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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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双发射碳量子点比率型荧光探针测定环境水样中Ag^(+)
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作者 张越诚 李淼 +3 位作者 张雅蓉 张新婕 孙凌波 马红燕 《材料导报》 北大核心 2026年第3期72-78,共7页
以邻苯二胺(OPD)为单一原料,通过水热法可一步制备出具有单激发双发射特性的新型碳量子点(OP-CQDs)。研究发现,在激发波长为300 nm时,OP-CQDs分别在348 nm与557 nm处有独立的双发射峰。引入Ag^(+)后可使OP-CQDs于348 nm处发射峰荧光信... 以邻苯二胺(OPD)为单一原料,通过水热法可一步制备出具有单激发双发射特性的新型碳量子点(OP-CQDs)。研究发现,在激发波长为300 nm时,OP-CQDs分别在348 nm与557 nm处有独立的双发射峰。引入Ag^(+)后可使OP-CQDs于348 nm处发射峰荧光信号淬灭,557 nm处荧光强度基本不变。据此,以557 nm处的荧光强度为参比信号,348 nm处的荧光强度为响应信号,可直接构建测定Ag^(+)的比率型荧光探针。在优化的条件下,Ag^(+)浓度在5.0×10^(-8)~3.0×10^(-6) mol/L和3.0×10^(-6)~5.0×10^(-5) mol/L范围内与OP-CQDs-Ag^(+)体系荧光比值(F_(557)/F_(348))呈现两段线性关系,检出限为4.0×10^(-8) mol/L。根据体系紫外-可见吸收光谱的变化和不同温度对淬灭常数的影响,讨论了Ag^(+)对OP-CQDs荧光探针的作用机理。本方法可对环境水样中Ag^(+)进行简单、快速、高灵敏度检测。 展开更多
关键词 双发射碳量子点 邻苯二胺(OPD) 比率型荧光探针 银离子(ag +)
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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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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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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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Ag^(+)改性ZnO-Al_(2)O_(3)复合金属氧化物催化剂催化合成甘油碳酸酯
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作者 张婧雯 王海彦 +4 位作者 郭云龙 王钰佳 孙娜 白英芝 康蕾 《石油学报(石油加工)》 北大核心 2026年第1期54-63,共10页
依据半导体金属氧化物的催化理论,在ZnO-Al_(2)O_(3)催化剂中引入受主杂质离子(Ag^(+)),设计开发了新型Ag_(2)O-ZnO-Al_(2)O_(3)催化剂,用于催化以甘油和尿素为原料合成甘油碳酸酯。采用XRD、SEM、XPS、CO_(2)-TPD、NH_(3)-TPD等分析手... 依据半导体金属氧化物的催化理论,在ZnO-Al_(2)O_(3)催化剂中引入受主杂质离子(Ag^(+)),设计开发了新型Ag_(2)O-ZnO-Al_(2)O_(3)催化剂,用于催化以甘油和尿素为原料合成甘油碳酸酯。采用XRD、SEM、XPS、CO_(2)-TPD、NH_(3)-TPD等分析手段对催化剂进行表征,并考察其催化性能的反应。结果表明,Ag^(+)的引入能够改变催化剂的晶体结构,调整催化剂的酸碱性,促进甘油和尿素醇解反应的发生。与未掺杂Ag_(2)O的ZnO-Al_(2)O_(3)催化剂相比,在甘油/尿素摩尔比1/4、温度140℃、真空压力0.01 MPa、反应时间3 h条件下,当Ag2O掺杂质量分数为1.0%时,甘油转化率从46.9%增加到84.1%,甘油碳酸酯选择性从79.2%增加到93.4%。 展开更多
关键词 甘油碳酸酯 甘油 尿素 醇解反应 ag^(+)
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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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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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Ag修饰多孔纳米Fe_(2)O_(3)/SnO_(2)的制备及C_(2)H_(2)气敏性能研究
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作者 王璇 解涛 +3 位作者 李国栋 刘宏 牛曙 吴启瑞 《中国陶瓷》 北大核心 2026年第3期24-32,共9页
