In this paper, various strategies of spiral irradiating scheme for the flame forming of a bowl shaped surface are investigated experimentally and numerically. Experimental work is performed using a flame torch integra...In this paper, various strategies of spiral irradiating scheme for the flame forming of a bowl shaped surface are investigated experimentally and numerically. Experimental work is performed using a flame torch integrated with a 2-axis CNC workstation. The ABAQUS implicit solver is used in the numerical simulation. Three different strategies of the spiral irradiating scheme are investigated for the flame forming of a bowl shaped surface. The first strategy is the Simple spi- ral irradiating scheme, the second is the Rotational spiral irradiating scheme, and the third is the Symmetrical-Rotational spiral irradiating scheme. The results show that using the Symmetrical- Rotational spiral irradiating scheme, a bowl shaped surface with the maximum deformation can be produced, followed by using the Rotational scheme, and the Simple spiral scheme. It is also concluded from the results that the spiral irradiating scheme with Symmetrical-Rotational, Rota- tional and Simple spiral schemes lead to the maximum symmetries in the produced bowl shaped surface, respectively. All the numerical results are in good agreement with the experimental ob- servations.展开更多
Therapeutic effect of bronchisl asthma treated With CO<sub>2</sub> laser irradiating points was ob-served.Ninety-six cases of bronchial asthma,that were considered cold and insufficiency type accord-ing to...Therapeutic effect of bronchisl asthma treated With CO<sub>2</sub> laser irradiating points was ob-served.Ninety-six cases of bronchial asthma,that were considered cold and insufficiency type accord-ing to TCM,were divided into two groups:one treated with CO<sub>2</sub> laser irradiation at Tiantu（CV 22）,Danzhong（CV 17）,Feishu（BL13）and Dingchuan（EX-BI）（n=48）,and the other with warmmoxibustion at same points（n=48）.The symptoms,physical signs and pulmonary ventilation（PEF.VC,FEV<sub>1</sub>.0,FEV1％and MMEF）were taken as parameter.xhe results showed that thetherapeutic effect In laser irradiation group was better than that in moxibustion group.Moreover,laser irradiation could obviously improve pulmonary ventilation in patients.Therefore,CO<sub>2</sub> laser irra-diation is an effective therapy for bronchial asthma.展开更多
The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure...The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure with low power reflection and high stability and standing-wave accelerator structure with high shunt impedance.The work frequency of this accelerator is 2856MHz.Designed by Code AccDesign which is coded by ourselves,the output electron beam with final energy 10MeV and peak current 300mA was reached.The length of the accelerating tube is 1.5m,and the power efficiency from microwave to electron beam is 66%.The temperature and stress distribution were simulated.And the frequency shift by microwave loss was calculated.展开更多
Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ...Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.展开更多
The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by deposit...The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.展开更多
Establishing Consensus with Users of Research Irradiator Devices to Facilitate Source Type Replacement Danette R.Fennesy1,Janet M.Gutiérrez1,2,Scott J.Patlovich1,Robert J.Emery1(1.The University of Texas Health S...Establishing Consensus with Users of Research Irradiator Devices to Facilitate Source Type Replacement Danette R.Fennesy1,Janet M.Gutiérrez1,2,Scott J.Patlovich1,Robert J.Emery1(1.The University of Texas Health Science Center at Houston,Environmental Health&Safety,6431 Fannin St,CYF G.102,Houston,TX,77030;2.Corresponding author)Abstract:The ability to irradiate cells,tissues,and other biological materials with high-energy photons has been an essential tool in the discovery of numerous biomedical research advancements.展开更多
To know about the radiation effects on the super large array 9 k×9 k CCDs used in a space telescope induced by energetic protons,the experiments of the super large array 9 k×9 k charge coupled devices(CCDs)u...To know about the radiation effects on the super large array 9 k×9 k CCDs used in a space telescope induced by energetic protons,the experiments of the super large array 9 k×9 k charge coupled devices(CCDs)used in the space telescope irradiated by 60 MeV and 100 MeV protons are presented.The samples were exposed by 60 MeV and 100 MeV protons at fluences of 5×10^(9)/cm^(2) and 1×10^(10)/cm^(2),respectively.The degradations of the main performance parameters of the super large array CCDs which are paid special attention to the space telescope are investigated.The full well capacity,mean dark current,and the charge transfer inefficiency(CTI)versus proton fluence are presented,which are tested at very low temperature of-85℃.The annealing tests of 168 h were carried out after proton irradiation.The dark images before and after proton irradiation are also presented to compare the image degradation.The degradation mechanisms of the super large array CCDs irradiated by protons are analyzed.The experimental results show that the main performance parameters of the CCDs are degraded after 60 MeV and 100 MeV protons and the degradations induced by 60 MeV protons are larger than that induced by 100 MeV protons.The experimental results of the super large array CCDs irradiated by protons will provide the basic test data support for orbit life assessment of the space telescope.展开更多
