A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation.This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiolog...A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation.This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiological mechanisms underlying hydrocephalus,one of the most common neurological conditions worldwide.In this review,we first outline the basic concepts and incidence of hydrocephalus along with the limitations of existing treatments for this condition.Then,we outline the definition,classification,and biological role of non-coding RNAs.Subsequently,we analyze the roles of non-coding RNAs in the formation of hydrocephalus in detail.Specifically,we have focused on the potential significance of non-coding RNAs in the pathophysiology of hydrocephalus,including glymphatic pathways,neuroinflammatory processes,and neurological dysplasia,on the basis of the existing evidence.Lastly,we review the potential of non-coding RNAs as biomarkers of hydrocephalus and for the creation of innovative treatments.展开更多
Background Sudden sensorineural hearing loss(SSNHL)is a common disease in otology,and steroids play an important role in its treatment.Steroids can be administered systemically or locally,and the efficacies of differe...Background Sudden sensorineural hearing loss(SSNHL)is a common disease in otology,and steroids play an important role in its treatment.Steroids can be administered systemically or locally,and the efficacies of different administration routes remain controversial.Methods We searched the Cochrane,EMBASE,PubMed,Web of Science,CNKI,Wanfang and Weipu databases for randomized controlled trials(RCTs)on glucocorticoid treatments for SSNHL to compare the efficacy of topical and systemic steroid administration.The Review Manager 5.4 software was used for synthesis of data:the rate of reported hearing improvement and change in pure-tone audiometry(PTA).Results In all the included studies,when intratympanic administration was compared to systemic therapies,the risk difference(RD)using reported hearing improvement as an outcome measure was 0.08(95%CI:0.01–0.14,I2=45%).Using PTA changes as an outcome measure in 4 studies,the mean difference(MD)was 10.43 dB(95%CI:3.68–17.18,I2=81%).Hearing improvement RD was also compared among different types of steroid,recovery criteria,follow-up times and diagnostic criteria,and showed no significant differences exception for recovery criteria(>10 dB)(RD-0.06,95%CI:0.14-0.2,I2=0%).Conclusion As the initial treatment for SSNHL,topical steroids seem to be superior to systemic steroid administration,especially in patients with contraindications to systemic steroids usage.However,further verification based on high-quality research is needed.展开更多
The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and e...The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However,it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI_(3) perovskite film on the glass substrate with/without the ionic liquid(IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_(4)) by a simple two-step sequential solution method. The additive of BMIMBF_(4)can improve the quality of crystal structure. Moreover, the photo-luminescence(PL) intensity of MAPbI_(3) film with BMIMBF_(4) is much stronger than the pure MAPbI_(3) film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave(CW) laser, the fluorescent duration of the MAPbI_(3) film with BMIMBF_(4) is approximately 2.75 min, while the pure MAPbI;film is only about 6 s. In fact, ionic liquid of BMIMBF_(4) in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI_(3) into CH_(3)NH_(3)and PbI_(2) and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF;possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.展开更多
In recent years,with the development of society and the progress of science and technology,online learning has penetrated into people’s daily life,and people’s demand for high-quality curriculum products is more and...In recent years,with the development of society and the progress of science and technology,online learning has penetrated into people’s daily life,and people’s demand for high-quality curriculum products is more and more strong.From a macro perspective,the continuous growth of national financial investment in education,the continuous upgrading of China’s consumption structure,the development of 5G technology and the popularization of AI intelligence make online teaching less limited.The online education industry is showing an explosive growth trend.More and more online education institutions are listed for financing,and the market value is soaring.However,in 2019,except for GSX,the latest online learning platforms such as New Oriental,Speak English Fluently and Sunlands,have been in a state of loss.Most of these agencies seize the market by increasing advertising investment,but at the same time,they also bring huge marketing costs,which affect the financial performance of the company.With