期刊文献+
共找到963篇文章
< 1 2 49 >
每页显示 20 50 100
Atmospheric photochemistry and secondary aerosol formation of urban air in Lyon,France 被引量:2
1
作者 Salah Eddine Sbai Chunlin Li +6 位作者 Antoinette Boreave Nicolas Charbonnel Sebastien Perrier Philippe Vernoux Farida Bentayeb Christian George Sonia Gil 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2021年第1期311-323,共13页
Photochemical aging of volatile organic compounds(VOCs)in the atmosphere is an important source of secondary organic aerosol(SOA).To evaluate the formation potential of SOA at an urban site in Lyon(France),an outdoor ... Photochemical aging of volatile organic compounds(VOCs)in the atmosphere is an important source of secondary organic aerosol(SOA).To evaluate the formation potential of SOA at an urban site in Lyon(France),an outdoor experiment using a Potential Aerosol Mass(PAM)oxidation flow reactor(OFR)was conducted throughout entire days during JanuaryFebruary 2017.Diurnal variation of SOA formations and their correlation with OH radical exposure(OHexp),ambient pollutants(VOCs and particulate matters,PM),Relative Humidity(RH),and temperature were explored in this study.Ambient urban air was exposed to high concentration of OH radicals with OHexp in range of(0.2-1.2)×10^12 molecule/(cm^3·sec),corresponding to several days to weeks of equivalent atmospheric photochemical aging.The results informed that urban air at Lyon has high potency to contribute to SOA,and these SOA productions were favored from OH radical photochemical oxidation rather than via ozonolysis.Maximum SOA formation(36μg/m^3)was obtained at OHexp of about 7.4×10^11 molecule/(cm^3·sec),equivalent to approximately 5 days of atmospheric oxidation.The correlation between SOA formation and ambient environment conditions(RH&temperature,VOCs and PM)was observed.It was the first time to estimate SOA formation potential from ambient air over a long period in urban environment of Lyon. 展开更多
关键词 Urban air Oxidation Flow Reactor(OFR) Secondary Organic Aerosol(SOA) Volatile Organic Compounds(VOC) PHOTOCHEMISTRY Lyon
原文传递
数据去重与缩减技术的系统分类与性能分析
2
作者 奎晓燕 张敏 +4 位作者 肖伶 李钦松 陈立明 张文生 邹北骥 《浙江大学学报(工学版)》 北大核心 2026年第2期287-302,共16页
深入研究各类数据缩减技术,为存储系统的优化和数据处理的高效性提供有效的解决方案.结合冗余数据分布特性及不同应用场景,从数据相似性和层次结构出发,将现有数据缩减技术分成4个类别:重复数据缩减、文件间相似缩减、文件内相似缩减和... 深入研究各类数据缩减技术,为存储系统的优化和数据处理的高效性提供有效的解决方案.结合冗余数据分布特性及不同应用场景,从数据相似性和层次结构出发,将现有数据缩减技术分成4个类别:重复数据缩减、文件间相似缩减、文件内相似缩减和混合缩减.数据缩减技术对存储系统的存储效率、系统响应时间、数据传输和可靠性有显著影响,分析与总结不同类别数据缩减技术的性能,讨论现有技术的优点和局限性.介绍数据缩减技术在多个场景的应用,指出未来研究的挑战与方向. 展开更多
关键词 数据缩减 数据去重 数据压缩 存储系统 可靠性
在线阅读 下载PDF
Multibipolar radiofrequency vs single needle microwave ablation for the treatment of newly diagnosed hepatocellular carcinoma
3
作者 Cécilia Bahloul Agnès Rode +6 位作者 Pierre Pradat Laurent Milot Jérôme Dumortier Philippe Merle Jean-Yves Mabrut Loïc Boussel Angelo Della Corte 《World Journal of Gastroenterology》 2026年第2期104-113,共10页
BACKGROUND Data comparing the outcomes of hepatocellular carcinoma(HCC)ablation by multibipolar radiofrequency ablation(mbp-RFA)and microwave ablation(MWA)are lacking.This study compares safety and efficacy of the two... BACKGROUND Data comparing the outcomes of hepatocellular carcinoma(HCC)ablation by multibipolar radiofrequency ablation(mbp-RFA)and microwave ablation(MWA)are lacking.This study compares safety and efficacy of the two techniques in treatment-naive HCC.AIM To compare the risk of local tumor progression(LTP)according to the technique;secondary endpoints included technique efficacy rate at one-month,overall survival and major complication rate.METHODS A bi-institutional retrospective analysis of patients undergoing treatment-naive HCC ablation by either technique was performed.Inverse probability of treatment weighting