The emergence of laser technology has led to the gradual integration of laser weapon system(LaWS)into military scene,particularly in the field of anti-unmanned aerial vehicle(UAV),showcasing significant potential.Howe...The emergence of laser technology has led to the gradual integration of laser weapon system(LaWS)into military scene,particularly in the field of anti-unmanned aerial vehicle(UAV),showcasing significant potential.However,A current limitation lies in the absence of a comprehensive quantitative approach to assess the capabilities of LaWS.To address this issue,a damage effectiveness characterization model for LaWS is established,taking into account the properties of laser transmission through the atmosphere and the thermal damage effects.By employing this model,key parameters pertaining to the effectiveness of laser damage are determined.The impact of various spatial positions and atmospheric conditions on the damage effectiveness of LaWS have been examined,employing simulation experiments with diverse parameters.The conclusions indicate that the damage effectiveness of LaWS is contingent upon the spatial position of the target,resulting in a diminished effectiveness to damage on distant,low-altitude targets.Additionally,the damage effectiveness of LaWS is heavily reliant on the atmospheric condition,particularly in complex settings such as midday and low visibility conditions,where the damage effectiveness is substantially reduced.This paper provides an accurate and effective calculation method for the rapid decisionmaking of the operators.展开更多
The study of the mechanical property and damage state of coal materials under compression is a fundamental area of research in underground mining engineering.Drawing upon the compaction effect and linear energy dissip...The study of the mechanical property and damage state of coal materials under compression is a fundamental area of research in underground mining engineering.Drawing upon the compaction effect and linear energy dissipation(LED)law,a novel compressive damage constitutive model for brittle coal is proposed.Utilizing the energy-defined damage method for mate-rials,the LED law is innovatively introduced to accurately characterize the energy dissipation during the loading process,and a novel formula for characterizing the damage variable of brittle coal is proposed.On this basis,considering that the constitutive model based on the hypothesis of strain equivalence is incapable of accurately describing the compaction effect exhibited by coal material during the compression process,a correction coefficient is proposed and apply it in the novel damage constitutive model.The established conventional monotone loading and single-cyclic loading-unloading uniaxial compression damage constitutive models have been validated using experimental data from cylindrical and cuboid coal specimens.In addition,compared with the constitutive model obtained via the traditional energy calculation method based on the hypothesis that the unloading curve is a straight line,the constitutive model employing LED law can describe the stress-strain state of brittle coal more precisely.This approach introduces a new perspective and enhances the convenience for constructing the constitutive model based on energy theory.展开更多
Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the...Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the excised region. Accumulation of DNA damage with failure of repair processes leads to fatal diseases such as cancer. Recent studies have suggested that intra- and extra-nuclear environments play essential roles in DNA damage. However, numerous questions regarding the role of the nuclear mechanical environment in DNA damage remain unanswered. In this study, we investigated the effects of cell confluency (cell crowding) on the morphology of cell nuclei, and cytoskeletal structures, and DNA damage in NIH3T3 skin fibroblasts and HeLa cervical cancer cells. Although nuclear downsizing was observed in both NIH3T3 and HeLa cells with cell crowding, intracellular mechanical changes in the two cell types displayed opposite tendencies. Cell crowding in NIH3T3 cells induced reinforcement of actin filament structures, cell stiffening, and nuclear downsizing, resulting in a significant decrease in endogenous DNA damage, whereas cell crowding in HeLa cells caused partial depolymerization of actin filaments and cell softening, inducing endogenous DNA damage. Ultraviolet (UV) radiation significantly increased DNA damage in NIH3T3;however, this response did not change with cell crowding. In contrast, UV radiation did not cause DNA damage in HeLa cells under either sparse or confluent conditions. These results suggested that cell crowding significantly influenced endogenous DNA damage in cells and was quite different in NIH3T3 and HeLa cells. However, cell crowding did not affect the UV-induced DNA damage in either cell type.展开更多
AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-fou...AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-four rats were categorized into four groups of six rats:healthy(HG),5-FU(FUG),ATP+5-FU(AFU),and melatonin+5-FU(MFU).ATP(4 mg/kg)and melatonin(10 mg/kg)were administered intraperitoneally and orally,respectively.One hour after ATP and melatonin administration,rats in the AFU,MFU,and FUG were intraperitoneally injected with 5-FU(100 mg/kg).ATP and melatonin were administered once daily for 10d.5-FU was administered at a single dose on days 1,3,and 5 of the experiment.After 10d,the rats were euthanized and optic nerve tissues were extracted.Optic nerve tissues were biochemically and histopathologically examined.RESULTS:ATP and melatonin treatments inhibited the increase in malondialdehyde(MDA)and interleukin-6(IL-6)levels,which were elevated in the FUG.The treatments also prevented the decrease in total glutathione(tGSH)levels and the superoxide dismutase(SOD)and catalase(CAT)activities(P<0.001).This inhibition was higher in the ATP group than in the melatonin group(P<0.001).ATP prevented histopathological damage better than melatonin(P<0.05).CONCLUSION:ATP and melatonin have the potential to be used in alleviating 5-FU-induced optic nerve damage.In addition,ATP treatment shows better protective effects than melatonin.展开更多
Investigation techniques,such as uniaxial compression tests,acoustic emission,digital image correlation monitoring,and scanning electron microscopy,were used from macroscopic and microscopic perspectives to investigat...Investigation techniques,such as uniaxial compression tests,acoustic emission,digital image correlation monitoring,and scanning electron microscopy,were used from macroscopic and microscopic perspectives to investigate the effects of gangue particle-size gradation on the damage characteristics of cemented backfill.The peak strength,acoustic emission characteristics,and failure modes of cemented backfills with different gangue size gradations were examined.Test results indicated that with an increase in the gradation coefficient,the compressive strength of the gangue-cemented backfill first increased and then decreased.When the gradation coefficient is 0.5,the maximum compressive strength of the backfill is 4.28 MPa.The acoustic emission counts during the loading of gangue-cemented fills with different gradation coefficients passed through three phases:rising,active,and significantly active.The number of internal pores and cracks,as well as the uneven distribution of their locations,cause differences in acoustic emission characteristics at the same stage and variations in the strength of the backfill due to the different gangue particle-size gradations in the filler sample.展开更多