the enhancement of Matthew effect,largescale educational institutions occupy a large market through free classes and low-price classes,while small and medium-sized institutions with weak capital strength are often unable to afford high sales costs,facing the risk of capital chain rupture.Taking new Oriental online as an example,this paper analyzes the problems existing in the marketing strategies of online education institutions.It also puts forward suggestions on four aspects,which are target market,differentiated value,marketing mix and marketing mode,so as to make sure that online education institutions can control marketing expenses and achieve profits by improving course quality,expanding marketing channels and implementing precise positioning.展开更多
BACKGROUND Natural killer(NK)/T-cell non-Hodgkin's lymphoma(NHL)in the nasal cavities and paranasal sinuses accounts for approximately 10%of all lymphomas,and the occurrence of nasal NHL is related to Epstein-Barr...BACKGROUND Natural killer(NK)/T-cell non-Hodgkin's lymphoma(NHL)in the nasal cavities and paranasal sinuses accounts for approximately 10%of all lymphomas,and the occurrence of nasal NHL is related to Epstein-Barr virus infection.AIM To explore the anxiety and depression status of patients with NK/T-cell NHL in the nasal cavities and paranasal sinuses and analyzes the relevant influencing factors.METHODS A retrospective analysis was performed,which included 30 patients with primary nasal NK/T-cell NHL treated in Shaanxi Provincial People’s Hospital from January 2017 to January 2023.An additional 50 healthy volunteers were selected as the control group.Both groups were assessed using the self-rating anxiety scale(SAS)and Self-rating(SDS).SDS and SAS scores of patients with NHL at different disease stages were analyzed,and they were further grouped into negative emotion(NE)(n=19)and non-NE(n=11)groups based on their depression and anxiety.Factors affecting the occurrence of NEs in patients with NHL were analyzed using univariate and multivariate logistic regression models.RESULTS Patients with NHL exhibited higher SDS and SAS scores than healthy controls.Moreover,patients with NHL at stages III and IV had higher SDS and SAS scores than those in stage I.Among the 30 patients,there were 13 patients with depression(43.3%),16 patients with anxiety(53.3%),and 10 patients with both anxiety and depression(33.3%).Univariate analysis identified a higher proportion of people in the NE group with stage III-IV NHL,an educational level≤high school,and a monthly household income<5000 yuan compared with the non-NE group.Multiple logistic regression analysis further revealed that stage III-IV was a risk factor for NEs in patients with NHL.CONCLUSION The stage of NK/T-cell NHL in nasal cavities and paranasal sinuses is closely related to patient anxiety and depression.The higher the staging,the greater the incidence of anxiety and depression.展开更多
To further promote the achievable average secrecy rate for UAV-ground communications, a UAV-aided mobile jamming strategy was proposed in this paper. Specifically, an additional cooperative UAV is employed as a mobile...To further promote the achievable average secrecy rate for UAV-ground communications, a UAV-aided mobile jamming strategy was proposed in this paper. Specifically, an additional cooperative UAV is employed as a mobile jammer to transmit the jamming signal to help keep the source UAV closer to the ground destination, thus establishing more favorable legitimate link and enhancing the secrecy performance. We aimed to maximize the achievable secrecy rate by jointly optimizing the trajectories and transmit power of both source UAV and jammer UAV. To solve the considered non-convex optimization problem, we presented a block coordinate descent based iterative algorithm to address a sequence of approximated convex problems for the optimized parameter block by block to find a local optimal solution. Numerical results verify that the proposed algorithm can achieve significant secrecy rate gain compared to all the benchmark schemes.展开更多
Hong Kong has a long history of applying masonry retaining walls to provide horizontal platforms and stabilize man-made slopes.Due to the sub-tropical climate,some masonry retaining walls are colonized by trees.Extrem...Hong Kong has a long history of applying masonry retaining walls to provide horizontal platforms and stabilize man-made slopes.Due to the sub-tropical climate,some masonry retaining walls are colonized by trees.Extreme weather,such as typhoons and heavy rains,may cause rupture or root failure of those trees,thus resulting in instability of the retaining walls.A monitoring and warning system for the movement of masonry retaining walls and sway of trees has been designed with the application of fiber Bragg grating(FBG)sensing technology.The monitoring system is also equipped with a solar power system and 4G data transmission devices.The key functions of the proposed monitoring system include remote sensing and data access,early warning,and real-time data visualization.The setups and working principles of the monitoring systems and related transducers are introduced.The feasibility,accuracy,serviceability and reliability of this monitoring system have been checked by in-site calibration tests and four-month monitoring.Besides,a two-level interface has been developed for data visualization.The monitoring results show that the monitored masonry retaining wall had a reversible movement up to 2.5 mm during the monitoring period.Besides,it is found that the locations of the maximum strain on trees depend on the crown spread of trees.展开更多