was used to compare the two groups.Mixed effects multivariate Cox regression was applied to identify risk factors for LTP.RESULTS A total of 362 patients(mean age,66.1±6.2 years,308 men)were included,of which 242(323 tumors)treated by mbp-RFA and 120(168 tumors)by MWA.After a median follow-up of 27 months,cumulative LTP was 11.4%after mbp-RFA and 25.2%after MWA.Independent risk factors for LTP at multivariate analysis were MWA(hazard ratio=2.85,P<0.001)and tumor size(hazard ratio=1.08,P<0.001).Two-year LTP-free survival was higher after mbp-RFA than MWA regardless of size(<3 cm:96%vs 87.1%,P<0.01;≥3 cm:87.5%vs 74%,P=0.04).Technique efficacy rate was higher after mbp-RFA(94.1%vs 87.5%,P=0.01).No difference was observed in major complication rate(9.5%vs 7.5%,P=0.59),nor 5-year overall survival(63.6%vs 58.3%,P=0.33).CONCLUSION Mbp-RFA leads to better local tumor control of treatment-naïve HCC than MWA regardless of tumor size and has better primary efficacy,while maintaining a comparable safety profile. 展开更多
关键词 Local tumor progression Ablation MICROWAVE RADIOFREQUENCY Hepatocellular carcinoma
暂未订购
Application of systems engineering for development of multifunctional metro systems:Case study on the fifth metro line of the Lyon metro,France
4
作者 Nicolas Ziv Andrea Kindinis +1 位作者 Jeremie Simon Christophe Gobin 《Underground Space》 SCIE EI 2021年第1期24-34,共11页
Several studies,from both the private sector(McKinsey,Engie,and EY)and international organizations(OECD,World Bank,and IMF),have shown that urban population in cities will grow in the coming decades.This growth implie... Several studies,from both the private sector(McKinsey,Engie,and EY)and international organizations(OECD,World Bank,and IMF),have shown that urban population in cities will grow in the coming decades.This growth implies an increased pressure on all urban networks-transporting people,goods,water,waste,electricity,information,heat,and so on.These functions are executed by urban infrastructures entailing huge investments.We have dedicated our research to the optimization of infrastructures and more precisely of metro systems to offer global solutions to fulfill city needs-the multifunctional metro.The innovative multifunctional metro system incorporates several other urban networks—optical fiber,high-voltage electric cables,water and sewage pipes,geothermal piles,pneumatic systems,merchandise shuttles,and many others depending on the context of each project.The aim of the multifunctional metro is to meet several needs of cities with one common infrastructure.Adding a function to a system increases its complexity.For this reason,we focus our research on the application of methods that allow better management of the complexity:systems engineering applied to infrastructures.In the first part of the paper,we will present a benchmark of multipurpose infrastructures across the world and the benefits of such a system for cities.In the second part,we will present and illustrate the concept of the multifunctional metro.Next,we will present the method based on systems engineering to analyse multifunctional systems.Finally,the concept of a multifunctional metro is illustrated with a case study on the future fifth metro line of Lyon,France.In conclusion,we will discuss the current barriers for the development of multifunctional infrastructures. 展开更多
关键词 Multifunctionality Systems engineering Infrastructure UNDERGROUND METRO
在线阅读 下载PDF
青藏高原东缘汶川-茂县断裂韧性变形对龙门山早期隆升的制约 被引量:1
5
作者 葛成隆 李海兵 +6 位作者 Philippe Hervé LELOUP 张蕾 郑勇 刘栋梁 Clémentine FELLAH 叶小舟 张进江 《地质学报》 北大核心 2025年第4期1134-1149,共16页