Reinforced concrete buildings may experience partial damage after earthquakes or some human-induced actions.A decision about the future of those buildings requires detailed analyses,while determining the dynamic chara...Reinforced concrete buildings may experience partial damage after earthquakes or some human-induced actions.A decision about the future of those buildings requires detailed analyses,while determining the dynamic characteristics of a real building in its pre-and post-event situations can guide the analysis.Hence,this study was planned to monitor the dynamic response of an existing six-story,reinforced concrete building with regard to structural damage.The modal characteristics of the original building were initially determined by the use of operational modal analysis.Next,three steps of progressive structural damage were applied to the building.The first damage level peeled off the clear cover of a beam and three columns on a corner of the building’s ground floor.whereas the second and third levels completely razed the damaged columns.Operational modal analysis was repeated at each damage stage to extract the frequencies and detailed mode shapes.Moreover,numerical models based on the finite element method were constructed to confirm the obtained experimental findings.The well-agreed experimental and numerical findings revealed the damage sensitivity of the building’s dynamic response.The quantified amount of frequency change favored a retrofit of the partially damaged buildings rather than their replacement.展开更多
Thermomechanical Fatigue (TMF) is one of the most dangerous failure modes of high-temperature structures. The effect of coarsened and rafted microstructures on the TMF behavior of Nickel-Base Single Crystal Superalloy...Thermomechanical Fatigue (TMF) is one of the most dangerous failure modes of high-temperature structures. The effect of coarsened and rafted microstructures on the TMF behavior of Nickel-Base Single Crystal Superalloys (NBSX) was experimentally studied. TMF tests under In-Phase (IP) and Out-of-Phase (OP) paths revealed significant variations in TMF life reduction. Cyclic deformation behaviors of alloys with different microstructures were compared. The effect of microstructure on TMF damage mechanisms was unveiled from characterizations of fracture surfaces and longitudinal sections by scanning electronic microscope and optical microscope. A transition from mode-I to crystallographic fracture in the coarsened alloy during IP-TMF was observed and discussed. Due to the degraded microstructure, the dispersed distribution of crystal slips was distinguished in the coarsened and rafted alloys. The competitive or synergetic interactions among oxidation-assisted mode-I opening, casting pore-related mode-I creep and crystallographic slipping were discussed. This study underscores the complex interplay among microstructure, deformation behaviors and damage mechanisms, offering valuable insights into alloy performance under TMF conditions.展开更多
Prolonged cyclic water intrusion has progressively developed joints in the hydro-fluctuation belt,elevating the instability risk of reservoir bank slopes.To investigate its impact on joint shear damage evolution,joint...Prolonged cyclic water intrusion has progressively developed joints in the hydro-fluctuation belt,elevating the instability risk of reservoir bank slopes.To investigate its impact on joint shear damage evolution,joint samples were prepared using three representative roughness curves and subjected to direct shear testing following cyclic water intrusion.A shear damage constitutive model considering the coupling effect of cyclic water intrusion and load was developed based on macroscopic phenomenological damage mechanics and micro-statistical theory.Results indicate:(1)All critical shear mechanical parameters(including peak shear strength,shear stiffness,basic friction angle,and joint compressive strength)exhibit progressive deterioration with increasing water intrusion cycles;(2)Model validation through experimental curve comparisons confirms its reliability.The model demonstrates that intensified water intrusion cycles reduce key mechanical indices,inducing a brittle-to-ductile transition in joint surface deformation—a behavior consistent with experimental observations;(3)Damage under cyclic water intrusion and load coupling follows an S-shaped trend,divided into stabilization(water-dominated stage),development(load-dominated stage),and completion stages.The research provides valuable insights for stability studies,such as similar model experiments for reservoir bank slopes and other water-related projects.展开更多
To address the issue of extreme thermal-induced arching in CRTS II slab tracks due to joint damage,an optimized joint repair model was proposed.First,the formula for calculating the safe temperature rise of the track ...To address the issue of extreme thermal-induced arching in CRTS II slab tracks due to joint damage,an optimized joint repair model was proposed.First,the formula for calculating the safe temperature rise of the track was derived based on the principle of stationary potential energy.Considering interlayer evolution and structural crack propagation,an optimized joint repair model for the track was established and validated.Subsequently,the impact of joint repair on track damage and arch stability under extreme temperatures was studied,and a comprehensive evaluation of the feasibility of joint repair and the evolution of damage after repair was conducted.The results show that after the joint repair,the temperature rise of the initial damage of the track structure can be increased by 11℃.Under the most unfavorable heating load with a superimposed temperature gradient,the maximum stiffness degradation index SDEG in the track structure is reduced by about 81.16%following joint repair.The joint repair process could effectively reduce the deformation of the slab arching under high temperatures,resulting in a reduction of 93.96%in upward arching deformation.After repair,with the damage to interfacing shear strength,the track arch increases by 2.616 mm.展开更多