金属氧化物半导体气体传感器因其具备响应快速、结构简单、易于集成等优点,在电力设备状态监测,特别是变压器油中溶解气体检测中展现出广泛的应用前景。本文首先采用水热法制备多孔SnO_(2),再通过溶剂热与化学还原协同策略,引入Fe_(2)O_... 金属氧化物半导体气体传感器因其具备响应快速、结构简单、易于集成等优点,在电力设备状态监测,特别是变压器油中溶解气体检测中展现出广泛的应用前景。本文首先采用水热法制备多孔SnO_(2),再通过溶剂热与化学还原协同策略,引入Fe_(2)O_(3)构建异质结结构并调控Ag纳米颗粒的负载量,成功获得了一系列的多孔Ag-Fe_(2)O_(3)/SnO_(2)复合材料。研究表明,Fe_(2)O_(3)的引入可与SnO_(2)形成n-n型异质结结构,提高其比表面积和气体扩散效率;Ag纳米颗粒的负载可显著提升材料表面催化活性和电子传输能力。气敏测试性能显示,2 at%Ag修饰Fe_(2)O_(3)/SnO_(2)在150℃下对20 ppm C_(2)H_(2)响应最佳,响应值40.3 s,响应与恢复时间短分别为51.2 s与62.4 s,且具有良好浓度线性、选择性与长期稳定性。该材料体系为构建面向电力设备油中气体监测的高性能C_(2)H_(2)传感器提供了新的研究思路和技术基础。 展开更多
关键词 Fe_(2)O_(3)/SnO_(2) ag修饰 多孔纳米材料 C_(2)H_(2)
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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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光电协同作用下Ag@AgBr/MgAl-LDH催化性能的研究
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作者 林双龙 何超 +3 位作者 齐跃红 次立杰 周二鹏 李贺 《燃料化学学报(中英文)》 北大核心 2026年第1期26-34,共9页
本工作通过水热法、沉淀法和光还原法制备Ag@AgBr/MgAl-LDH,并在光电协同的条件下催化降解目标产物:亚甲基蓝(MB)溶液,通过降解率研究样品的催化活性。对所制备的材料进行一系列表征以及活性测试,确定了样品的物质组成、微观形貌和粒径... 本工作通过水热法、沉淀法和光还原法制备Ag@AgBr/MgAl-LDH,并在光电协同的条件下催化降解目标产物:亚甲基蓝(MB)溶液,通过降解率研究样品的催化活性。对所制备的材料进行一系列表征以及活性测试,确定了样品的物质组成、微观形貌和粒径尺寸等;使用电化学工作站表征材料的电化学性能等参数;探究不同修饰量Ag@AgBr/MgAl-LDH的降解率确定催化剂的最佳修饰量;对样品进行多次测试循环实验表征该催化剂的回收性能;进行淬灭实验确定该催化剂的反应机理。本研究证明了12.5%的Ag@AgBr/MgAl-LDH的光电协同降解率最高,降解率为90.97%。通过XRD、SEM、UVvis、FT-IR等表征方式证明了Ag@AgBr修饰到MgAl-LDH上,同时材料具有较好的亲水性;对Ag@AgBr/MgAl-LDH进行了一系列的电化学测试表征电化学性能,表明该复合电极材料具有较低的禁带宽度和阻抗,较高的催化降解能力和活性位点;在对该材料进行五次循环实验后,依然具有很高的降解率,因此,发现该复合材料具有良好的稳定性,催化剂损失较少且降解率没有明显下降;使用不同的淬灭剂淬灭Ag@AgBr/MgAl-LDH在光电协同降解过程中的活性物种,实验结果表明,该过程中的活性物种为h^(+)和O_(2)^(-);结合本实验中一系列的表征和测试结果,探索了Ag@AgBr/MgAl-LDH在降解过程中的电子转移机理。 展开更多
关键词 亚甲基蓝 ag@agBr/MgAl-LDH 光电催化
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Melatonin and mitochondrial stress: New insights into age-related neurodegeneration
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作者 Silvia Carloni Francesca Luchetti +3 位作者 Maria Gemma Nasoni Walter Balduini Walter Manucha Russel J.Reiter 《Neural Regeneration Research》 2026年第4期1564-1565,共2页
Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mo... Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mortality.Although organis m-wide deterioration is observed during aging,organs with high metabolic demand,such as the brain,are more vulnerable. 展开更多
关键词 buildup changes neurodegenerative diseases aging neurodegenerative diseases MITOCHONDRIA mitochondrial stress MELATONIN age related neurodegeneration agING
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Alpha-synuclein-induced upregulation of SKI family transcriptional corepressor 1: A new player in aging and Parkinson's disease?