The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the respon...The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the response functions and detection efficiency of three SPs developed at CAEP are simulated by Geant4.The simulated spectra are compared with pulse-height spectra measured at 0.165,0.575,1.4,and 14.1 MeV of incident neutrons.And the calculated detector efficiencies agree within 5%with the data obtained by neutron activation.展开更多
Purpose:To observe the efficacy of combined use of brimonidine and betaxolol in treatment of primary open angle glaucoma(POAG)and ocular hypertension.Methods:A total of 54 patients(90 eyes)with POAG and ocular hyperte...Purpose:To observe the efficacy of combined use of brimonidine and betaxolol in treatment of primary open angle glaucoma(POAG)and ocular hypertension.Methods:A total of 54 patients(90 eyes)with POAG and ocular hypertension were randomly divided into three groups(receiving betaxolol,.brimonidine and combined administration of betaxolol and brimonidine respectively).The administration was given twice daily in all groups(0.5%betaxolol,0.2%brimonidine and 0.5%betaxolol combined with 0.2%brimonidine).The changes in intraocular pressure(IOP)were observed before,and 2,4,6,and 8 weeks after treatment.In addition,the adverse reactions were also recorded post-treatment.Results:.The mean IOPs at all the time points after treatment were significantly reduced compared with pre-treatment levels(P<0.05).Patients receiving brimonidine had a greater reduction in IOP compared with their counterparts in the betaxolol group but the difference was not statistically significant.The IOP decline was significantly higher in the combined therapy group than in the other two groups(P<0.01).Few cases presented with slight discomfort,.such as sensation of foreign bodies,.ocular irritation,.dizziness,.headache,.fatigue,.and dryness of mouth and nose.No severe adverse reactions were noted following administration.Conclusion:Combined use of brimonidine and betaxolol is an efficacious treatment of reducing IOP without severe side effects.展开更多
The application of amorphous high entropy ceramics as wear-resistant materials is limited due to their inherent brittleness at room temperature and strain softening during deformation.In order to overcome this limitat...The application of amorphous high entropy ceramics as wear-resistant materials is limited due to their inherent brittleness at room temperature and strain softening during deformation.In order to overcome this limitation,we constructed amorphous/amorphous(AlCrFeNi)N/TiN nanolaminates with varying mod-ulation period thickness by introducing a second amorphous phase through reactive radio frequency(RF)magnetron sputtering,along with corresponding monolithic amorphous films.Microstructure,mechanical properties,and tribological behaviors of the films were characterized wear in detail.Fretting wear results show that the nanolaminates with an average modulation period of 6 nm exhibited a wear rate of 2.8 times lower than that of the(AlCrFeNi)N film and 8.4 times lower than that of the TiN film.Further anal-ysis using FIB-TEM revealed that the enhanced wear resistance of(AlCrFeNi)N/TiN nanolaminates was at-tributed to the high-density heterointerfaces.These interfaces inhibited the initiation and propagation of mature shear bands and acted as barriers to stress distribution.Additionally,the oxide composite layer at the interface demonstrated a synergistic effect through a mechanically induced tribo-chemical reaction,resulting in slight plastic deformation.For the amorphous(AlCrFeNi)N film,moderate wear resistance was achieved through the formation of transfer layer at the interface.For the amorphous TiN film,the dimensional stability of the film deteriorates due to the significant strain softening that occurs during deformation.This study deepens our understanding of the friction mechanisms involved in amorphous high entropy ceramics,offering valuable insights for the design of high damage-resistant materials.展开更多
基金supported by the National Natural Science Foundation of China,Nos.82171347,82371362the Natural Science Foundation of Hunan Province,No.2022JJ30971the Scientific Research Project of Hunan Provincial Health Commission of China,No.202204040024(all to GX).
