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Spermidine for cognitive ageing:insights into observational and interventional studies
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作者 Lirong Yu Bin Li +10 位作者 Na Li Kaisy Xinhong Ye Kai Xuan Lim Anderson Li Yang Khoo Bingxue Han Guohua Lu Mei Song Wei Ma Brian Keith Kennedy Andrea Britta Maier Lei Feng 《General Psychiatry》 2025年第5期409-414,共6页
INTRODUCTION With the expansion of the ageing population,cognitive decline has become an increas-ingly pressing challenge.1 As life expectancy increases,its socioeconomic burden is also increasing,highlighting the urg... INTRODUCTION With the expansion of the ageing population,cognitive decline has become an increas-ingly pressing challenge.1 As life expectancy increases,its socioeconomic burden is also increasing,highlighting the urgent need for effective interventions.Numerous studies suggest that specific dietary patterns and nutritional interventions may help mitigate cognitive decline associated with ageing. 展开更多
关键词 socioeconomic burden dietary patterns nutritional interventions cognitive ageing nutritional interventions SPERMIDINE dietary patterns cognitive decline
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Effect of solution treatment temperature on ageing behaviour and mechanical properties of AlSi7Mg produced by laser powder bed fusion
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作者 James H.Warner Cecilie V.Funch +2 位作者 Kevin Sisco Simon P.Ringer Gwénaëlle Proust 《Journal of Materials Science & Technology》 2025年第29期227-238,共12页
AlSi7Mg is an age hardening aluminium alloy that is growing in popularity in additive manufacturing as its good processability makes it well suited to the powder bed fusion process,allowing for its use in the aerospac... AlSi7Mg is an age hardening aluminium alloy that is growing in popularity in additive manufacturing as its good processability makes it well suited to the powder bed fusion process,allowing for its use in the aerospace and automotive industries.The alloy relies on heat treatment to reach its peak strength,with precipitates in the Mg_(2) Si precipitation sequence providing the majority of this strengthening.Powder bed fusion,however,produces components with unique microstructures that differ to those of traditional manufacturing methods such as casting,meaning heat treatments must be carefully tailored for additively manufactured parts.This study therefore investigated the effects of solution treatment temperatures on the final properties and microstructures of T6 treated,additively manufactured AlSi7Mg.Due to the use of a heated build plate,samples aged from the as built and stress relieved conditions exhibited over ageing behaviour,necessitating a solution treatment step to induce useful strength properties.Solution treatments below 500℃were found to provide minimal strengthening upon ageing due to the pres-ence