期刊文献+
共找到280篇文章
< 1 2 14 >
每页显示 20 50 100
基于共价自适应网络重排的环氧树脂封装材料应力释放研究
1
作者 周博 王之昊 +1 位作者 周鹏 张新星 《高分子学报》 北大核心 2025年第12期2441-2451,共11页
5G时代高功率电子器件的高集成微型化,要求封装材料兼具高导热、强黏附与高效应力释放能力.然而,传统环氧树脂因高度交联网络易积聚内应力导致器件失效,严重制约了高端设备的发展.为此,我们基于共价自适应网络(CANs)的动态拓扑重排特性... 5G时代高功率电子器件的高集成微型化,要求封装材料兼具高导热、强黏附与高效应力释放能力.然而,传统环氧树脂因高度交联网络易积聚内应力导致器件失效,严重制约了高端设备的发展.为此,我们基于共价自适应网络(CANs)的动态拓扑重排特性,从分子结构设计出发设计了一种具有应力释放能力的高导热环氧树脂封装材料.通过将一维碳纳米管与二维三氧化二铝微球进行协同互配,成功构建了三维导热网络,显著提升了材料的导热能力.体系中引入的动态共价键与多重氢键产生协同效应,在实现环氧树脂内应力有效释放的同时,还大幅增强了其界面粘接强度与再加工性能.高过载测试及环境老化实验结果表明,该材料在严苛工况下仍具备优异的服役可靠性.本研究为发展新一代高性能电子封装材料提供了新的设计思路. 展开更多
关键词 共价自适应网络 环氧树脂 应力释放 电子封装 导热散热
原文传递
X16老年人平衡能力测试量表的信度和效度评估(摘译) 被引量:1
2
作者 姜玉(摘译) 夏庆华(审校) +8 位作者 Jingjuan Ju peng zhou Lin Li Xiaolei Ye Hongmei Wu Bin Shen Jialei Zhang Xiaoding He Chunjin Niu 《伤害医学(电子版)》 2021年第1期54-60,共7页
近几十年来,老龄化已成为当今社会的重要公共卫生问题之一。全世界几乎所有国家中60岁及以上的人口数都在逐步、迅速地增长。2012年,全球老年人口占总人口的11%以上。据联合国人口基金会估计,到2050年这一比例将达到约22%。2012年,我国... 近几十年来,老龄化已成为当今社会的重要公共卫生问题之一。全世界几乎所有国家中60岁及以上的人口数都在逐步、迅速地增长。2012年,全球老年人口占总人口的11%以上。据联合国人口基金会估计,到2050年这一比例将达到约22%。2012年,我国有1.8亿老年人,截至2015年,65岁及以上老人占全国总人口的10.5%,预计到2050年该比例还会增长近三分之一。上海是我国人口最多也是平均期望寿命最高的城市,2014年老年人口比例达到28.8%。随着年龄的增长,老年人的生理、认知和行动能力均有不同程度下降,因此,有必要对老龄化进程中的特点进行研究。 展开更多
关键词 联合国人口基金 平均期望寿命 老年人口比例 测试量表 三分之一 信度和效度 老龄化
暂未订购
加强前瞻研究部署应对新发突发传染病重大挑战
3
作者 方冬 粟斌 +9 位作者 程功 王奇慧 蓝柯 王辉 周鹏 毕玉海 刘翠华 窦豆 孙瑞娟 闫章才 《中国科学基金》 北大核心 2025年第3期519-531,共13页
21世纪以来,全球气候变化持续加剧,人员及物资交流日益频繁,人与自然的接触日趋密切,新发突发传染病在全球范围内流行的挑战不断增加,严重威胁人类健康和社会经济发展。针对国家重大安全需求和人民生命健康需求,前瞻性部署基础研究和技... 21世纪以来,全球气候变化持续加剧,人员及物资交流日益频繁,人与自然的接触日趋密切,新发突发传染病在全球范围内流行的挑战不断增加,严重威胁人类健康和社会经济发展。针对国家重大安全需求和人民生命健康需求,前瞻性部署基础研究和技术研发,引领广大科技工作者积极开展新发突发传染病防控的基础和应用基础研究,已成为当前亟需加强的重点任务。本文从以下五个方面梳理了我国在该方向的研究现状,包括:(1)动物源性病原体的发现与鉴定;(2)重要新发病原体检测技术开发;(3)重要致病微生物类群典型病原体结构解析及重要靶点筛选;(4)重要病原体致病性与机体免疫应答机制研究;(5)重要致病微生物类群变异与进化规律及跨种传播分析。同时,本文通过对我国传染病领域的研究进展分析,指出了当前传染病防控工作的不足,并提出了亟需加强布局的领域方向,旨在为有效应对疫情防控和公共卫生事业发展提供国家战略科技力量和技术储备,进而为国家安全发展战略的顺利实施提供科技保障。 展开更多
关键词 新发突发传染病 动物源性病原体 病原体致病性与免疫原性 病原体检测技术 病原体变异与进化
原文传递
高强免涂装耐候钢光伏支架在“渔光互补”光伏项目上的应用 被引量:1
4
作者 黄宇洲 黄立宽 +7 位作者 马晓蔚 刘陈 彭周 文艳 徐锐 陈建军 祝愿 白会平 《武汉工程职业技术学院学报》 2025年第1期17-21,共5页
“渔光互补”是光伏发电的重要形式之一,为了保证所使用的光伏支架环保无污染,便于在较为简易的施工平台上安装,支架的轻量化势在必行。宝钢通过采用高强免涂装耐候钢代替常规碳钢镀锌后制备光伏支架,利用耐候钢的基体自防腐能力来替代... “渔光互补”是光伏发电的重要形式之一,为了保证所使用的光伏支架环保无污染,便于在较为简易的施工平台上安装,支架的轻量化势在必行。宝钢通过采用高强免涂装耐候钢代替常规碳钢镀锌后制备光伏支架,利用耐候钢的基体自防腐能力来替代常规支架的镀层防腐,提升原材料的强度来减少支架用钢量。最终实现降低支架成本10%,大幅减少碳排放,且与自然环境融为一体。该新型支架的应用,不仅增强了光伏发电项目可持续发展的动力,也为类似场景结构支撑件的原材料选择提供了新的方案。 展开更多
关键词 渔光互补 光伏支架 免涂装 耐候钢 光伏发电 钢铁腐蚀
在线阅读 下载PDF
Bridge for the thermodynamics and kinetics of electrochemical corrosion:The design of self-densified plasma electrolytic oxidation coating on Mg alloys 被引量:1
5
作者 peng zhou Chen Li +3 位作者 Guangyao Jiao Tingxi Lv Tao Zhang Fuhui Wang 《Journal of Materials Science & Technology》 2025年第13期66-80,共15页
