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陆相湖盆高盐度对伽马蜡烷生成的抑制机制
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作者 赵子斌 王晓梅 +4 位作者 侯读杰 侯卫国 张坤 刘诗局 Ralf LITTKE 《地学前缘》 北大核心 2026年第2期493-502,共10页
伽马蜡烷传统上被认为是一种与水体分层密切相关的C 30三萜类生物标志物,并将这种分层性与盐度紧密关联。但高盐度水环境沉积物中伽马蜡烷缺失的机制仍不明确。本研究以德国南部中新世诺德林根(N rdlinger Ries)湖相页岩为对象,通过矿... 伽马蜡烷传统上被认为是一种与水体分层密切相关的C 30三萜类生物标志物,并将这种分层性与盐度紧密关联。但高盐度水环境沉积物中伽马蜡烷缺失的机制仍不明确。本研究以德国南部中新世诺德林根(N rdlinger Ries)湖相页岩为对象,通过矿物学、有机地球化学(总有机碳、总硫、生物标志化合物、干酪根元素和热解分析)等多指标综合研究,揭示了伽马蜡烷的保存与水化学环境控制的微生物活动间的关联。结果表明:湖盆水体古盐度演化经历了中盐度→超咸水→中盐度→淡水的变化,但伽马蜡烷丰度在相对低、高盐度下与盐度分别呈现出正、负向协同演化关系。淡水-正常海、弱氧化-弱还原条件下(盐度<40‰,剖面中、上部),伽马蜡烷丰度与水体分层性、盐度呈正相关关系。中盐度-超咸水、强还原条件下(盐度>40‰,剖面中、下部),因水化学环境改变(盐度、缺氧度增大)引发的食物链断裂(伽马变形菌门等原核生物减少),导致纤毛虫活性受抑制,进而降低伽马蜡烷生成和反硝化作用强度。同时,伽马变形菌衰亡削弱了硫酸盐还原菌的增殖,抑制有机质硫化过程,表现为有机硫含量与热解T max值的协同变化。研究证实,伽马蜡烷的保存不仅依赖水体分层,更受控于微生物群落的生态响应,为高盐湖盆中伽马蜡烷地质意义的复杂性与局限性提供了新解释。 展开更多
关键词 伽马蜡烷 水体分层 超咸水 硫酸盐型湖盆 陆相盆地
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设计赋能乡村六次产业:基本路径、演化过程及创新实践 被引量:2
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作者 张犁 李思佳 《西北农林科技大学学报(社会科学版)》 北大核心 2025年第1期53-59,共7页
六次产业化是乡村产业发展的必然趋势,是推动乡村高质量发展的重要路径和有效抓手。从分析六次产业化的内涵入手,探寻设计赋能乡村六次产业的基本逻辑和演化机制;从“设计乡村化和乡村设计化”双路径赋能机制和“设计介入-产业协同-融... 六次产业化是乡村产业发展的必然趋势,是推动乡村高质量发展的重要路径和有效抓手。从分析六次产业化的内涵入手,探寻设计赋能乡村六次产业的基本逻辑和演化机制;从“设计乡村化和乡村设计化”双路径赋能机制和“设计介入-产业协同-融合共生”三个赋能维度,探索设计赋能的运行方式;构建一个包含资源支撑、设计驱动、制度保障的理论框架,提出乡村设计实践可以通过“一个框架、一个体系和一套制度”来实现设计赋能,并以农产品包装设计和非遗信息图形设计为案例进行实证分析。指出设计驱动产业融合创新,可促进乡村“三产融合、两化融合、全域融合”,赋能优质资源不断转化为乡村永续发展动能,促进乡村六次产业发展,更好地服务于乡村产业兴旺和高质量发展。 展开更多
关键词 第六产业 设计赋能 产业融合 创新生态
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沥青路面降温技术研究进展与展望 被引量:3
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作者 金娇 皮培屹 +3 位作者 刘培 高玉超 张扮 LIU Pengfei 《北京工业大学学报》 北大核心 2025年第6期736-755,共20页
沥青路面高温会带来车辙等病害,并增加城市热岛效应,这对路面的使用质量、使用寿命和人类的生活环境产生不利影响,所以急需开发行之有效的沥青路面降温技术,以减少车辙等病害和缓解城市热岛效应。现有的沥青路面降温技术分为被动降温技... 沥青路面高温会带来车辙等病害,并增加城市热岛效应,这对路面的使用质量、使用寿命和人类的生活环境产生不利影响,所以急需开发行之有效的沥青路面降温技术,以减少车辙等病害和缓解城市热岛效应。现有的沥青路面降温技术分为被动降温技术和主动降温技术,而主动降温技术能够更为有效地降低沥青路面温度,且具有智能性、自发性等特点。主动降温技术对应的降温沥青路面主要有热反射路面、相变调温路面、热阻路面、透水路面、能量收集路面、高导热路面。针对上述沥青路面主动降温技术,总结了沥青路面主动降温技术的原理特点、应用方式、运用于沥青路面的实际降温及路用效果,以及降温技术的新方法、新思路,探讨了沥青路面主动降温技术的缺陷和局限性,并对未来沥青路面降温技术发展趋势进行展望。 展开更多