In this study,a uniaxial cyclic compression test is conducted on coal-rock composite structures under two cyclic loads using MTSE45.104 testing apparatus to investigate the macro-mesoscopic deformation,damage behavior...In this study,a uniaxial cyclic compression test is conducted on coal-rock composite structures under two cyclic loads using MTSE45.104 testing apparatus to investigate the macro-mesoscopic deformation,damage behavior,and energy evolution characteristics of these structures under different cyclic stress disturbances.Three loading and unloading rates(LURs)are tested to examine the damage behaviors and energy-driven characteristics of the composites.The findings reveal that the energy-driven behavior,mechanical properties,and macro-micro degradation characteristics of the composites are significantly influenced by the loading rate.Under the gradual cyclic loading and unloading(CLU)path with a constant lower limit(path I)and the CLU path with variable upper and lower boundaries(path II),an increase in LURs from 0.05 to 0.15 mm/min reduces the average loading time by 32.39%and 48.60%,respectively.Consequently,the total number of cracks in the samples increases by 1.66-fold for path I and 1.41-fold for path II.As LURs further increase,the energy storage limit of samples expands,leading to a higher proportion of transmatrix and shear cracks.Under both cyclic loading conditions,a broader cyclic stress range promotes energy dissipation and the formation of internal fractures.Notably,at higher loading rates,cracks tend to propagate along primary weak surfaces,leading to an increased incidence of intermatrix fractures.This behavior indicates a microscopic feature of the failure mechanisms in composite structures.These results provide a theoretical basis for elucidating the damage and failure characteristics of coal-rock composite structures under cyclic stress disturbances.展开更多
This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the Chi...This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the China spallation neutron source(CSNS)and Xi'an pulsed reactor(XAPR).The mean dark signal,dark signal non-uniformity(DSNU),dark signal distribution,and hot pixels of the CIS were compared between the CSNS back-n and XAPR neutron irradiations.The nonionizing energy loss and energy distribution of primary knock-on atoms in silicon,induced by neutrons,were calculated using the open-source package Geant4.An analysis combining experimental and simulation results showed a noticeable proportionality between the increase in the mean dark signal and the displacement damage dose(DDD).Additionally,neutron energies influence DSNU,dark signal distribution,and hot pixels.High neutron energies at the same DDD level may lead to pronounced dark signal non-uniformity and elevated hot pixel values.展开更多
To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and thre...To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.展开更多
Various industrial waste binders(IWBs)are being recycled in soil stabilization to save cement consumption.However,the coupled effects brought out by combined IWBs on stabilized soils are still unclear.IWBs are categor...Various industrial waste binders(IWBs)are being recycled in soil stabilization to save cement consumption.However,the coupled effects brought out by combined IWBs on stabilized soils are still unclear.IWBs are categorized into two typical categories(IWB-A and IWB-B)referring to their chemical role in this study.The alkali-source effect,pore-filling effect and cementation damage effect by IWBs in soil stabilization are explored.A series of mechanical and microscopic tests is performed on stabilized clay with different proportions of IWB-A and IWB-B.Moreover,initial water contents and cement contents of cement-stabilized clay are varied to examine the evolution of coupled effect with void ratio and cementation level.The results indicate that the alkali-source effect strengthens the cementation bonds and increases the early strength by 0.5e1.3 times,whereas the pore-filling effect improves the microfabric especially for the specimen with a large void ratio.The alkali-source effect increases soil cohesion cu at the pre-yield stage,and the pore-filling effect increases frictional angle 4u at the post-yield stage.The cementation damage effect is remarkable at a low void ratio,which may result in many extruded pores among soil aggregates.The strength evolution with IWB proportions can be well stimulated by considering the coupled alkali-source effect,pore-filling effect and cementation damage effect.The optimal proportion of IWBs corresponds to an optimal combination of coupled effect.展开更多
Owing to the unique characteristics of ultra-thin body and nanoscale sensitivity volume,MoS_(2)-based field-effect tran-sistors(FETs)are regarded as optimal components for radiation-hardened integrated circuits(ICs),w...Owing to the unique characteristics of ultra-thin body and nanoscale sensitivity volume,MoS_(2)-based field-effect tran-sistors(FETs)are regarded as optimal components for radiation-hardened integrated circuits(ICs),which is exponentially grow-ing demanded especially in the fields of space exploration and the nuclear industry.Many researches on MoS_(2)-based radiation tolerance electronics focused on the total ionizing dose(TID)effect,while few works concerned the displacement damage(DD)effects,which is more challenging to measure and more crucial for practical applications.We first conducted measurements to assess the DD effects of MoS_(2) FETs,and then presented the stopping and ranges of ions in matter(SRIM)simulation to analysis the DD degradation mechanism in MoS_(2) electronics.The monolayer MoS_(2)-based FETs exhibit DD radiation tolerance up to 1.56×1013 MeV/g,which is at least two order of magnitude than that in conventional radiation hardened ICs.The exceptional DD radiation tolerance will significantly enhance the deployment of MoS_(2) integrated circuits in environments characterized by high-energy solar and cosmic radiation exposure.展开更多
Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechani...Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of rocks.In this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics framework.Regarding the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock matrix.After proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental results.The model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.展开更多
The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fou...The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt reactors.The competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this paper.Conceptual approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.展开更多