of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase,which reduced the amount of magnesium in solid solution and so reduced the age hardening response of the alloy by restricting the growth of strengthening precipitates.Solution treatments over 500℃,however,demonstrated excellent age hardening due to the replacement of theπ-Al_(18) Fe_(2)Mg_(7) Si_(10) phase with theβ-Al_(9)Fe_(2)Si_(2) phase,increasing the concentration of magnesium in solid solution and therefore improving its age hardening response.A T6 treatment then demonstrated an improvement in yield strength and ductility when compared to the as built state,but a decrease in tensile strength and impact toughness.The variability in the age hardening response of AlSi7Mg suggests that the careful selection of a solution treatment temperature is crucial to property optimisation. 展开更多
关键词 Additive manufacturing Aluminium alloy Microstructure evolution ageing behaviour
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Active Ageing and Labour Market Outcomes-An Analysis Using Survey Data in Urban India
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作者 Panchanan Das 《Management Studies》 2025年第3期122-134,共13页
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
关键词 ageing population labour force participation developing Asia
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Ag/β-Mo_(2)C催化逆水煤气变换反应性能及其机理研究
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作者 范帅 丁巍 +5 位作者 孙振宇 戴咏川 么志伟 宋官龙 马金玉 杨生文 《石油学报(石油加工)》 北大核心 2026年第2期357-367,共11页
采用程序升温碳化法合成β-Mo_(2)C载体,再通过沉积-沉淀法制备不同Ag负载量的系列Ag/β-Mo_(2)C催化剂。借助XRD、BET、TEM和XPS等手段对Ag/β-Mo_(2)C催化剂的物化性质进行表征,采用微型加氢反应装置对催化剂的逆水煤气变换(RWGS)反... 采用程序升温碳化法合成β-Mo_(2)C载体,再通过沉积-沉淀法制备不同Ag负载量的系列Ag/β-Mo_(2)C催化剂。借助XRD、BET、TEM和XPS等手段对Ag/β-Mo_(2)C催化剂的物化性质进行表征,采用微型加氢反应装置对催化剂的逆水煤气变换(RWGS)反应的催化性能进行评价。结果表明:β-Mo_(2)C载体具有六方密堆积的晶体结构,负载Ag后催化剂的结晶度较纯相β-Mo_(2)C提升1.38百分点,其中,0.5%Ag/β-Mo_(2)C催化剂中Ag的锚定作用使低负载量的Ag纳米粒子具有高分散性且孔结构良好;在H_(2)/CO_(2)体积比3/1、质量空速24000 h^(-1)的条件下,RWGS反应在300℃低温区CO选择性为61.86%,在600℃高温区CO选择性为97.44%,同时拥有高CO_(2)转化率52.37%,说明此类催化剂在RWGS反应中具有良好的催化活性;Ag的引入优化了Mo_(2)C电子结构,调节了Mo_(2)C的电子密度,提升了CO_(2)的吸附与活化能力,在提高催化剂热稳定性的同时可替代贵金属催化剂,降低了工业应用成本。 展开更多
关键词 沉积-沉淀法 碳化钼 AG纳米粒子 逆水煤气变换反应 CO选择性
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西藏日喀则地区辣椒根腐病病原菌鉴定与致病性评价
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作者 李欣 格桑旺姆 +6 位作者 王冠杰 谢学文 石延霞 李磊 范腾飞 李宝聚 柴阿丽 《华北农学报》 北大核心 2026年第1期194-201,共8页
为检测和鉴定引起西藏日喀则地区的辣椒根腐病病原菌种类,2024年7—9月从西藏日喀则白朗县巴扎乡彭仓村、桑珠孜区聂日雄乡盘孔村、江孜县达孜乡德吉村和拉孜县拉孜镇玉哲村4个区域采集了16份辣椒感病植株样品。采用常规组织分离法对发... 为检测和鉴定引起西藏日喀则地区的辣椒根腐病病原菌种类,2024年7—9月从西藏日喀则白朗县巴扎乡彭仓村、桑珠孜区聂日雄乡盘孔村、江孜县达孜乡德吉村和拉孜县拉孜镇玉哲村4个区域采集了16份辣椒感病植株样品。采用常规组织分离法对发病部位进行病原菌分离与培养后得到25株病原真菌,利用显微形态学观察将分离物代表菌株分为LJ1、LJ2和LJ3共3类真菌分离物。结合分子生物学方法及系统发育树构建,将LJ1类病原菌鉴定为镰孢菌属茄病镰孢菌,LJ2类病原菌为丝核菌属立枯丝核菌AG-4菌丝融合群的HGⅠ亚群(Rhizoctonia solani AG 4 HG-Ⅰ),LJ3类病原菌为镰孢菌属尖孢镰孢菌。采用幼苗刺伤接种法进行病原菌致病性评价,3类真菌分离物均能够侵染辣椒幼苗造成根腐病,且尖孢镰孢菌致病性最强。日喀则各地辣椒根腐病病原菌优势菌有差异,尖孢镰孢菌是优势致病菌,分离频率为52.0%;茄病镰孢菌分离频率为32.0%;立枯丝核菌分离频率为16.0%。西藏日喀则地区的辣椒根腐病是由尖孢镰孢菌、茄病镰孢菌和立枯丝核菌AG-4菌丝融合群的HGI亚群复合侵染导致,茄病镰孢菌和立枯丝核菌AG-4菌丝融合群的HGI亚群均是首次在西藏被分离鉴定。 展开更多