文摘A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation.This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiological mechanisms underlying hydrocephalus,one of the most common neurological conditions worldwide.In this review,we first outline the basic concepts and incidence of hydrocephalus along with the limitations of existing treatments for this condition.Then,we outline the definition,classification,and biological role of non-coding RNAs.Subsequently,we analyze the roles of non-coding RNAs in the formation of hydrocephalus in detail.Specifically,we have focused on the potential significance of non-coding RNAs in the pathophysiology of hydrocephalus,including glymphatic pathways,neuroinflammatory processes,and neurological dysplasia,on the basis of the existing evidence.Lastly,we review the potential of non-coding RNAs as biomarkers of hydrocephalus and for the creation of innovative treatments.
文摘Background Sudden sensorineural hearing loss(SSNHL)is a common disease in otology,and steroids play an important role in its treatment.Steroids can be administered systemically or locally,and the efficacies of different administration routes remain controversial.Methods We searched the Cochrane,EMBASE,PubMed,Web of Science,CNKI,Wanfang and Weipu databases for randomized controlled trials(RCTs)on glucocorticoid treatments for SSNHL to compare the efficacy of topical and systemic steroid administration.The Review Manager 5.4 software was used for synthesis of data:the rate of reported hearing improvement and change in pure-tone audiometry(PTA).Results In all the included studies,when intratympanic administration was compared to systemic therapies,the risk difference(RD)using reported hearing improvement as an outcome measure was 0.08(95%CI:0.01–0.14,I2=45%).Using PTA changes as an outcome measure in 4 studies,the mean difference(MD)was 10.43 dB(95%CI:3.68–17.18,I2=81%).Hearing improvement RD was also compared among different types of steroid,recovery criteria,follow-up times and diagnostic criteria,and showed no significant differences exception for recovery criteria(>10 dB)(RD-0.06,95%CI:0.14-0.2,I2=0%).Conclusion As the initial treatment for SSNHL,topical steroids seem to be superior to systemic steroid administration,especially in patients with contraindications to systemic steroids usage.However,further verification based on high-quality research is needed.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2018YFC2001100)the Natural National Science Foundation of China (Grant No. 61574017)+1 种基金the Fundamental Research Funds for Central Universities, China (Grant No. 2017CX10007)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, Guangxi University (Grant No. 2020GXYSOF08)。
文摘The methylammonium lead triiodide(CH_(3)NH_(3)PbI_(3))-based perovskite shows a great alluring prospect in areas of solar cells, lasers, photodetectors, and light emitting diodes owing to their excellent optical and electrical advantages. However,it is very sensitive to the surrounding oxygen and moisture, which limits its development seriously. It is urgent to spare no effort to enhance its optical and electrical stability for further application. In this paper, we synthesize the MAPbI_(3) perovskite film on the glass substrate with/without the ionic liquid(IL) of 1-Butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_(4)) by a simple two-step sequential solution method. The additive of BMIMBF_(4)can improve the quality of crystal structure. Moreover, the photo-luminescence(PL) intensity of MAPbI_(3) film with BMIMBF_(4) is much stronger than the pure MAPbI_(3) film after a week in the air, which is almost ten-fold of the pure one. Meanwhile, under the illumination of 405-nm continuous wave(CW) laser, the fluorescent duration of the MAPbI_(3) film with BMIMBF_(4) is approximately 2.75 min, while the pure MAPbI;film is only about 6 s. In fact, ionic liquid of BMIMBF_(4) in the perovskite film plays a role of passivation, which prevents the dissolution of MAPbI_(3) into CH_(3)NH_(3)and PbI_(2) and thus enhances the stability of environment. In addition, the ionic liquid of BMIMBF;possesses high ionic conductivity, which accelerates the electron transport, so it is beneficial for the perovskite film in the areas of solar cells, photodetectors, and lasers. This interesting experiment provides a promising way to develop the perovskite’s further application.
文摘In recent years,with the development of society and the progress of science and technology,online learning has penetrated into people’s daily life,and people’s demand for high-quality curriculum products is more and more strong.From a macro perspective,the continuous growth of national financial investment in education,the continuous upgrading of China’s consumption structure,the development of 5G technology and the popularization of AI intelligence make online teaching less limited.The online education industry is showing an explosive growth trend.More and more online education institutions are listed for financing,and the market value is soaring.However,in 2019,except for GSX,the latest online learning platforms such as New Oriental,Speak English Fluently and Sunlands,have been in a state of loss.Most of these agencies seize the market by increasing advertising investment,but at the same time,they also bring huge marketing costs,which affect the financial performance of the company.With the enhancement of Matthew effect,largescale educational institutions occupy a large market through free classes and low-price classes,while small and medium-sized institutions with weak capital strength are often unable to afford high sales costs,facing the risk of capital chain rupture.Taking new Oriental online as an example,this paper analyzes the problems existing in the marketing strategies of online education institutions.It also puts forward suggestions on four aspects,which are target market,differentiated value,marketing mix and marketing mode,so as to make sure that online education institutions can control marketing expenses and achieve profits by improving course quality,expanding marketing channels and implementing precise positioning.
