Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystalliz...Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.展开更多
The limited charge extraction efficiency and suboptimal energy-level alignment of poly(3,4-ethylenediox ythiophene)polystyrene sulfonate(PEDOT:PSS)as a hole transport layer restrict its performance in solar cell appli...The limited charge extraction efficiency and suboptimal energy-level alignment of poly(3,4-ethylenediox ythiophene)polystyrene sulfonate(PEDOT:PSS)as a hole transport layer restrict its performance in solar cell applications.In this study,we developed effective copper-ion(Cu(Ⅱ))-modified oxyl-terminated melem two-dimensional(2D)nanodisks(Cu(Ⅱ)@OMN)that improved the performance of PEDOT:PSS as a representative hole-transport layer(HTL)in organic and perovskite solar cells.Based on theoretical calculations and experimental data,the interaction between Cu(Ⅱ)@OMN and PEDOT or PSS led to electron redistribution in PEDOT:PSS and the dissociation of PEDOT and PSS,promoting enhanced charge extraction and transfer.In addition,the work function of the Cu(Ⅱ)@OMN-PEDOT:PSS is modified to achieve a more beneficial energy-level alignment,thereby facilitating improved hole transport and inhibited nonradiative recombination.Methylammonium(MA)-based perovskite and organic binary PM6:Y6solar cells achieved power conversion efficiencies(PCEs)of 19.21% and 17.15%,respectively.These PCEs are among the highest reported for MA-based perovskite and binary PM6:Y6 organic solar cells that use 2D nanomaterial-modified PEDOT:PSS,demonstrating the potential of Cu(Ⅱ)@OMN in solar cell applications.展开更多
Ag nanowire(NW)film is the promising next generation transparent conductor.However,the residual long-chain polyvinylpyrrolidone(PVP,introduced during the synthesis of Ag NWs)layer greatly deteriorates the carrier tran...Ag nanowire(NW)film is the promising next generation transparent conductor.However,the residual long-chain polyvinylpyrrolidone(PVP,introduced during the synthesis of Ag NWs)layer greatly deteriorates the carrier transport capability of the Ag NW film and as well its long-term stability.Here,we report a one-step I−ion modification strategy to completely replace the PVP layer with an ultrathin,dense layer of I^(−)ions,which not only greatly diminishes the resistance of the Ag NW film itself and that at interface of the Ag NW film and a functional layer(e.g.,a current collect electrode)but also effectively isolates the approaching of corrosive species.Consequently,this strategy can simultaneously improve the carrier transport properties of the Ag NW film and its long-term stability,making it an ideal electric component in diverse devices.For example,the transparent heater and pressure sensor made from the I^(−)-wrapped Ag NW film,relative to their counterparts made from the PVP-wrapped Ag NW film,deliver much improved heating performance and pressure sensing performance,respectively.These results suggest a facile post treatment approach for thin Ag NW film with improved carrier transport properties and long-term stability,thereby greatly facilitating its downstream applications.展开更多
Tetragonal zirconia polycrystals containing 3 mol% yttria (3Y-TZP), which show Superplasticity at high temperatures, were irradiated using 130 MeV Zr+" ions in the TANDEM accelerator facility at Tokai Research Es...Tetragonal zirconia polycrystals containing 3 mol% yttria (3Y-TZP), which show Superplasticity at high temperatures, were irradiated using 130 MeV Zr+" ions in the TANDEM accelerator facility at Tokai Research Establishment, JAERI. The irradiation induced atomic displacement damage was analyzed by TRIM code. Changes in the mechanical properties and fracture behavior caused by the ion irradiation and the effects of subsequent annealing were studied. The distribution of micro-indentation depth as a function of the indentation position from the irradiated surface to the specimen interior was also examined. The occurrence of compressive residual stresses and increases in hardness and fracture toughness were found in the as-irradiated surface region of the specimen. The subsequent annealing revealed that these quantities were decreased gradually with raising the annealing temperature. Probable causes of the generation of the residual stress and the changes in mechanical properties and fracture mode due to the irradiation are discussed.展开更多