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作者 Lauren Barrett Rebekah Bevans +2 位作者 Aideen M.Sullivan Louise M.Collins Gerard W.O’Keeffe 《Neural Regeneration Research》 2026年第1期320-321,共2页
SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, tha... SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, that has a molecular weight of approximately 100 kDa. Skor1 is highly expressed in neurons in the central nervous system of both humans and rodents. 展开更多
关键词 Alpha Cor agING
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Analysis of DC Aging Characteristics of Stable ZnO Varistors Based on Voronoi Network and Finite Element Simulation Model
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作者 ZHANG Ping LU Mingtai +1 位作者 LU Tiantian YUE Yinghu 《材料导报》 北大核心 2026年第2期20-28,共9页
In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results i... In modern ZnO varistors,traditional aging mechanisms based on increased power consumption are no longer relevant due to reduced power consumption during DC aging.Prolonged exposure to both AC and DC voltages results in increased leakage current,decreased breakdown voltage,and lower nonlinearity,ultimately compromising their protective performance.To investigate the evolution in electrical properties during DC aging,this work developed a finite element model based on Voronoi networks and conducted accelerated aging tests on commercial varistors.Throughout the aging process,current-voltage characteristics and Schottky barrier parameters were measured and analyzed.The results indicate that when subjected to constant voltage,current flows through regions with larger grain sizes,forming discharge channels.As aging progresses,the current focus increases on these channels,leading to a decline in the varistor’s overall performance.Furthermore,analysis of the Schottky barrier parameters shows that the changes in electrical performance during aging are non-monotonic.These findings offer theoretical support for understanding the aging mechanisms and condition assessment of modern stable ZnO varistors. 展开更多
关键词 ZnO varistors Voronoi network DC aging finite element method(FEM) current distribution double Schottky barrier theory
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采前1-甲基环丙烯结合采后Ag/ZSM-5分子筛纳米保鲜纸对东魁杨梅成熟度及采后品质的影响
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作者 宣晓婷 周阳 +3 位作者 车浩妍 尚海涛 林旭东 朱麟 《食品安全质量检测学报》 2026年第2期142-153,共12页
目的 探究采前1-甲基环丙烯(1-methylcyclopropene, 1-MCP)处理与采后Ag/ZSM-5分子筛纳米保鲜纸对东魁杨梅成熟进程及贮藏品质的影响。方法 基于留树期果实外观、果径、可溶性固形物、可滴定酸和色泽等方面评估采前1-MCP喷施对杨梅果实... 目的 探究采前1-甲基环丙烯(1-methylcyclopropene, 1-MCP)处理与采后Ag/ZSM-5分子筛纳米保鲜纸对东魁杨梅成熟进程及贮藏品质的影响。方法 基于留树期果实外观、果径、可溶性固形物、可滴定酸和色泽等方面评估采前1-MCP喷施对杨梅果实成熟度的影响,同时协同采后Ag/ZSM-5纳米保鲜技术,分析其对杨梅常温和低温贮藏环境下失重率、糖酸度、质构、色泽、多酚氧化酶(polyphenol oxidase, PPO)、过氧化物酶(peroxidase, POD)活性的影响。结果 采前1-MCP处理可有效延缓东魁杨梅留树期成熟进程,推迟转色启动4 d,抑制果实膨大,且对降低杨梅采后低温贮藏的失重率具有一定作用,维持了果实糖酸度和色泽,提高了果实POD酶活性,从而延缓果实衰老。同时,采后单一Ag/ZSM-5纳米保鲜纸降低了杨梅果实常温贮藏失重率,维持果实硬度、胶黏性及红色色泽(a),并减轻细胞膜损伤。采前采后协同处理显著降低了低温贮藏环境下杨梅的PPO酶活性86.31%,延缓膜脂过氧化进程。结论 采前喷施1-MCP可延迟杨梅成熟,同时联合采后Ag/ZSM-5纳米保鲜纸通过维持东魁杨梅常温和低温贮藏期的果实品质及提升抗氧化活性,从而显著增强果实耐贮性并延长保鲜期。 展开更多
关键词 东魁杨梅 1-甲基环丙烯 ag/ZSM-5分子筛纳米保鲜纸 贮藏 品质
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Synaptic mitochondria in aging and neurodegenerative diseases:Functional decline and vulnerability
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作者 Karina A.Cicali Angie K.Torres Cheril Tapia-Rojas 《Neural Regeneration Research》 2026年第6期2145-2152,共8页
Aging is a physiological and complex process produced by accumulative age-dependent cellular damage,which significantly impacts brain regions like the hippocampus,an essential region involved in memory and learning.A ... Aging is a physiological and complex process produced by accumulative age-dependent cellular damage,which significantly impacts brain regions like the hippocampus,an essential region involved in memory and learning.A crucial factor contributing to this decline is the dysfunction of mitochondria,particularly those located at synapses.Synaptic mitochondria are specialized organelles that produce the energy required for synaptic transmission but are also important for calcium homeostasis at these sites.In contrast,non-synaptic mitochondria primarily involve cellular metabolism and long-term energy supply.Both pools of mitochondria differ in their form,proteome,functionality,and