increased.These results indicate that the coordination and electrostatic interaction between egg white protein and Ca2＋ significantly affect the calcium carbonate crystalization.展开更多
Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and mor...Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.展开更多
Lattice defects induced by ion implantation into SiC have been widely investigated in the decades by various techniques.One of the non-destructive techniques suitable to study the lattice defects in SiC is the optical...Lattice defects induced by ion implantation into SiC have been widely investigated in the decades by various techniques.One of the non-destructive techniques suitable to study the lattice defects in SiC is the optical characterization.In this work,confocal Raman scattering spectroscopy and photoluminescence spectrum have been used to study the effects of 134-keV H_(2)^(+)implantation and thermal treatment in the microstructure of 6H-SiC single crystal.The radiation-induced changes in the microstructure were assessed by integrating Raman-scattering peaks intensity and considering the asymmetry of Raman-scattering peaks.The integrated intensities of Raman scattering spectroscopy and photoluminescence spectrum decrease with increasing the fluence.The recovery of the optical intensities depends on the combination of the implantation temperature and the annealing temperature with the thermal treatment from 700℃to 1100℃.The different characterizations of Raman scattering spectroscopy and photoluminescence spectrum are compared and discussed in this study.展开更多
The coatings of microorganism-induced calcium carbonate onto the stone surface carried out by using both of the immersion method and coating method were investigated. Various analysis and testing techniques such as sc...The coatings of microorganism-induced calcium carbonate onto the stone surface carried out by using both of the immersion method and coating method were investigated. Various analysis and testing techniques such as scanning electron micrograph （SEM） and X-ray diffraction （XRD） were used to characterize the deposited mineral layer. The adhesive property, acid re- sistance, frost resistance, light and aging resistance, water adsorption and permeability were investigated in detail. The results showed that both immersion method and coating method could produce calcium carbonate granules with sizes ranging from 1 to 10 pm and form a layer of dense mineralization membrane which is about 50 to 100 pm thick. Immersion method was more efficient than coating method. The large cohesive force between calcium carbonate layer and stone materials could improve the acid rain resistance as well as excellent heat tolerance, frost resistance and light aging resistance. The coating process could not only help the stone materials maintain its original permeability with the aid of calcium carbonate layers but also improve the penetration resistance significantly. Therefore, this type of technology shows a great potential in the protection of stone relics.展开更多
Adhesively Bonded Carbon Fibre Reinforced Plastic(CFRP)and titanium alloy have been extensively used as a hybrid structure in modern aircrafts due to their excellent combination of mechanical properties and chemical s...Adhesively Bonded Carbon Fibre Reinforced Plastic(CFRP)and titanium alloy have been extensively used as a hybrid structure in modern aircrafts due to their excellent combination of mechanical properties and chemical stabilities.This study utilised NaOH anodising method to create micro-rough titanium surfaces for enhancing adhesive bonding between titanium alloy and CFRP laminates.A special and simple technique named Resin Pre-Coating(RPC)was also employed to improve the surface wetting of anodised titanium and grinded CFRP substrates.The influences of anodising temperature and duration on the surface morphology,wettability and adhesive bond strength were investigated.The single lap shear test results showed that the bond strength of specimens anodised at 20℃for 15 min improved by 135.9%and 95.4%,respectively,in comparison with that of acid pickled and grinded specimens(without RPC treatment).Although increasing the anodising temperature and duration produced rougher titanium surfaces,the adhesively bonded joints were not strong enough due to relatively friable titanium oxide layers.展开更多
Safe and efficient capturing of volatile radioiodine is of extremely important significance in the treatment of spent fuel.Herein,the flake channels in gelatin-hydroxyapatite(HAP@Ge)cryogel with excellent flame retard...Safe and efficient capturing of volatile radioiodine is of extremely important significance in the treatment of spent fuel.Herein,the flake channels in gelatin-hydroxyapatite(HAP@Ge)cryogel with excellent flame retardant properties were constructed by immobilizing hydroxyapatite nanorods(HAP)on Gelatin(Ge)cryogel for enhancing the capturing of iodine.The immobilization of HAP nanorods enhanced thermal stability,provided low rates of dynamic heat transfer and dissipation,and remarkably improved the flame retardant and smoke suppression properties of the Ge cryogel,which can effectively prevent the occurrence of safety incidents caused by further thermal degradation or combustion of this cryogel.More importantly,it was effective in improving the rapid enrichment of iodine,resulting