In this study, the polyacrylate intraocularr lens is irradiated by argon ion which can produce free radicals. In order to obtain better hydrophilic and lower platelets adhesion, monomer vinyl pyrrolidone (NVP) is graf...In this study, the polyacrylate intraocularr lens is irradiated by argon ion which can produce free radicals. In order to obtain better hydrophilic and lower platelets adhesion, monomer vinyl pyrrolidone (NVP) is grafted onto the hydrophobic polyacrylate intraocular lens surface in a certain reaction conditions. Specific changes in intraocular lens are detected by static contact angle (CA), scanning electron microscope (SEM) and light transmittance. The results show that this surface modification can greatly improve its hydrophilic character and surface formation.展开更多
The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is model...The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.展开更多
The catalytic cracking of coal tar asphaltene(CTA)pyrolysis vapors was carried out over transition metalion modified zeolites to promote the generation of light aromatic hydrocarbons(L-ArHs)in a pyrolysisgas chromatog...The catalytic cracking of coal tar asphaltene(CTA)pyrolysis vapors was carried out over transition metalion modified zeolites to promote the generation of light aromatic hydrocarbons(L-ArHs)in a pyrolysisgas chromatography/mass spectrometry(Py-GC/MS)micro-reactor system.The effects of ultra stable Y(USY),Co/USY and Mo/USY on the selectivity and yield of L-ArHs products and the extent of deoxygenation(Edeoxygenation),lightweight(Elightweight)from CTA pyrolysis volatiles were investigated.Results showed that the yields of L-ArHs are mainly controlled by the acid sites and specific surface area of the catalysts,while the deoxygenation effect is determined by theirs pore size.The Eligltweight of CTA pyrolysis volatiles over USY is 9.65%,while the Edeoxygenation of CTA pyrolysis volatiles over Mo/USY reaches 20.85%.Additionally,the modified zeolites(Mo/USY and Co/USY)exhibit better performance than USY on L-ArHs production,owing to the synergistic effect of metal ions(Mo,Co)and acid sites of USY.Compared with the non-catalytic fast pyrolysis of CTA,the total yield of L-ArHs obtained over USY(4032 mg·kg^(-1)),Co/USY(4363 mg·kg^(-1))and Mo/USY(4953 mg·kg^(-1))were increased by 27.03%,38.19%and 54.78%,respectively.Furthermore,the possible catalytic conversion mechanism of transition metal ion(Co and Mo)modified zeolites was proposed based on the distribution of products and the characterizations of catalysts.展开更多
The primary motivation for studying how irradiation modifies the structures and properties of solid materials involves the understanding of undesirable phenomena,including irradiation-induced degradation of components...The primary motivation for studying how irradiation modifies the structures and properties of solid materials involves the understanding of undesirable phenomena,including irradiation-induced degradation of components in nuclear reactors and space exploration,and beneficial applications,including material performance tailoring through ion beam modification and defect engineering.In this work,the formation mechanism of latent tracks with different damage morphologies in LiNbO_(3)crystals under 0.09-6.17 Me V/u ion irradiation with an electronic energy loss from 2.6-13.2 ke V/nm is analyzed by experimental characterizations and numerical calculations.Irradiation-induced damage is preliminarily evaluated via the prism coupling technique to analyze the correlation between the dark-mode spectra and energy loss profiles of irradiated regions.Under the irradiation conditions of different ion velocities and electronic energy losses,different damage morphologies,from individual spherical defects to discontinuous and continuous tracks,are experimentally characterized.During ion penetration process,the ion velocity determines the spatiotemporal distribution of deposited irradiation energy induced by electronic energy loss,meaning that the two essential factors including electronic energy loss and ion velocity coaffect the track damage.The inelastic thermal spike model is used to numerically calculate the spatiotemporal evolutions of energy deposition and the corresponding atomic temperature under different irradiation conditions,and a quantitative relationship is proposed by comparison with corresponding experimentally observed track damage morphologies.The obtained quantitative relationship between irradiation conditions and track damage provides deep insight and guidance for understanding the damage behavior of crystal materials in extreme radiation environments and selecting irradiation parameters,including ion species and energies,for ion beam technique application in atomic-level defect manipulation,material modification,and micro/nanofabrication.展开更多