High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate ma...High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate materials for nuclear applications.Despite the growth of the nuclear power sector,the effects of high-temperature and high-dose irradiation-induced voids on the mechanical properties of HEA in higher power nuclear reactors remain insufficiently researched,hindering its industrial application.In this study,we establish a consistent parameterization crystal plastic constitutive model for the hardening and creep behaviors of HEA,incorporating the spatial distribution of void size and shape effects,in contrast to traditional creep models that rely on temperature-related fitting parameters of the phenomenological power law equation.The model matches well with experimental data at different temperatures and irradiation doses,demonstrating its robustness.The effects of irradiation dose,temperature,and degree of lattice distortion on irradiation hardening and creep behavior of void-containing HEA are investigated.The results indicate that HEA with high lattice distortion exhibits better creep resistance under higher stress loads.The yield stress of irradiated HEA increases with increasing irradiation dose and temperature.The creep resistance increases with increasing irradiation dose and decreases with increasing irradiation temperature.The increase in irradiation dose causes a specific morphological transformation from spherical to cubic voids.The modeling and results could provide an effective theoretical way for tuning the yield strength and alloy design in advanced HEAs to meet irradiation properties.展开更多
Additively manufactured stainless steel exhibits different oxidation and corrosion properties compared with traditional counterparts.Molecular dynamics simulations were performed to systematically investigate Cr diffu...Additively manufactured stainless steel exhibits different oxidation and corrosion properties compared with traditional counterparts.Molecular dynamics simulations were performed to systematically investigate Cr diffusion near nanopores,in order to elucidate the fast formation of dense oxidation layers in laser powder bed fusion processed 304L stainless steel after ion irradiation.The influence of pore diameter and temperature on Cr diffusion was studied in Fe simulation boxes with 1 at.%Cr and random nanometric pores.The results show that the existence of nanopores significantly accelerates Cr diffusion,facilitating the formation of oxide layers.While increasing with temperature,the diffusion coefficient does not increase uniformly with pore diameter.Regarding the nanopores with diameters of 4.82-13.25Å,the diffusion coefficient of Cr in their vicinity is maximized at diameter of about 6Å.The specific fast diffusion paths near the nanopores were exposed and discussed.展开更多
Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been...Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been proved that laser irradiation can improve drilling and blasting efficiency when combined with mechanical rock fracturing methods,which are irrelevant for borehole stabilization.To improve the latter,this study used laser ablation for borehole reinforcement.The high-power laser was applied to typical rock samples(sandstone,mudstone and coal)in both dry and saturated conditions.Multi-technique observations and measurements were used to fully understand the peculiar modifications of the specimens under laser treatment,i.e.mechanical loading,acoustic emission(AE)monitoring,digital image correlation(DIC)strain field evaluation,infrared thermography(IRT)monitoring and X-ray computed tomography(CT)scanning.The results showed that,in addition to the effects already demonstrated,laser irradiation can improve the strength of the soft rock,especially in the saturated state.The process involved a complicated phase change including melting and evaporation of the matrix under high-temperature and high-pressure to form a glassy high strength silicate material.This process is similar to the reaction between molten lava and water,or the impact of an asteroid on the earth.Inspired by the results,a conceptual path for a new borehole stabilization technology using laser ablation was outlined.展开更多
The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to inv...The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to investigate the effects of He ion irradiation fluences and subsequent annealing on the microstructure and defects of the matrix graphite.He ions with 500 keV energy and fluences ranging from 1.1×10^(15)ions∕cm^(2)to 3.5×10^(17)ions∕cm^(2)were used to simulate neutron irradiation at 300 K.The samples with an irradiation fluence of 3.5×10^(16)ions∕cm^(2)were subjected to isochronal annealing at different temperatures(573 K,873 K and 1173 K)for 3 h.The Raman results revealed that the D peak gradually increased,whereas the intrinsic G peak decreased with increasing irradiation fluence.At the same irradiation fluence,the D peak gradually decreased,whereas the intrinsic G peak increased with increasing annealing temperature.Slow positron beam analysis demonstrated that the density or size of irradiation defects(vacancy type)increased with higher irradiation fluence,but decreased rapidly with increasing annealing temperature.The Raman spectral analysis of sample cross sections subjected to high irradiation fluences revealed the emergence of amorphization precisely at the depth where ion damage was most pronounced,whereas the surface retained its crystalline structure.Raman and positron annihilation analyses indicated that the matrix graphite exhibited good irradiation resistance to He ions at 300 K.However,vacancy-type defects induced by He ion irradiation exhibit poor thermal stability and can be easily removed during annealing.展开更多
The features of optical defects in a chemical vapor deposition (CVD) synthetic type Ⅱ a diamond were characterized using photoluminescence (PL) spectroscopy, before and after electron irradiation. The sample was cut ...The features of optical defects in a chemical vapor deposition (CVD) synthetic type Ⅱ a diamond were characterized using photoluminescence (PL) spectroscopy, before and after electron irradiation. The sample was cut within a {100} growth layer, and irradiated with 2 MeV electrons along the <100> axis. PL spectra of sample were collected under 532 nm and 355 nm laser excitation, at room temperature and 77 K, and linear scanning analysis along incident depth was applied to determine the distribution of defects. The pre-irradiation characterization results revealed uniformly distributed PL centers at 389 nm, 469 nm, 533 nm, 575 nm (ZPL of NV 0), 637 nm (ZPL of NV -), and 736.7/737.1 nm (ZPL doublet of SiV -). After irradiation, the differential responses of these as-grown defects were observed, alongside the emergence of irradiation-induced defects, namely 489 nm center, H3 center (ZPL at 504 nm) and GR1 center (ZPL at 741 nm). The maximum penetration depth of 2 MeV electron-irradiation induced defects was determined to be 2.1 mm. This work primarily presents the depth profiles of both as-grown and irradiation-induced defects in 2 MeV electrons irradiated diamond. The result provides experimental data for better understanding of the radiation effect in diamonds. Serving as a reference for diamond enhancement by electron irradiation.展开更多
Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation toler...Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation tolerance of three Cr-based coatings with different microstructures(Cr,CrAlSi,and CrAlSiN)through He2+ion irradiation and 1200℃ steam oxidation.The Cr and CrAlSi coatings experienced significant structural degradation,characterized by He bubble aggregation and amplified Kirkendall effects at elevated temperatures.In contrast,the irradiated CrAlSiN coating maintained structural integrity without measurable irradiation hardening.Following annealing at 800℃ for 30 min,approximately 40%of injected He atoms were released,indicating a“self-healing”mechanism.The mechanism is attributed to uniformly distributed,low-density channels that act as sinks and release paths for irradiation-induced defects.Density functional theory simulations suggest that N atoms promote significant rearrangement of ions surrounding the free volume,inhibiting the formation of sites capable of trapping He atoms.Moreover,the CrAlSiN coating exhibited superior oxidation resistance compared to the Cr and CrAlSi coatings,even under high-temperature steam conditions.Notably,the irradiated CrAlSiN sample displayed a significantly thinner oxide scale compared to the pristine one(almost half),owing to a more protective oxide scale and rapid outward diffusion of Cr,Al,and Si through nanochannel veins.These findings illuminate the effects of structure and composition on irradiation and oxidation behavior in Cr-based coatings,offering insights for developing new-generation accident-tolerance fuel coatings for Zr-alloy claddings.展开更多
Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent qua...Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent quantitative defect production,evolution dynamics,and evolution statistics were revealed in-situ for two prism foils(z=[1.210],[10.10]),in as-received and heat-treated pure Mg,after 300 keV electron irradiation up to 0.468 dpa at R.T.Preferred nucleation of basal-plane interstitial-type 1/6<20.23>loops was confirmed,in addition to a small portion of prism-plane 1/3<11.20>loops.No cavities were found.A higher yield of point defect concentration and a more evident trend of defect coarsening were identified in[1.210]than in[10.10].Pre-existing dislocations(on the orders of 10^(13)−10^(14) m^(−2))in pure Mg resulted in a delay of the first occurrence of visible defects.Defect migration and elastic interactions governed the microstructural evolution of electron irradiation damage in pure Mg,giving rise to events of loop coalescence,growth,and sometimes rotation of habit plane.The influence of incident electron energy can be correlated to the rates of point defect production,and is quantifiable;however,interfered by defect cluster stability,defect mobility,and defect interactions.This forms an important theoretical basis for the application of Mg subjected to MeV-level β-decay radiation in Brachytherapy.The paper concludes with a brief comparison between Mg and conventional Ti casing,outlines the advantages and challenges,and provides reference points for the validation of Mg/Mg-alloys in Brachytherapy seed application.展开更多
This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-bas...This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-based elastomer(PBE)at concentrations ranging from 0 to 50 wt%,underwent a melt blending process and subsequent cobalt-60 gamma-ray irradiation with doses ranging from 0 to 250 kGy.Electrical conductivity,trap distribution,and alternating(AC)breakdown strength were chosen to assess the insulation performance.These results indicate that the addition of PBE significantly improves the electrical properties of PP under irradiation.For PP,the electrical conductivity increased with irradiation,whereas the trap depth and breakdown strength decreased sharply.Conversely,for the blend,these changes initially exhibit opposite trends.When the irradiation was increased to 250 kGy,the AC breakdown strength of the blend improved by more than 21%compared to that of PP.The physical and chemical structures of the samples were investigated to explore the improvement mechanisms.The results offer insights into the design of new cable-insulation materials suitable for NPPs.展开更多
GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates...GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates,Schottky and pin diodes,and different active layer thicknesses.Pin diodes fabricated on a sapphire substrate are the best choice for a GaN proton detector working at 0 V bias.They are sensitive(minimum detectable proton beam<1 pA/cm^(2)),linear as a function of proton current and fast(<1 s).High proton current sensitivity and high spatial resolution of GaN diodes can be exploited in the future for proton imaging of patients in proton therapy.展开更多
Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels.However,the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation...Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels.However,the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation and prediction.Accurately simulating and predicting solar radiation and its variability are crucial for optimizing solar energy utilization.This study conducted simulation experiments using the WRF-Solar model from 25 June to 25 July 2022,to evaluate the accuracy and performance of the simulated solar radiation across China.The simulations covered the whole country with a grid spacing of 27 km and were compared with ground observation network data from the Chinese Ecosystem Research Network.The results indicated that WRF-Solar can accurately capture the spatiotemporal patterns of global horizontal irradiance over China,but there is still an overestimation of solar radiation,and the model underestimates the total cloud cover.The root-mean-square error ranged from 92.83 to 188.13 W m^(-2) and the mean bias(MB)ranged from 21.05 to 56.22 W m^(-2).The simulation showed the smallest MB at Lhasa on the Qinghai–Tibet Plateau,while the largest MB was observed in Southeast China.To enhance the accuracy of solar radiation simulation,the authors compared the Fast All-sky Radiation Model for Solar with the Rapid Radiative Transfer Model for General Circulation Models and found that the former provides better simulation.展开更多