A new perspective was reported to design the self-densified plasma electrolytic oxidation(SDF-PEO)coat-ings on magnesium alloys based on the dissolution-ionization-diffusion-deposition(DIDD)model.The main consideratio... A new perspective was reported to design the self-densified plasma electrolytic oxidation(SDF-PEO)coat-ings on magnesium alloys based on the dissolution-ionization-diffusion-deposition(DIDD)model.The main considerations of the new PEO electrolyte include the establishment of a thermodynamics diagram,the construction of a liquid-solid sintering system and the regulation of plasma sparkling kinetics.The SDF-PEO coating exhibited a homogeneous and dense microstructure,superior corrosion resistance and good technological adaptability.This work offers a novel theory to design surface treatment solutions with superior corrosion resistance and promising application prospects. 展开更多
关键词 Self-densified coating Plasma electrolytic oxidation Dissolution-ionization-diffusion-deposition (DIDD)model Corrosion resistance Mg alloys
原文传递
Diffusion-based generative drug-like molecular editing with chemical natural language 被引量:1
6
作者 Jianmin Wang peng zhou +6 位作者 Zixu Wang Wei Long Yangyang Chen Kyoung Tai No Dongsheng Ouyang Jiashun Mao Xiangxiang Zeng 《Journal of Pharmaceutical Analysis》 2025年第6期1215-1225,共11页
Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited ... Recently,diffusion models have emerged as a promising paradigm for molecular design and optimization.However,most diffusion-based molecular generative models focus on modeling 2D graphs or 3D geom-etries,with limited research on molecular sequence diffusion models.The International Union of Pure and Applied Chemistry(IUPAC)names are more akin to chemical natural language than the simplified molecular input line entry system(SMILES)for organic compounds.In this work,we apply an IUPAC-guided conditional diffusion model to facilitate molecular editing from chemical natural language to chemical language(SMILES)and explore whether the pre-trained generative performance of diffusion models can be transferred to chemical natural language.We propose DiffIUPAC,a controllable molecular editing diffusion model that converts IUPAC names to SMILES strings.Evaluation results demonstrate that our model out-performs existing methods and successfully captures the semantic rules of both chemical languages.Chemical space and scaffold analysis show that the model can generate similar compounds with diverse scaffolds within the specified constraints.Additionally,to illustrate the model’s applicability in drug design,we conducted case studies in functional group editing,analogue design and linker design. 展开更多
关键词 Diffusion model IUPAC Molecular generative model Chemical natural language Transformer
在线阅读 下载PDF
祛脂方调控ITGB6/IL23A/STAT3信号通路改善MASH相关肝纤维化
7
作者 陈慧洁 彭舟 张琴 《肝脏》 2025年第5期675-682,699,共9页
