This paper undertakes an analysis of labour market outcomes among aging population in Indian labour market by using household and personal level characteristics obtained from periodic labour force survey(PLFS)data for...This paper undertakes an analysis of labour market outcomes among aging population in Indian labour market by using household and personal level characteristics obtained from periodic labour force survey(PLFS)data for 2023-2024.It provides an analysis of the association of demographic and household characteristics with probability of choosing either paid-employment or self-employment by applying discrete choice model,after controlling for sample selection bias.By following strategic choice framework,endogenous sample selected probit model is used in finding out the role of different covariates in determining the chance of continuing work in self-employment and wage employment of any type after the age of statutory retirement.Social,economic,and other factors like gender are considered as key factors towards labour market participation of the aging population.This study examines the effects of age and education on decision to choose type of employment by the people beyond their statutory retirement age.The coefficient of female dummy is positive in regular-paid jobs and unpaid household work,but negative for own accounts work and employer irrespective of age cohorts suggesting that women are more likely to continue as regular paid jobs and unpaid household work,but less likely to be employer and own account worker as compared to men even after age 60 years and above.展开更多
Background Depression,anxiety and schizophrenia among older persons have become global public health challenges.However,the burden of these disorders in ageing and aged countries has not been analysed.Aims To investig...Background Depression,anxiety and schizophrenia among older persons have become global public health challenges.However,the burden of these disorders in ageing and aged countries has not been analysed.Aims To investigate the burden of depression,anxiety and schizophrenia among older adults in ageing and aged countries.Methods Using data from the Global Burden of Disease Study 2019,we calculated the estimated annual percentage change(EAPC)in the age-standardised incidence rates(ASiR)and age-standardised disability-adjusted life years(DALYs)rates(ASDR)for depression,anxiety and schizophrenia of older people in ageing countries(China,India,Indonesia)and aged countries(Japan,Italy,Portugal)between 1990 and 2019.Trends in incidence and DALYs were analysed by gender and age.Results In 2019,the highest incidence of depression,anxiety and schizophrenia in the older population in aged countries was in Japan(927271.3(752552.3-1125796.5),51498.2(37625.7-70487.3)and 126.0(61.0-223.2),respectively),while the highest incidence in ageing countries was in China(5797556.9(4599403.4-7133006.5),330256.1(246448.9-445987.4)and 1067.7(556.2-1775.9),respectively).DALYs for these disorders were similar,with the highest in Japan and China.From 1990 to 2019,the ASIR for depressive disorders decreased in aged countries but increased in ageing countries;the ASIR for anxiety disorders and schizophrenia declined in both ageing and aged countries.The ASDR for depressive disorders was consistent with the ASIR but not for anxiety disorders and schizophrenia.The ASIR for depressive disorders was higher in older women,while the opposite was observed in anxiety disorders and schizophrenia.Notably,the conditions of burden of depressive disorders,anxiety disorders and schizophrenia in the 65-70-year-old age group were the most burdensome.Conclusions The incidence and DALYs of these three mental disorders increased while exhibiting differences between ageing and aged countries.Raising awareness about formulating health policies for preventing and treating mental disorders in the older population is necessary to reduce the future burden posed by the ageing challenge.展开更多
The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain amplitudes.We showed that NIA improved the low cycle fatigue life(more than 7000 cycles)...The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain amplitudes.We showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,simultaneously.Experimental observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue performance.As the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.展开更多
The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formabilit...The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×10^(15)m^(−2).At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4−6 times and 30−50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.展开更多
Creep aging is well-known to be a time-dependent,coupled process of deformation and precipitation strengthening for age-hardening alloys.Its existing mechanisms are mainly attributed to those interac-tions between ato...Creep aging is well-known to be a time-dependent,coupled process of deformation and precipitation strengthening for age-hardening alloys.Its existing mechanisms are mainly attributed to those interac-tions between atomic diffusion and dislocation motion.However,an understanding of the relationship between dislocation density and a special multistage creep behavior,i.e.,double steady creep feature,is still far limited.Here we investigate the effect of various dislocation density levels on such an abnormal multistage creep of an Al-Cu-Li alloy.We find that the increased dislocation densities enable an apparent time decrease(from 6.2 h to 0.8 h)of their first steadyⅡ-stage.The yield strength of post-aged sam-ples increases from 425.0 MPa to 580.0 MPa while the corresponding elongation decreases from 12.3%to 7.3%for the creep-aged samples#1 to#4.Microstructural results also reveal that a great difference in dislocation configuration,tailored by various density levels,results in varying creep processes of theⅡ-stage.This stage is closely related to the nucleation and early growth of T_(1)precipitates.Their number densities(maximum:2.9×10^(19)m^(-3))and the average length(maximum:21.3 nm)of T_(1)precipitates are much smaller than those of the stable peak-aged T_(1)phases,suggesting that creepⅡ-stage of all three creep-aged samples is dominant by the nucleation and initial growth of those T_(1)precipitates.This study provides valuable insights into the dislocation density-mediated creep deformation of an Al-Cu-Li alloy.展开更多