cellular role.The proper functioning of synaptic mitochondria depends on processes such as mitochondrial dynamics,transport,and quality control.However,synaptic mitochondria are particularly vulnerable to age-associated damage,characterized by oxidative stress,impaired energy production,and calcium dysregulation.These changes compromise synaptic transmission,reducing synaptic activity and cognitive decline during aging.In the context of neurodegenerative diseases such as Alzheimer’s,Parkinson’s,and Huntington’s,the decline of synaptic mitochondrial function is even more pronounced.These diseases are marked by pathological protein accumulation,disrupted mitochondrial dynamics,and heightened oxidative stress,accelerating synaptic dysfunction and neuronal loss.Due to their specialized role and location,synaptic mitochondria are among the first organelles to exhibit dysfunction,underscoring their critical role in disease progression.This review delves into the main differences at structural and functional levels between synaptic and non-synaptic mitochondria,emphasizing the vulnerability of synaptic mitochondria to the aging process and neurodegeneration.These approaches highlight the potential of targeting synaptic mitochondria to mitigate age-associated cognitive impairment and synaptic degeneration.This review emphasizes the distinct vulnerabilities of hippocampal synaptic mitochondria,highlighting their essential role in sustaining brain function throughout life and their promise as therapeutic targets for safeguarding the cognitive capacities of people of advanced age. 展开更多
关键词 agING HIPPOCAMPUS MEMORY MITOCHONDRIA synaptic mitochondria
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Fitness and exercise effects on brain age:A randomized clinical trial
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作者 Lu Wan Cristina Molina-Hidalgo +11 位作者 Mary E.Crisafio George Grove Regina L.Leckie Thomas W.Kamarck Chaeryon Kang Mia DeCataldo Anna L.Marsland Matthew F.Muldoon Mark R.Scudder Javier Rasero Peter J.Gianaros Kirk I.Erickson 《Journal of Sport and Health Science》 2026年第2期41-51,共11页
Background:Midlife lifestyle factors,including physical activity,are associated with late-life brain health,yet the role of aerobic exercise on structural brain health in early and mid-adulthood remains poorly underst... Background:Midlife lifestyle factors,including physical activity,are associated with late-life brain health,yet the role of aerobic exercise on structural brain health in early and mid-adulthood remains poorly understood.This study aimed to examine the effect of aerobic exercise on structural brain age and to explore potential mediators.Methods:In a single-blind,12-month randomized clinical trial,130 healthy participants aged 26-58 years were randomized into a moderate-to-vigorous intensity aerobic exercise group or a usual-care control group.The exercise group attended two supervised 60-min sessions per week in a laboratory setting plus engaged in home-based exercise to achieve 150 min of exercise per week.Brain-predicted age difference(brain-PAD)and cardiorespiratory fitness(CRF)were assessed at baseline and 12 months.Both intention-to-treat(ITT)and completers analyses(including participants who completed post-intervention assessments)were performed.Results:The 130 participants(67.7%female)had an age of 41.28±9.93 years(mean±SD).At baseline,higher CRF(peak oxygen uptake,VO_(2peak))was associated with smaller brain-PAD(β=-0.309,p=0.012).After the intervention,the exercise group showed a decrease in brainPAD(estimated mean difference(EMD)=-0.60;95%confidence interval(95%CI):-1.15 to-0.04;p=0.034)compared to the control group(EMD=0.35;95%CI:-0.21 to 0.92;p=0.217);time×group interaction(between-group difference(BGD)=-0.95;95%CI:-1.72 to-0.17;p=0.019).VO2peak improved in the exercise group(EMD=1.60;95%CI:0.29-2.90;p=0.017)compared to the control group(EMD=-0.78;95%CI:-2.17 to 0.60;p=0.265);time×group interaction(BGD=2.38;95%CI:0.52-4.25;p=0.015).Body composition,blood pressure,and brain-derived neurotrophic factor levels were unaffected.None of the proposed pathways statistically mediated the effect of exercise on brain-PAD.The results from completers were similar.Conclusion:Engaging in 12 months of moderate-to-vigorous exercise reduced brain-PAD in early-to-midlife adults.The pathways by which these effects occur remain unknown. 展开更多