文摘BACKGROUND Natural killer(NK)/T-cell non-Hodgkin's lymphoma(NHL)in the nasal cavities and paranasal sinuses accounts for approximately 10%of all lymphomas,and the occurrence of nasal NHL is related to Epstein-Barr virus infection.AIM To explore the anxiety and depression status of patients with NK/T-cell NHL in the nasal cavities and paranasal sinuses and analyzes the relevant influencing factors.METHODS A retrospective analysis was performed,which included 30 patients with primary nasal NK/T-cell NHL treated in Shaanxi Provincial People’s Hospital from January 2017 to January 2023.An additional 50 healthy volunteers were selected as the control group.Both groups were assessed using the self-rating anxiety scale(SAS)and Self-rating(SDS).SDS and SAS scores of patients with NHL at different disease stages were analyzed,and they were further grouped into negative emotion(NE)(n=19)and non-NE(n=11)groups based on their depression and anxiety.Factors affecting the occurrence of NEs in patients with NHL were analyzed using univariate and multivariate logistic regression models.RESULTS Patients with NHL exhibited higher SDS and SAS scores than healthy controls.Moreover,patients with NHL at stages III and IV had higher SDS and SAS scores than those in stage I.Among the 30 patients,there were 13 patients with depression(43.3%),16 patients with anxiety(53.3%),and 10 patients with both anxiety and depression(33.3%).Univariate analysis identified a higher proportion of people in the NE group with stage III-IV NHL,an educational level≤high school,and a monthly household income<5000 yuan compared with the non-NE group.Multiple logistic regression analysis further revealed that stage III-IV was a risk factor for NEs in patients with NHL.CONCLUSION The stage of NK/T-cell NHL in nasal cavities and paranasal sinuses is closely related to patient anxiety and depression.The higher the staging,the greater the incidence of anxiety and depression.
基金partly supported by National Natural Science Foundation of China (No. 41504026, 61362009)Natural Science Foundation of Jiangxi (No.20152ACB21003)Foundation for Distinguished Young Talents Training Programme of Jiangxi (No.20171BCB23006)
文摘To further promote the achievable average secrecy rate for UAV-ground communications, a UAV-aided mobile jamming strategy was proposed in this paper. Specifically, an additional cooperative UAV is employed as a mobile jammer to transmit the jamming signal to help keep the source UAV closer to the ground destination, thus establishing more favorable legitimate link and enhancing the secrecy performance. We aimed to maximize the achievable secrecy rate by jointly optimizing the trajectories and transmit power of both source UAV and jammer UAV. To solve the considered non-convex optimization problem, we presented a block coordinate descent based iterative algorithm to address a sequence of approximated convex problems for the optimized parameter block by block to find a local optimal solution. Numerical results verify that the proposed algorithm can achieve significant secrecy rate gain compared to all the benchmark schemes.
基金supported by the Development Bureau of Hong Kong SAR Government,a Research Impact Fund(RIF)project(Grant No.R5037-18)a Theme-based Research Scheme Fund(TRS)project(Grant No.T22-502/18-R)a General Research Fund(GRF)projects(Grant No.PolyU 152130/19E)from Research Grants Council(RGC)of Hong Kong SAR.