Correction:Nuclear Science and Techniques(2025)36:4 https://doi.org/10.1007/s41365-024-01548-5 In this article,the caption for Fig(s)1,3,and 4 was inadvert-ently truncated.The incorrect and the corrected captions are ...Correction:Nuclear Science and Techniques(2025)36:4 https://doi.org/10.1007/s41365-024-01548-5 In this article,the caption for Fig(s)1,3,and 4 was inadvert-ently truncated.The incorrect and the corrected captions are given below.展开更多
Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the s...Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the safety and resilience of structures.This paper is aimed at investigating the failure mode and damage of gamma-irradiated repurposed pultruded glass fibre-reinforced polyester subjected to lowvelocity impact using three types of non-destructive techniques.Three sets of differently layered configurations(CRC,WCRW,W2CR2C)consisting of chopped(c),roving(r),and weaved(w)fibre-reinforced polyester are applied in this study.Drop hammer test is applied to evaluate the low-impact resistance properties of Gamma-irradiated composite at 100 kGy,500 kGy,and 1000 kGy.Preliminary flexural and hardness tests are conducted to further assess the behaviour of irradiated polymer composites.Further,the damage modes associated with the low-impact test are characterised using infrared thermography,flat panel digital radiography,and microscope observation.The results show that the composites irradiated with various doses display good impact resistance at 20 J,presenting minor damages in the form of dents on the surface.The irradiated CRC and WCRW display best impact resistance at 500 kGy,while W2CR2C at 1000 kGy.This shows that the layering sequence of reinforcement fibre can influence the impact resistance of irradiated composites.Apart from that,the application of non-destructive techniques show different damage mechanisms in the form resin cracks,yarn splitting/fracture,and matrix splitting when the composites are exposed at high and low irradiation doses.These findings offer valuable data for the defence industry,particularly in the areas of repair,maintenance,and the development of new materials.展开更多
Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a...Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a kind of unique core-shell heterojunction CuS@PPy nanostructures was synthesized and then incorporated in polycaprolactone(PCL)to construct an intelligent coating(CuS@PPy/PCL)on micro-arc-oxidized Mg implants.The PCL-based coating can realize near-infrared(NIR)-driven antibacterial and controllable Mg dissolution according to different bone healing stages.At the beginning of bone remodelling,the coating exhibits promising antibacterial properties with 99.67%and 99.17%efficacy against S.aureus and E.coli,respectively,thanks to the singlet oxygen(^(1)O_(2))and alkoxyl radicals(RO·)generated by the photodynamic effect of CuS@PPy heterojunction under low-power NIR light(1.5 W/cm^(2)).In the bone reparative stage,the PCL-based coating can maintain high corrosion resistance to meet the mechanical requirements of Mg implants in human body fluid.However,after the complete rehabilitation of bones,through a high-power(2 W/cm^(2))NIR light,the PCL-based coating changed from an elastic to a viscous flow state(44.7℃)under the photothermal effects of CuS@PPy,leading to quick degradation of the PCL-based coating and following accelerating dissolution of the Mg implant(avoiding secondary surgery).Hopefully,this NIR-responsive coating may provide an innovative method for the antibacterial and controllable dissolution of Mg implants.展开更多
文摘In this paper, various strategies of spiral irradiating scheme for the flame forming of a bowl shaped surface are investigated experimentally and numerically. Experimental work is performed using a flame torch integrated with a 2-axis CNC workstation. The ABAQUS implicit solver is used in the numerical simulation. Three different strategies of the spiral irradiating scheme are investigated for the flame forming of a bowl shaped surface. The first strategy is the Simple spi- ral irradiating scheme, the second is the Rotational spiral irradiating scheme, and the third is the Symmetrical-Rotational spiral irradiating scheme. The results show that using the Symmetrical- Rotational spiral irradiating scheme, a bowl shaped surface with the maximum deformation can be produced, followed by using the Rotational scheme, and the Simple spiral scheme. It is also concluded from the results that the spiral irradiating scheme with Symmetrical-Rotational, Rota- tional and Simple spiral schemes lead to the maximum symmetries in the produced bowl shaped surface, respectively. All the numerical results are in good agreement with the experimental ob- servations.
文摘Therapeutic effect of bronchisl asthma treated With CO<sub>2</sub> laser irradiating points was ob-served.Ninety-six cases of bronchial asthma,that were considered cold and insufficiency type accord-ing to TCM,were divided into two groups:one treated with CO<sub>2</sub> laser irradiation at Tiantu（CV 22）,Danzhong（CV 17）,Feishu（BL13）and Dingchuan（EX-BI）（n=48）,and the other with warmmoxibustion at same points（n=48）.The symptoms,physical signs and pulmonary ventilation（PEF.VC,FEV<sub>1</sub>.0,FEV1％and MMEF）were taken as parameter.xhe results showed that thetherapeutic effect In laser irradiation group was better than that in moxibustion group.Moreover,laser irradiation could obviously improve pulmonary ventilation in patients.Therefore,CO<sub>2</sub> laser irra-diation is an effective therapy for bronchial asthma.
文摘The design of 10MeV/20kW high power irradiating accelerator is presented.The Backward-Traveling-Wave (BTW)accelerating structure is adopted.This structure combines the advantage of traveling-wave accelerator structure with low power reflection and high stability and standing-wave accelerator structure with high shunt impedance.The work frequency of this accelerator is 2856MHz.Designed by Code AccDesign which is coded by ourselves,the output electron beam with final energy 10MeV and peak current 300mA was reached.The length of the accelerating tube is 1.5m,and the power efficiency from microwave to electron beam is 66%.The temperature and stress distribution were simulated.And the frequency shift by microwave loss was calculated.