in a high adsorption capacity.The maximum adsorption capacity of HAP@Ge cryogel for iodine vapor reached 2693 mg/g at equilibrium.The high adsorption capacity for iodine was attributed to the multi-scale porous structure in HAP@Ge cryogel,which offered effective channels for iodine diffusion,whereas the numerous complex and irregular flakes provided sufficient number of active sites for iodine capture.The adsorption process was chemical in nature and involved the-PO_(4)^(3-),-OH,-C=O,and-NHR groups on HAP@Ge cryogel.Moreover,the complex porous structure of HAP@Ge cryogel enhanced the physical capturing of iodine.These advantages,such as low-cost raw material,simple preparation method,good flame retardancy,and excellent capturing performance for iodine indicated that HAP@Ge cryogel is a potential candidate for the removal of radioactive iodine in the exhaust gas stream of post-treatment plants.展开更多
Filtering media is anything placed in a filter that changes the quality of water flowing through it.With the variety of media available,proper selection of filter media is of great importance for filter performance.Re...Filtering media is anything placed in a filter that changes the quality of water flowing through it.With the variety of media available,proper selection of filter media is of great importance for filter performance.Recycled glass is evaluated as an alternative to silica sand in media filters and is an effective medium with the advantages of lower cost than silica sand,more environmental friendliness as it is a recycled product,and ease to pulverize into different sizes for specific design requirements.However,the filtration efficiency of regenerated recycled glass is limited by the formation of biofilms on its surfaces due to the large number of microorganisms such as bacteria and algae existing in the water.In this study,hydrofluoric(HF)acid etched glass spheres(GSs)modified with polydopamine(PDA)and silver nanoparticles(PDA-AgHF/GSs)were fabricated on the surface of soda-lime GSs by HF etching,crystal in situ growth,and PDA coating.HF etching and the modification of PDA coating imparted good hydrophilicity to PDA-Ag-HF/GSs.The modification of the silver coating also rendered PDA-Ag-HF/GSs excellent antibacterial properties and reduced Chlorella adhesion,and inhibited microorganism growth ability by releasing Ag^+.The catechol functional group on the PDA coating could regulate the Ag^+release by chelation.Good antibacterial properties,anti-algae adhesion,and controlled release of Ag^+indicate that PDA-Ag-HF/GS coating can effectively inhibit the formation of biofilm on the surface of the material,providing a new strategy for the formation of anti-biofilm.展开更多
Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP speci...Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP specimens with 0,2,4,6,8 g/m^(2)AP were tested under uniaxial compression.Those flexible AP fibers,filling the resin-rich regions and further constructing the fiber bridging at the ply interfaces,can effectively suppress delamination growth and lead to very good improvements both in the compressive strength and the elastic modulus.The CFRP specimen with an optimum interlay thickness has a distinct shear failure mode instead of the typical delamination cracking along the direction of continuous carbon fibers.Compressive Strengths After Impacts(CAI)of 12.35 J were also measured,up to 90%improvement in CAI has been observed.It is concluded those ultra-thin interlays of non-woven AP micro/nano-fibers are beneficial to design and manufacture“high strength”CFRP composites.展开更多
Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the i...Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the issues in the Resin-Rich Region(RRR)and Interfacial Transition Region(ITR)of fiber reinforced polymer composites,the characteristic Aramid Pulp(AP)fibers with micro-fiber trunk and nano-fiber branches were manufactured into multiple non-woven ultra-thin interleaving at the interlayers of BFRP composites via compression molding to reinforce the flexural strengths and elastic moduli.AP fibers were introduced into RRR to form interleaving at the interlayer,the brittle epoxy adhesive layer was improved and enabled to avoid cracking under a low external load.Free fiber branches of AP were also embedded into BF layer to construct quasi-vertical fiber bridging behaviors in ITR,stronger mechanical interlocking was created to prevent crack propagation along the bonding interface of BF/epoxy.Three-point bending testing results showed the interleaving film with 4 g/m^(2)AP exhibited the best effect among various areal densities and yielded average 315.75 MPa in flexural strength and 21.38 GPa in elastic modulus,having a 63.4%increment and a 47.1%increment respectively compared with the bases.Overall,the simple and low-cost AP interleaving is confirmed as an effective method in improving interlayer structure and flexural performance of BFRP composites,which may be considered to manufacture high-performance laminated fiber reinforced polymer composites in civil aviation industry.展开更多
Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characteriz...Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence(XRF), and Fourier transform infrared reflection(FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(Ⅵ) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U.Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10^(6)Bq/kg, and the β-activity concentration was 2.27×10^(5)Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.展开更多