A Zn Cl2-modified ion exchange resin as the catalyst for bisphenol-A synthesis was prepared by the ion exchange method. Scanning electron microscope（SEM）, Fourier transform infrared spectrophotometer（FT-IR）, therm...A Zn Cl2-modified ion exchange resin as the catalyst for bisphenol-A synthesis was prepared by the ion exchange method. Scanning electron microscope（SEM）, Fourier transform infrared spectrophotometer（FT-IR）, thermo gravimetric analyzer（TGA） and pyridine adsorbed IR were employed to characterize the catalyst. As a result, the modified catalyst showed high acidity and good thermal stability. Zn2＋coordinated with a sulfonic acid group to form a stable active site, which effectively decreased the deactivation caused by the degradation of sulfonic acid. Thus the prepared catalyst exhibited excellent catalytic activity, selectivity and stability compared to the unmodified counterpart.展开更多
This study investigated the interaction between Cu^2＋and nano zero-valent iron（NZVI）coated with three types of stabilizers（i.e., polyacrylic acid [PAA], Tween-20 and starch） by examining the Cu^2＋ uptake, coll...This study investigated the interaction between Cu^2＋and nano zero-valent iron（NZVI）coated with three types of stabilizers（i.e., polyacrylic acid [PAA], Tween-20 and starch） by examining the Cu^2＋ uptake, colloidal stability and mobility of surface-modified NZVI（SM-NZVI） in the presence of Cu^2＋. The uptake of Cu^2＋ by SM-NZVI and the colloidal stability of the Cu-bearing SM-NZVI were examined in batch tests. The results showed that NZVI coated with different modifiers exhibited different affinities for Cu^2＋, which resulted in varying colloidal stability of different SM-NZVI in the presence of Cu^2＋. The presence of Cu^2＋ exerted a slight influence on the aggregation and settling of NZVI modified with PAA or Tween-20. However, the presence of Cu^2＋caused significant aggregation and sedimentation of starch-modified NZVI, which is due to Cu^2＋complexation with the starch molecules coated on the surface of the particles. Column experiments were conducted to investigate the co-transport of Cu^2＋ in association with SM-NZVI in water-saturated quartz sand. It was presumed that a physical straining mechanism accounted for the retention of Cu-bearing SM-NZVI in the porous media. Moreover, the enhanced aggregation of SM-NZVI in the presence of Cu^2＋ may be contributing to this straining effect.展开更多
基金Project supported by Anhui Natural Science(1808085ME136)。
文摘Eu^(2+)ions'occupancy in a-cordierite structure has been a hot research topic.In this study,Eu^(2+)ions were introduced intoα-Mg_(2)Al_(4)Si_(5)O_(18)structure by glass skeleton modification relaxation crystallization route,and optimizing Eu^(2+)ions'occupancy was induced by changing the skeleton structure through Al^(3+)content and B^(3+)-P^(5+)double substituting 2Si4+.Three occupied luminescent structures'evolution was verified by combining photo luminescence spectra and lattice parameters.The results show that within the range of Al^(3+)content lower than 1.1 mol or B^(3+)-P^(5+)content higher than 3 mol%,the lattice parameters are dominated by the a/b direction.This is beneficial for Eu^(2+)ions to occupy structural channel sites and Ca^(2+)sites,which forms occupied luminescent structures Eu^(2+)_(vac)and Eu^(2+)_(Ca).When the Al^(3+)content is higher than 1.1 mol or B^(3+)-P^(5+)content is lower than 3 mol%,the lattice parameters are dominated by c direction,which is more conducive to Eu^(2+)ions occupying Mg2+sites and occupied luminescent structure Eu^(2+)_(Mg)formation.By sensitivity calculations,occupancy priority of Eu^(2+)ions are derived as Eu^(2+)_(Ca)>Eu^(2+)_(vac)>Eu^(2+)_(Mg).This study provides an effective strategy to modulate Eu^(2+)occupancy thereby achieving single-component white light emission.