基金supported by the National Key R&D Program under Grant No.2021YFA1400500the National Natural Science Foundation of China under Grant No.22273029+1 种基金the New Cornerstone Science Foundation through the New Cornerstone Investigator Program under Grant No.NCI202303 and the XPLORER PRIZEthe Beijing Outstanding Young Scientist Program under Grant No.JWZQ20240101002。
文摘Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.
基金supported by the Science and Technology Planning Project of Fujian Province(No.2023Y4015)the Marine and Fishery Development Special Fund of Xiamen(No.23YYST064QCB36)the Natural Science Foundation of Fujian Province(No.2021J011210).
文摘The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.
文摘Establishing Consensus with Users of Research Irradiator Devices to Facilitate Source Type Replacement Danette R.Fennesy1,Janet M.Gutiérrez1,2,Scott J.Patlovich1,Robert J.Emery1(1.The University of Texas Health Science Center at Houston,Environmental Health&Safety,6431 Fannin St,CYF G.102,Houston,TX,77030;2.Corresponding author)Abstract:The ability to irradiate cells,tissues,and other biological materials with high-energy photons has been an essential tool in the discovery of numerous biomedical research advancements.
基金The National Science Foundation of China(U2167208,11875223)Natural Science Basic Research Program of Shaanxi(2024JC-JCQN)The Foundation of State Key Laboratory of China(NKLIPR2320)。
文摘To know about the radiation effects on the super large array 9 k×9 k CCDs used in a space telescope induced by energetic protons,the experiments of the super large array 9 k×9 k charge coupled devices(CCDs)used in the space telescope irradiated by 60 MeV and 100 MeV protons are presented.The samples were exposed by 60 MeV and 100 MeV protons at fluences of 5×10^(9)/cm^(2) and 1×10^(10)/cm^(2),respectively.The degradations of the main performance parameters of the super large array CCDs which are paid special attention to the space telescope are investigated.The full well capacity,mean dark current,and the charge transfer inefficiency(CTI)versus proton fluence are presented,which are tested at very low temperature of-85℃.The annealing tests of 168 h were carried out after proton irradiation.The dark images before and after proton irradiation are also presented to compare the image degradation.The degradation mechanisms of the super large array CCDs irradiated by protons are analyzed.The experimental results show that the main performance parameters of the CCDs are degraded after 60 MeV and 100 MeV protons and the degradations induced by 60 MeV protons are larger than that induced by 100 MeV protons.The experimental results of the super large array CCDs irradiated by protons will provide the basic test data support for orbit life assessment of the space telescope.
基金support from the National Natural Science Foundation of China(Nos.12302083,U2267252,12372069,and 12172123)the China Postdoctoral Science Foundation(Nos.2023M731061 and BX20230109)+1 种基金the Natural Science Foundation of Hunan Province(No.2022JJ20001)the Hunan Provincial Innovation Foundation for Postgraduate(No.CX20230420).
文摘High-entropy alloys(HEAs)exhibit the excellent elevated-temperature performance and irradiation resistance due to the important core effect of serious lattice distortion for impeding dislocation motion,as candidate materials for nuclear applications.Despite the growth of the nuclear power sector,the effects of high-temperature and high-dose irradiation-induced voids on the mechanical properties of HEA in higher power nuclear reactors remain insufficiently researched,hindering its industrial application.In this study,we establish a consistent parameterization crystal plastic constitutive model for the hardening and creep behaviors of HEA,incorporating the spatial distribution of void size and shape effects,in contrast to traditional creep models that rely on temperature-related fitting parameters of the phenomenological power law equation.The model matches well with experimental data at different temperatures and irradiation doses,demonstrating its robustness.The effects of irradiation dose,temperature,and degree of lattice distortion on irradiation hardening and creep behavior of void-containing HEA are investigated.The results indicate that HEA with high lattice distortion exhibits better creep resistance under higher stress loads.The yield stress of irradiated HEA increases with increasing irradiation dose and temperature.The creep resistance increases with increasing irradiation dose and decreases with increasing irradiation temperature.The increase in irradiation dose causes a specific morphological transformation from spherical to cubic voids.The modeling and results could provide an effective theoretical way for tuning the yield strength and alloy design in advanced HEAs to meet irradiation properties.
基金financial support of National Natural Science Foundation of China(Nos.U2241245,52073176 and U22B2067)Natural Science Foundation of Shenyang(No.23-503-6-05)Shanghai Engineering Research Center of High-Performance Medical Device Materials(No.20DZ2255500).
文摘Additively manufactured stainless steel exhibits different oxidation and corrosion properties compared with traditional counterparts.Molecular dynamics simulations were performed to systematically investigate Cr diffusion near nanopores,in order to elucidate the fast formation of dense oxidation layers in laser powder bed fusion processed 304L stainless steel after ion irradiation.The influence of pore diameter and temperature on Cr diffusion was studied in Fe simulation boxes with 1 at.%Cr and random nanometric pores.The results show that the existence of nanopores significantly accelerates Cr diffusion,facilitating the formation of oxide layers.While increasing with temperature,the diffusion coefficient does not increase uniformly with pore diameter.Regarding the nanopores with diameters of 4.82-13.25Å,the diffusion coefficient of Cr in their vicinity is maximized at diameter of about 6Å.The specific fast diffusion paths near the nanopores were exposed and discussed.