关键词 辣椒根腐病 尖孢镰孢菌 茄病镰孢菌 立枯丝核菌AG 4 HG-Ⅰ 致病性
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固溶处理对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金组织和力学性能的影响
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作者 李旻昊 万步炎 +3 位作者 卢立伟 黄谦仁 金永平 刘德顺 《材料热处理学报》 北大核心 2026年第2期88-98,共11页
采用光学显微镜、扫描电镜、X射线衍射和万能实验机等研究了固溶处理温度和时间对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金显微组织与力学性能的影响。结果表明:当固溶处理工艺为520℃×22 h时,合金具有较好的力学性能,其屈服抗拉强度为154.40 ... 采用光学显微镜、扫描电镜、X射线衍射和万能实验机等研究了固溶处理温度和时间对Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金显微组织与力学性能的影响。结果表明:当固溶处理工艺为520℃×22 h时,合金具有较好的力学性能,其屈服抗拉强度为154.40 MPa、极限抗拉强度为270.04 MPa、平均硬度为128.43 HV0.5,其强化主要来源于固溶强化;固溶处理促使合金的平均晶粒尺寸由13.56μm增至32.89μm,但静态再结晶程度的加深,显著改善合金的组织均匀性,晶粒有向等轴晶转变的趋势,此外,部分共晶相呈粒状弥散分布于基体,这些相的出现有利于合金强度的提升;固溶处理前,合金中的Y和Zr存在聚集区,Gd与Ag呈现弥散分布;固溶处理后,合金中的第二相占比一开始略微增多,但随着固溶温度升高及时间延长,其总量减少,种类发生变化,Gd与Ag逐渐聚集,并与Mg、Y和Zr的分布形状贴近并交叠,AgY与稳定的Mg5Gd在第二相中占比也随之增加。 展开更多
关键词 Mg-9Gd-4Y-0.4Zr-0.2Ag镁合金 固溶处理 第二相 显微组织 力学性能
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基于森林火灾风险的AG600消防飞机机场选址研究
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作者 王诗琪 孙智 +2 位作者 陈涛 朱培 张剑高 《控制与决策》 北大核心 2026年第2期531-542,共12页
针对消防飞机的机场选址问题,构建基于森林火灾风险因子的多目标规划模型,旨在最小化总任务时间与经济成本.该模型综合考虑森林火灾风险、灭火资源需求、消防飞机性能参数及部署运营成本+等多种因素,为提升高风险区域的优先覆盖能力,引... 针对消防飞机的机场选址问题,构建基于森林火灾风险因子的多目标规划模型,旨在最小化总任务时间与经济成本.该模型综合考虑森林火灾风险、灭火资源需求、消防飞机性能参数及部署运营成本+等多种因素,为提升高风险区域的优先覆盖能力,引入基于风速、相对湿度和植被覆盖度的森林火灾风险因子.此外,针对所构建的高维度整数多目标优化模型,引入自适应因子和双层决策选择策略,以提升NSGA-Ⅱ算法的求解能力.以广西地区为例,利用ArcGIS进行空间数据处理,并采用改进的NSGA-Ⅱ算法对选址模型进行求解.研究结果表明:改进的NSGA-Ⅱ算法能够有效提升求解速度和求解质量;在广西地区,柳州白莲机场部署2架AG600消防飞机为最优方案,其解的相对接近度较其他方案提高39%.所提出基于森林火灾风险因子构建的机场选址模型可为我国AG600消防飞机机场选址和部署提供理论依据和参考. 展开更多
关键词 机场选址 多目标优化 航空消防 森林火灾 森林火灾风险因子 消防飞机 AG600
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Effect of ageing time on corrosion behavior of Mg-10Gd-4.8Y-0.6Zr extruded-alloy 被引量:1
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作者 李慧中 刘洪挺 +3 位作者 郭菲菲 王海军 梁霄鹏 刘楚明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1498-1505,共8页
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
关键词 Mg-10Gd-4.8Y-0.6Zr alloy corrosion behavior ageing time
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TEM STUDY ON MICROSTRUCTURAL DEVELOPMENT OF SINGLE-AGEING 7055 ALUMINUM ALLOYS 被引量:1
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作者 沈凯 尹志民 王涛 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第3期265-269,共5页
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
关键词 7055 aluminum alloys ageing TEM
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Mice with postsurgical pain exhibit age-dependent spinal microglial activation and inhibitory synapse loss 被引量:1
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作者 WANG Jia-Ning SHEN Yu +2 位作者 WANG Shi-Hao LIAO Ping JIANG Ruo-Tian 《生理学报》 北大核心 2026年第1期182-194,共13页