基金supported by the Nano Material Technology Development Program(2021M3H4A1A02057007)funded by the Ministry of Science and ICT through the National Research Foundation of Koreasupported by the Basic Science Research Program through NRF funded by the Ministry of Education(2022R1A6A1A03051158,2022R1A2C4002248,RS-202300247069)。
文摘The limited charge extraction efficiency and suboptimal energy-level alignment of poly(3,4-ethylenediox ythiophene)polystyrene sulfonate(PEDOT:PSS)as a hole transport layer restrict its performance in solar cell applications.In this study,we developed effective copper-ion(Cu(Ⅱ))-modified oxyl-terminated melem two-dimensional(2D)nanodisks(Cu(Ⅱ)@OMN)that improved the performance of PEDOT:PSS as a representative hole-transport layer(HTL)in organic and perovskite solar cells.Based on theoretical calculations and experimental data,the interaction between Cu(Ⅱ)@OMN and PEDOT or PSS led to electron redistribution in PEDOT:PSS and the dissociation of PEDOT and PSS,promoting enhanced charge extraction and transfer.In addition,the work function of the Cu(Ⅱ)@OMN-PEDOT:PSS is modified to achieve a more beneficial energy-level alignment,thereby facilitating improved hole transport and inhibited nonradiative recombination.Methylammonium(MA)-based perovskite and organic binary PM6:Y6solar cells achieved power conversion efficiencies(PCEs)of 19.21% and 17.15%,respectively.These PCEs are among the highest reported for MA-based perovskite and binary PM6:Y6 organic solar cells that use 2D nanomaterial-modified PEDOT:PSS,demonstrating the potential of Cu(Ⅱ)@OMN in solar cell applications.
基金support from the National Natural Science Foundation of China(Nos.21872047,21673070,and 22072039)Hunan Key Laboratory of Two-Dimensional Materials(No.2018TP1010).
文摘Ag nanowire(NW)film is the promising next generation transparent conductor.However,the residual long-chain polyvinylpyrrolidone(PVP,introduced during the synthesis of Ag NWs)layer greatly deteriorates the carrier transport capability of the Ag NW film and as well its long-term stability.Here,we report a one-step I−ion modification strategy to completely replace the PVP layer with an ultrathin,dense layer of I^(−)ions,which not only greatly diminishes the resistance of the Ag NW film itself and that at interface of the Ag NW film and a functional layer(e.g.,a current collect electrode)but also effectively isolates the approaching of corrosive species.Consequently,this strategy can simultaneously improve the carrier transport properties of the Ag NW film and its long-term stability,making it an ideal electric component in diverse devices.For example,the transparent heater and pressure sensor made from the I^(−)-wrapped Ag NW film,relative to their counterparts made from the PVP-wrapped Ag NW film,deliver much improved heating performance and pressure sensing performance,respectively.These results suggest a facile post treatment approach for thin Ag NW film with improved carrier transport properties and long-term stability,thereby greatly facilitating its downstream applications.
文摘Tetragonal zirconia polycrystals containing 3 mol% yttria (3Y-TZP), which show Superplasticity at high temperatures, were irradiated using 130 MeV Zr+" ions in the TANDEM accelerator facility at Tokai Research Establishment, JAERI. The irradiation induced atomic displacement damage was analyzed by TRIM code. Changes in the mechanical properties and fracture behavior caused by the ion irradiation and the effects of subsequent annealing were studied. The distribution of micro-indentation depth as a function of the indentation position from the irradiated surface to the specimen interior was also examined. The occurrence of compressive residual stresses and increases in hardness and fracture toughness were found in the as-irradiated surface region of the specimen. The subsequent annealing revealed that these quantities were decreased gradually with raising the annealing temperature. Probable causes of the generation of the residual stress and the changes in mechanical properties and fracture mode due to the irradiation are discussed.
基金National Natural Science of Foundation of Chinagrant number:81070716
文摘In this study, the polyacrylate intraocularr lens is irradiated by argon ion which can produce free radicals. In order to obtain better hydrophilic and lower platelets adhesion, monomer vinyl pyrrolidone (NVP) is grafted onto the hydrophobic polyacrylate intraocular lens surface in a certain reaction conditions. Specific changes in intraocular lens are detected by static contact angle (CA), scanning electron microscope (SEM) and light transmittance. The results show that this surface modification can greatly improve its hydrophilic character and surface formation.