Design of rapidly detachable adhesives with high initial bonding strength is of great significance but it is full of great challenge. Here, we report the fast electrically detaching behavior (100% detaching efficiency...Design of rapidly detachable adhesives with high initial bonding strength is of great significance but it is full of great challenge. Here, we report the fast electrically detaching behavior (100% detaching efficiency in just 1 min under dozens of DC voltage) and high initial bonding strength (>12 MPa) of epoxy-based ionic conductive adhesives (ICAs). The epoxy-based ICAs are fabricated by introducing polyethylene glycol dimethyl ether (PEGDE) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM]OTF) into epoxy. The combination of PEGDE and [EMIM]OTF enables the free ions to migrate directively in electric field, and the anchoring of PEG chains onto epoxy chains ensures the long-term reliability of ICAs. The investigation on the electrically detaching mechanism suggests that the enrichment and following rapid interfacial electrochemical reactions of [EMIM]OTF lead to formation of metal hydroxide (Me(OH)n) nanoparticles at the bonding interfaces, thus the strong interactions containing interlocked forces, van de Waals’ forces and hydrogen bonding interactions between ICAs and bonding substrates are destroyed. This work provides a promising direction for detachable adhesives with both high initial bonding strength and high detaching efficiency in short time.展开更多
Fourfold benzocyclobutene-functionalized perylene bisimide（PBI 4） has been synthesized and its structure was characterized by FTIR,MS and NMR.PBI 4 can react either with itself,or the appropriate dienophiles to form...Fourfold benzocyclobutene-functionalized perylene bisimide（PBI 4） has been synthesized and its structure was characterized by FTIR,MS and NMR.PBI 4 can react either with itself,or the appropriate dienophiles to form the corresponding products under appropriate temperature.The polymer film obtained from the reaction of PBI 4 with methyl vinyl silicone rubber possessed excellent film forming properties including flatness.The optical properties of PBI 4 and polymer film obtained from the reaction of PBI 4 and methyl vinyl silicone rubber have been determined by UV/vis and fluorescence spectroscopy.展开更多
The high-strength Basalt Carbon Fiber Reinforced Polymer(BCFRP)composites had been manufactured by guiding Imitating Tree-root Micro/Nano Aramid Short Fiber(ITMNASF)into the interlayer of Basalt Fiber(BF)and Carbon Fi...The high-strength Basalt Carbon Fiber Reinforced Polymer(BCFRP)composites had been manufactured by guiding Imitating Tree-root Micro/Nano Aramid Short Fiber(ITMNASF)into the interlayer of Basalt Fiber(BF)and Carbon Fiber(CF)plies to form thin interleaving,and various mass proportions of IT-MNASF were designed to discuss the reinforcing effect on the BCFRP heterogeneous composites.The results of three points bending tests showed that flexural strength and energy absorption of 4wt%IT-MNASF reinforced BCFRP heterogeneous composites had been improved by 32.4%and 134.4%respectively compared with that of unreinforced specimens.The 4wt%IT-MNASF reinforced BCFRP specimens showed both a greater strength and a lower cost(reduced by 31%around)than that of plain CFRP composites.X-ray micro-computed tomography scanning results exhibited that the delamination-dominated failure of plain BCFRP composites was changed into multi-layer BF and CF fabrics damage.The reinforcing mechanism revealed that the introduced IT-MNASF could construct quasi-vertical fiber bridging,and it was used as"mechanical claws"to grasp adjacent fiber layers for creating a stronger mechanical interlocking,and this effectively improved resin-rich region and interfacial transition region at the interlayers.The simple and effective IT-MNASF interleaving technique was very successful in low-cost and high-strength development of BCFRP heterogeneous composites.展开更多
High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chi...High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chinese Baijiu.In this study,the potential functional microbiota responsible for production of acetic acid was explored by correlation analysis and function prediction in Nong-xiang Daqu from different geographical regions.Our results revealed that the microbial community of Daqu starter was correlated with its acetic acid content.In addition,the relative abundances of Weissella,Lactobacillus,Bacillus,Kroppenstedtia,and Pichia were higher in the Daqu with high content of acetic acid.Furthermore,Acetobacter,Weissella,Lactobacillus,Pichia,Candida,and Rhizo-mucor were significantly(p<0.01)and positively correlated with acetic acid.Meanwhile,higher abundances of most genes that encoding enzymes participated in glycolysis and pentose phosphate pathways for acetic acid synthesis,were observed by PICRUSt2 approach in the Daqu starters with high content of acetic acid.Taken together,Acetobacter,Weissella,Lactobacillus,Pichia,and Candida were determined as the potential functional microbiota for producing acetic acid in Nong-xiang Daqu starters.These results provided evidence of microbiota for revealing the possible causes of high acetic acid and ethyl acetate in Nong-xiang Baijiu brewing process,and laid theoretical foundation for regulation of Baijiu fermentation by functional microbiota.展开更多