青藏高原东缘的汶川-茂县断裂是龙门山构造带中发育有深层次韧性变形的断裂,对于揭示龙门山隆升中的深部过程有着重要的意义。本文通过断裂带物质组成、宏观/微观构造变形和石英组构的分析,对断裂带内韧性变形的运动学、流变特征和变形... 青藏高原东缘的汶川-茂县断裂是龙门山构造带中发育有深层次韧性变形的断裂,对于揭示龙门山隆升中的深部过程有着重要的意义。本文通过断裂带物质组成、宏观/微观构造变形和石英组构的分析,对断裂带内韧性变形的运动学、流变特征和变形条件进行了约束。结果表明:(1)断裂带内存在宽约3 km、向北西陡倾的韧性剪切带;(2)在剪切带内部识别出两期剪切变形:早期北西向正断剪切和晚期东向逆冲剪切;(3)石英晶格组构特征显示逆冲韧性变形以石英底面滑移为主,伴随膨凸重结晶作用,指示变形温度为300~400℃;正断韧性变形以石英柱面滑移为主,伴随亚颗粒旋转重结晶作用,对应温度为350~650℃。结合已发表的地质年代学和低温热年代学数据,我们认为汶川-茂县断裂带在渐新世发生了北西向的正断韧性剪切,在中新世发生东向的逆冲韧性变形。汶川-茂县断裂在中晚新生代期间的强烈活动导致了龙门山后缘大量深部物质的抬升,最终形成了现今构造地貌雏形。 展开更多
关键词 龙门山 汶川-茂县断裂 韧性变形 石英组构 EBSD
在线阅读 下载PDF
Decoding the nexus:branched-chain amino acids and their connection with sleep,circadian rhythms,and cardiometabolic health 被引量:2
6
作者 Hui Li Laurent Seugnet 《Neural Regeneration Research》 SCIE CAS 2025年第5期1350-1363,共14页
The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and,either directly or indirectly,overall body health,encompassing metabolic and cardiovascular well-being.Given th... The sleep-wake cycle stands as an integrative process essential for sustaining optimal brain function and,either directly or indirectly,overall body health,encompassing metabolic and cardiovascular well-being.Given the heightened metabolic activity of the brain,there exists a considerable demand for nutrients in comparison to other organs.Among these,the branched-chain amino acids,comprising leucine,isoleucine,and valine,display distinctive significance,from their contribution to protein structure to their involvement in overall metabolism,especially in cerebral processes.Among the first amino acids that are released into circulation post-food intake,branched-chain amino acids assume a pivotal role in the regulation of protein synthesis,modulating insulin secretion and the amino acid sensing pathway of target of rapamycin.Branched-chain amino acids are key players in influencing the brain's uptake of monoamine precursors,competing for a shared transporter.Beyond their involvement in protein synthesis,these amino acids contribute to the metabolic cycles ofγ-aminobutyric acid and glutamate,as well as energy metabolism.Notably,they impact GABAergic neurons and the excitation/inhibition balance.The rhythmicity of branchedchain amino acids in plasma concentrations,observed over a 24-hour cycle and conserved in rodent models,is under circadian clock control.The mechanisms underlying those rhythms and the physiological consequences of their disruption are not fully understood.Disturbed sleep,obesity,diabetes,and cardiovascular diseases can elevate branched-chain amino acid concentrations or modify their oscillatory dynamics.The mechanisms driving these effects are currently the focal point of ongoing research efforts,since normalizing branched-chain amino acid levels has the ability to alleviate the severity of these pathologies.In this context,the Drosophila model,though underutilized,holds promise in shedding new light on these mechanisms.Initial findings indicate its potential to introduce novel concepts,particularly in elucidating the intricate connections between the circadian clock,sleep/wake,and metabolism.Consequently,the use and transport of branched-chain amino acids emerge as critical components and orchestrators in the web of interactions across multiple organs throughout the sleep/wake cycle.They could represent one of the so far elusive mechanisms connecting sleep patterns to metabolic and cardiovascular health,paving the way for potential therapeutic interventions. 展开更多
关键词 branched-chain amino acids cardiovascular health circadian clock DROSOPHILA INSULIN metabolism SLEEP γ-aminobutyric acid
暂未订购
基于NSGA-Ⅱ优化的电动汽车热管理系统MPC策略开发及性能
7
作者 戴春江 林文野 +4 位作者 李帅旗 陈翔 宋文吉 冯自平 Frédéric KUZNIK 《储能科学与技术》 北大核心 2025年第6期2200-2214,共15页