基金supported by the National Natural Science Foundation of China(Grant No.51804296)China Scholarship Council Grant(Grant No.CSC#202006425019).
文摘Controllable rock cracking technology is crucial for the exploration and exploitation of deep underground resources.Many existing studies have been dedicated to the laser-assisted rock-weakening technology.It has been proved that laser irradiation can improve drilling and blasting efficiency when combined with mechanical rock fracturing methods,which are irrelevant for borehole stabilization.To improve the latter,this study used laser ablation for borehole reinforcement.The high-power laser was applied to typical rock samples(sandstone,mudstone and coal)in both dry and saturated conditions.Multi-technique observations and measurements were used to fully understand the peculiar modifications of the specimens under laser treatment,i.e.mechanical loading,acoustic emission(AE)monitoring,digital image correlation(DIC)strain field evaluation,infrared thermography(IRT)monitoring and X-ray computed tomography(CT)scanning.The results showed that,in addition to the effects already demonstrated,laser irradiation can improve the strength of the soft rock,especially in the saturated state.The process involved a complicated phase change including melting and evaporation of the matrix under high-temperature and high-pressure to form a glassy high strength silicate material.This process is similar to the reaction between molten lava and water,or the impact of an asteroid on the earth.Inspired by the results,a conceptual path for a new borehole stabilization technology using laser ablation was outlined.
基金supported by the National Natural Science Foundation of China(Nos.12005289,52072397)State Key Laboratory of Nuclear Detection and Electronics,University of Science and Technology of China(SKLPDE-KF-202316).
文摘The stability of matrix graphite under neutron irradiation and in corrosive environments is crucial for the safe operation of molten salt reactors(MSRs).Raman spectroscopy and a slow positron beam were employed to investigate the effects of He ion irradiation fluences and subsequent annealing on the microstructure and defects of the matrix graphite.He ions with 500 keV energy and fluences ranging from 1.1×10^(15)ions∕cm^(2)to 3.5×10^(17)ions∕cm^(2)were used to simulate neutron irradiation at 300 K.The samples with an irradiation fluence of 3.5×10^(16)ions∕cm^(2)were subjected to isochronal annealing at different temperatures(573 K,873 K and 1173 K)for 3 h.The Raman results revealed that the D peak gradually increased,whereas the intrinsic G peak decreased with increasing irradiation fluence.At the same irradiation fluence,the D peak gradually decreased,whereas the intrinsic G peak increased with increasing annealing temperature.Slow positron beam analysis demonstrated that the density or size of irradiation defects(vacancy type)increased with higher irradiation fluence,but decreased rapidly with increasing annealing temperature.The Raman spectral analysis of sample cross sections subjected to high irradiation fluences revealed the emergence of amorphization precisely at the depth where ion damage was most pronounced,whereas the surface retained its crystalline structure.Raman and positron annihilation analyses indicated that the matrix graphite exhibited good irradiation resistance to He ions at 300 K.However,vacancy-type defects induced by He ion irradiation exhibit poor thermal stability and can be easily removed during annealing.
基金This work is supported by National Natural Science Foundation of China(No.42372054)。
文摘The features of optical defects in a chemical vapor deposition (CVD) synthetic type Ⅱ a diamond were characterized using photoluminescence (PL) spectroscopy, before and after electron irradiation. The sample was cut within a {100} growth layer, and irradiated with 2 MeV electrons along the <100> axis. PL spectra of sample were collected under 532 nm and 355 nm laser excitation, at room temperature and 77 K, and linear scanning analysis along incident depth was applied to determine the distribution of defects. The pre-irradiation characterization results revealed uniformly distributed PL centers at 389 nm, 469 nm, 533 nm, 575 nm (ZPL of NV 0), 637 nm (ZPL of NV -), and 736.7/737.1 nm (ZPL doublet of SiV -). After irradiation, the differential responses of these as-grown defects were observed, alongside the emergence of irradiation-induced defects, namely 489 nm center, H3 center (ZPL at 504 nm) and GR1 center (ZPL at 741 nm). The maximum penetration depth of 2 MeV electron-irradiation induced defects was determined to be 2.1 mm. This work primarily presents the depth profiles of both as-grown and irradiation-induced defects in 2 MeV electrons irradiated diamond. The result provides experimental data for better understanding of the radiation effect in diamonds. Serving as a reference for diamond enhancement by electron irradiation.