Objective: To investigate the effects of different concentrations of β-glucan on the repair of damaged vaginal mucosa, the expression of vascular endothelial growth factor (VEGF), and the inflammatory factor-6 (IL-6)...Objective: To investigate the effects of different concentrations of β-glucan on the repair of damaged vaginal mucosa, the expression of vascular endothelial growth factor (VEGF), and the inflammatory factor-6 (IL-6) in vaginal tissues. Methods: Thirty-six adult female specific pathogen free (SPF)-grade Wistar rats were randomly divided into 3 phase groups with 12 rats each. Vaginal inflammation rat models were established by injecting phenol gel into the vagina of each rat at a dose of 0.1 ml/100g body weight. After modeling, rats were divided into 4 groups based on different concentrations of the test agent. The control group was injected with 0.5 ml of saline, experimental group A was injected with 0.375 ml saline 0.125 ml β-glucan, experimental group B was injected with 0.25 ml saline 0.25 ml β-glucan, and experimental group C was injected with 0.50 ml β-glucan. The injection sites were selected at the 3 o’clock and 9 o’clock positions of the vagina. Rats were sacrificed at 7-, 14-, and 28-days post-injection, and tissue samples were collected from the injection sites and prepared for histological analysis. New blood vessels and fibroblast numbers in the tissues were observed after Hematoxylin-eosin (HE) staining. The expression levels of VEGF and IL-6 in the tissues were measured using quantificational reverse transcription polymerase chain reaction (qRT-PCR). Results: Histological examination of vaginal tissue specimens at 7-, 14-, and 28-days post-injection showed that on day 7, there were no significant changes in the experimental groups compared to the control group. However, on days 14 and 28, the experimental groups showed more new blood vessels, macrophages, and fibroblasts with increased activity compared to the control group. The expression levels of VEGF in vaginal tissues were elevated on days 14 and 28 in the experimental groups. The comparison of IL-6 levels in vaginal tissues on day 28 showed that serum IL-6 levels returned to normal, and there was no statistically significant difference between the experimental and control groups. Conclusion: In the 3 experimental phases, the increase in VEGF levels in vaginal tissues on day 14 post-injection was more pronounced with higher concentrations of β-glucan, and IL-6 levels returned to normal on day 28. β-Glucan can enhance VEGF levels in damaged vaginal tissues, promote the repair of damaged vaginal tissues, and higher concentrations of β-glucan have a better effect.展开更多
Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of ne...Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder.展开更多
Fine particulate matter(PM_(2.5))exposure is associated with cardiovascular disease(CVD)morbidity and mortality.Mitochondria are sensitive targets of PM_(2.5),and mitochondrial dysfunction is closely related to the oc...Fine particulate matter(PM_(2.5))exposure is associated with cardiovascular disease(CVD)morbidity and mortality.Mitochondria are sensitive targets of PM_(2.5),and mitochondrial dysfunction is closely related to the occurrence of CVD.The epigenetic mechanism of PM_(2.5)-triggered mitochondrial injury of cardiomyocytes is unclear.This study focused on the mi R-421/SIRT3 signaling pathway to investigate the regulatory mechanism in cardiac mitochondrial dynamics imbalance in rat H9c2 cells induced by PM_(2.5).Results illustrated that PM_(2.5)impaired mitochondrial function and caused dynamics homeostasis imbalance.Besides,PM_(2.5)up-regulated mi R-421 and down-regulated SIRT3 gene expression,along with decreasing p-FOXO3a(SIRT3 downstream target gene)and p-Parkin expression and triggering abnormal expression of fusion gene OPA1 and fission gene Drp1.Further,mi R-421 inhibitor(mi R-421i)and resveratrol significantly elevated the SIRT3 levels in H9c2 cells after PM_(2.5)exposure and mediated the expression of SOD2,OPA1 and Drp1,restoring the mitochondrial morphology and function.It suggests that mi R-421/SIRT3 pathway plays an epigenetic regulatory role in mitochondrial damage induced by PM_(2.5)and that mi R-421i and resveratrol exert protective effects against PM_(2.5)-incurred cardiotoxicity.展开更多
Iron(Fe)-based alloys,which have been widely used as structural materials in nuclear reactors,can significantly change their microstructure properties and macroscopic properties under high flux neutron irradiation dur...Iron(Fe)-based alloys,which have been widely used as structural materials in nuclear reactors,can significantly change their microstructure properties and macroscopic properties under high flux neutron irradiation during operation,thus,the problems associated with the safe operation of nuclear reactors have been put forward naturally.In this work,a molecular dynamics simulation approach combined with electronic effects is developed for investigating the primary radiation damage process inα-Fe.Specifically,the influence of electronic effects on the collision cascade in Fe is systematically evaluated based on two commonly used interatomic potentials for Fe.The simulation results reveal that both electronic stopping(ES)and electron-phonon coupling(EPC)can contribute to the decrease of the number of defects in the thermal spike phase.The application of ES reduces the number of residual defects after the cascade evolution,whereas EPC has a reverse effect.The introduction of electronic effects promotes the formation of the dispersive subcascade:ES significantly changes the geometry of the damaged region in the thermal spike phase,whereas EPC mainly reduces the extent of the damaged region.Furthermore,the incorporation of electronic effects effectively mitigates discrepancies in simulation outcomes when using different interatomic potentials.展开更多
基金supported by the National Social Science Foundation of China(2022-SKJJ-C-037)the National Natural Science Foundation of China General Program(72071209).
文摘The emergence of laser technology has led to the gradual integration of laser weapon system(LaWS)into military scene,particularly in the field of anti-unmanned aerial vehicle(UAV),showcasing significant potential.However,A current limitation lies in the absence of a comprehensive quantitative approach to assess the capabilities of LaWS.To address this issue,a damage effectiveness characterization model for LaWS is established,taking into account the properties of laser transmission through the atmosphere and the thermal damage effects.By employing this model,key parameters pertaining to the effectiveness of laser damage are determined.The impact of various spatial positions and atmospheric conditions on the damage effectiveness of LaWS have been examined,employing simulation experiments with diverse parameters.The conclusions indicate that the damage effectiveness of LaWS is contingent upon the spatial position of the target,resulting in a diminished effectiveness to damage on distant,low-altitude targets.Additionally,the damage effectiveness of LaWS is heavily reliant on the atmospheric condition,particularly in complex settings such as midday and low visibility conditions,where the damage effectiveness is substantially reduced.This paper provides an accurate and effective calculation method for the rapid decisionmaking of the operators.
基金supported by the National Science Fund for Distinguished Young Scholars(52225403)the National Natural Science Foundation of China(42077244).