Objective:Gambling is a complex topic in relation to health systems.It is always unclear how to strike a balance between the gambling economy and the impact of gambling on public health or social wellbeing at any age....Objective:Gambling is a complex topic in relation to health systems.It is always unclear how to strike a balance between the gambling economy and the impact of gambling on public health or social wellbeing at any age.There are limited studies considering the association between determinants of gambling and the life expectancy of the ageing population in a country.From an evaluation perspective,this article aims to demonstrate the correlation between life expectancy and gambling and public health systems.Methods:The approach of analysis has two parts.One is the influence of gambling prevalence in populations on life expectancy among old adults.Another is the association between the effect of changes in legal gambling provisions within public health systems and life expectancy among old adults.Healthy adjusted life expectancy at age 60 from the World Health Organization and gross gambling yield were used.ANOVA was performed with SPSS.Results:The population groups with HALE at age 60 of 15 years or over are likely more active in gambling than the population groups with smaller HALE at age 60 of 14 years or less.On the other hand,the influence of a health policy may be sidelined when it is implemented for older adult populations because the resource distribution magnitude or number of strategical techniques may not be the same for younger adult populations.The study here is marked as a good practical start,and there is room for further research with big data analysis on additional gambling variables against other life expectancy variables,quality of life variables or public health system variables.Conclusion:Associations between the determinants of gambling and the life expectancy of the ageing population in a country have not yet been identified.Continuous measurements of policy implementation and effectiveness and assessments of health equity,while gambling policies worldwide continue to change,have not yet been performed.Researchers and policy makers should understand the importance of holistic integration of the gambling economy and policy within a public health and social paradigm with the help of big data insights to achieve sustainability in their cities and health equity in their communities.展开更多
The high-temperature oxidation behaviour of the Inconel 625 alloy at 950℃ was investigated after different ageing treatments.The effect of heat treatment on the oxidation behaviour of the alloy was analysed by charac...The high-temperature oxidation behaviour of the Inconel 625 alloy at 950℃ was investigated after different ageing treatments.The effect of heat treatment on the oxidation behaviour of the alloy was analysed by characterizing the structure and elemental distribution before and after oxidation.The results reveal that the two ageing treatments at 650℃ for 500 h and at 750℃ for 400 h both reduced the oxidation mass gain.After oxidation at 950℃,an outer Cr_(2)O_(3) layer and inner Al_(2)O_(3) are identified as the main oxidation products.Moreover,Nb_(2)O_(5) andδ(Ni_(3)Nb)phases precipitated after oxidation.The ageing treatments cause the rapid generation of a dense Cr_(2)O_(3) layer on the surface,which prevents the diffusion of oxygen into the matrix,reduce the Al_(2)O_(3) inward growth depth,and improve the oxidation resistance of the alloy.展开更多
This research considered the effect of non-natural aging on the microstructural characteristics and mechanical properties of as-cast aluminum 6063 alloys. The samples were developed through a sand casting process and ...This research considered the effect of non-natural aging on the microstructural characteristics and mechanical properties of as-cast aluminum 6063 alloys. The samples were developed through a sand casting process and machined into tensile and impact test samples before carrying out solution heat treatment at 550?C (0.83 T<sub>m</sub>) on two parts of the samples while retaining one part as the control. The two parts were further divided into sets denoted A and B and were aged at 180?C (0.27 T<sub>m</sub>) and 160?C (0.24 T<sub>m</sub>), respectively, for 12 hours. The results showed that sample A has the optimal yield strength and ultimate tensile strength of 192 and 206 MPa, respectively. Likewise, the sample gave the highest impact strength value of about 9.63 J/mm<sup>2</sup>. The observed results were supported by the optical micrograph, which revealed that the sample has evenly dispersed precipitates in its microstructure. This is deemed responsible for the observed increase in strength of the sample.展开更多
The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due t...The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.展开更多
The corrosion behaviors of Mg-10Gd-4.8Y-0.6Zr extruded-alloys with various ageing time were investigated by immersion test and electrochemical measurements.The results show that the corrosion rate of the experimental ...The corrosion behaviors of Mg-10Gd-4.8Y-0.6Zr extruded-alloys with various ageing time were investigated by immersion test and electrochemical measurements.The results show that the corrosion rate of the experimental alloy decreases with the increase of ageing time from 0 to 108 h.The corrosion resistance of the experimental alloy was found to increase with the increase of the size of the precipitate phases.The open circuit potential of the experimental alloy increases with the increase of the ageing time.The potentiodynamic polarization curves show that the cathodic over-potential increases with the increase of ageing time,leading to a decrease in the current density of anodic current plateau with the increase of ageing time.展开更多