Raw and modified albite catalysts, including Pb/Atbite and Fe/Albite catalysts, have been investigated for methane conversion to C2 hydrocarbons under non-oxidative conditions. Introduction of Pb to albite improved th...Raw and modified albite catalysts, including Pb/Atbite and Fe/Albite catalysts, have been investigated for methane conversion to C2 hydrocarbons under non-oxidative conditions. Introduction of Pb to albite improved the activity and selectivity to non-coke products. Based on characterization, it was found that Pb entered into the alkali and alkaline-earth metal sites of albite, while partial Fedoped in the tetrahedron sites and the other loaded on the surface of albite. At the reaction temperature of 1073 K, methane gas hourly space velocity （GHSV） of 2 L.gcat-1·h-1, catalyst dosage of 0.25 g （300 mesh）, the methane conversion catalyzed by raw albite in the fixed-bed micro reactor exhibited a methane conversion of 3.32%. Notably, introducing a Pb content of 3.4 wt% into albite greatly enhanced the conversion of methane up to 8.19%, and the selectivity of C2 hydrocarbons reached 99% without any coke under the same reaction conditions. While Fe-doping could weakly heighten the methane conversion to 3.97%, and coke was formed. Thus, a comparison of Pb/Albite and Fe/Albite catalysts demonstrates that the catalytic activity of albite is mainly decided by alkali and alkaline-earth metal sites, and lead-modification can effectively improve the catalytic activity of albite.展开更多
Calcite surface was modified with stearic acids,and the interaction between them was investigated both experimentally and theoretically.Stearic-acid-modified calcite powders were investigated with Fourier transform in...Calcite surface was modified with stearic acids,and the interaction between them was investigated both experimentally and theoretically.Stearic-acid-modified calcite powders were investigated with Fourier transform infrared spectroscopy,X-ray diffraction,zeta potential analyser and contact angle measurement.Then,the density functional theory calculations were performed to explore the interaction at the atomic scale.The experi-mental results and simulation indicated that stearic acids interact with calcite surface via chelation between the double-bond O atom of-COOH and the Ca atom on calcite surface.The terminal methyl group of the stearic acids decreases the hydrophilicity of the calcite surface,and the interaction between different crystal faces of calcite is different.展开更多
基金Supported by the Key Projects in the National Science & Technology Pillar Program During the Eleventh Five-year Plan Period,China(No.2007BAB18B08)
文摘Crystal growth of calcium carbonate in biological simulation was investigated via egg white protein with different volume fractions,during which calcium carbonate was synthesized by calcium chloride and sodium carbonate.The morphology,thermal properties and microstructure of the calcium carbonate micro-to-nanoscale crystals were characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infrared spectroscopy（FTIR）,thermogravimetric analysis（TG） and X-ray diffraction（XRD） analysis.The results show that the volume fraction of egg white protein has great influence on the shape,size and morphology of calcium carbonate crystals.The calcium carbonate crystals were the mixtures of calcite-vaterite-like crystals including spherical and rough surface,which are different from that formed in pure water.With the increase of egg white protein concentration,the diameter of calcium carbonate crystals changed,the amount of formed spherical calcium carbonate particles decreased and that of vaterite increased.These results indicate that the coordination and electrostatic interaction between egg white protein and Ca2＋ significantly affect the calcium carbonate crystalization.
文摘Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.
基金the National Natural Science Foundation of China(Grant No.12075194)the Sichuan Provincial Science and Technology Program,China(Grant No.2020ZYD055)the National Key Research and Development Program of China(Grant No.2017YFE0301306).
文摘Lattice defects induced by ion implantation into SiC have been widely investigated in the decades by various techniques.One of the non-destructive techniques suitable to study the lattice defects in SiC is the optical characterization.In this work,confocal Raman scattering spectroscopy and photoluminescence spectrum have been used to study the effects of 134-keV H_(2)^(+)implantation and thermal treatment in the microstructure of 6H-SiC single crystal.The radiation-induced changes in the microstructure were assessed by integrating Raman-scattering peaks intensity and considering the asymmetry of Raman-scattering peaks.The integrated intensities of Raman scattering spectroscopy and photoluminescence spectrum decrease with increasing the fluence.The recovery of the optical intensities depends on the combination of the implantation temperature and the annealing temperature with the thermal treatment from 700℃to 1100℃.The different characterizations of Raman scattering spectroscopy and photoluminescence spectrum are compared and discussed in this study.