Persistent postsurgical pain is a major clinical concern,especially in the aging population,who represent a growing proportion of surgical patients.Although age is a known pain risk factor,the mechanisms driving age-r... Persistent postsurgical pain is a major clinical concern,especially in the aging population,who represent a growing proportion of surgical patients.Although age is a known pain risk factor,the mechanisms driving age-related vulnerability to chronic postoperative pain remain poorly understood.This study aims to investigate how aging influences the resolution of postoperative pain and to elucidate the roles of microglial activation and synaptic remodeling in the spinal dorsal horn.A plantar incision model in young(3-month-old)and aged(18-month-old)male and female mice was used to mimic postoperative pain conditions.Mechanical and thermal hypersensitivity at various postoperative intervals were assessed by von Frey and Hargreaves tests.Microglial activation and inhibitory/excitatory synaptic densities in the spinal dorsal horn were evaluated using immunofluorescence and 3D reconstruction with Imaris software.On postoperative day(POD)3,both age groups exhibited reduced pain thresholds on the ipsilateral side,along with microglial activation in the dorsal horn.On POD 7,pain thresholds in young mice had returned to baseline with no significant microglial activation,while aged mice showed sustained reduction in pain thresholds,continuous microglial activation,and significant loss of inhibitory synapses without detectable changes in excitatory synapse density.These findings are consistent across both sexes,with no sex-related differences.Collectively,these results suggest that aging is associated with persistent postoperative pain,which correlates with microglial activation and inhibitory synapse loss.These insights advance our understanding of age-related pain vulnerability and may inform the development of more effective,targeted,and age-specific therapeutic strategies to prevent or alleviate persistent postoperative pain in elderly patients. 展开更多
关键词 incisional pain AGING spinal dorsal horn MICROGLIA inhibitory synapses
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2.79μm侧面泵浦激光器及光纤耦合性能研究
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作者 杨航 崔建丰 +5 位作者 贾红宝 王浪 邬小娇 朱佳辉 裴文娣 李福玖 《激光与红外》 北大核心 2026年第1期18-24,共7页
实验通过设计并搭建一套LD侧面泵浦Er,Cr∶YSGG晶体的电光调Q中红外固体激光器,通过对热焦距的仿真确定500mm平-平对称腔结构。对比分析了不同泵浦脉宽下的静态、动态能量输出,实验表明在泵浦脉宽14ms下性能最佳,分别获得静态、动态能... 实验通过设计并搭建一套LD侧面泵浦Er,Cr∶YSGG晶体的电光调Q中红外固体激光器,通过对热焦距的仿真确定500mm平-平对称腔结构。对比分析了不同泵浦脉宽下的静态、动态能量输出,实验表明在泵浦脉宽14ms下性能最佳,分别获得静态、动态能量输出12835mJ和1551mJ、动静比为3126、电-光转换效率079。此外,实验通过耦合空芯光纤与光子晶体光纤进行传能测试,结果表明空芯光纤与光子晶体光纤传输效率分别为50和70,并进行有限元仿真分析,其中光子晶体光纤在279μm波段的损耗和色散分别为001224dB/m和-230 ps/(nm·km)。 展开更多
关键词 Er Cr∶YSGG激光器 LD侧面泵浦 光纤耦合 Ag/AgI空芯光纤 光子晶体光纤
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痘苗病毒天坛株感染AG6小鼠脑病模型的建立与初步分析
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作者 杨琳 金梦 +2 位作者 吴汗青 李顺 周晓辉 《实验动物与比较医学》 2026年第1期3-10,共8页