Mierostruetural development of a commercial 7055 （Al-Zn-Mg-Cu）alloy is studied by transmission electron mieroseope（TEM） during the process of single-ageing for up to 48 h. It is observed that Guinier-Preston （GP...Mierostruetural development of a commercial 7055 （Al-Zn-Mg-Cu）alloy is studied by transmission electron mieroseope（TEM） during the process of single-ageing for up to 48 h. It is observed that Guinier-Preston （GP） zones are formed on { 111} planes when the sample is aged for a short time and grows up gradually with increase of ageing time. η＇ phase is formsed after ageing for 4 h at 120℃, having the orientation relationship with the matrix as[0 0 0 1]η＇//[1 1^- 1]Al and （1 0 1^- 1）η＇//（1 1 0）Al.η phase starts to occur after 24 h ageing and has an orientation relationship with matrix as [1^- 1 0 0]η//[1 1 0]Al and （0 0 0 1）η// （1 1 1）Al. Since the density of both η＇ phase and η phase particles is much lower than that of GP zone on aged alloy, GP zones are important to control the properties of the alloy.展开更多
Different artificial two-stage ageing behaviors and their effect on stress corrosion cracking （SCC） susceptibility of AI-Zn-Mg alloy have been investigated. The experimental results show that two hardness peaks pres...Different artificial two-stage ageing behaviors and their effect on stress corrosion cracking （SCC） susceptibility of AI-Zn-Mg alloy have been investigated. The experimental results show that two hardness peaks present on the second-stage ageing-hardening curve when the first-stage ageing is dealt with comparatively lower temperature than the conventional one. The first peak is caused by dispersive and evenly distributed G.P. zones, while η ′phases and coarsened G.P. zones contribute to the second peak. Tensile strength of experimental alloy raises 9.6% （33.2 MPa） and SCC susceptibility decreases 38.9% by applying the second peak ageing regime instead of conventional T73. AI-Zn-Mg alloy obtains high strength and SCC resistance due to its finely dispersive matrix precipitates （MPts）, coarsened and discontinuous grain boundary precipitates （GBPs）, as well as the narrow precipitate free zone （PFZ） in the second peak ageing condition. 2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
MicroRNAs （miRNAs） are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. They are involved in important biological processes including development, homeostasis, and ag...MicroRNAs （miRNAs） are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. They are involved in important biological processes including development, homeostasis, and ageing. Recently, extracellular miRNAs have been discovered in the bloodstream and bodily fluids. These miRNAs are shown to be secreted and circulating in microvesicles （MVs）, or in complex with other factors such as RNA-binding proteins and high-density lipoprotein （HDL） particles. These cell-free, circulating miRNAs can be taken into and function as negative regulators of target genes in recipient cells. Here we review the biogenesis and uptake of circulating miRNAs as well as their profiles in ageing and ageing-related diseases. We discuss the emerging role of circulating miRNAs as biomarkers and therapeutic targets.展开更多
The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The sam...The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The samples were exposed in an artificial xenon arc lamp ageing cell or a thermo-oxidative ageing cell. Morphology and gloss of the specimens were investigated by using a microscope and a gloss-meter, respectively. The tensile strength, bending strength and inter-laminar shear strength （ILSS） of GFRPC were tested before and after exposure, and were considered to evaluate the durability performance of this material. The polyester resin was analyzed by fourier transform infrared （FT-IR） spectroscopy. The results showed that the glossiness of the specimens got worse and some cracks appeared on their surface during the course of ageing, the tensile strength and bending strengths of the specimens first increased and then decreased. The ILSS of the composites decreased after they were aged in the xenon arc lamp cell, but increased while they were aged in the thermo-oxidative cell. The changes of these trends become more obvious during ageing in the xenon arc lamp cell, so the main influencing factor leading to the failure of this material is UV irradiation.展开更多
In order to improve the through-thickness homogeneity and properties of aviation aluminum alloy thick plate.The effect of heating-cooling retrogression and re-ageing on the performance of Al-8Zn-2Mg-2Cu alloy thick pl...In order to improve the through-thickness homogeneity and properties of aviation aluminum alloy thick plate.The effect of heating-cooling retrogression and re-ageing on the performance of Al-8Zn-2Mg-2Cu alloy thick plate was investigated by hardness tests, electrical conductivity tests and transmission electron microscopy(TEM) observation.Results revealed that, during retrogression heating, the fine pre-precipitates in surface layer dissolve more and the undissolved η′ or η phases are more coarsened than that of center layer. During slow cooling after retrogression,precipitates continue coarsening but with a lower rate and the secondary precipitation occurs in both layers. Finer precipitates resulting from the secondary precipitation are more in surface. However, the coarsening and secondary precipitation behaviors are restrained in both layers under quick cooling condition. The electrical conductivity and through-thickness homogeneity of precipitates increases while the hardness decreases with cooling rate decreasing. After the optimized non-isothermal retrogression and re-ageing(NRRA) including air-cooling retrogression, the throughthickness homogeneity which is evaluated by integrated retrogression effects has been improved to 94%. The tensile strength, fracture toughness and exfoliation corrosion grade of Al-8Zn-2Mg-2Cu alloy plate is 619 MPa, 24.7 MPa·m^(1/2)and EB, respectively, which indicates that the non-isothermal retrogression and re-aging(NRRA) could improve the mechanical properties and corrosion resistance with higher through-thickness homogeneity.展开更多