文摘The study of the mechanical property and damage state of coal materials under compression is a fundamental area of research in underground mining engineering.Drawing upon the compaction effect and linear energy dissipation(LED)law,a novel compressive damage constitutive model for brittle coal is proposed.Utilizing the energy-defined damage method for mate-rials,the LED law is innovatively introduced to accurately characterize the energy dissipation during the loading process,and a novel formula for characterizing the damage variable of brittle coal is proposed.On this basis,considering that the constitutive model based on the hypothesis of strain equivalence is incapable of accurately describing the compaction effect exhibited by coal material during the compression process,a correction coefficient is proposed and apply it in the novel damage constitutive model.The established conventional monotone loading and single-cyclic loading-unloading uniaxial compression damage constitutive models have been validated using experimental data from cylindrical and cuboid coal specimens.In addition,compared with the constitutive model obtained via the traditional energy calculation method based on the hypothesis that the unloading curve is a straight line,the constitutive model employing LED law can describe the stress-strain state of brittle coal more precisely.This approach introduces a new perspective and enhances the convenience for constructing the constitutive model based on energy theory.
文摘Nuclear DNA, which is essential for the transmission of genetic information, is constantly damaged by external stresses and is subsequently repaired by the removal of the damaged region, followed by resynthesis of the excised region. Accumulation of DNA damage with failure of repair processes leads to fatal diseases such as cancer. Recent studies have suggested that intra- and extra-nuclear environments play essential roles in DNA damage. However, numerous questions regarding the role of the nuclear mechanical environment in DNA damage remain unanswered. In this study, we investigated the effects of cell confluency (cell crowding) on the morphology of cell nuclei, and cytoskeletal structures, and DNA damage in NIH3T3 skin fibroblasts and HeLa cervical cancer cells. Although nuclear downsizing was observed in both NIH3T3 and HeLa cells with cell crowding, intracellular mechanical changes in the two cell types displayed opposite tendencies. Cell crowding in NIH3T3 cells induced reinforcement of actin filament structures, cell stiffening, and nuclear downsizing, resulting in a significant decrease in endogenous DNA damage, whereas cell crowding in HeLa cells caused partial depolymerization of actin filaments and cell softening, inducing endogenous DNA damage. Ultraviolet (UV) radiation significantly increased DNA damage in NIH3T3;however, this response did not change with cell crowding. In contrast, UV radiation did not cause DNA damage in HeLa cells under either sparse or confluent conditions. These results suggested that cell crowding significantly influenced endogenous DNA damage in cells and was quite different in NIH3T3 and HeLa cells. However, cell crowding did not affect the UV-induced DNA damage in either cell type.
文摘AIM:To investigate the effects of adenosine triphosphate(ATP)and melatonin,which have antioxidant and antiinflammatory activities,on potential 5-fluorouracil(5-FU)-induced optic nerve damage in rats.METHODS:Twenty-four rats were categorized into four groups of six rats:healthy(HG),5-FU(FUG),ATP+5-FU(AFU),and melatonin+5-FU(MFU).ATP(4 mg/kg)and melatonin(10 mg/kg)were administered intraperitoneally and orally,respectively.One hour after ATP and melatonin administration,rats in the AFU,MFU,and FUG were intraperitoneally injected with 5-FU(100 mg/kg).ATP and melatonin were administered once daily for 10d.5-FU was administered at a single dose on days 1,3,and 5 of the experiment.After 10d,the rats were euthanized and optic nerve tissues were extracted.Optic nerve tissues were biochemically and histopathologically examined.RESULTS:ATP and melatonin treatments inhibited the increase in malondialdehyde(MDA)and interleukin-6(IL-6)levels,which were elevated in the FUG.The treatments also prevented the decrease in total glutathione(tGSH)levels and the superoxide dismutase(SOD)and catalase(CAT)activities(P<0.001).This inhibition was higher in the ATP group than in the melatonin group(P<0.001).ATP prevented histopathological damage better than melatonin(P<0.05).CONCLUSION:ATP and melatonin have the potential to be used in alleviating 5-FU-induced optic nerve damage.In addition,ATP treatment shows better protective effects than melatonin.
基金financially supported by the National Natural Science Foundation of China(Nos.52174095 and51804310)。
文摘Investigation techniques,such as uniaxial compression tests,acoustic emission,digital image correlation monitoring,and scanning electron microscopy,were used from macroscopic and microscopic perspectives to investigate the effects of gangue particle-size gradation on the damage characteristics of cemented backfill.The peak strength,acoustic emission characteristics,and failure modes of cemented backfills with different gangue size gradations were examined.Test results indicated that with an increase in the gradation coefficient,the compressive strength of the gangue-cemented backfill first increased and then decreased.When the gradation coefficient is 0.5,the maximum compressive strength of the backfill is 4.28 MPa.The acoustic emission counts during the loading of gangue-cemented fills with different gradation coefficients passed through three phases:rising,active,and significantly active.The number of internal pores and cracks,as well as the uneven distribution of their locations,cause differences in acoustic emission characteristics at the same stage and variations in the strength of the backfill due to the different gangue particle-size gradations in the filler sample.
基金supported by the Scientific and Technological Research Council of Türkiye(TUBITAK)under Research Grant 116M254.
文摘Reinforced concrete buildings may experience partial damage after earthquakes or some human-induced actions.A decision about the future of those buildings requires detailed analyses,while determining the dynamic characteristics of a real building in its pre-and post-event situations can guide the analysis.Hence,this study was planned to monitor the dynamic response of an existing six-story,reinforced concrete building with regard to structural damage.The modal characteristics of the original building were initially determined by the use of operational modal analysis.Next,three steps of progressive structural damage were applied to the building.The first damage level peeled off the clear cover of a beam and three columns on a corner of the building’s ground floor.whereas the second and third levels completely razed the damaged columns.Operational modal analysis was repeated at each damage stage to extract the frequencies and detailed mode shapes.Moreover,numerical models based on the finite element method were constructed to confirm the obtained experimental findings.The well-agreed experimental and numerical findings revealed the damage sensitivity of the building’s dynamic response.The quantified amount of frequency change favored a retrofit of the partially damaged buildings rather than their replacement.