基金supported by National Natural Science Foundation of China(Nos.50725519,51271048,51321004)
文摘The inner surface modification process by plasma-based low-energy ion implantation（PBLEII）with an electron cyclotron resonance（ECR）microwave plasma source located at the central axis of a cylindrical tube is modeled to optimize the low-energy ion implantation parameters for industrial applications.In this paper,a magnetized plasma diffusion fluid model has been established to describe the plasma nonuniformity caused by plasma diffusion under an axial magnetic field during the pulse-off time of low pulsed negative bias.Using this plasma density distribution as the initial condition,a sheath collisional fluid model is built up to describe the sheath evolution and ion implantation during the pulse-on time.The plasma nonuniformity at the end of the pulse-off time is more apparent along the radial direction compared with that in the axial direction due to the geometry of the linear plasma source in the center and the difference between perpendicular and parallel plasma diffusion coefficients with respect to the magnetic field.The normalized nitrogen plasma densities on the inner and outer surfaces of the tube are observed to be about 0.39 and 0.24,respectively,of which the value is 1 at the central plasma source.After a 5μs pulse-on time,in the area less than 2 cm from the end of the tube,the nitrogen ion implantation energy decreases from 1.5 keV to 1.3 keV and the ion implantation angle increases from several degrees to more than 40°;both variations reduce the nitrogen ion implantation depth.However,the nitrogen ion implantation dose peaks of about 2×10^（10）-7×10^（10）ions/cm^2 in this area are 2-4 times higher than that of 1.18×10^（10）ions/cm^2 and 1.63×10^（10）ions/cm^2 on the inner and outer surfaces of the tube.The sufficient ion implantation dose ensures an acceptable modification effect near the end of the tube under the low energy and large angle conditions for nitrogen ion implantation,because the modification effect is mainly determined by the ion implantation dose,just as the mass transfer process in PBLEII is dominated by low-energy ion implantation and thermal diffusion.Therefore,a comparatively uniform surface modification by the low-energy nitrogen ion implantation is achieved along the cylindrical tube on both the inner and outer surfaces.
基金financed by the projects of the National Natural Science Foundation of China(21776229,21908180,22078266)the National Key Research&Development Program of China(2018YFB0604603)the Key Research and Development Program of Shaanxi(2020ZDLGY11-02,2018ZDXM-GY-167)。
文摘The catalytic cracking of coal tar asphaltene(CTA)pyrolysis vapors was carried out over transition metalion modified zeolites to promote the generation of light aromatic hydrocarbons(L-ArHs)in a pyrolysisgas chromatography/mass spectrometry(Py-GC/MS)micro-reactor system.The effects of ultra stable Y(USY),Co/USY and Mo/USY on the selectivity and yield of L-ArHs products and the extent of deoxygenation(Edeoxygenation),lightweight(Elightweight)from CTA pyrolysis volatiles were investigated.Results showed that the yields of L-ArHs are mainly controlled by the acid sites and specific surface area of the catalysts,while the deoxygenation effect is determined by theirs pore size.The Eligltweight of CTA pyrolysis volatiles over USY is 9.65%,while the Edeoxygenation of CTA pyrolysis volatiles over Mo/USY reaches 20.85%.Additionally,the modified zeolites(Mo/USY and Co/USY)exhibit better performance than USY on L-ArHs production,owing to the synergistic effect of metal ions(Mo,Co)and acid sites of USY.Compared with the non-catalytic fast pyrolysis of CTA,the total yield of L-ArHs obtained over USY(4032 mg·kg^(-1)),Co/USY(4363 mg·kg^(-1))and Mo/USY(4953 mg·kg^(-1))were increased by 27.03%,38.19%and 54.78%,respectively.Furthermore,the possible catalytic conversion mechanism of transition metal ion(Co and Mo)modified zeolites was proposed based on the distribution of products and the characterizations of catalysts.