This study focuses on the development stages of ageing and its regional differences in China based on examination of official statistics and documents. The development of ageing in China has experienced three major st...This study focuses on the development stages of ageing and its regional differences in China based on examination of official statistics and documents. The development of ageing in China has experienced three major stages. Firstly, in the 1950s, low coefficient of elderly population (over 65 years) paced up to primary adult type. Secondly, there was a deeply drop of the elderly population because of natural disaster and political factors in the 1960s. Thirdly, from the 1970s to the end of 20th century, the constant increasing of elderly coefficient made China close to elderly society. With statistic data of population, Logistic model is used to simulate the future development of ageing, and two characteristics of development of ageing are presented. Firstly, as for ageing from 2005 to 2050, the elderly coefficient will grow up significantly from 8.48% to 16.30%. Secondly, after 2025, the increasing rate of elderly coefficient will slow down gradually. The regional differences of elderly population in China can be summarized as follows: 1) the eastern China possesses higher elderly coefficient and huger elder population than the western China; 2) about 47.4% of municipalities and provinces in the eastern China become elderly especially Shanghai, Zhejiang Province, Jiangsu Province, Beijing, Tianjin and Shandong Province; 3) ageing intensity is higher in rural area than urban area but getting close each other, and there are more elderly people in rural area than in urban area. Therefore, these will arose aged care problems, and it becomes important issue to establish the social security system in rural areas as soon as possible for elderly people.展开更多
A stochastic model of conducting crack propagation is presented to provide a conceptual framework dedicated to the study of the formation of fractal structure of dielectric ageing patterns as a result of a competition...A stochastic model of conducting crack propagation is presented to provide a conceptual framework dedicated to the study of the formation of fractal structure of dielectric ageing patterns as a result of a competition between random fluctuation growth and applied electric strength enhanced deterministic growth. The necessary and sufficient conditions resulting in fractal behaviour in dielectric ageing are found.展开更多
A kinetic model of dielectric ageing is presented. The central finding of this investigation is that there is a power-law relationship between the local electric field concentration and the rate of defect-tip initiate...A kinetic model of dielectric ageing is presented. The central finding of this investigation is that there is a power-law relationship between the local electric field concentration and the rate of defect-tip initiated conducting crack growth. By applying such a power-law conducting crack growth rate expression to the evaluation of the life of solid dielectrics, the empirical classical ageing law of insulation materials can be derived theoretically as a lobical result. All the results are universal and agree with the experimental data of oxide films.展开更多
Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-o...Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs,such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance.Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing,and the UV light parameters effect on the ageing rate of asphalt binder.However,the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions,and the UV ageing mechanism of asphalt binder is not very clear.Therefore,it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders.This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders.With the increase of UV ageing time,the UV ageing of asphalt binder develops gradually from the surface to inner part.There are various methods,such as low-penetration grade asphalt,less air void ratio,UV stabilizers and UV light absorbers,that can improve the UV ageing resistance of asphalt binders.A new theory of sensitive wavelengths of asphalt UV ageing is proposed,which can enrich the basic theory of asphalt UV ageing.Depending on this theory,different wavelengths of UV light have different ageing effects on asphalt binder.The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed,and may have better improvement effect on the anti-UV ageing performance of asphalt binder.展开更多
Compared with developed countries, the main characteristics of population ageing in China have been regarded as a rapid ageing society. However, China and other Asian countries have been experiencing the demographic t...Compared with developed countries, the main characteristics of population ageing in China have been regarded as a rapid ageing society. However, China and other Asian countries have been experiencing the demographic transition simultaneously, it is better to understand the characteristics of population ageing in China when compared with other Asian countries. Using the latest UN data, this paper compares the percentage of elderly population, the speed of ageing and the size of aged population among China and other Asian countries. The result indicates that China has a relatively high percentage of aged population, relatively rapid ageing population and will keep the largest size of aged population of the world in the next 60 years.展开更多
文摘This paper undertakes an analysis of labour market outcomes among aging population in Indian labour market by using household and personal level characteristics obtained from periodic labour force survey(PLFS)data for 2023-2024.It provides an analysis of the association of demographic and household characteristics with probability of choosing either paid-employment or self-employment by applying discrete choice model,after controlling for sample selection bias.By following strategic choice framework,endogenous sample selected probit model is used in finding out the role of different covariates in determining the chance of continuing work in self-employment and wage employment of any type after the age of statutory retirement.Social,economic,and other factors like gender are considered as key factors towards labour market participation of the aging population.This study examines the effects of age and education on decision to choose type of employment by the people beyond their statutory retirement age.The coefficient of female dummy is positive in regular-paid jobs and unpaid household work,but negative for own accounts work and employer irrespective of age cohorts suggesting that women are more likely to continue as regular paid jobs and unpaid household work,but less likely to be employer and own account worker as compared to men even after age 60 years and above.