目的构建痘苗病毒天坛株(vaccinia virus Tiantan strain,VTT)感染AG6小鼠脑病动物模型。方法通过以0.01的感染复数(multiplicity of infection,MOI)感染Vero细胞,扩增VTT并进行浓缩和滴定,孵育72 h后,收集含病毒的细胞进行浓缩;将浓缩... 目的构建痘苗病毒天坛株(vaccinia virus Tiantan strain,VTT)感染AG6小鼠脑病动物模型。方法通过以0.01的感染复数(multiplicity of infection,MOI)感染Vero细胞,扩增VTT并进行浓缩和滴定,孵育72 h后,收集含病毒的细胞进行浓缩;将浓缩的病毒悬浮液连续稀释(10倍梯度)并加入到含有形成致密单层Vero细胞的6孔板中进行噬斑实验,计数每孔形成的空斑数目,并根据样品的稀释倍数计算病毒滴度。将14只5~6周龄的AG6小鼠(雌雄各半,并按性别分笼饲养)随机分为对照组(n=3,PBS)、低接种量组(n=6,1×10^(5)PFU)和高接种量组(n=5,5×10^(5)PFU)。将小鼠经异氟烷吸入麻醉后,进行滴鼻感染。每日观察各组小鼠精神状态,记录其体重及死亡情况,并在感染后第13天经尾静脉注射2%伊文思蓝(Evans Blue)(4 mL/kg体重)以评估各组小鼠血脑屏障(blood-brain barrier,BBB)的破损情况,然后收集小鼠脑组织样本进行星形胶质细胞和小胶质细胞活化的免疫荧光分析。结果纯化后的VTT滴度为1×10^(7)PFU/mL。与对照组相比,低接种量组小鼠的体重无明显变化,且未出现死亡;高接种量组小鼠在感染后第5天开始体重显著减轻(P<0.05),并伴有致死结果。感染后第13天,低接种量组小鼠的脑组织中未检测到伊文思蓝外渗,高接种量组小鼠的嗅球区域显示出明显的蓝色染色,提示BBB破裂。免疫荧光分析显示,感染后第13天,低接种量组小鼠嗅球区域星形胶质细胞和小胶质细胞没有明显增殖,高接种量组小鼠中可观察到明显的胶质细胞活化。结论成功建立VTT感染AG6小鼠的脑病动物模型,其特征是小鼠BBB损伤和特异性定位于嗅球区域的反应性胶质增生(表现为星形胶质细胞和小胶质细胞增生)。 展开更多
关键词 痘苗病毒天坛株 脑病动物模型 血脑屏障 胶质细胞 AG6小鼠
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纳米SiO_(2)和纳米Ag对水泥基材料力学性能和压敏性能的影响
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作者 朱玉胜 姜锦磊 +1 位作者 孙敏 方有珍 《混凝土与水泥制品》 2026年第1期24-28,36,共6页
研究了纳米SiO_(2)掺量(0、0.5%、1.0%、1.5%)对水泥基材料力学性能的影响,优选出了最佳掺量。在此基础上,进一步通过掺入纳米Ag设计制备了自感知水泥基材料,研究了其在不同应力环境(等幅值循环加载、变幅值循环加载)下的压敏性能。结... 研究了纳米SiO_(2)掺量(0、0.5%、1.0%、1.5%)对水泥基材料力学性能的影响,优选出了最佳掺量。在此基础上,进一步通过掺入纳米Ag设计制备了自感知水泥基材料,研究了其在不同应力环境(等幅值循环加载、变幅值循环加载)下的压敏性能。结果表明:随着纳米SiO_(2)掺量的增加,试件的28 d抗折、抗压强度均先增大后减小,最佳掺量为1.0%;在等幅值循环加载工况下,试件的电阻率变化率表现为稳定的周期性波动趋势,且电阻率变化率与外力之间具有高度线性相关性,说明该水泥基材料在动态应力条件下具有优异的压敏性能和长期稳定性;在变幅值循环加载工况下,试件的电阻率变化率波动范围为-50%~-10%,其中,试件在高幅值阶段的导电网络虽然发生了重组和变化,但仍保持良好的周期性和完整性。 展开更多
关键词 自感知水泥基材料 纳米SiO_(2) 纳米AG 力学性能 压敏性能 稳定性 应力环境
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构建高催化活性的BiVO_(4)@Ag复合材料
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作者 蔡旭鹏 王月荣 +4 位作者 蔡依辰 洪先健 郭少波 郭小华 季晓晖 《化学试剂》 2026年第1期28-35,共8页
针对钒酸铋(BiVO_(4))光催化剂存在的载流子复合率高、表面反应动力学迟缓等问题,以球形BiVO_(4)为基底,通过3种不同光化学还原方法(直接还原法、银氨配合物-还原法、溴化钾调控还原法)构建BiVO_(4)@Ag-6%复合材料,系统探究不同负载方... 针对钒酸铋(BiVO_(4))光催化剂存在的载流子复合率高、表面反应动力学迟缓等问题,以球形BiVO_(4)为基底,通过3种不同光化学还原方法(直接还原法、银氨配合物-还原法、溴化钾调控还原法)构建BiVO_(4)@Ag-6%复合材料,系统探究不同负载方式对材料微观结构及光催化性能的影响。利用透射电子显微镜(TEM)、X射线光电子能谱(XPS)、X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis DRS)以及电化学测试等对复合材料的结构和性质进行了系统表征。实验结果表明,通过溴化钾调控还原法制备的目标材料具有较好催化活性。这是由于利用AgBr配合物缓释Ag^(+)机制,显著优化了Ag纳米颗粒(Ag NPs)的分散度及界面结合强度,其光催化降解Cr^(6+)和罗丹明B(RhB)的活性最佳(Cr^(6+)在20 min内完全降解,RhB降解效率较纯BiVO_(4)提升明显)。结合表征分析,其优异性能归因于Ag NPs的等离子体共振效应(SPR)和肖特基势垒的协同作用,能够有效抑制载流子复合,并加速界面电荷传输。 展开更多
关键词 BiVO_(4) 银纳米颗粒(Ag NPs) 光催化降解 等离子体共振效应(SPR) 降解率
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Quantifying Global Black Carbon Aging Responses to Emission Reductions Using a Machine Learning-based Climate Model 被引量:1
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作者 Wenxiang SHEN Minghuai WANG +5 位作者 Junchang WANG Yawen LIU Xinyi DONG Xinyue SHAO Man YUE Yaman LIU 《Advances in Atmospheric Sciences》 2026年第2期361-372,I0004-I0009,共18页