基金supported by the National Natu-ral Science Foundation of China(No.U2230126)the Natural Science Foundation of Zhejiang Province(No.LZ23E010001)+1 种基金This work was co-funded by the European Union under the Project Robotics and Advanced Industrial Production(Reg.No.CZ.02.01.01/00/22_008/0004590)supported by the Ministry of Education,Youth and Sports of the Czech Repub-lic through the e-INFRA CZ grant number ID:90140.Access to the computational infrastructure of the OP VVV funded Project No.CZ.02.1.01/0.0/0.0/16_019/0000765“Research Center for Informat-ics”and the use of the VESTA software[https://doi.org/10.1107/S0021889808012016]are also acknowledged.The authors thank the staffof HIRFL for the help with the irradiation experiment and the support of the Sharing Service Platform of CAS Large Re-search Infrastructures(2022-HIRFL-ZD-002017)。
文摘Cr coatings,as protective coatings of Zr-alloy fuel claddings,inevitably suffer from irradiation damage before they would possibly run into the accident condition.This study evaluates the radiation and oxidation tolerance of three Cr-based coatings with different microstructures(Cr,CrAlSi,and CrAlSiN)through He2+ion irradiation and 1200℃ steam oxidation.The Cr and CrAlSi coatings experienced significant structural degradation,characterized by He bubble aggregation and amplified Kirkendall effects at elevated temperatures.In contrast,the irradiated CrAlSiN coating maintained structural integrity without measurable irradiation hardening.Following annealing at 800℃ for 30 min,approximately 40%of injected He atoms were released,indicating a“self-healing”mechanism.The mechanism is attributed to uniformly distributed,low-density channels that act as sinks and release paths for irradiation-induced defects.Density functional theory simulations suggest that N atoms promote significant rearrangement of ions surrounding the free volume,inhibiting the formation of sites capable of trapping He atoms.Moreover,the CrAlSiN coating exhibited superior oxidation resistance compared to the Cr and CrAlSi coatings,even under high-temperature steam conditions.Notably,the irradiated CrAlSiN sample displayed a significantly thinner oxide scale compared to the pristine one(almost half),owing to a more protective oxide scale and rapid outward diffusion of Cr,Al,and Si through nanochannel veins.These findings illuminate the effects of structure and composition on irradiation and oxidation behavior in Cr-based coatings,offering insights for developing new-generation accident-tolerance fuel coatings for Zr-alloy claddings.
基金National Natural Science Foundation of China for funding support via grant No 12175013the Interdisciplinary Research Project for Young Researchers of USTB and the Youth Teacher International Exchange&Growth Program of USTB(Fundamental Research Funds for the Central Universities,China)for funding support via grant No FRF-IDRY-21–018 and QNXM20250033,respectively.
文摘Evaluation of damage evolution effects in biodegradable pure Mg was carried out,using transmission electron microscope as surrogate irradiation for high-energy radionuclide β decay in Brachytherapy.Time-dependent quantitative defect production,evolution dynamics,and evolution statistics were revealed in-situ for two prism foils(z=[1.210],[10.10]),in as-received and heat-treated pure Mg,after 300 keV electron irradiation up to 0.468 dpa at R.T.Preferred nucleation of basal-plane interstitial-type 1/6<20.23>loops was confirmed,in addition to a small portion of prism-plane 1/3<11.20>loops.No cavities were found.A higher yield of point defect concentration and a more evident trend of defect coarsening were identified in[1.210]than in[10.10].Pre-existing dislocations(on the orders of 10^(13)−10^(14) m^(−2))in pure Mg resulted in a delay of the first occurrence of visible defects.Defect migration and elastic interactions governed the microstructural evolution of electron irradiation damage in pure Mg,giving rise to events of loop coalescence,growth,and sometimes rotation of habit plane.The influence of incident electron energy can be correlated to the rates of point defect production,and is quantifiable;however,interfered by defect cluster stability,defect mobility,and defect interactions.This forms an important theoretical basis for the application of Mg subjected to MeV-level β-decay radiation in Brachytherapy.The paper concludes with a brief comparison between Mg and conventional Ti casing,outlines the advantages and challenges,and provides reference points for the validation of Mg/Mg-alloys in Brachytherapy seed application.
基金supported by the National Natural Science Foundation of China(No.52077151)the State Key Laboratory of Electrical Insulation and Power Equipment(No.EIPE23208)the Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education(No.KFM202203).
文摘This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-based elastomer(PBE)at concentrations ranging from 0 to 50 wt%,underwent a melt blending process and subsequent cobalt-60 gamma-ray irradiation with doses ranging from 0 to 250 kGy.Electrical conductivity,trap distribution,and alternating(AC)breakdown strength were chosen to assess the insulation performance.These results indicate that the addition of PBE significantly improves the electrical properties of PP under irradiation.For PP,the electrical conductivity increased with irradiation,whereas the trap depth and breakdown strength decreased sharply.Conversely,for the blend,these changes initially exhibit opposite trends.When the irradiation was increased to 250 kGy,the AC breakdown strength of the blend improved by more than 21%compared to that of PP.The physical and chemical structures of the samples were investigated to explore the improvement mechanisms.The results offer insights into the design of new cable-insulation materials suitable for NPPs.
基金support from MATRIX(ANR-22-CE92-0047)with financial support from ITMI Cancer of Aviesan within the framework of the 2021−2030 Cancer Control Strategy,on funds administrated by INSERM through the project NECTAR.Matilde Siviero acknowledges funding from the French−German University/Saarbrücken(contract CDOC-06-2022).
文摘GaN diodes for high energy(64.8 MeV)proton detection were fabricated and investigated.A comparison of the performance of GaN diodes with different structures is presented,with a focus on sapphire and on GaN substrates,Schottky and pin diodes,and different active layer thicknesses.Pin diodes fabricated on a sapphire substrate are the best choice for a GaN proton detector working at 0 V bias.They are sensitive(minimum detectable proton beam<1 pA/cm^(2)),linear as a function of proton current and fast(<1 s).High proton current sensitivity and high spatial resolution of GaN diodes can be exploited in the future for proton imaging of patients in proton therapy.