基金Shanghai'Science and Technology Innovation Action Plan'medical innovation research(21Y11905600)Shanghai'Science and Technology Innovation Action Plan'Natural Science Foundation of Shanghai(21ZR1455100)+1 种基金the National Natural Science Foundation of China(81701344)the Shanghai Mental Health Center General Projects(2021-YJ-02).
文摘Background Depression,anxiety and schizophrenia among older persons have become global public health challenges.However,the burden of these disorders in ageing and aged countries has not been analysed.Aims To investigate the burden of depression,anxiety and schizophrenia among older adults in ageing and aged countries.Methods Using data from the Global Burden of Disease Study 2019,we calculated the estimated annual percentage change(EAPC)in the age-standardised incidence rates(ASiR)and age-standardised disability-adjusted life years(DALYs)rates(ASDR)for depression,anxiety and schizophrenia of older people in ageing countries(China,India,Indonesia)and aged countries(Japan,Italy,Portugal)between 1990 and 2019.Trends in incidence and DALYs were analysed by gender and age.Results In 2019,the highest incidence of depression,anxiety and schizophrenia in the older population in aged countries was in Japan(927271.3(752552.3-1125796.5),51498.2(37625.7-70487.3)and 126.0(61.0-223.2),respectively),while the highest incidence in ageing countries was in China(5797556.9(4599403.4-7133006.5),330256.1(246448.9-445987.4)and 1067.7(556.2-1775.9),respectively).DALYs for these disorders were similar,with the highest in Japan and China.From 1990 to 2019,the ASIR for depressive disorders decreased in aged countries but increased in ageing countries;the ASIR for anxiety disorders and schizophrenia declined in both ageing and aged countries.The ASDR for depressive disorders was consistent with the ASIR but not for anxiety disorders and schizophrenia.The ASIR for depressive disorders was higher in older women,while the opposite was observed in anxiety disorders and schizophrenia.Notably,the conditions of burden of depressive disorders,anxiety disorders and schizophrenia in the 65-70-year-old age group were the most burdensome.Conclusions The incidence and DALYs of these three mental disorders increased while exhibiting differences between ageing and aged countries.Raising awareness about formulating health policies for preventing and treating mental disorders in the older population is necessary to reduce the future burden posed by the ageing challenge.
基金supported by the State’s Key Project of Re-search and Development Plan(No.2021YFC1910505)the Key Research and Development Program of Guangdong Province(No.2020B010186002).
文摘The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain amplitudes.We showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,simultaneously.Experimental observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue performance.As the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.
基金Projects(52274404,52305441,U22A20190)supported by the National Natural Science Foundation of ChinaProjects(2022JJ20065,2023JJ40739)supported by the Natural Science Foundation of Hunan Province,China+2 种基金Project(2022RC1001)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(2023ZZTS0972)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2021YFB3400903)supported by the National Key R&D Program of China。
文摘The creep strain of conventionally treated 2195 alloy is very low,increasing the difficulty of manufacturing Al-Cu-Li alloy sheet parts by creep age forming.Therefore,finding a solution to improve the creep formability of Al-Cu-Li alloy is vital.A thorough comparison of the effects of cryo-deformation and ambient temperature large pre-deformation(LPD)on the creep ageing response in the 2195 alloy sheet at 160℃with different stresses has been made.The evolution of dislocations and precipitates during creep ageing of LPD alloys are revealed by X-ray diffraction and transmission electron microscopy.High-quality 2195 alloy sheet largely pre-deformed by 80%without edge-cracking is obtained by cryo-rolling at liquid nitrogen temperature,while severe edge-cracking occurs during room temperature rolling.The creep formability and strength of the 2195 alloy are both enhanced by introducing pre-existing dislocations with a density over 1.4×10^(15)m^(−2).At 160℃and 150 MPa,creep strain and creep-aged strength generally increases by 4−6 times and 30−50 MPa in the LPD sample,respectively,compared to conventional T3 alloy counterpart.The elongation of creep-aged LPD sample is low but remains relevant for application.The high-density dislocations,though existing in the form of dislocation tangles,promote the formation of refined T1 precipitates with a uniform dispersion.
基金supported by the National Natu-ral Science Foundation of China(No.U22A20190)the Science and Technology Innovation Program of Hunan Province(Nos.2020RC4001 and 2022RC1001)+1 种基金Natural Science Foundation of Hu-nan Province(Nos.2022JJ20065 and 2023JJ40739)the National Key R&D Program of China(No.2021YFB3400903).