目的探讨祛脂方(QZF)是否具有改善代谢功能障碍相关脂肪性肝炎(MASH)相关纤维化的作用以及潜在机制。方法人肝星状细胞(LX-2)在不含胎牛血清的DMEM培养基饥饿培养24小时后,用10 ng/mL浓度的转化生长因子-β1(TGF-β1)处理24小时。随后,... 目的探讨祛脂方(QZF)是否具有改善代谢功能障碍相关脂肪性肝炎(MASH)相关纤维化的作用以及潜在机制。方法人肝星状细胞(LX-2)在不含胎牛血清的DMEM培养基饥饿培养24小时后,用10 ng/mL浓度的转化生长因子-β1(TGF-β1)处理24小时。随后,细胞用含200μg/mL祛脂方的无血清DMEM培养基处理。采用Cell Counting Kit-8(CCK-8)法检测祛脂方对细胞的毒性,通过蛋白免疫印迹、实时荧光定量PCR反应和免疫荧光技术检测祛脂方是否逆转TGFβ-1诱导的LX-2细胞活化。体内实验中,选用6周龄C57BL/6 SPF小鼠,随机分为三组:对照组、CDAHFD组和祛脂方组(QZF组)。CDAHFD组和祛脂方组饲喂含62%千卡脂肪和0.1%甲硫氨酸且胆碱缺乏的饲料3周,对照组和CDAHFD组小鼠灌胃生理盐水,祛脂方组小鼠灌胃祛脂方(10 g/kg/d)。9周后小鼠安乐死,收集血浆和肝组织,进一步分析祛脂方的疗效。结果动物实验表明祛脂方可减轻MASH小鼠肝脏脂质积累和纤维化。细胞实验结果显示,祛脂方通过调节ITGB6/IL23A/STAT3信号通路,逆转了TGFβ-1诱导的LX-2细胞活化。此外,STAT3抑制剂也可能逆转TGFβ-1诱导的LX-2活化,进一步验证了祛脂方通过该信号通路改善MASH相关纤维化的作用。结论祛脂方不仅能改善MASH脂肪变性,还能减轻MASH相关纤维化。这表明,祛脂方有潜力作为一种新的治疗MASH的药物,其作用机制可能与调控ITGB6/IL23A/STAT3信号通路有关。 展开更多
关键词 祛脂方 代谢功能障碍相关脂肪性肝病 代谢功能障碍相关脂肪性肝炎 肝纤维化
暂未订购
细胞生物力学视角下的儿童肥胖研究进展
8
作者 彭舟 王晓雨 郭锡熔 《中国儿童保健杂志》 北大核心 2025年第10期1086-1090,共5页
近年来细胞生物力学在肥胖防治中的研究逐渐受到关注。儿童肥胖是成年代谢性疾病早期关键的防治窗口,细胞生物力学可为儿童肥胖的防治提供新的可能。传统上主要聚焦于宏观层面的运动力学,而近年来的研究已进一步深入至细胞和分子水平。... 近年来细胞生物力学在肥胖防治中的研究逐渐受到关注。儿童肥胖是成年代谢性疾病早期关键的防治窗口,细胞生物力学可为儿童肥胖的防治提供新的可能。传统上主要聚焦于宏观层面的运动力学,而近年来的研究已进一步深入至细胞和分子水平。为了解细胞生物力学下儿童肥胖研究进展,以细胞生物力学和儿童肥胖为检索词,通过计算机系统检索PubMed、Web of Science及CNKI等数据库,检索时限为2011—2025年,纳入近五年文献率90%以上。本文通过介绍生物力学作用元件,总结饮食运动管理和遗传因素相关的细胞生物力学研究成果,并对细胞生物力学视角下儿童肥胖的未来发展进行了展望,以期为儿童肥胖的研究拓展研究思路,提供参考。 展开更多
关键词 细胞生物力学 儿童肥胖 细胞外基质 机械信号转导 肥胖防治
原文传递
不同手术方案治疗腰椎间盘突出症合并腰椎失稳临床对比研究 被引量:8
9
作者 刘继波 李江龙 +3 位作者 谢大伟 周鹏 熊飞龙 龚光耀 《中国现代医学杂志》 CAS 2018年第19期107-111,共5页
目的探讨常规开放和微创改良经孔椎体间融合术(TLIF)对腰椎间盘突出症合并腰椎失稳患者围手术期临床指标、ODI评分及椎间融合率的影响。方法研究对象选取腰椎间盘突出症合并腰椎失稳患者共100例,以随机数字表法分为A组(50例)和B组(50例)... 目的探讨常规开放和微创改良经孔椎体间融合术(TLIF)对腰椎间盘突出症合并腰椎失稳患者围手术期临床指标、ODI评分及椎间融合率的影响。方法研究对象选取腰椎间盘突出症合并腰椎失稳患者共100例,以随机数字表法分为A组(50例)和B组(50例),分别采用常规开放和微创改良TLIF术式治疗;比较两组患者手术用时、术中出血量、术后引流量、首次下地活动时间以及手术前后VAS评分、JOA评分、ODI评分、椎间融合率等。结果两组患者手术用时比较差异无统计学意义(P>0.05);B组患者术中出血量、术后引流量及首次下地活动时间均优于A组(P<0.05);两组患者术后3、和12个月VAS评分低于术前(P<0.05);B组患者术后3个月VAS评分低于A组(P<0.05);两组患者术后12个月VAS评分比较差异无统计学意义(P>0.05);两组患者术后3和12个月JOA评分、ODI评分均优于术前(P<0.05);两组患者术后3和12个月JOA评分、ODI评分比较差异无统计学意义(P>0.05);同时两组患者椎间融合率比较差异无统计学意义(P>0.05)。结论常规开放和微创改良TLIF术式治疗腰椎间盘突出症合并腰椎失稳具有接近的临床疗效,但微创改良TLIF术式应用在降低手术创伤程度、促进术后康复及减轻术后腰腿疼痛程度方面更具优势。 展开更多
关键词 开放 微创 TLIF 腰椎间盘突出症 腰椎失稳
暂未订购
QP980和QP1180的塑性变形及断裂行为 被引量:6
10
作者 魏星 钟勇 +3 位作者 彭周 刘渊媛 连昌伟 张祥林 《塑性工程学报》 CAS CSCD 北大核心 2021年第12期103-114,共12页
完成了QP980和QP1180两种超高强钢从准静态到500 s^(-1)应变速率范围内的拉伸实验,归纳了应变速率对QP980和QP1180力学性能和断裂特性的影响规律,分析了高应变速率下QP钢的塑性断裂机理。结果表明,应变速率从准静态上升到500 s^(-1),QP... 完成了QP980和QP1180两种超高强钢从准静态到500 s^(-1)应变速率范围内的拉伸实验,归纳了应变速率对QP980和QP1180力学性能和断裂特性的影响规律,分析了高应变速率下QP钢的塑性断裂机理。结果表明,应变速率从准静态上升到500 s^(-1),QP980和QP1180的屈服强度和抗拉强度均略微增长,均匀伸长率和断裂伸长率也随应变速率的增加而增加。但是两种材料的纵向断裂应变随应变速率的增加而波动变化,此外,QP1180相比QP980具有较大的断裂应变和更优良的断裂塑性。不同应变速率下,QP980和QP1180断口均呈圆形韧窝形貌。随应变速率的增加,圆形韧窝直径逐渐增大,韧窝深度变深。在相同应变速率下,QP1180圆形韧窝的直径和深度均比QP980大。低应变速率下,两种材料的塑性应变速率敏感性低,"TRIP效应"无明显差异;当应变速率超过5 s^(-1)后,两种材料变形初期的应变速率敏感性指数相对较大,"TRIP效应"减弱,但材料强度仍然增加。两种材料均具有多段的硬化能力特性,且均对应变速率不敏感。 展开更多
关键词 QP980 QP1180 动态拉伸 应变速率 断裂应变
原文传递
Identification of a Fusobacterial RNA-binding protein involved in host small RNA-mediated growth inhibition