基金supported by the National Natural Science Foundation of China(No.11875038)the National Laboratory of Heavy Ion Accelerator in Lanzhou,and the State Key Laboratory of Nuclear Physics and Technology,Peking University+2 种基金financial support from the Young Scholars Program of Shandong Universityfinancial support from the Youth Innovation Promotion Association CAS(No.2019262)supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences and Engineering Division。
文摘The primary motivation for studying how irradiation modifies the structures and properties of solid materials involves the understanding of undesirable phenomena,including irradiation-induced degradation of components in nuclear reactors and space exploration,and beneficial applications,including material performance tailoring through ion beam modification and defect engineering.In this work,the formation mechanism of latent tracks with different damage morphologies in LiNbO_(3)crystals under 0.09-6.17 Me V/u ion irradiation with an electronic energy loss from 2.6-13.2 ke V/nm is analyzed by experimental characterizations and numerical calculations.Irradiation-induced damage is preliminarily evaluated via the prism coupling technique to analyze the correlation between the dark-mode spectra and energy loss profiles of irradiated regions.Under the irradiation conditions of different ion velocities and electronic energy losses,different damage morphologies,from individual spherical defects to discontinuous and continuous tracks,are experimentally characterized.During ion penetration process,the ion velocity determines the spatiotemporal distribution of deposited irradiation energy induced by electronic energy loss,meaning that the two essential factors including electronic energy loss and ion velocity coaffect the track damage.The inelastic thermal spike model is used to numerically calculate the spatiotemporal evolutions of energy deposition and the corresponding atomic temperature under different irradiation conditions,and a quantitative relationship is proposed by comparison with corresponding experimentally observed track damage morphologies.The obtained quantitative relationship between irradiation conditions and track damage provides deep insight and guidance for understanding the damage behavior of crystal materials in extreme radiation environments and selecting irradiation parameters,including ion species and energies,for ion beam technique application in atomic-level defect manipulation,material modification,and micro/nanofabrication.
文摘A Zn Cl2-modified ion exchange resin as the catalyst for bisphenol-A synthesis was prepared by the ion exchange method. Scanning electron microscope（SEM）, Fourier transform infrared spectrophotometer（FT-IR）, thermo gravimetric analyzer（TGA） and pyridine adsorbed IR were employed to characterize the catalyst. As a result, the modified catalyst showed high acidity and good thermal stability. Zn2＋coordinated with a sulfonic acid group to form a stable active site, which effectively decreased the deactivation caused by the degradation of sulfonic acid. Thus the prepared catalyst exhibited excellent catalytic activity, selectivity and stability compared to the unmodified counterpart.
基金supported by the Fundamental Research Funds for the Central Universities (531107040788)the National Natural Science Foundation of China (Nos. 51409100, 51039001, 51378190)the Program for Changjiang Scholars and Innovative Research Team in University (IRT-13R17)
文摘This study investigated the interaction between Cu^2＋and nano zero-valent iron（NZVI）coated with three types of stabilizers（i.e., polyacrylic acid [PAA], Tween-20 and starch） by examining the Cu^2＋ uptake, colloidal stability and mobility of surface-modified NZVI（SM-NZVI） in the presence of Cu^2＋. The uptake of Cu^2＋ by SM-NZVI and the colloidal stability of the Cu-bearing SM-NZVI were examined in batch tests. The results showed that NZVI coated with different modifiers exhibited different affinities for Cu^2＋, which resulted in varying colloidal stability of different SM-NZVI in the presence of Cu^2＋. The presence of Cu^2＋ exerted a slight influence on the aggregation and settling of NZVI modified with PAA or Tween-20. However, the presence of Cu^2＋caused significant aggregation and sedimentation of starch-modified NZVI, which is due to Cu^2＋complexation with the starch molecules coated on the surface of the particles. Column experiments were conducted to investigate the co-transport of Cu^2＋ in association with SM-NZVI in water-saturated quartz sand. It was presumed that a physical straining mechanism accounted for the retention of Cu-bearing SM-NZVI in the porous media. Moreover, the enhanced aggregation of SM-NZVI in the presence of Cu^2＋ may be contributing to this straining effect.