关键词 Aerobic exercise agING BRAIN Cardiorespiratory fitness
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Constitutive modeling of solvent plasticization and physical aging in glassy polymers
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作者 Xu CAO Kerong WU +1 位作者 Ji LIN Rui XIAO 《Applied Mathematics and Mechanics(English Edition)》 2026年第3期535-554,共20页
Glassy polymers are widely used in biomedical applications in a solvent environment,yet their long-term performance is governed by the competing effects of physical aging and solvent-induced plasticization.Here,we dev... Glassy polymers are widely used in biomedical applications in a solvent environment,yet their long-term performance is governed by the competing effects of physical aging and solvent-induced plasticization.Here,we develop a constitutive model that explicitly couples the solvent concentration,structural relaxation,and mechanical response.This framework is built on a multiplicative decomposition of deformation and an Eyring-type flow rule,with structural evolution described by an effective temperature.A generalized shift factor is introduced to quantify how the solvent concentration and effective temperature jointly affect the relaxation time,thereby integrating physical aging and plasticization.The model is subsequently applied to methacrylate(MA)-based copolymer networks immersed in phosphate-buffered saline for up to nine months.Simulations accurately capture key experimental features,including the strong softening of highly swellable networks,the partial recovery due to aging,and the mitigating role of hydrophobic crosslinking in reducing solvent uptake.While the current single-mode description cannot reproduce the full relaxation spectrum,it establishes an efficient framework for predicting the long-term mechanical performance under coupled environmental and mechanical loading.This study provides a constitutive description of solvent-swollen glassy polymers,offering mechanistic insight into the interplay between plasticization and aging.Beyond biomedical MA networks,this framework establishes a foundation for predicting the long-term performance of polymer glasses under coupled aqueous environmental and mechanical loading. 展开更多
关键词 glassy polymer SWELLING physical aging constitutive model
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Progress of Ganoderma lucidum in regulating aging-mediated disorders of glycolipid metabolism
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作者 Xiao-Hui Zhao Xiao-Wei Dai +3 位作者 Hong-Yan Pei Rui Du Wei Wang Zhong-Mei He 《Traditional Medicine Research》 2026年第5期68-80,共13页
As the aging population continues to grow,age-related health issues are becoming increasingly prominent,attracting widespread attention and concern from society.While research on the mechanisms of aging is relatively ... As the aging population continues to grow,age-related health issues are becoming increasingly prominent,attracting widespread attention and concern from society.While research on the mechanisms of aging is relatively extensive,studies on the association between aging and related diseases remain limited.G.lucidum,a traditional medicinal fungus,has garnered significant attention due to its diverse bioactive properties.Recent studies have revealed that G.lucidum and its active components exhibit significant potential in anti-aging and regulating dysregulation of glucose and lipid metabolism.However,a comprehensive and detailed review of recent research findings has yet to be thoroughly explored.This paper summarizes and elucidates the latest advances in the pathological mechanisms of aging-related glucose and lipid metabolism disorders by retrieving data from databases such as X-mol and PubMed,provides a detailed account of the regulatory effects of G.lucidum’s primary active components on aging and lipid metabolism,and explores their potential mechanisms.Additionally,it discusses the application prospects of G.lucidum in the fields of anti-aging and metabolic regulation,aiming to provide a reference for research on aging-mediated lipid metabolism disorders and to lay a theoretical foundation for the further development and application of G.lucidum. 展开更多
关键词 agING lipid metabolism G.lucidum
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