11
作者 Pu-Ting Dong Mengdi Yang +6 位作者 Jie Hu Lujia Cen peng zhou Difei Xu peng Xiong Jiahe Li Xuesong He 《International Journal of Oral Science》 2025年第5期654-666,共13页
Host-derived small RNAs are emerging as critical regulators in the dynamic interactions between host tissues and the microbiome,with implications for microbial pathogenesis and host defense.Among these,transfer RNA-de... Host-derived small RNAs are emerging as critical regulators in the dynamic interactions between host tissues and the microbiome,with implications for microbial pathogenesis and host defense.Among these,transfer RNA-derived small RNAs(tsRNAs)have garnered attention for their roles in modulating microbial behavior.However,the bacterial factors mediating tsRNA interaction and functionality remain poorly understood.In this study,using RNA affinity pull-down assay in combination with mass spectrometry,we identified a putative membrane-bound protein,annotated as P-type ATPase transporter(PtaT)in Fusobacterium nucleatum(Fn),which binds Fn-targeting tsRNAs in a sequence-specific manner.Through targeted mutagenesis and phenotypic characterization,we showed that in both the Fn type strain and a clinical tumor isolate,deletion of ptaT led to reduced tsRNA intake and enhanced resistance to tsRNA-induced growth inhibition.Global RNA sequencing and label-free Raman spectroscopy revealed the phenotypic differences between Fn wild type and PtaT-deficient mutant,highlighting the functional significance of PtaT in purine and pyrimidine metabolism.Furthermore,AlphaFold 3 prediction provides evidence supporting the specific binding between PtaT and Fn-targeting tsRNA.By uncovering the first RNA-binding protein in Fn implicated in growth modulation through interactions with host-derived small RNAs(sRNAs),our study offers new insights into sRNA-mediated host-pathogen interplay within the context of microbiome-host interactions. 展开更多
关键词 host tissues Fusobacterial RNA binding protein bacterial factors Mass spectrometry ATPase transporter RNA affinity pull down assay mass spectrometrywe modulating microbial
暂未订购
含硅改性磷-氮阻燃剂和双季戊四醇协同阻燃聚乙烯的制备及性能 被引量:4
12
作者 王固霞 董庭轩 +5 位作者 栗照帅 王哲 喻迎春 李丹 周鹏 郭生伟 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第4期59-69,共11页
以正硅酸四乙酯(TEOS)和乙烯基三乙氧基硅烷(A-151)对聚磷酸铵(APP)和三聚氰胺尿酸盐(MCA)进行改性,制备了Si-MAPP和Si-MMCA,解决了APP和MCA疏水性差的问题。将Si-MAPP和Si-MMCA与双季戊四醇(DPER)复配得到一种新的膨胀型阻燃剂(IFR)并... 以正硅酸四乙酯(TEOS)和乙烯基三乙氧基硅烷(A-151)对聚磷酸铵(APP)和三聚氰胺尿酸盐(MCA)进行改性,制备了Si-MAPP和Si-MMCA,解决了APP和MCA疏水性差的问题。将Si-MAPP和Si-MMCA与双季戊四醇(DPER)复配得到一种新的膨胀型阻燃剂(IFR)并用于LDPE阻燃。利用红外光谱、扫描电子显微镜和热重分析证明了APP和MCA成功被TEOS和A-151涂层修饰。采用万能材料试验机、极限氧指数仪、UL-94垂直燃烧试验和锥形量热试验测试了LDPE复合材料的阻燃性能。研究结果表明,经TEOS和A-151涂层修饰后,Si-MAPP和Si-MMCA疏水性能优异,与LDPE相容性好。加入含Si-MAPP/DPER/Si-MMCA的IFR大幅提高了LDPE复合材料的阻燃性。当加入质量分数43.75%的Si-MAPP/DPER/Si-MMCA后,复合材料极限氧指数为30.3%并达到V-0级别,拉伸强度达12.92 MPa,比同比例无Si-MMCA的LDPE/IFR高出了3.79%,比质量分数为41.6%无Si-MAPP的LDPE/IFR高出了6.81%。烟密度试验表明,Si-MAPP和Si-MMCA的加入有效提高了LDPE复合材料的残炭量和热稳定性,并使烟气排放明显改善。 展开更多