基金supported by the National Natural Science Foundation of China[grant number 42175132]the National Key R&D Program[grant number 2020YFA0607802]the CAS Information Technology Program[grant number CAS-WX2021SF-0107-02]。
文摘Solar energy is a pivotal clean energy source in the transition to carbon neutrality from fossil fuels.However,the intermittent and stochastic characteristics of solar radiation pose challenges for accurate simulation and prediction.Accurately simulating and predicting solar radiation and its variability are crucial for optimizing solar energy utilization.This study conducted simulation experiments using the WRF-Solar model from 25 June to 25 July 2022,to evaluate the accuracy and performance of the simulated solar radiation across China.The simulations covered the whole country with a grid spacing of 27 km and were compared with ground observation network data from the Chinese Ecosystem Research Network.The results indicated that WRF-Solar can accurately capture the spatiotemporal patterns of global horizontal irradiance over China,but there is still an overestimation of solar radiation,and the model underestimates the total cloud cover.The root-mean-square error ranged from 92.83 to 188.13 W m^(-2) and the mean bias(MB)ranged from 21.05 to 56.22 W m^(-2).The simulation showed the smallest MB at Lhasa on the Qinghai–Tibet Plateau,while the largest MB was observed in Southeast China.To enhance the accuracy of solar radiation simulation,the authors compared the Fast All-sky Radiation Model for Solar with the Rapid Radiative Transfer Model for General Circulation Models and found that the former provides better simulation.
文摘Correction:Nuclear Science and Techniques(2025)36:4 https://doi.org/10.1007/s41365-024-01548-5 In this article,the caption for Fig(s)1,3,and 4 was inadvert-ently truncated.The incorrect and the corrected captions are given below.
基金funded by Universiti Tenaga Nasional(UNITEN),Malaysia for supporting this research under the Dato'Low Tuck Kwong International Grant,project code 20238002DLTKsupport for this work from the Ministry of Higher EducationMalaysia through the Higher Institution Center of Excellence(HICoE 2023-JPT(BPKI)1000/016/018/34(5))program+2 种基金supported by Tenaga Nasional Berhad(TNB)and UNITEN through the BOLD Refresh Postdoctoral Fellowships under Grant J510050002-IC-6 BOLDREFRESH2023-Centre of ExcellencePrince Sultan University for their supportIndustrial Technology Division,Malaysian Nuclear Agency for their support in this research work.
文摘Investigating the influence of radiation on glass fibre composites is essential for their use in space and aerospace environment.Gaining insight into the damage mechanisms caused by gamma irradiation,can improve the safety and resilience of structures.This paper is aimed at investigating the failure mode and damage of gamma-irradiated repurposed pultruded glass fibre-reinforced polyester subjected to lowvelocity impact using three types of non-destructive techniques.Three sets of differently layered configurations(CRC,WCRW,W2CR2C)consisting of chopped(c),roving(r),and weaved(w)fibre-reinforced polyester are applied in this study.Drop hammer test is applied to evaluate the low-impact resistance properties of Gamma-irradiated composite at 100 kGy,500 kGy,and 1000 kGy.Preliminary flexural and hardness tests are conducted to further assess the behaviour of irradiated polymer composites.Further,the damage modes associated with the low-impact test are characterised using infrared thermography,flat panel digital radiography,and microscope observation.The results show that the composites irradiated with various doses display good impact resistance at 20 J,presenting minor damages in the form of dents on the surface.The irradiated CRC and WCRW display best impact resistance at 500 kGy,while W2CR2C at 1000 kGy.This shows that the layering sequence of reinforcement fibre can influence the impact resistance of irradiated composites.Apart from that,the application of non-destructive techniques show different damage mechanisms in the form resin cracks,yarn splitting/fracture,and matrix splitting when the composites are exposed at high and low irradiation doses.These findings offer valuable data for the defence industry,particularly in the areas of repair,maintenance,and the development of new materials.
基金support to this work:the National Natural Science Foundation of China(grant No.50971064,No.51361004)the Innovative Foundation of HUST(grant 2017KFYXJJ164).
文摘Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a kind of unique core-shell heterojunction CuS@PPy nanostructures was synthesized and then incorporated in polycaprolactone(PCL)to construct an intelligent coating(CuS@PPy/PCL)on micro-arc-oxidized Mg implants.The PCL-based coating can realize near-infrared(NIR)-driven antibacterial and controllable Mg dissolution according to different bone healing stages.At the beginning of bone remodelling,the coating exhibits promising antibacterial properties with 99.67%and 99.17%efficacy against S.aureus and E.coli,respectively,thanks to the singlet oxygen(^(1)O_(2))and alkoxyl radicals(RO·)generated by the photodynamic effect of CuS@PPy heterojunction under low-power NIR light(1.5 W/cm^(2)).In the bone reparative stage,the PCL-based coating can maintain high corrosion resistance to meet the mechanical requirements of Mg implants in human body fluid.However,after the complete rehabilitation of bones,through a high-power(2 W/cm^(2))NIR light,the PCL-based coating changed from an elastic to a viscous flow state(44.7℃)under the photothermal effects of CuS@PPy,leading to quick degradation of the PCL-based coating and following accelerating dissolution of the Mg implant(avoiding secondary surgery).Hopefully,this NIR-responsive coating may provide an innovative method for the antibacterial and controllable dissolution of Mg implants.