电动汽车热管理在保障电动汽车的安全性、提高舒适度和降低能耗等方面具有重要意义,而热管理系统的核心是优良的控制策略。本工作回顾了现有的电动汽车热管理系统控制策略的优点与不足,提出并评价了一种基于NSGA-Ⅱ算法优化的模型预测控... 电动汽车热管理在保障电动汽车的安全性、提高舒适度和降低能耗等方面具有重要意义,而热管理系统的核心是优良的控制策略。本工作回顾了现有的电动汽车热管理系统控制策略的优点与不足,提出并评价了一种基于NSGA-Ⅱ算法优化的模型预测控制(MPC)策略并用于电动汽车的热管理。首先建立了电动汽车热管理系统的仿真模型;随后通过融合MPC策略和NSGA-Ⅱ多目标优化提出了可以实现多目标控制的电动汽车热管理策略;最后通过比较多个工况下不同控制策略对汽车热管理系统性能的影响,以验证所提出的基于NSGA-Ⅱ优化的MPC策略的有效性。研究结果发现,在不同工况下,所提出的MPC策略均可有效控制乘员舱温度和电池温度,减小乘员舱温度和电池温度的波动幅度,削减汽车行驶工况剧烈变化对电池温度的影响;同时,MPC策略可有效降低热管理系统能耗,相对于开关控制策略和PID控制策略可实现可观的节能率,分别达到4%~15%和1%~6%。 展开更多
关键词 热管理 控制优化 MPC NSGA-Ⅱ 电动汽车
在线阅读 下载PDF
基于SPH方法的盾构隧道开挖面失稳全过程模拟
8
作者 马阳晨 翁效林 +4 位作者 孙钰丰 叶飞 马越 WONG K K Henry PARDOEN Benoit 《岩土工程学报》 北大核心 2025年第10期2204-2214,共11页
鉴于传统上基于网格的数值方法在模拟岩土材料大变形问题中的局限性,将一种无网格数值方法——光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)应用于盾构隧道开挖失稳全过程模拟,包括土体渐进性失稳至极限平衡状态,再到土体... 鉴于传统上基于网格的数值方法在模拟岩土材料大变形问题中的局限性,将一种无网格数值方法——光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)应用于盾构隧道开挖失稳全过程模拟,包括土体渐进性失稳至极限平衡状态,再到土体破坏后的坍塌大变形。首先,建立了盾构隧道开挖SPH模型,通过将SPH模拟结果与理论解以及模型试验得到的极限支护力和开挖面破坏模式进行对比,验证了SPH方法在分析隧道开挖失稳大变形问题中的可行性。然后,在无支护力条件下对隧道开挖失稳全过程进行模拟,并分析了覆跨比、内摩擦角和黏聚力3个关键参数对土体破坏后坍塌大变形的影响。研究结果为今后解决隧道大变形问题提供了一种新的分析方法与视角。 展开更多
关键词 隧道工程 大变形 开挖面失稳 光滑粒子流体动力学
原文传递
人文主义视域下法国人文学科建设和高校改革困境——对话法国里昂第三大学哲学学院原院长、荣休教授布吕诺·潘夏
9
作者 布吕诺·潘夏 王治博 张力玮 《世界教育信息》 2025年第7期3-9,共7页
人文学科在世界范围内面临影响力边缘化的困境,不仅如此,整个当代社会都因为人文主义传统的逐渐退场而面临危机。人文主义对促进社会理解与和平具有重要价值。人文主义不是一套普世价值观,而是对文明整体的研究,它首先建立在古典文献知... 人文学科在世界范围内面临影响力边缘化的困境,不仅如此,整个当代社会都因为人文主义传统的逐渐退场而面临危机。人文主义对促进社会理解与和平具有重要价值。人文主义不是一套普世价值观,而是对文明整体的研究,它首先建立在古典文献知识之上,并且在文明自身的内部比较中进行研究,传承算法无从把握的文字背后的内涵。人文主义哲学为人文科学在20世纪的法国诞生奠定了基础,但当前西方人文科学更多地导向一种社会斗争,而不再致力于理解社会现象,背离了人文主义守护文明发展的使命,转向解构西方文明。然而,法国当前的高等教育体系因过度依赖欧洲机构而受到干预,没有能力做出改变。法国政府推进的高等教育改革背离了人文科学研究的原则,首先追求规模扩大和媒体影响力,不仅不能为深度研究提供长期稳定的结构,反而加剧了对欧洲的依赖。欧盟主导的国际交流对人文科学至关重要,但随着人文科学吸引力下降和岗位不足,欧洲也面临人才流失的困境。 展开更多
关键词 人文主义 人文学科 教育改革 西方文明
在线阅读 下载PDF
网络效应下即需平台的跨界合作模式选择
10
作者 陈铭洋 谭新月 +1 位作者 龚业明 袁紫微 《管理学报》 北大核心 2025年第3期585-594,共10页
基于即需平台与零售企业的跨界合作现象,结合平台供需两端存在的网络效应和服务提供者的自调度行为等特点,构建由即需市场和零售市场组成的3种合作模式(不合作、单向合作和双向合作),分析不同模式下各利益相关者的最优策略、不同模式的... 基于即需平台与零售企业的跨界合作现象,结合平台供需两端存在的网络效应和服务提供者的自调度行为等特点,构建由即需市场和零售市场组成的3种合作模式(不合作、单向合作和双向合作),分析不同模式下各利益相关者的最优策略、不同模式的适用区间和平台的最优模式选择。研究发现,双向合作模式下即需平台所投入的努力水平小于单向合作模式下的努力水平,且平台选择单向合作模式总是劣于不合作模式;当需求潜力较大时,平台选择双向合作模式最优,反之选择不合作模式最优;采用双向合作模式可以在一些区域出现三赢和双赢的结果。 展开更多
关键词 即需平台 跨界合作 横向联合销售 网络效应 博弈论
在线阅读 下载PDF
Tailoring sub-5 nm Fe-doped CeO_(2)nanocrystals within confined spaces to boost photocatalytic hydrogen evolution under visible light
11
作者 Giuseppina Iervolino Olimpia Tammaro +4 位作者 Marco Fontana Bruno Masenelli Anne D.Lamirand Vincenzo Vaiano Serena Esposito 《Journal of Energy Chemistry》 2025年第2期263-277,I0007,共16页
This work aimed to study the efficiency of the reverse micelle(RM)preparation route in the syntheses of sub-5 nm Fe-doped CeO_(2)nanocrystals for boosting the visible-light-driven photocatalytic hydrogen production fr... This work aimed to study the efficiency of the reverse micelle(RM)preparation route in the syntheses of sub-5 nm Fe-doped CeO_(2)nanocrystals for boosting the visible-light-driven photocatalytic hydrogen production from methanol aqueous solutions.The effectiveness of confining precipitation reactions within micellar cages was evaluated through extensive physicochemical cha racterization.In particula r,the nominal composition(0-5 mol%Fe)was preserved as ascertained by ICP-MS analysis,and the absence of separate iron-containing crystalline phases was supported by X-ray diffraction.The effective aliovalent doping and modulation of the optical properties were investigated using UV-Vis,Raman,and photoluminescence spectroscopies.2.5 mol%iron was found to be an optimal content to achieve a significant decrease in the band gap,enhance the concentration of oxygen vacancy defects,and increase the charge carrier lifetime.The photocatalytic activity of