关键词 磷-氮阻燃剂 双季戊四醇 改性 协同 低密度聚乙烯
在线阅读 下载PDF
原位相分离合成V2O5/Fe2V4O13纳米复合材料及其储钠性能 被引量:4
13
作者 周鹏 盛进之 +3 位作者 高崇伟 董君 安琴友 麦立强 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第5期134-140,共7页
钠具有资源丰富、成本低廉等优势,因此钠离子电池被认为是未来替代锂离子电池的最佳候选者之一。然而,寻找合适的电极材料是当前制备高性能钠离子电池面临的难题之一。在众多候选材料中,钒酸盐材料通过引入阳离子增加钒的配位数,使得材... 钠具有资源丰富、成本低廉等优势,因此钠离子电池被认为是未来替代锂离子电池的最佳候选者之一。然而,寻找合适的电极材料是当前制备高性能钠离子电池面临的难题之一。在众多候选材料中,钒酸盐材料通过引入阳离子增加钒的配位数,使得材料结构的稳定性得到提高,从而改善了钠离子电池的电化学性能。本文研究了一种原位相分离法合成V2O5/Fe2V4O13纳米复合材料。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)等对电极材料形貌、组成和结构进行了表征。实验结果显示,V2O5/Fe2V4O13纳米复合材料相对于V2O5纳米线材料,结构更加稳定,在0.1 A·g^−1电流密度下,初始放电容量由295.4 mAh·g^−1提升到342 mAh·g^−1,循环100圈容量保持率由26.6%提高到65.8%,获得了更加优异的倍率性能(在1.0 A·g^−1电流密度下,容量由44 mAh·g^−1提高到160 mAh·g^−1)。因此,V2O5/Fe2V4O13纳米复合材料的研究为开拓新型高性能钠离子电池负极材料拓宽了思路。 展开更多
关键词 钠离子电池 负极材料 V2O5/Fe2V4O13 电化学
在线阅读 下载PDF
Corrigendum to‘Tuning the nucleation kinetics of phosphate chemical conversion coating on Mg-Gd-Y-Zr magnesium alloy:The effect of pretreatment and organic additive’[Journal of Magnesium and Alloys 13(2025)207–218]
14
作者 Siyu Sun peng zhou +5 位作者 Yan Chen JinTao Xiao Jingli Sun Yong Yuan Tao Zhang Fuhui Wang 《Journal of Magnesium and Alloys》 2025年第5期2433-2434,共2页
The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error do... The authors regret that due to negligence,the picture was misplaced in the original manuscript,resulting in Fig.6d being incorrectly included.The correct version of Fig.6d is provided below for reference.This error does not affect the conclusions of the study,and we apologize for any confusion it may have caused. 展开更多
关键词 nucleation kinetics fig d PRETREATMENT phosphate chemical conversion coating organic additive magnesium alloy
在线阅读 下载PDF
Vibration characteristics of ballastless track and its effect on wheel-rail broadband dynamic interaction
15
作者 Chaozhi MA Liang GAO +3 位作者 Pu WANG Bolun AN peng zhou Mahantesh M NADAKATTI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 2025年第6期585-604,共20页
The wheel-rail dynamic load(WRL)and its vibration energy transfer(VET)are foundational for studying ballastless track dynamics in high-speed railways.In this study,the higher-order modal parameters of track beds with ... The wheel-rail dynamic load(WRL)and its vibration energy transfer(VET)are foundational for studying ballastless track dynamics in high-speed railways.In this study,the higher-order modal parameters of track beds with different isolating layers were identified experimentally and a vehicle-track coupled dynamic model considering track bed broadband vibrations(TBBVs)was established.The WRL and its VET were investigated,and the contribution law as well as the influence mechanism of TBBVs on them was determined.The results showed the WRL and track bed vibration energy exhibited significant