基金financed by the National Natural Science Foundation of China(Nos.12402071,92160204)the China Postdoctoral Science Foundation(No.2024M751635)+1 种基金the Postdoctoral Fellowship Program of CPSF,China(No.GZB20240365)the National Science and Technology Major Projects of China(No.J2019-IV-0011-0079).
文摘Thermomechanical Fatigue (TMF) is one of the most dangerous failure modes of high-temperature structures. The effect of coarsened and rafted microstructures on the TMF behavior of Nickel-Base Single Crystal Superalloys (NBSX) was experimentally studied. TMF tests under In-Phase (IP) and Out-of-Phase (OP) paths revealed significant variations in TMF life reduction. Cyclic deformation behaviors of alloys with different microstructures were compared. The effect of microstructure on TMF damage mechanisms was unveiled from characterizations of fracture surfaces and longitudinal sections by scanning electronic microscope and optical microscope. A transition from mode-I to crystallographic fracture in the coarsened alloy during IP-TMF was observed and discussed. Due to the degraded microstructure, the dispersed distribution of crystal slips was distinguished in the coarsened and rafted alloys. The competitive or synergetic interactions among oxidation-assisted mode-I opening, casting pore-related mode-I creep and crystallographic slipping were discussed. This study underscores the complex interplay among microstructure, deformation behaviors and damage mechanisms, offering valuable insights into alloy performance under TMF conditions.
基金supported by Shandong Provincial Colleges and Universities Youth Innovation Technol ogy Support Program(No.2023KJ092)Natural Science Foundation of Shandong Province(No.ZR2024ME060)Key Laboratory of Geological Safety of Coastal Urban Underground Space,Ministry of Natural Resources(No.BHKF2024Z06)。
文摘Prolonged cyclic water intrusion has progressively developed joints in the hydro-fluctuation belt,elevating the instability risk of reservoir bank slopes.To investigate its impact on joint shear damage evolution,joint samples were prepared using three representative roughness curves and subjected to direct shear testing following cyclic water intrusion.A shear damage constitutive model considering the coupling effect of cyclic water intrusion and load was developed based on macroscopic phenomenological damage mechanics and micro-statistical theory.Results indicate:(1)All critical shear mechanical parameters(including peak shear strength,shear stiffness,basic friction angle,and joint compressive strength)exhibit progressive deterioration with increasing water intrusion cycles;(2)Model validation through experimental curve comparisons confirms its reliability.The model demonstrates that intensified water intrusion cycles reduce key mechanical indices,inducing a brittle-to-ductile transition in joint surface deformation—a behavior consistent with experimental observations;(3)Damage under cyclic water intrusion and load coupling follows an S-shaped trend,divided into stabilization(water-dominated stage),development(load-dominated stage),and completion stages.The research provides valuable insights for stability studies,such as similar model experiments for reservoir bank slopes and other water-related projects.
基金Project(K2022G038)supported by the Science Technology Research and Development Program of China State Railway Group Co.,LtdProject(52178405)supported by the National Natural Science Foundation of China。
文摘To address the issue of extreme thermal-induced arching in CRTS II slab tracks due to joint damage,an optimized joint repair model was proposed.First,the formula for calculating the safe temperature rise of the track was derived based on the principle of stationary potential energy.Considering interlayer evolution and structural crack propagation,an optimized joint repair model for the track was established and validated.Subsequently,the impact of joint repair on track damage and arch stability under extreme temperatures was studied,and a comprehensive evaluation of the feasibility of joint repair and the evolution of damage after repair was conducted.The results show that after the joint repair,the temperature rise of the initial damage of the track structure can be increased by 11℃.Under the most unfavorable heating load with a superimposed temperature gradient,the maximum stiffness degradation index SDEG in the track structure is reduced by about 81.16%following joint repair.The joint repair process could effectively reduce the deformation of the slab arching under high temperatures,resulting in a reduction of 93.96%in upward arching deformation.After repair,with the damage to interfacing shear strength,the track arch increases by 2.616 mm.
基金Project(2023YFC3009003) supported by the National Key R&D Program of ChinaProjects(52130409, 52121003, 52374249, 52204220) supported by the National Natural Science Foundation of ChinaProject(2024JCCXAQ01) supported by the Fundamental Research Funds for the Central Universities,China。
文摘In this study,a uniaxial cyclic compression test is conducted on coal-rock composite structures under two cyclic loads using MTSE45.104 testing apparatus to investigate the macro-mesoscopic deformation,damage behavior,and energy evolution characteristics of these structures under different cyclic stress disturbances.Three loading and unloading rates(LURs)are tested to examine the damage behaviors and energy-driven characteristics of the composites.The findings reveal that the energy-driven behavior,mechanical properties,and macro-micro degradation characteristics of the composites are significantly influenced by the loading rate.Under the gradual cyclic loading and unloading(CLU)path with a constant lower limit(path I)and the CLU path with variable upper and lower boundaries(path II),an increase in LURs from 0.05 to 0.15 mm/min reduces the average loading time by 32.39%and 48.60%,respectively.Consequently,the total number of cracks in the samples increases by 1.66-fold for path I and 1.41-fold for path II.As LURs further increase,the energy storage limit of samples expands,leading to a higher proportion of transmatrix and shear cracks.Under both cyclic loading conditions,a broader cyclic stress range promotes energy dissipation and the formation of internal fractures.Notably,at higher loading rates,cracks tend to propagate along primary weak surfaces,leading to an increased incidence of intermatrix fractures.This behavior indicates a microscopic feature of the failure mechanisms in composite structures.These results provide a theoretical basis for elucidating the damage and failure characteristics of coal-rock composite structures under cyclic stress disturbances.