Fe-doped CeO_(2)prepared at different Fe contents with RM preparation was studied and compared with undoped CeO_(2).The optimal iron load was identified to be2.5 mol%,achieving the highest hydrogen production(7566μmol L-1after 240 min under visible light).Moreover,for comparison,the conventional precipitation(P)method was adopted to prepare iron containing CeO_(2)at the optimal content(2.5 mol%Fe).The Fe-doped CeO_(2)catalyst prepared by RM showed a significantly higher hydrogen production than that obtained with the sample prepared by the P method.The optimal Fe-doped CeO_(2),prepared by the RM method,was stable for six reuse cycles.Moreover,the role of water in the mechanism of photocatalytic hydrogen evolution under visible light was studied through the test in the presence of D2O.The obtained results evidenced that hydrogen was produced from the reduction of H^(+)by the electrons promoted in the conduction band,while methanol was preferentially oxidized by the photogenerated positive holes. 展开更多
关键词 Sub-5nm Fe-doped CeO_(2) Hydrogen evolution Photocatalysis Visible light Reverse micelles Mesoporous CeO_(2)
在线阅读 下载PDF
现代“工夫茶”:传统、传承与创新
12
作者 郭倩(译) 《文化遗产》 2025年第5期93-100,共8页
对于潮汕本土居民而言,共同饮茶构成了日常生活中不可或缺的一部分,其本质更接近于一种生活实践,而非舞台化的“茶艺”。此种实践一方面讲究冲泡、斟茶与品饮环节的细节把控,另一方面又强调灵活应变与创造性发挥,而非拘泥于固定程式。... 对于潮汕本土居民而言,共同饮茶构成了日常生活中不可或缺的一部分,其本质更接近于一种生活实践,而非舞台化的“茶艺”。此种实践一方面讲究冲泡、斟茶与品饮环节的细节把控,另一方面又强调灵活应变与创造性发挥,而非拘泥于固定程式。实践者在遵循与家庭、地域紧密相连的传统习俗之余,部分人选择进一步学习相关知识与技能,以精进其工夫茶实践,并将其转化为可供文化创意产业推广的茶艺形态。茶艺师系统培训学员掌握品鉴技巧、呈现茶道礼仪、运用茶具与茶语;企业家将品茶活动商业化,使其从山野或工作室走入购物中心,并适应多元茶品的消费场景。本文旨在探究中国茶文化的实践者如何借助“文化遗产”标签实现传统承续,又如何通过挖掘茶与文创产业的共通价值,实现其文化与经济层面的双重增值。文末引入法国葡萄酒盲品案例进行跨文化比较,以期为此研究议题提供更广阔的参照视角。 展开更多
关键词 茶道 工夫茶 非物质文化遗产 文化与创意产业 新媒体
在线阅读 下载PDF
Progress toward cervical cancer elimination:global disparities and China's contributions
13
作者 Partha Basu 《Cancer Biology & Medicine》 2025年第9期991-996,共6页
Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have ac... Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have achieved high human papillomavirus(HPV)vaccination coverage and implemented quality-assured cervical cancer screening programs-have successfully decreased the incidence rates to below 8 cases per 100,000 women~1.These countries are on track to reach the elimination threshold of fewer than 4 cases per 100,000 women within the next few years,as defined by the World Health Organization(WHO). 展开更多
关键词 HPV vaccination screening programs elimination threshold high income nations ELIMINATION global disparities AUSTRALIA cervical cancer
暂未订购
Real-Time Classroom Behavior Detection and Visualization System Based on an Improved YOLOv11
14
作者 Jiajun Li Nannan Wang +2 位作者 Junhao Zhang Xiaozhou Yao Wei Wei 《教育技术与创新》 2025年第4期1-13,共13页
Automatic analysis of student behavior in classrooms has gained importance with the rise of smart education and vision technologies.However,the limited real-time accuracy of existing methods severely constrains their ... Automatic analysis of student behavior in classrooms has gained importance with the rise of smart education and vision technologies.However,the limited real-time accuracy of existing methods severely constrains their practical classroom deployment.To address this issue of low accuracy,we propose an improved YOLOv11-based detector that integrates CARAFE upsampling,DySnakeConv,DyHead,and SMFA fusion modules.This new model for real-time classroom behavior detection captures fine-grained student behaviors with low latency.Additionally,we have developed a visualization system that presents data through intuitive dashboards.This system enables teachers to dynamically grasp classroom engagement by tracking student participation and involvement.The enhanced YOLOv11 model achieves an mAP@0.5 of 87.2%on the evaluated datasets,surpassing baseline models.This significance lies in two aspects.First,it provides a practical technical route for deployable live classroom behavior monitoring and engagement feedback systems.Second,by integrating this proposed system,educators could make data-informed and fine-grained teaching decisions,ultimately improving instructional quality and learning outcomes. 展开更多