基金supported by the Open Foundation of Joint Laboratory for Extreme Conditions Matter Properties,Southwest University of Science and Technology and Research Center of Laser Fusion,CAEP(Grant No.12zxjk09)the Science and Technology Project of Mian yang City(Grant No.12G031-2)+2 种基金the Scientific Research Fund of Sichuan Provincial Education Department(Grant No.11ZB191)the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials(Grant No.12zxnp08)the Fundamental Science on Nuclear Waste and Environmental Security Laboratory(Grant No.12zxnp08)
文摘The coatings of microorganism-induced calcium carbonate onto the stone surface carried out by using both of the immersion method and coating method were investigated. Various analysis and testing techniques such as scanning electron micrograph （SEM） and X-ray diffraction （XRD） were used to characterize the deposited mineral layer. The adhesive property, acid re- sistance, frost resistance, light and aging resistance, water adsorption and permeability were investigated in detail. The results showed that both immersion method and coating method could produce calcium carbonate granules with sizes ranging from 1 to 10 pm and form a layer of dense mineralization membrane which is about 50 to 100 pm thick. Immersion method was more efficient than coating method. The large cohesive force between calcium carbonate layer and stone materials could improve the acid rain resistance as well as excellent heat tolerance, frost resistance and light aging resistance. The coating process could not only help the stone materials maintain its original permeability with the aid of calcium carbonate layers but also improve the penetration resistance significantly. Therefore, this type of technology shows a great potential in the protection of stone relics.
基金supported by the National Natural Science Foundations of China(No.52102115)the Natural Science Foundations of Sichuan Province,China(No.2023NSFSC0961)the Fundamental Research Funds of Jiangsu University of Science and Technology,China(No.1022932318)。
文摘Adhesively Bonded Carbon Fibre Reinforced Plastic(CFRP)and titanium alloy have been extensively used as a hybrid structure in modern aircrafts due to their excellent combination of mechanical properties and chemical stabilities.This study utilised NaOH anodising method to create micro-rough titanium surfaces for enhancing adhesive bonding between titanium alloy and CFRP laminates.A special and simple technique named Resin Pre-Coating(RPC)was also employed to improve the surface wetting of anodised titanium and grinded CFRP substrates.The influences of anodising temperature and duration on the surface morphology,wettability and adhesive bond strength were investigated.The single lap shear test results showed that the bond strength of specimens anodised at 20℃for 15 min improved by 135.9%and 95.4%,respectively,in comparison with that of acid pickled and grinded specimens(without RPC treatment).Although increasing the anodising temperature and duration produced rougher titanium surfaces,the adhesively bonded joints were not strong enough due to relatively friable titanium oxide layers.
基金Natural Science Foundation of Sichuan Province(2022NSFSC0303,2022NSFSC0388,2022NSFSC0293)NHC Key Laboratory of Nuclear Technology Medical Transformation(Mianyang Central Hospital)(2022HYX016)Doctoral Foundation of Southwest University of Science and Technology(20zx7131).
文摘Safe and efficient capturing of volatile radioiodine is of extremely important significance in the treatment of spent fuel.Herein,the flake channels in gelatin-hydroxyapatite(HAP@Ge)cryogel with excellent flame retardant properties were constructed by immobilizing hydroxyapatite nanorods(HAP)on Gelatin(Ge)cryogel for enhancing the capturing of iodine.The immobilization of HAP nanorods enhanced thermal stability,provided low rates of dynamic heat transfer and dissipation,and remarkably improved the flame retardant and smoke suppression properties of the Ge cryogel,which can effectively prevent the occurrence of safety incidents caused by further thermal degradation or combustion of this cryogel.More importantly,it was effective in improving the rapid enrichment of iodine,resulting in a high adsorption capacity.The maximum adsorption capacity of HAP@Ge cryogel for iodine vapor reached 2693 mg/g at equilibrium.The high adsorption capacity for iodine was attributed to the multi-scale porous structure in HAP@Ge cryogel,which offered effective channels for iodine diffusion,whereas the numerous complex and irregular flakes provided sufficient number of active sites for iodine capture.The adsorption process was chemical in nature and involved the-PO_(4)^(3-),-OH,-C=O,and-NHR groups on HAP@Ge cryogel.Moreover,the complex porous structure of HAP@Ge cryogel enhanced the physical capturing of iodine.These advantages,such as low-cost raw material,simple preparation method,good flame retardancy,and excellent capturing performance for iodine indicated that HAP@Ge cryogel is a potential candidate for the removal of radioactive iodine in the exhaust gas stream of post-treatment plants.