resonances,with more prominent high-frequency resonance peaks in the track bed vibration energy.TBBVs had a significant effect on low-frequency WRLs,and markedly influenced the VET across various frequency bands.Intense low-frequency and weak high-frequency intermodulation effects between the wheel-rail and track beds were observed.The effect of track bed vibrations can be disregarded when focusing on high-frequency WRLs above 200 Hz.Variations in the isolating layer stiffness have more significant effects on the track bed vibration energy than the WRL.Rational stiffness of the isolating layer should be selected to avoid mode-coupling resonance from track beds to the wheel-rail subsystem. 展开更多
关键词 Ballastless track Higher-order modal testing Wheel-rail dynamic load(WRL) Vibration energy transfer (VET) Intermodulation effect Rational stiffness
原文传递
Platinum modification of metallic cobalt defect sites for efficient electrocatalytic oxidation of 5-hydroxymethylfurfural
16
作者 Haoyu Zhan Baixue Cheng +6 位作者 Yankun Lu Danning Xing Xingshuai Lv Huining Huang Thomas Frauenheim Tao Wang peng zhou 《Journal of Energy Chemistry》 2025年第2期463-473,I0010,共12页
Co_(3)O_(4)possesses both direct and indirect oxidation effects and is considered as a promising catalyst for the oxidation of 5-hydroxymethylfurfural(HMF).However,the enrichment and activation effects of Co_(3)O_(4)o... Co_(3)O_(4)possesses both direct and indirect oxidation effects and is considered as a promising catalyst for the oxidation of 5-hydroxymethylfurfural(HMF).However,the enrichment and activation effects of Co_(3)O_(4)on OH-and HMF are weak,which limits its further application.Metal defect engineering can regulate the electronic structure,optimize the adsorption of intermediates,and improve the catalytic activity by breaking the symmetry of the material,which is rarely involved in the upgrading of biomass.In this work,we prepare Co_(3)O_(4)with metal defects and load the precious metal platinum at the defect sites(PtVco).The results of in-situ characterizatio ns,electrochemical measurements,and theoretical calculations indicate that the reduction of Co-Co coordination number and the formation of Pt-Co bond induce the decrease of electron filling in the antibonding orbitals of Co element.The resulting upward shift of the d-band center of Co combined with the characteristic adsorption of Pt species synergically enhances the enrichment and activation of organic molecules and OH species,thus exhibiting excellent HMF oxidation activity(including a lower onset potential(1.14 V)and 19 times higher current density than pure Co_(3)O_(4)at 1.35 V).In summary,this work explores the adsorption enhancement mechanism of metal defect sites modified by precious metal in detail,provides a new option for improving the HMF oxidation activity of cobalt-based materials,broadens the application field of metal defect based materials,and gives an innovative guidance for the functional utilization of metal defect sites in biomass conversion. 展开更多