基金supported by the Young Elite Scientists Sponsorship Program by CAST(No.YESS20210441)the National Natural Science Foundation of China(Nos.U2167208,11875223)。
文摘This study investigates the effects of displacement damage on the dark signal of a pinned photodiode CMOS image sensor(CIS)following irradiation with back-streaming white neutrons from white neutron sources at the China spallation neutron source(CSNS)and Xi'an pulsed reactor(XAPR).The mean dark signal,dark signal non-uniformity(DSNU),dark signal distribution,and hot pixels of the CIS were compared between the CSNS back-n and XAPR neutron irradiations.The nonionizing energy loss and energy distribution of primary knock-on atoms in silicon,induced by neutrons,were calculated using the open-source package Geant4.An analysis combining experimental and simulation results showed a noticeable proportionality between the increase in the mean dark signal and the displacement damage dose(DDD).Additionally,neutron energies influence DSNU,dark signal distribution,and hot pixels.High neutron energies at the same DDD level may lead to pronounced dark signal non-uniformity and elevated hot pixel values.
基金supported by the National Natural Science Foundation of China (No.52204085)the Interdisciplinary Research Project for Young Teachers of USTB,Fundamental Research Funds for the Central Universities (No.FRF-IDRY-21-006).
文摘To study the effects of the initiation position on the damage and fracture characteristics of linear-charge blasting, blasting model experiments were conducted in this study using computed tomography scanning and three-dimensional reconstruction methods. The fractal damage theory was used to quantify the crack distribution and damage degree of sandstone specimens after blasting. The results showed that regardless of an inverse or top initiation, due to compression deformation and sliding frictional resistance, the plugging medium of the borehole is effective. The energy of the explosive gas near the top of the borehole is consumed. This affects the effective crushing of rocks near the top of the borehole, where the extent of damage to Sections Ⅰ and Ⅱ is less than that of Sections Ⅲ and Ⅳ. In addition, the analysis revealed that under conditions of top initiation, the reflected tensile damage of the rock at the free face of the top of the borehole and the compression deformation of the plug and friction consume more blasting energy, resulting in lower blasting energy efficiency for top initiation. As a result, the overall damage degree of the specimens in the top-initiation group was significantly smaller than that in the inverse-initiation group. Under conditions of inverse initiation, the blasting energy efficiency is greater, causing the specimen to experience greater damage. Therefore, in the engineering practice of rock tunnel cut blasting, to utilize blasting energy effectively and enhance the effects of rock fragmentation, using the inverse-initiation method is recommended. In addition, in three-dimensional(3D) rock blasting, the bottom of the borehole has obvious end effects under the conditions of inverse initiation, and the crack distribution at the bottom of the borehole is trumpet-shaped. The occurrence of an end effect in the 3D linear-charge blasting model experiment is related to the initiation position and the blocking condition.
基金supported by the National Natural Science Foundation of China(Grant No.52378330)National Key R&D Program of China(Grant No.2015BAB07B06)Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBPY2162).
文摘Various industrial waste binders(IWBs)are being recycled in soil stabilization to save cement consumption.However,the coupled effects brought out by combined IWBs on stabilized soils are still unclear.IWBs are categorized into two typical categories(IWB-A and IWB-B)referring to their chemical role in this study.The alkali-source effect,pore-filling effect and cementation damage effect by IWBs in soil stabilization are explored.A series of mechanical and microscopic tests is performed on stabilized clay with different proportions of IWB-A and IWB-B.Moreover,initial water contents and cement contents of cement-stabilized clay are varied to examine the evolution of coupled effect with void ratio and cementation level.The results indicate that the alkali-source effect strengthens the cementation bonds and increases the early strength by 0.5e1.3 times,whereas the pore-filling effect improves the microfabric especially for the specimen with a large void ratio.The alkali-source effect increases soil cohesion cu at the pre-yield stage,and the pore-filling effect increases frictional angle 4u at the post-yield stage.The cementation damage effect is remarkable at a low void ratio,which may result in many extruded pores among soil aggregates.The strength evolution with IWB proportions can be well stimulated by considering the coupled alkali-source effect,pore-filling effect and cementation damage effect.The optimal proportion of IWBs corresponds to an optimal combination of coupled effect.
基金supported by the National Natural Science Foundation of China (Grant No.62301247)the Fundamental Research Funds for the Central Universities (Grant No.2024300427)+4 种基金the Natural Science Foundation of Jiangsu Province (Grant No.BK20230778)the Key Research and Development Program of Jiangsu Province (Grant No.BK20232009)the Innovation Leading Talent Foundation of Suzhou (Grant No.ZXL2023164)Guangdong Major Project of Basic Research (Grant No.2021B0301030003)Jihua Laboratory (Project No.X210141TL210).
文摘Owing to the unique characteristics of ultra-thin body and nanoscale sensitivity volume,MoS_(2)-based field-effect tran-sistors(FETs)are regarded as optimal components for radiation-hardened integrated circuits(ICs),which is exponentially grow-ing demanded especially in the fields of space exploration and the nuclear industry.Many researches on MoS_(2)-based radiation tolerance electronics focused on the total ionizing dose(TID)effect,while few works concerned the displacement damage(DD)effects,which is more challenging to measure and more crucial for practical applications.We first conducted measurements to assess the DD effects of MoS_(2) FETs,and then presented the stopping and ranges of ions in matter(SRIM)simulation to analysis the DD degradation mechanism in MoS_(2) electronics.The monolayer MoS_(2)-based FETs exhibit DD radiation tolerance up to 1.56×1013 MeV/g,which is at least two order of magnitude than that in conventional radiation hardened ICs.The exceptional DD radiation tolerance will significantly enhance the deployment of MoS_(2) integrated circuits in environments characterized by high-energy solar and cosmic radiation exposure.