Countries around the world have been making efforts to reduce pollutant emissions. However, the response of global black carbon(BC) aging to emission changes remains unclear. Using the Community Atmosphere Model versi... Countries around the world have been making efforts to reduce pollutant emissions. However, the response of global black carbon(BC) aging to emission changes remains unclear. Using the Community Atmosphere Model version 6 with a machine-learning-integrated four-mode version of the Modal Aerosol Module, we quantify global BC aging responses to emission reductions for 2011–2018 and for 2050 and 2100 under carbon neutrality. During 2011–18, global trends in BC aging degree(mass ratio of coatings to BC, R_(BC)) exhibited marked regional disparities, with a significant increase in China(5.4% yr^(-1)), which contrasts with minimal changes in the USA, Europe, and India. The divergence is attributed to opposing trends in secondary organic aerosol(SOA) and sulfate coatings, driven by regional changes in the emission ratios of corresponding coating precursors to BC(volatile organic compounds-VOCs/BC and SO_(2)/BC). Projections under carbon neutrality reveal that R_(BC) will increase globally by 47%(118%) in 2050(2100), with strong convergent increases expected across major source regions. The R_(BC) increase, primarily driven by enhanced SOA coatings due to sharper BC reductions relative to VOCs, will enhance the global BC mass absorption cross-section(MAC) by 11%(17%) in 2050(2100).Consequently, although the global BC burden will decline sharply by 60%(76%), the enhanced MAC partially offsets the magnitude of the decline in the BC direct radiative effect, resulting in the moderation of global BC DRE decreases to 88%(92%) of the BC burden reductions in 2050(2100). This study highlights the globally enhanced BC aging and light absorption capacity under carbon neutrality, thereby partly offsetting the impact of BC direct emission reductions on future changes in BC radiative effects globally. 展开更多
关键词 black carbon aging trend emission reduction carbon neutrality machine learning
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Ag/TiO_(2)微胶囊的制备及其在纺织中的应用
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作者 何奕鸣 尚润玲 堵国君 《轻纺工业与技术》 2026年第1期10-12,19,共4页
为了赋予纯棉织物持久的抗菌和防紫外线性能,文章采用光化学还原法制备了Ag/TiO_(2)纳米颗粒,进而利用乳化-交联法,将Ag/TiO_(2)纳米颗粒乳化后的分散液与壳聚糖溶液交联固化,制备了Ag/TiO_(2)微胶囊。实验中,采用Ag/TiO_(2)微胶囊对纯... 为了赋予纯棉织物持久的抗菌和防紫外线性能,文章采用光化学还原法制备了Ag/TiO_(2)纳米颗粒,进而利用乳化-交联法,将Ag/TiO_(2)纳米颗粒乳化后的分散液与壳聚糖溶液交联固化,制备了Ag/TiO_(2)微胶囊。实验中,采用Ag/TiO_(2)微胶囊对纯棉织物进行整理,对整理前后样品的抗菌和防紫外线性能分别进行测试后,结果表明:经Ag/TiO_(2)微胶囊整理后的纯棉织物具有优异且持久的抗菌性和防紫外线性能;经过80次水洗后,其对金黄色葡萄球菌和大肠杆菌的抑菌率均可以达到98%,对白色念珠菌的抑菌率可以达到70%,T(UVA)AV可达到2.4%,UPF可达到87.9。 展开更多
关键词 Ag/TiO_(2) 微胶囊 棉织物 抗菌性 防紫外线性能
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Fractal Studies on Dielectric Ageing