基金Supporting Program of SWUST(18LZX447)the biofilm research&innovation consortium from the College of Science and Engineering,Flinders University for supporting this research,respectively.
文摘Filtering media is anything placed in a filter that changes the quality of water flowing through it.With the variety of media available,proper selection of filter media is of great importance for filter performance.Recycled glass is evaluated as an alternative to silica sand in media filters and is an effective medium with the advantages of lower cost than silica sand,more environmental friendliness as it is a recycled product,and ease to pulverize into different sizes for specific design requirements.However,the filtration efficiency of regenerated recycled glass is limited by the formation of biofilms on its surfaces due to the large number of microorganisms such as bacteria and algae existing in the water.In this study,hydrofluoric(HF)acid etched glass spheres(GSs)modified with polydopamine(PDA)and silver nanoparticles(PDA-AgHF/GSs)were fabricated on the surface of soda-lime GSs by HF etching,crystal in situ growth,and PDA coating.HF etching and the modification of PDA coating imparted good hydrophilicity to PDA-Ag-HF/GSs.The modification of the silver coating also rendered PDA-Ag-HF/GSs excellent antibacterial properties and reduced Chlorella adhesion,and inhibited microorganism growth ability by releasing Ag^+.The catechol functional group on the PDA coating could regulate the Ag^+release by chelation.Good antibacterial properties,anti-algae adhesion,and controlled release of Ag^+indicate that PDA-Ag-HF/GS coating can effectively inhibit the formation of biofilm on the surface of the material,providing a new strategy for the formation of anti-biofilm.
基金the National Natural Science Foundation of China(No.52102115)the Fundamental Research Funds of Southwestern University of Science and Technology,China(No.20zx7141).
文摘Compressive strengths and elastic moduli of Carbon Fiber Reinforced Polymer(CFRP)composites can be noticeably improved by multiple ultra-thin interlays with non-woven Aramid Pulp(AP)micro/nano-fibers.10-ply CFRP specimens with 0,2,4,6,8 g/m^(2)AP were tested under uniaxial compression.Those flexible AP fibers,filling the resin-rich regions and further constructing the fiber bridging at the ply interfaces,can effectively suppress delamination growth and lead to very good improvements both in the compressive strength and the elastic modulus.The CFRP specimen with an optimum interlay thickness has a distinct shear failure mode instead of the typical delamination cracking along the direction of continuous carbon fibers.Compressive Strengths After Impacts(CAI)of 12.35 J were also measured,up to 90%improvement in CAI has been observed.It is concluded those ultra-thin interlays of non-woven AP micro/nano-fibers are beneficial to design and manufacture“high strength”CFRP composites.
基金supported financially by the National Natural Science Foundations of China(No.52102115)the Overseas High-End Talent Introduction Project of Sichuan Province,China(No.2023JDGD0013)the Natural Science Foundations of Sichuan Province,China(No.2023NSFSC0961)。
文摘Basalt Fiber Reinforced Polymer(BFRP)composites have huge potential application respects for some civil fields due to enough strength/modulus to weight and low cost by replacing carbon fiber composites.Aiming at the issues in the Resin-Rich Region(RRR)and Interfacial Transition Region(ITR)of fiber reinforced polymer composites,the characteristic Aramid Pulp(AP)fibers with micro-fiber trunk and nano-fiber branches were manufactured into multiple non-woven ultra-thin interleaving at the interlayers of BFRP composites via compression molding to reinforce the flexural strengths and elastic moduli.AP fibers were introduced into RRR to form interleaving at the interlayer,the brittle epoxy adhesive layer was improved and enabled to avoid cracking under a low external load.Free fiber branches of AP were also embedded into BF layer to construct quasi-vertical fiber bridging behaviors in ITR,stronger mechanical interlocking was created to prevent crack propagation along the bonding interface of BF/epoxy.Three-point bending testing results showed the interleaving film with 4 g/m^(2)AP exhibited the best effect among various areal densities and yielded average 315.75 MPa in flexural strength and 21.38 GPa in elastic modulus,having a 63.4%increment and a 47.1%increment respectively compared with the bases.Overall,the simple and low-cost AP interleaving is confirmed as an effective method in improving interlayer structure and flexural performance of BFRP composites,which may be considered to manufacture high-performance laminated fiber reinforced polymer composites in civil aviation industry.