文摘Creep aging is well-known to be a time-dependent,coupled process of deformation and precipitation strengthening for age-hardening alloys.Its existing mechanisms are mainly attributed to those interac-tions between atomic diffusion and dislocation motion.However,an understanding of the relationship between dislocation density and a special multistage creep behavior,i.e.,double steady creep feature,is still far limited.Here we investigate the effect of various dislocation density levels on such an abnormal multistage creep of an Al-Cu-Li alloy.We find that the increased dislocation densities enable an apparent time decrease(from 6.2 h to 0.8 h)of their first steadyⅡ-stage.The yield strength of post-aged sam-ples increases from 425.0 MPa to 580.0 MPa while the corresponding elongation decreases from 12.3%to 7.3%for the creep-aged samples#1 to#4.Microstructural results also reveal that a great difference in dislocation configuration,tailored by various density levels,results in varying creep processes of theⅡ-stage.This stage is closely related to the nucleation and early growth of T_(1)precipitates.Their number densities(maximum:2.9×10^(19)m^(-3))and the average length(maximum:21.3 nm)of T_(1)precipitates are much smaller than those of the stable peak-aged T_(1)phases,suggesting that creepⅡ-stage of all three creep-aged samples is dominant by the nucleation and initial growth of those T_(1)precipitates.This study provides valuable insights into the dislocation density-mediated creep deformation of an Al-Cu-Li alloy.
文摘Objective:Gambling is a complex topic in relation to health systems.It is always unclear how to strike a balance between the gambling economy and the impact of gambling on public health or social wellbeing at any age.There are limited studies considering the association between determinants of gambling and the life expectancy of the ageing population in a country.From an evaluation perspective,this article aims to demonstrate the correlation between life expectancy and gambling and public health systems.Methods:The approach of analysis has two parts.One is the influence of gambling prevalence in populations on life expectancy among old adults.Another is the association between the effect of changes in legal gambling provisions within public health systems and life expectancy among old adults.Healthy adjusted life expectancy at age 60 from the World Health Organization and gross gambling yield were used.ANOVA was performed with SPSS.Results:The population groups with HALE at age 60 of 15 years or over are likely more active in gambling than the population groups with smaller HALE at age 60 of 14 years or less.On the other hand,the influence of a health policy may be sidelined when it is implemented for older adult populations because the resource distribution magnitude or number of strategical techniques may not be the same for younger adult populations.The study here is marked as a good practical start,and there is room for further research with big data analysis on additional gambling variables against other life expectancy variables,quality of life variables or public health system variables.Conclusion:Associations between the determinants of gambling and the life expectancy of the ageing population in a country have not yet been identified.Continuous measurements of policy implementation and effectiveness and assessments of health equity,while gambling policies worldwide continue to change,have not yet been performed.Researchers and policy makers should understand the importance of holistic integration of the gambling economy and policy within a public health and social paradigm with the help of big data insights to achieve sustainability in their cities and health equity in their communities.
基金financially supported by the National Science and Technology Major Project of China (Nos.MJ-2018-G-48,J2019-Ⅵ-0023-0140)the Research Fund of the State Key Laboratory of Solidification Processing (NPU),China (No.2022-TS-04)。
文摘The high-temperature oxidation behaviour of the Inconel 625 alloy at 950℃ was investigated after different ageing treatments.The effect of heat treatment on the oxidation behaviour of the alloy was analysed by characterizing the structure and elemental distribution before and after oxidation.The results reveal that the two ageing treatments at 650℃ for 500 h and at 750℃ for 400 h both reduced the oxidation mass gain.After oxidation at 950℃,an outer Cr_(2)O_(3) layer and inner Al_(2)O_(3) are identified as the main oxidation products.Moreover,Nb_(2)O_(5) andδ(Ni_(3)Nb)phases precipitated after oxidation.The ageing treatments cause the rapid generation of a dense Cr_(2)O_(3) layer on the surface,which prevents the diffusion of oxygen into the matrix,reduce the Al_(2)O_(3) inward growth depth,and improve the oxidation resistance of the alloy.
文摘This research considered the effect of non-natural aging on the microstructural characteristics and mechanical properties of as-cast aluminum 6063 alloys. The samples were developed through a sand casting process and machined into tensile and impact test samples before carrying out solution heat treatment at 550?C (0.83 T<sub>m</sub>) on two parts of the samples while retaining one part as the control. The two parts were further divided into sets denoted A and B and were aged at 180?C (0.27 T<sub>m</sub>) and 160?C (0.24 T<sub>m</sub>), respectively, for 12 hours. The results showed that sample A has the optimal yield strength and ultimate tensile strength of 192 and 206 MPa, respectively. Likewise, the sample gave the highest impact strength value of about 9.63 J/mm<sup>2</sup>. The observed results were supported by the optical micrograph, which revealed that the sample has evenly dispersed precipitates in its microstructure. This is deemed responsible for the observed increase in strength of the sample.
基金supported by the National Natural Science Foundation of China(Grant No.22275092)。
文摘The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.
基金Project(51074186) supported by the National Natural Science Foundation of China
文摘The corrosion behaviors of Mg-10Gd-4.8Y-0.6Zr extruded-alloys with various ageing time were investigated by immersion test and electrochemical measurements.The results show that the corrosion rate of the experimental alloy decreases with the increase of ageing time from 0 to 108 h.The corrosion resistance of the experimental alloy was found to increase with the increase of the size of the precipitate phases.The open circuit potential of the experimental alloy increases with the increase of the ageing time.The potentiodynamic polarization curves show that the cathodic over-potential increases with the increase of ageing time,leading to a decrease in the current density of anodic current plateau with the increase of ageing time.