文摘Hong Kong has a long history of applying masonry retaining walls to provide horizontal platforms and stabilize man-made slopes.Due to the sub-tropical climate,some masonry retaining walls are colonized by trees.Extreme weather,such as typhoons and heavy rains,may cause rupture or root failure of those trees,thus resulting in instability of the retaining walls.A monitoring and warning system for the movement of masonry retaining walls and sway of trees has been designed with the application of fiber Bragg grating(FBG)sensing technology.The monitoring system is also equipped with a solar power system and 4G data transmission devices.The key functions of the proposed monitoring system include remote sensing and data access,early warning,and real-time data visualization.The setups and working principles of the monitoring systems and related transducers are introduced.The feasibility,accuracy,serviceability and reliability of this monitoring system have been checked by in-site calibration tests and four-month monitoring.Besides,a two-level interface has been developed for data visualization.The monitoring results show that the monitored masonry retaining wall had a reversible movement up to 2.5 mm during the monitoring period.Besides,it is found that the locations of the maximum strain on trees depend on the crown spread of trees.
文摘The neutron response function and detection efficiency of a spherical proton recoil proportional counter (SP) play key roles in precise measurement of neutron spectra of the interior materials.In this paper,the response functions and detection efficiency of three SPs developed at CAEP are simulated by Geant4.The simulated spectra are compared with pulse-height spectra measured at 0.165,0.575,1.4,and 14.1 MeV of incident neutrons.And the calculated detector efficiencies agree within 5%with the data obtained by neutron activation.
基金supported by the Natural Science Foundation of Guangdong Province(Grant No.S20120100086 18,S2013010016642)
文摘Purpose:To observe the efficacy of combined use of brimonidine and betaxolol in treatment of primary open angle glaucoma(POAG)and ocular hypertension.Methods:A total of 54 patients(90 eyes)with POAG and ocular hypertension were randomly divided into three groups(receiving betaxolol,.brimonidine and combined administration of betaxolol and brimonidine respectively).The administration was given twice daily in all groups(0.5%betaxolol,0.2%brimonidine and 0.5%betaxolol combined with 0.2%brimonidine).The changes in intraocular pressure(IOP)were observed before,and 2,4,6,and 8 weeks after treatment.In addition,the adverse reactions were also recorded post-treatment.Results:.The mean IOPs at all the time points after treatment were significantly reduced compared with pre-treatment levels(P<0.05).Patients receiving brimonidine had a greater reduction in IOP compared with their counterparts in the betaxolol group but the difference was not statistically significant.The IOP decline was significantly higher in the combined therapy group than in the other two groups(P<0.01).Few cases presented with slight discomfort,.such as sensation of foreign bodies,.ocular irritation,.dizziness,.headache,.fatigue,.and dryness of mouth and nose.No severe adverse reactions were noted following administration.Conclusion:Combined use of brimonidine and betaxolol is an efficacious treatment of reducing IOP without severe side effects.
基金supported by the National Natural Science Foundation of China(No.11775150)Natural Science Foun-dation of Sichuan,China(No.2023NSFSC0408)the Founda-tion of Key Laboratory of Radiation Physics and Technology of the Ministry of Education(No.2021SCURPT02).
文摘The application of amorphous high entropy ceramics as wear-resistant materials is limited due to their inherent brittleness at room temperature and strain softening during deformation.In order to overcome this limitation,we constructed amorphous/amorphous(AlCrFeNi)N/TiN nanolaminates with varying mod-ulation period thickness by introducing a second amorphous phase through reactive radio frequency(RF)magnetron sputtering,along with corresponding monolithic amorphous films.Microstructure,mechanical properties,and tribological behaviors of the films were characterized wear in detail.Fretting wear results show that the nanolaminates with an average modulation period of 6 nm exhibited a wear rate of 2.8 times lower than that of the(AlCrFeNi)N film and 8.4 times lower than that of the TiN film.Further anal-ysis using FIB-TEM revealed that the enhanced wear resistance of(AlCrFeNi)N/TiN nanolaminates was at-tributed to the high-density heterointerfaces.These interfaces inhibited the initiation and propagation of mature shear bands and acted as barriers to stress distribution.Additionally,the oxide composite layer at the interface demonstrated a synergistic effect through a mechanically induced tribo-chemical reaction,resulting in slight plastic deformation.For the amorphous(AlCrFeNi)N film,moderate wear resistance was achieved through the formation of transfer layer at the interface.For the amorphous TiN film,the dimensional stability of the film deteriorates due to the significant strain softening that occurs during deformation.This study deepens our understanding of the friction mechanisms involved in amorphous high entropy ceramics,offering valuable insights for the design of high damage-resistant materials.