关键词 ELECTROCATALYSIS Biomass upgrading Metallic defect Coordination environment Adsorption enhancement
在线阅读 下载PDF
An Efficient Clustering Algorithm for Enhancing the Lifetime and Energy Efficiency of Wireless Sensor Networks
17
作者 peng zhou Wei Chen Bingyu Cao 《Computers, Materials & Continua》 2025年第9期5337-5360,共24页
Wireless Sensor Networks(WSNs),as a crucial component of the Internet of Things(IoT),are widely used in environmental monitoring,industrial control,and security surveillance.However,WSNs still face challenges such as ... Wireless Sensor Networks(WSNs),as a crucial component of the Internet of Things(IoT),are widely used in environmental monitoring,industrial control,and security surveillance.However,WSNs still face challenges such as inaccurate node clustering,low energy efficiency,and shortened network lifespan in practical deployments,which significantly limit their large-scale application.To address these issues,this paper proposes an Adaptive Chaotic Ant Colony Optimization algorithm(AC-ACO),aiming to optimize the energy utilization and system lifespan of WSNs.AC-ACO combines the path-planning capability of Ant Colony Optimization(ACO)with the dynamic characteristics of chaotic mapping and introduces an adaptive mechanism to enhance the algorithm’s flexibility and adaptability.By dynamically adjusting the pheromone evaporation factor and heuristic weights,efficient node clustering is achieved.Additionally,a chaotic mapping initialization strategy is employed to enhance population diversity and avoid premature convergence.To validate the algorithm’s performance,this paper compares AC-ACO with clustering methods such as Low-Energy Adaptive Clustering Hierarchy(LEACH),ACO,Particle Swarm Optimization(PSO),and Genetic Algorithm(GA).Simulation results demonstrate that AC-ACO outperforms the compared algorithms in key metrics such as energy consumption optimization,network lifetime extension,and communication delay reduction,providing an efficient solution for improving energy efficiency and ensuring long-term stable operation of wireless sensor networks. 展开更多
关键词 Internet of Things wireless sensor networks ant colony optimization clustering algorithm energy efficiency
在线阅读 下载PDF
涂阴和涂阳肺结核患者结核分枝杆菌特异性CD4^(+)T细胞活化在监测抗结核治疗中的意义
18
作者 刘芳 杜庆 +4 位作者 邓高炎 周亮 粟茜 彭舟 汪娟 《传染病信息》 2025年第5期447-453,共7页