关键词 classroom behavior detection real-time object detection student engagement visualization dashboard AI in education
在线阅读 下载PDF
Modeling stopping power of ions in plasmas using parametric potentials
15
作者 Tanguy Barges Delattre Sébastien Rassou Jean-Christophe Pain 《Matter and Radiation at Extremes》 2025年第6期86-100,共15页
We present a study of the ion stopping power due to free and bound electrons in a warm dense plasma.Our main goal is to propose a method of stopping-power calculation expected to be valid for any ionization degree.The... We present a study of the ion stopping power due to free and bound electrons in a warm dense plasma.Our main goal is to propose a method of stopping-power calculation expected to be valid for any ionization degree.The free-electron contribution is described by the Maynard–Deutsch–Zimmerman formula,and the bound-electron contribution relies on the Bethe formula with corrections,in particular taking into account density and shell effects.The results of the bound-state computation using three different parametric potentials are investigated within the Garbet formalism for the mean excitation energy.The first parametric potential is due to Green,Sellin,and Zachor,the second one was proposed by Yunta,and the third one was introduced by Klapisch in the framework of atomic-structure computations.The results are compared with those of self-consistent average-atom calculations.This approach correctly bridges the limits of neutral and fully ionized matter. 展开更多
关键词 warm dense plasmaour free bound electrons maynard deutsch zimmerman formulaand parametric potentials ion stopping power bethe formula free electrons bound electrons
在线阅读 下载PDF
Impact of different anesthetic protocols during anesthesia for the establishment of a porcine model of acute kidney injury
16
作者 Axel Guilpin Mathieu Magnin +7 位作者 Axel Aigle Timothée Schuhler Jean-Yves Ayoub Romain Lac Charlotte Slek Thomas Brichart Abdessalem Hammed Vanessa Louzier 《Animal Models and Experimental Medicine》 2025年第8期1493-1502,共10页
Background:During the establishment of a model of acute kidney injury(AKI)in pigs,we observed a high prevalence of malignant hyperthermia(MH).These complications led us to refine the anesthetic protocol.This publicati... Background:During the establishment of a model of acute kidney injury(AKI)in pigs,we observed a high prevalence of malignant hyperthermia(MH).These complications led us to refine the anesthetic protocol.This publication describes the impact of the choice of anesthetics on the results obtained.Methods:Pigs were euthanized at the end of the procedure,without recovery from anesthesia.Three anesthetic protocols were used:sevoflurane inhalation(ProtocolA,n=5),a combination of ketamine,medetomidine and diazepam by intravenous infusion(ProtocolB,n=5),and a combination of ketamine,diazepam,medetomidine,glucose,and noradrenaline(ProtocolC,n=5).All pigs received morphine for analgesia.AKI was induced by interrupting renal perfusion for 90 min.MH was diagnosed based on clinical and biological parameters.Results:All MH pigs belonged to ProtocolA.MH pigs showed significantly higher maximum rectal temperature(p=0.04),maximum expired carbon dioxide(CO_(2);p=0.04),maximum heart rate(HR;p=0.03),plasma concentration of creatinine