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作者 丁洪志 赵如宝 +1 位作者 邢修三 朱鹤孙 《Journal of Beijing Institute of Technology》 EI CAS 1996年第2期176+171-176,共7页
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
关键词 dielectric ageing fractal behaviour conductiong crack Fokker-Planck equation scale invariance
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A Kinetic Model of Dielectric Ageing
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作者 丁洪志 赵如宝 +1 位作者 邢修三 朱鹤孙 《Journal of Beijing Institute of Technology》 EI CAS 1996年第1期55-62,共8页
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
关键词 dielectric ageing KINETICS conducting crack electric field intensity factor
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Research progress in 7-ketocholesterol and age-related macular degeneration
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作者 Luo Qin Fu Changzhen Liu Qingping 《中华实验眼科杂志(中英文)》 北大核心 2026年第1期85-97,共13页
Age-related macular degeneration(AMD)is the leading cause of irreversible vision loss in older adults,with early-stage features including subretinal lipid deposits and progressing to retinal geographic atrophy and cho... Age-related macular degeneration(AMD)is the leading cause of irreversible vision loss in older adults,with early-stage features including subretinal lipid deposits and progressing to retinal geographic atrophy and choroidal neovascularization in advanced stages.The dysregulation of ocular lipid metabolism,oxidative stress,and inflammation are critical risk factors for AMD pathogenesis.7-ketocholesterol(7-KC),a hallmark of ocular lipid metabolism disorders,is a significant component of subretinal lipid deposits in AMD patients,exhibiting toxicity to retinal cells and exacerbating lipotoxic aging.This review elaborates on the biosynthesis and metabolism of 7-KC in the retina,investigates its detoxification mechanisms by examining its binding proteins,and summarizes recent progress on kinase signaling pathways induced by 7-KC through inflammatory cytokines and intracellular effectors.The aim is to pinpoint potential pharmacological targets,nutritional compounds,and synthetic molecules to explore the potential of targeting 7-KC for AMD treatment. 展开更多
关键词 Age-related macular degeneration 7-ketocholesterol AGING Binding protein INFLAMMATION Pharmacological targets
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AGS布置形式对前舱散热性能及空调能耗的影响研究
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作者 胡晓辉 赵梦迪 +2 位作者 郭俊江 上官郑伟 路昭 《汽车技术》 北大核心 2026年第2期56-62,共7页
采用一维-三维联合仿真的计算方法,探究了主动进气格栅(AGS)布置形式对前舱进气量、冷却模块散热量以及空调压缩机能耗的影响。研究发现:AGS叶片与格栅距离处于57~97 mm时,正对与非正对布置对散热性能及能耗的影响趋于一致,进气量衰减... 采用一维-三维联合仿真的计算方法,探究了主动进气格栅(AGS)布置形式对前舱进气量、冷却模块散热量以及空调压缩机能耗的影响。研究发现:AGS叶片与格栅距离处于57~97 mm时,正对与非正对布置对散热性能及能耗的影响趋于一致,进气量衰减幅度约为2.4%,散热量降低幅度低于1%,压缩机能耗几乎无影响;距离小于57 mm(靠近格栅)时,正对布置的方式优于错开布置,体现在相对于错开布置进气量提升3.16%,散热量提升约2%,压缩机能耗降低约2%;距离大于97 mm(靠近冷却模块)时,采用错开布置形式更有利于降低AGS叶片造成的进气量衰减。 展开更多
关键词 AGS叶片布置形式 进气量 散热量 空调能耗
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