基金supported by the State Key Laboratory of NBC Protection for Civilian Open Fund Project (No. SKLNBC201921)。
文摘Human industrial activities have caused environmental uranium(U) pollution, resulting in uranium(Ⅵ) had radiotoxicity and chemical toxicity. Here, a cellulase-producing Penicillium fungus was screened and characterized by X-ray fluorescence(XRF), and Fourier transform infrared reflection(FT-IR), as well as by GC/MS metabolomics analysis, to study the response to uranium(Ⅵ) stress. The biomass of Penicillium decreased after exposure to 100 mg/L U.Uranium combined with carboxyl groups, amino groups, and phosphate groups to form uranium mineralized deposits on the surface of this fungal strain. The α-activity concentration of uranium in the strain was 2.57×10^(6)Bq/kg, and the β-activity concentration was 2.27×10^(5)Bq/kg. Metabolomics analysis identified 118 different metabolites, as well as metabolic disruption of organic acids and derivatives. Further analysis showed that uranium significantly affected the metabolism of 9 amino acids in Penicillium. These amino acids were related to the TCA cycle and ABC transporter. At the same time, uranium exhibited nucleotide metabolism toxicity to Penicillium. This study provides an in-depth understanding of the uranium tolerance mechanism of Penicillium and provides a theoretical basis for Penicillium to degrade hyper-enriched plants.
基金supported by the National Natural Science Foundation of China (No. 52103097)the Doctor Foundation of Southwest University of Science and Technology (No. 20zx7144)+3 种基金the Special Foundation for Young Scientists of Sichuan Province (No. 71112541)the Guangdong Natural Science Foundation (No. 2021A1515010675)the Key Project of Guangzhou Science and Technology Plan Project (No. 201904020034)the Guangdong Project of R&D Plan in Key Areas (No. 2020B010180001).
文摘Design of rapidly detachable adhesives with high initial bonding strength is of great significance but it is full of great challenge. Here, we report the fast electrically detaching behavior (100% detaching efficiency in just 1 min under dozens of DC voltage) and high initial bonding strength (>12 MPa) of epoxy-based ionic conductive adhesives (ICAs). The epoxy-based ICAs are fabricated by introducing polyethylene glycol dimethyl ether (PEGDE) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM]OTF) into epoxy. The combination of PEGDE and [EMIM]OTF enables the free ions to migrate directively in electric field, and the anchoring of PEG chains onto epoxy chains ensures the long-term reliability of ICAs. The investigation on the electrically detaching mechanism suggests that the enrichment and following rapid interfacial electrochemical reactions of [EMIM]OTF lead to formation of metal hydroxide (Me(OH)n) nanoparticles at the bonding interfaces, thus the strong interactions containing interlocked forces, van de Waals’ forces and hydrogen bonding interactions between ICAs and bonding substrates are destroyed. This work provides a promising direction for detachable adhesives with both high initial bonding strength and high detaching efficiency in short time.
基金supported by the Science and Technology Development Foundation of China Academy of Engineering Physics (Nos.2012A0302015,2012B0302050 and 2013B0302051)Doctoral Fund of Southwest University of Science and Technology (No.13zx7133)
文摘Fourfold benzocyclobutene-functionalized perylene bisimide（PBI 4） has been synthesized and its structure was characterized by FTIR,MS and NMR.PBI 4 can react either with itself,or the appropriate dienophiles to form the corresponding products under appropriate temperature.The polymer film obtained from the reaction of PBI 4 with methyl vinyl silicone rubber possessed excellent film forming properties including flatness.The optical properties of PBI 4 and polymer film obtained from the reaction of PBI 4 and methyl vinyl silicone rubber have been determined by UV/vis and fluorescence spectroscopy.
基金Supported financially by the National Natural Science Foundation of China(No.52102115)the High-end Foreign Expert Recruitment Plan of China(No.G2023036002L)+2 种基金the Natural Science Foundation of Sichuan Province,China(No.2023NSFSC0961)Shock and Vibration of Engineering Materials and Structures Key Lab of Sichuan Province,China(No.23kfgk06)the Postgraduate Innovation Fund Project by Southwest University of Science and Technology,China(No.24ycx2027).