and potassium(p<0.0001).Protocol A pigs had a significantly higher maximum HR(p=0.01)and hyperkalemia compared to the two other groups(ProtocolB,p=0.005 and ProtocolC,p<0.0001).Pigs from ProtocolA had a significantly lower minimum mean arterial pressure(MAP)than ProtocolC group(p=0.03)and MAP remained below 60 mmHg for longer(p=0.004).In ProtocolB,minimum glycemia was lower than other groups(p=0.01).Conclusion:Sevoflurane use was associated with the occurrence of MH,hemodynamic alterations and changes in plasma concentration of creatinine and potassium.These modifications can have a major impact on the validation of an experimental AKI model. 展开更多
关键词 acute kidney injury ANESTHESIA KETAMINE malignant hyperthermia SEVOFLURANE
暂未订购
Effects of Zr^(4+)and Hf^(4+)co-doping on luminescence and scintillation properties of LuYAG:Pr^(3+)single crystals grown by micro-pulling-down technique
17
作者 Yufeng Tong Yunyun Li +6 位作者 Qingsong Song Jie Xu Xiaodong Xu Mikhail Korzhik Jun Xu Kheirreddine Lebbou Yuntao Wu 《Journal of Rare Earths》 2025年第4期701-706,I0003,共7页
In this study,we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr^(3+)-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down(μ-PD)method.... In this study,we aim to clarify the luminescence and scintillation performance of 0.2 at%Pr^(3+)-doped LuYAG scintillators with either zirconium or hafnium co-doping obtained using the micro-pulling-down(μ-PD)method.Under radiation excitation,scintillation properties such as light yield,decay time,and afterglow level were measured and compared to non-co-doped LuYAG:Pr^(3+).The positive effect of Zr and Hf co-doping is to significantly shorten the scintillation time response.The negative effect is the decrease of scintillation yield and increase of afterglow.We propose that the positively charged defects induced by Zr/Hf co-doping are responsible for the spatial correlated traps around Pr centers causing the shortened scintillation decay via non-radiative recombination processes,and the deep traps as well for the prolonged afterglow. 展开更多
关键词 LuYAG:Pr SCINTILLATORS CO-DOPING ZIRCONIUM HAFNIUM μ-PD
原文传递
Machine learning in electrochemical oxidation process:A mini-review
18
作者 Zonglin Li Shihua Zou +3 位作者 Zining Wang Georgeta Postole Liang Hu Hongying Zhao 《Chinese Chemical Letters》 2025年第8期28-38,共11页
In recent years,machine learning(ML)techniques have demonstrated a strong ability to solve highly complex and non-linear problems by analyzing large datasets and learning their intrinsic patterns and relationships.Par... In recent years,machine learning(ML)techniques have demonstrated a strong ability to solve highly complex and non-linear problems by analyzing large datasets and learning their intrinsic patterns and relationships.Particularly in chemical engineering and materials science,ML can be used to discover microstructural composition,optimize chemical processes,and create novel synthetic pathways.Electrochemical processes offer the advantages of precise process control,environmental friendliness,high energy conversion efficiency and low cost.This review article provides the first systematic summary of ML in the application of electrochemical oxidation,including pollutant removal,battery remediation,substance synthesis and material characterization prediction.Hot trends at the intersection of ML and electrochemical oxidation were analyzed through bibliometrics.Common ML models were outlined.The role of ML in improving removal efficiency,optimizing experimental conditions,aiding battery diagnosis and predictive maintenance,and revealing material characterization was highlighted.In addition,current issues and future perspectives were presented in relation to the strengths and weaknesses of ML algorithms applied to electrochemical oxidation.In order to further support the sustainable growth of electrochemistry from basic research to useful applications,this review attempts to make it easier to integrate ML into electrochemical oxidation. 展开更多