文摘Mierostruetural development of a commercial 7055 （Al-Zn-Mg-Cu）alloy is studied by transmission electron mieroseope（TEM） during the process of single-ageing for up to 48 h. It is observed that Guinier-Preston （GP） zones are formed on { 111} planes when the sample is aged for a short time and grows up gradually with increase of ageing time. η＇ phase is formsed after ageing for 4 h at 120℃, having the orientation relationship with the matrix as[0 0 0 1]η＇//[1 1^- 1]Al and （1 0 1^- 1）η＇//（1 1 0）Al.η phase starts to occur after 24 h ageing and has an orientation relationship with matrix as [1^- 1 0 0]η//[1 1 0]Al and （0 0 0 1）η// （1 1 1）Al. Since the density of both η＇ phase and η phase particles is much lower than that of GP zone on aged alloy, GP zones are important to control the properties of the alloy.
基金financial supports by National Key R&D Program of China (No. 2016YFB1200600 and No. 2016YFB1200504)Strategic Priority Program of the Chinese Academy of Sciences (No. XDB22000000)
文摘Different artificial two-stage ageing behaviors and their effect on stress corrosion cracking （SCC） susceptibility of AI-Zn-Mg alloy have been investigated. The experimental results show that two hardness peaks present on the second-stage ageing-hardening curve when the first-stage ageing is dealt with comparatively lower temperature than the conventional one. The first peak is caused by dispersive and evenly distributed G.P. zones, while η ′phases and coarsened G.P. zones contribute to the second peak. Tensile strength of experimental alloy raises 9.6% （33.2 MPa） and SCC susceptibility decreases 38.9% by applying the second peak ageing regime instead of conventional T73. AI-Zn-Mg alloy obtains high strength and SCC resistance due to its finely dispersive matrix precipitates （MPts）, coarsened and discontinuous grain boundary precipitates （GBPs）, as well as the narrow precipitate free zone （PFZ） in the second peak ageing condition. 2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金supported by the grants from the National Institutes of Health(AG17242 and GM 104459)(to Y.S.)a grant from KRIBB Research Initiative Program(to Y.S.)
文摘MicroRNAs （miRNAs） are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. They are involved in important biological processes including development, homeostasis, and ageing. Recently, extracellular miRNAs have been discovered in the bloodstream and bodily fluids. These miRNAs are shown to be secreted and circulating in microvesicles （MVs）, or in complex with other factors such as RNA-binding proteins and high-density lipoprotein （HDL） particles. These cell-free, circulating miRNAs can be taken into and function as negative regulators of target genes in recipient cells. Here we review the biogenesis and uptake of circulating miRNAs as well as their profiles in ageing and ageing-related diseases. We discuss the emerging role of circulating miRNAs as biomarkers and therapeutic targets.
基金supported by the National Natural Science Foundation of China (No.50533060)
文摘The paper presented accelerated ageing test results of a durability study on ortho-phthalic anhydride-type unsaturated polyester resin （191#） and its glass-fiber reinforcement polyester composites （GFRPC）. The samples were exposed in an artificial xenon arc lamp ageing cell or a thermo-oxidative ageing cell. Morphology and gloss of the specimens were investigated by using a microscope and a gloss-meter, respectively. The tensile strength, bending strength and inter-laminar shear strength （ILSS） of GFRPC were tested before and after exposure, and were considered to evaluate the durability performance of this material. The polyester resin was analyzed by fourier transform infrared （FT-IR） spectroscopy. The results showed that the glossiness of the specimens got worse and some cracks appeared on their surface during the course of ageing, the tensile strength and bending strengths of the specimens first increased and then decreased. The ILSS of the composites decreased after they were aged in the xenon arc lamp cell, but increased while they were aged in the thermo-oxidative cell. The changes of these trends become more obvious during ageing in the xenon arc lamp cell, so the main influencing factor leading to the failure of this material is UV irradiation.
基金Project(51801082) supported by National Natural Science Foundation of ChinaProjects(GY2021003, GY2021020)supported by the Key Research and Development Program of Zhenjiang City,China+1 种基金Project(KYCX21_3453) supported by Graduate Research and Innovation Projects in Jiangsu Province,ChinaProject(202110289002Z) supported by Undergraduate Innovation and Entrepreneurship Training Program of Jiangsu Province,China。
文摘In order to improve the through-thickness homogeneity and properties of aviation aluminum alloy thick plate.The effect of heating-cooling retrogression and re-ageing on the performance of Al-8Zn-2Mg-2Cu alloy thick plate was investigated by hardness tests, electrical conductivity tests and transmission electron microscopy(TEM) observation.Results revealed that, during retrogression heating, the fine pre-precipitates in surface layer dissolve more and the undissolved η′ or η phases are more coarsened than that of center layer. During slow cooling after retrogression,precipitates continue coarsening but with a lower rate and the secondary precipitation occurs in both layers. Finer precipitates resulting from the secondary precipitation are more in surface. However, the coarsening and secondary precipitation behaviors are restrained in both layers under quick cooling condition. The electrical conductivity and through-thickness homogeneity of precipitates increases while the hardness decreases with cooling rate decreasing. After the optimized non-isothermal retrogression and re-ageing(NRRA) including air-cooling retrogression, the throughthickness homogeneity which is evaluated by integrated retrogression effects has been improved to 94%. The tensile strength, fracture toughness and exfoliation corrosion grade of Al-8Zn-2Mg-2Cu alloy plate is 619 MPa, 24.7 MPa·m^(1/2)and EB, respectively, which indicates that the non-isothermal retrogression and re-aging(NRRA) could improve the mechanical properties and corrosion resistance with higher through-thickness homogeneity.