文摘The high-strength Basalt Carbon Fiber Reinforced Polymer(BCFRP)composites had been manufactured by guiding Imitating Tree-root Micro/Nano Aramid Short Fiber(ITMNASF)into the interlayer of Basalt Fiber(BF)and Carbon Fiber(CF)plies to form thin interleaving,and various mass proportions of IT-MNASF were designed to discuss the reinforcing effect on the BCFRP heterogeneous composites.The results of three points bending tests showed that flexural strength and energy absorption of 4wt%IT-MNASF reinforced BCFRP heterogeneous composites had been improved by 32.4%and 134.4%respectively compared with that of unreinforced specimens.The 4wt%IT-MNASF reinforced BCFRP specimens showed both a greater strength and a lower cost(reduced by 31%around)than that of plain CFRP composites.X-ray micro-computed tomography scanning results exhibited that the delamination-dominated failure of plain BCFRP composites was changed into multi-layer BF and CF fabrics damage.The reinforcing mechanism revealed that the introduced IT-MNASF could construct quasi-vertical fiber bridging,and it was used as"mechanical claws"to grasp adjacent fiber layers for creating a stronger mechanical interlocking,and this effectively improved resin-rich region and interfacial transition region at the interlayers.The simple and effective IT-MNASF interleaving technique was very successful in low-cost and high-strength development of BCFRP heterogeneous composites.
基金funded by the Sichuan Province Key Research and Development Project(2021YFS0340)Doctoral Scientific Fund Project of Southwest University of Science and Technology(20zx7130)Open Fund of Key Laboratory in Luzhou(NJ202201)。
文摘High content of ethyl acetate may destroy the typical flavor of Chinese Nong-xiang Baijiu.Formation of ethyl acetate is closely related to its precursor acetic acid from Daqu starter in the fermentation process of Chinese Baijiu.In this study,the potential functional microbiota responsible for production of acetic acid was explored by correlation analysis and function prediction in Nong-xiang Daqu from different geographical regions.Our results revealed that the microbial community of Daqu starter was correlated with its acetic acid content.In addition,the relative abundances of Weissella,Lactobacillus,Bacillus,Kroppenstedtia,and Pichia were higher in the Daqu with high content of acetic acid.Furthermore,Acetobacter,Weissella,Lactobacillus,Pichia,Candida,and Rhizo-mucor were significantly(p<0.01)and positively correlated with acetic acid.Meanwhile,higher abundances of most genes that encoding enzymes participated in glycolysis and pentose phosphate pathways for acetic acid synthesis,were observed by PICRUSt2 approach in the Daqu starters with high content of acetic acid.Taken together,Acetobacter,Weissella,Lactobacillus,Pichia,and Candida were determined as the potential functional microbiota for producing acetic acid in Nong-xiang Daqu starters.These results provided evidence of microbiota for revealing the possible causes of high acetic acid and ethyl acetate in Nong-xiang Baijiu brewing process,and laid theoretical foundation for regulation of Baijiu fermentation by functional microbiota.
文摘Raw and modified albite catalysts, including Pb/Atbite and Fe/Albite catalysts, have been investigated for methane conversion to C2 hydrocarbons under non-oxidative conditions. Introduction of Pb to albite improved the activity and selectivity to non-coke products. Based on characterization, it was found that Pb entered into the alkali and alkaline-earth metal sites of albite, while partial Fedoped in the tetrahedron sites and the other loaded on the surface of albite. At the reaction temperature of 1073 K, methane gas hourly space velocity （GHSV） of 2 L.gcat-1·h-1, catalyst dosage of 0.25 g （300 mesh）, the methane conversion catalyzed by raw albite in the fixed-bed micro reactor exhibited a methane conversion of 3.32%. Notably, introducing a Pb content of 3.4 wt% into albite greatly enhanced the conversion of methane up to 8.19%, and the selectivity of C2 hydrocarbons reached 99% without any coke under the same reaction conditions. While Fe-doping could weakly heighten the methane conversion to 3.97%, and coke was formed. Thus, a comparison of Pb/Albite and Fe/Albite catalysts demonstrates that the catalytic activity of albite is mainly decided by alkali and alkaline-earth metal sites, and lead-modification can effectively improve the catalytic activity of albite.
基金The authors are grateful to the National Natural Science Foundation of China(No.51808464)for supporting this research.
文摘Calcite surface was modified with stearic acids,and the interaction between them was investigated both experimentally and theoretically.Stearic-acid-modified calcite powders were investigated with Fourier transform infrared spectroscopy,X-ray diffraction,zeta potential analyser and contact angle measurement.Then,the density functional theory calculations were performed to explore the interaction at the atomic scale.The experi-mental results and simulation indicated that stearic acids interact with calcite surface via chelation between the double-bond O atom of-COOH and the Ca atom on calcite surface.The terminal methyl group of the stearic acids decreases the hydrophilicity of the calcite surface,and the interaction between different crystal faces of calcite is different.