目的探讨结核分枝杆菌(Mycobacterium tuberculosis,MT)特异性CD154^(+)CD4^(+)T细胞表面活化分子CD38、人类白细胞抗原DR(human leukocyte antigen,HLA-DR)和细胞核相关抗原Ki-67(nuclear-associated antigen ki-67,Ki-67)表达用于区... 目的探讨结核分枝杆菌(Mycobacterium tuberculosis,MT)特异性CD154^(+)CD4^(+)T细胞表面活化分子CD38、人类白细胞抗原DR(human leukocyte antigen,HLA-DR)和细胞核相关抗原Ki-67(nuclear-associated antigen ki-67,Ki-67)表达用于区分痰涂阴和涂阳肺结核(pulmonary tuberculosis,PTB)以及监测抗结核治疗中的意义。方法选取2021年1月至2023年6月湖南省胸科医院收治的100例初治PTB患者作为研究对象,分为涂阴组(n=48)和涂阳组(n=52)。所有患者均进行标准抗结核治疗。在强化治疗2个月后进行痰培养随访。分析外周血单核细胞对MT抗原纯化蛋白衍生物(purified protein derivative,PPD)或早期分泌抗原靶标6kDa/培养滤液蛋白10(early secretory antigenic target-6/culture filtrate protein 10,ESAT-6/CFP-10)有反应的CD4^(+)T细胞。根据Ki-67、活化标志物分化簇38分子(cluster of differentiation,CD38)和HLA-DR的表达谱,评估通过CD154^(+)表面表达鉴定的结核病抗原反应性T细胞的活化状态。结果涂阴组和涂阳组PPD反应性CD154^(+)CD4^(+)T细胞比例比较差异无统计学意义(P>0.05);涂阳组ESAT-6/CFP-10反应性CD154^(+)CD4^(+)T细胞比例高于涂阴组(P<0.05)。然而在受试者工作特征曲线分析中,ESAT-6/CFP-10反应性CD154^(+)CD4^(+)T细胞比例鉴别涂阳组的曲线下面积仅为0.601。涂阳组CD38^(+)、HLA-DR^(+)、Ki-67^(+)PPD和ESAT-6/CFP-10特异性CD154^(+)CD4^(+)T细胞比例明显高于涂阴组(均P<0.05)。受试者工作特征曲线分析结果显示,CD38^(+)、HLA-DR^(+)、Ki-67^(+)PPD或ESAT-6/CFP-10反应性CD154^(+)CD4^(+)T细胞比例鉴别涂阳患者的灵敏度和特异度分别为59.62%~86.54%和72.92%~91.67%。涂阴组治疗前和治疗2个月后CD38^(+)、HLA-DR^(+)和Ki67^(+)表达比较差异无统计学意义(均P>0.05),但是涂阳组患者抗结核治疗2个月后CD38^(+)、HLA-DR^(+)和Ki-67^(+)的MT特异性T细胞比例明显下降(均P<0.05)。涂阳PTB患者治疗2个月后,痰未转阴组的CD38^(+)、HLA-DR^(+)和Ki-67^(+)MT特异性CD154^(+)CD4^(+)T细胞比例显著高于痰转阴组(均P<0.05),且痰未转阴组CD38^(+)、HLA-DR^(+)和Ki-67^(+)MT特异性CD154^(+)CD4^(+)T细胞比例的下降幅度均显著低于痰转阴组(P<0.05)。结论MT特异性CD154^(+)CD4^(+)T细胞活化和增殖标志物CD38、HLA-DR和Ki-67表达可辅助区分痰涂阴和涂阳PTB和监测涂阳PTB患者的抗结核治疗应答。 展开更多
关键词 肺结核 CD38 人类白细胞抗原DR 细胞核相关抗原Ki-67 抗结核治疗监测
暂未订购
Cationic Adsorption‑Induced Microlevelling Effect:A Pathway to Dendrite‑Free Zinc Anodes
19
作者 Long Jiang Yiqing Ding +5 位作者 Le Li Yan Tang peng zhou Bingan Lu Siyu Tian Jiang zhou 《Nano-Micro Letters》 2025年第9期16-28,共13页
Dendrite growth represents one of the most significant challenges that impede the development of aqueous zinc-ion batteries.Herein,Gd^(3+)ions are introduced into conventional electrolytes as a microlevelling agent to... Dendrite growth represents one of the most significant challenges that impede the development of aqueous zinc-ion batteries.Herein,Gd^(3+)ions are introduced into conventional electrolytes as a microlevelling agent to achieve dendrite-free zinc electrodeposition.Simulation and experimental results demonstrate that these Gd^(3+)ions are preferentially adsorbed onto the zinc surface,which enables dendritefree zinc anodes by activating the microlevelling effect during electrodeposition.In addition,the Gd^(3+)additives effectively inhibit side reactions and facilitate the desolvation of[Zn(H_(2)O)_(6)]^(2+),leading to highly reversible zinc plating/stripping.Due to these improvements,the zinc anode demonstrates a significantly prolonged cycle life of 2100 h and achieves an exceptional average Coulombic efficiency of 99.72%over 1400 cycles.More importantly,the Zn//NH_(4)V_(4)O_(10)full cell shows a high capacity retention rate of 85.6%after 1000 cycles.This work not only broadens the application of metallic cations in battery electrolytes but also provides fundamental insights into their working mechanisms. 展开更多
关键词 Aqueous zinc-ion batteries Zinc anodes Rare-earth cations Microlevelling Zinc dendrites
在线阅读 下载PDF
上一页 1 2 14 下一页 到第
使用帮助 返回顶部