基金financially supported by the National Natural Science Foundation of China(Nos.42001053 and 42277147)the General Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202352363)the University Natural Science Foundation of Jiangsu Province(No.23KJD130001)。
文摘Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of rocks.In this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics framework.Regarding the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock matrix.After proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental results.The model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.
基金supported by the National Natural Science Foundation of China(Nos.12022515 and 11975304)the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.Y202063)。
文摘The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt reactors.The competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this paper.Conceptual approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.
文摘Objective: To investigate the effects of different concentrations of β-glucan on the repair of damaged vaginal mucosa, the expression of vascular endothelial growth factor (VEGF), and the inflammatory factor-6 (IL-6) in vaginal tissues. Methods: Thirty-six adult female specific pathogen free (SPF)-grade Wistar rats were randomly divided into 3 phase groups with 12 rats each. Vaginal inflammation rat models were established by injecting phenol gel into the vagina of each rat at a dose of 0.1 ml/100g body weight. After modeling, rats were divided into 4 groups based on different concentrations of the test agent. The control group was injected with 0.5 ml of saline, experimental group A was injected with 0.375 ml saline 0.125 ml β-glucan, experimental group B was injected with 0.25 ml saline 0.25 ml β-glucan, and experimental group C was injected with 0.50 ml β-glucan. The injection sites were selected at the 3 o’clock and 9 o’clock positions of the vagina. Rats were sacrificed at 7-, 14-, and 28-days post-injection, and tissue samples were collected from the injection sites and prepared for histological analysis. New blood vessels and fibroblast numbers in the tissues were observed after Hematoxylin-eosin (HE) staining. The expression levels of VEGF and IL-6 in the tissues were measured using quantificational reverse transcription polymerase chain reaction (qRT-PCR). Results: Histological examination of vaginal tissue specimens at 7-, 14-, and 28-days post-injection showed that on day 7, there were no significant changes in the experimental groups compared to the control group. However, on days 14 and 28, the experimental groups showed more new blood vessels, macrophages, and fibroblasts with increased activity compared to the control group. The expression levels of VEGF in vaginal tissues were elevated on days 14 and 28 in the experimental groups. The comparison of IL-6 levels in vaginal tissues on day 28 showed that serum IL-6 levels returned to normal, and there was no statistically significant difference between the experimental and control groups. Conclusion: In the 3 experimental phases, the increase in VEGF levels in vaginal tissues on day 14 post-injection was more pronounced with higher concentrations of β-glucan, and IL-6 levels returned to normal on day 28. β-Glucan can enhance VEGF levels in damaged vaginal tissues, promote the repair of damaged vaginal tissues, and higher concentrations of β-glucan have a better effect.
基金National Natural Science Foundation of China(U22B20131)for supporting this project.
文摘Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder.
基金supported by the National Natural Science Foundation of China(No.22176116)the Natural Science Foundation of Shanxi Province in China(No.201801D121260)the Hundred Talents Program of Shanxi Province in China(2017-7)。
文摘Fine particulate matter(PM_(2.5))exposure is associated with cardiovascular disease(CVD)morbidity and mortality.Mitochondria are sensitive targets of PM_(2.5),and mitochondrial dysfunction is closely related to the occurrence of CVD.The epigenetic mechanism of PM_(2.5)-triggered mitochondrial injury of cardiomyocytes is unclear.This study focused on the mi R-421/SIRT3 signaling pathway to investigate the regulatory mechanism in cardiac mitochondrial dynamics imbalance in rat H9c2 cells induced by PM_(2.5).Results illustrated that PM_(2.5)impaired mitochondrial function and caused dynamics homeostasis imbalance.Besides,PM_(2.5)up-regulated mi R-421 and down-regulated SIRT3 gene expression,along with decreasing p-FOXO3a(SIRT3 downstream target gene)and p-Parkin expression and triggering abnormal expression of fusion gene OPA1 and fission gene Drp1.Further,mi R-421 inhibitor(mi R-421i)and resveratrol significantly elevated the SIRT3 levels in H9c2 cells after PM_(2.5)exposure and mediated the expression of SOD2,OPA1 and Drp1,restoring the mitochondrial morphology and function.It suggests that mi R-421/SIRT3 pathway plays an epigenetic regulatory role in mitochondrial damage induced by PM_(2.5)and that mi R-421i and resveratrol exert protective effects against PM_(2.5)-incurred cardiotoxicity.
基金Project supported by the National MCF Energy Research and Development Program of China(Grant Nos.2022YFE03200200 and 2018YFE0308101)the National Natural Science Foundation of China(Grant No.12105194)the Natural Science Foundation of Sichuan Province,China(Grant Nos.2022NSFSC1265 and 2022NSFSC1251).
文摘Iron(Fe)-based alloys,which have been widely used as structural materials in nuclear reactors,can significantly change their microstructure properties and macroscopic properties under high flux neutron irradiation during operation,thus,the problems associated with the safe operation of nuclear reactors have been put forward naturally.In this work,a molecular dynamics simulation approach combined with electronic effects is developed for investigating the primary radiation damage process inα-Fe.Specifically,the influence of electronic effects on the collision cascade in Fe is systematically evaluated based on two commonly used interatomic potentials for Fe.The simulation results reveal that both electronic stopping(ES)and electron-phonon coupling(EPC)can contribute to the decrease of the number of defects in the thermal spike phase.The application of ES reduces the number of residual defects after the cascade evolution,whereas EPC has a reverse effect.The introduction of electronic effects promotes the formation of the dispersive subcascade:ES significantly changes the geometry of the damaged region in the thermal spike phase,whereas EPC mainly reduces the extent of the damaged region.Furthermore,the incorporation of electronic effects effectively mitigates discrepancies in simulation outcomes when using different interatomic potentials.