文摘This study focuses on the development stages of ageing and its regional differences in China based on examination of official statistics and documents. The development of ageing in China has experienced three major stages. Firstly, in the 1950s, low coefficient of elderly population (over 65 years) paced up to primary adult type. Secondly, there was a deeply drop of the elderly population because of natural disaster and political factors in the 1960s. Thirdly, from the 1970s to the end of 20th century, the constant increasing of elderly coefficient made China close to elderly society. With statistic data of population, Logistic model is used to simulate the future development of ageing, and two characteristics of development of ageing are presented. Firstly, as for ageing from 2005 to 2050, the elderly coefficient will grow up significantly from 8.48% to 16.30%. Secondly, after 2025, the increasing rate of elderly coefficient will slow down gradually. The regional differences of elderly population in China can be summarized as follows: 1) the eastern China possesses higher elderly coefficient and huger elder population than the western China; 2) about 47.4% of municipalities and provinces in the eastern China become elderly especially Shanghai, Zhejiang Province, Jiangsu Province, Beijing, Tianjin and Shandong Province; 3) ageing intensity is higher in rural area than urban area but getting close each other, and there are more elderly people in rural area than in urban area. Therefore, these will arose aged care problems, and it becomes important issue to establish the social security system in rural areas as soon as possible for elderly people.
文摘A stochastic model of conducting crack propagation is presented to provide a conceptual framework dedicated to the study of the formation of fractal structure of dielectric ageing patterns as a result of a competition between random fluctuation growth and applied electric strength enhanced deterministic growth. The necessary and sufficient conditions resulting in fractal behaviour in dielectric ageing are found.
文摘A kinetic model of dielectric ageing is presented. The central finding of this investigation is that there is a power-law relationship between the local electric field concentration and the rate of defect-tip initiated conducting crack growth. By applying such a power-law conducting crack growth rate expression to the evaluation of the life of solid dielectrics, the empirical classical ageing law of insulation materials can be derived theoretically as a lobical result. All the results are universal and agree with the experimental data of oxide films.
基金The authors acknowledge the financial supported by National Natural Science Foundation of China(No.52108415 and No.51808517)the National Key R&D Program of China(No.2018YFB1600200)+5 种基金the Key Technical Innovation Projects of Hubei Province(No.2019AEE023)the Key R&D Program of Hubei Province(No.2020BCB064)the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2022-21),the Transportation Technology Project of Department of Transport of Hubei Province(No.2022-11-1-10)the European Union's Horizon 2020 Research and Innovation Programme Under the Marie Skłodowska-Curie Grant Agreement(No.101030767)the Scientific Research Fund Project of Wuhan Institute of Technology(No.K2021032)the Open Fund of National&Local Joint Engineering Laboratory of Traffic Civil Engineering Materials,Chongqing Jiaotong University(No.LHSYS-2020-004).
文摘Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs,such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance.Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing,and the UV light parameters effect on the ageing rate of asphalt binder.However,the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions,and the UV ageing mechanism of asphalt binder is not very clear.Therefore,it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders.This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders.With the increase of UV ageing time,the UV ageing of asphalt binder develops gradually from the surface to inner part.There are various methods,such as low-penetration grade asphalt,less air void ratio,UV stabilizers and UV light absorbers,that can improve the UV ageing resistance of asphalt binders.A new theory of sensitive wavelengths of asphalt UV ageing is proposed,which can enrich the basic theory of asphalt UV ageing.Depending on this theory,different wavelengths of UV light have different ageing effects on asphalt binder.The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed,and may have better improvement effect on the anti-UV ageing performance of asphalt binder.
文摘Compared with developed countries, the main characteristics of population ageing in China have been regarded as a rapid ageing society. However, China and other Asian countries have been experiencing the demographic transition simultaneously, it is better to understand the characteristics of population ageing in China when compared with other Asian countries. Using the latest UN data, this paper compares the percentage of elderly population, the speed of ageing and the size of aged population among China and other Asian countries. The result indicates that China has a relatively high percentage of aged population, relatively rapid ageing population and will keep the largest size of aged population of the world in the next 60 years.