关键词 Machine learning Electrochemical oxidation Pollutant removal Lithium-ion battery Material synthesis
原文传递
Damage mechanisms of a metastableβ-titanium alloy with bimodal microstructure revealed by void growth models using synchrotron X-ray microtomography
19
作者 Bin Gu Jérôme Adrien +2 位作者 Eric Maire Ning Dang Werner Skrotzki 《Rare Metals》 2025年第3期1972-1981,共10页
In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing... In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing was performed during X-ray microtomography experiments.Compared with investigations of surface voids by traditional two-dimensional(2D)methods involving post-mortem characterization,three-dimensional(3D)information on void evolution inside optically opaque samples obtained through X-ray microtomography is essential.The Rice and Tracey model and Huang model were applied to predict void growth and show good agreement with experimental data using calibration of the damage parameterα.The void growth kinetics of Ti5321 with bimodal microstructure was analyzed by comparing theαvalue with that of Ti64 for different microstructure morphologies.The damage mechanism of ductile fracture of Ti5321 with bimodal microstructure is discussed.It was found that the size of the voids apparently increases with the triaxiality of stress.Post-mortem scanning electron microscopy(SEM)was also used to demonstrate this damage mechanism of ductile fracture of Ti5321. 展开更多
关键词 Titanium alloys DAMAGE X-ray microtomography Modeling Growth kinetics
原文传递
A Comprehensive Review of Key Technologies for Robot Motion Planning in Contact Tasks in Industrial Automation Scenarios
20
作者 Shibo Jin Kaichen Ke +2 位作者 Boyang Gao Li Fu Xingrong Huang 《Chinese Journal of Mechanical Engineering》 2025年第6期208-226,共19页
With the swift advancement of industrial automation,robots have emerged as an essential component in emerging industries and high-end equipment,thereby propelling industrial production towards greater intelligence and... With the swift advancement of industrial automation,robots have emerged as an essential component in emerging industries and high-end equipment,thereby propelling industrial production towards greater intelligence and efficiency.This paper reviews the pivotal technologies for motion planning of robots engaged in contact tasks within industrial automation contexts,encompassing environmental recognition,trajectory generation strategies,and sim-to-real transfer.Environmental recognition technology empowers robots to accurately discern objects and obstacles in their operational environment.Trajectory generation strategies formulate optimal motion paths based on environmental data and task specifications.Sim-to-real transfer is committed to effectively translating strategies from simulated environments to actual production,thereby diminishing the discrepancies between simulation and reality.The article also delves into the application of artificial intelligence in robot motion planning and how embodied intelligence models catalyze the evolution of robotics technology towards enhanced intelligence and automation.The paper concludes with a synthesis of the methodologies addressing this challenge and a perspective on the myriad challenges that warrant attention. 展开更多
关键词 Industrial automation Motion planning Environmental recognition Trajectory generation Sim-to-real transfer
在线阅读 下载PDF
上一页 1 2 49 下一页 到第
使用帮助 返回顶部