关键词 沥青路面 降温技术 热反射 热传导 能量收集 能量转换
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岩石非线性黏弹塑性损伤蠕变模型研究 被引量:1
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作者 陈有亮 肖鹏 +2 位作者 杜曦 王苏然 RAFIG A 《应用力学学报》 北大核心 2025年第1期133-140,共8页
准确描述岩石蠕变行为的各阶段特征对岩石力学与岩体工程的研究具有重要的意义。由于经典元件组合模型不能较好地描述岩石蠕变过程中的非线性特征,基于损伤力学理论及Kachanov蠕变损伤演化规律,通过改进传统的Kelvin模型和村山体模型,... 准确描述岩石蠕变行为的各阶段特征对岩石力学与岩体工程的研究具有重要的意义。由于经典元件组合模型不能较好地描述岩石蠕变过程中的非线性特征,基于损伤力学理论及Kachanov蠕变损伤演化规律,通过改进传统的Kelvin模型和村山体模型,建立起能够描述岩石衰减蠕变阶段和加速蠕变阶段的非线性函数。将弹性体、线性Kelvin体、非线性Kelvin体、损伤黏弹塑性体进行串联,建立能够同时描述岩石瞬时弹性应变、非线性黏弹性应变、非线性黏塑性应变和黏性应变的非线性黏弹塑性损伤蠕变模型,采用Origin软件的Levenberg-Marquardt算法对模型参数进行了辨识,最后通过用不同应力水平下的砂岩单以及三轴压缩蠕变试验,验证该模型的合理性。结果表明:试验曲线和理论曲线的吻合度较高,所建模型不仅能够准确地描述岩石的瞬时弹性应变阶段、等速蠕变阶段的蠕变曲线特征,而且能够较好地描述衰减蠕变阶段和加速蠕变阶段蠕变曲线的非线性特征,验证了该模型的合理性与准确性。 展开更多
关键词 岩石力学 损伤 非线性 加速蠕变 黏弹塑性蠕变模型
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管网压力对火排燃烧器燃烧及排放特性影响
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作者 李洪涛 宋佳佳 +3 位作者 张佳琦 纪运广 席亚宾 MANFRED Wirsum 《科学技术与工程》 北大核心 2025年第7期2800-2807,共8页
壁挂炉供热是北方农村冬季采暖的主要方式之一。由于供气管网压力波动,壁挂炉易于出现燃烧不稳定现象,甚至发生CO中毒事故。为揭示管网压力变动下燃气壁挂炉内温度场及燃烧产物的变化规律,以火排燃烧器为研究对象,通过数值模拟与实验相... 壁挂炉供热是北方农村冬季采暖的主要方式之一。由于供气管网压力波动,壁挂炉易于出现燃烧不稳定现象,甚至发生CO中毒事故。为揭示管网压力变动下燃气壁挂炉内温度场及燃烧产物的变化规律,以火排燃烧器为研究对象,通过数值模拟与实验相结合的方法研究了单排燃烧器在不同管道压力下引射装置出口处燃气组分的分布、燃烧室内温度、燃烧室出口烟气中CO及NO浓度的变化规律。结果表明:(1)随着燃气入口压力减小,火排出口处甲烷浓度随之上升,甲烷浓度不均匀性增强;(2)随着燃气入口压力减小,燃烧室出口处CO质量浓度逐渐增加,燃气入口压力为500 Pa时,CO质量浓度达到25.2 mg/m^(3),高于人体CO中毒事故限值23 mg/m^(3);燃烧室出口处NO质量浓度呈先增加后减少的趋势,在1500 Pa时达到峰值为18.99 mg/m^(3);(3)随着燃气入口压力减小,燃烧室内最高温度先增加后减小,在500 Pa时温度最低为1840 K,燃烧不充分,燃烧生成的热量少;可见,管网压力变小使壁挂炉燃烧的不稳定性增加且CO浓度也显著变大。本文研究结果可为燃气壁挂炉生产厂家在增强设备安全性方面提供一定的理论支持。 展开更多
关键词 燃烧学 火排燃烧器 压力变动 燃烧特性 烟气组分
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煤变质过程中生物产气特征及微生物代谢机制
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作者 郭红玉 赵树峰 +6 位作者 Norbert Klitzsch 宋晓夏 赵金贵 刘汉斌 王乾 张斌 陈振宏 《天然气工业》 北大核心 2025年第8期181-194,共14页
生物成因煤层气的生成与演化受到多种地质因素的影响,目前对于煤变质过程中生物产气及微生物代谢的影响机制尚缺乏深入研究。为此,选取采自山西省大同市东周窑井田和太原市西山井田马兰矿2个矿区6个不同变质程度的煤样,通过全岩黏土矿... 生物成因煤层气的生成与演化受到多种地质因素的影响,目前对于煤变质过程中生物产气及微生物代谢的影响机制尚缺乏深入研究。为此,选取采自山西省大同市东周窑井田和太原市西山井田马兰矿2个矿区6个不同变质程度的煤样,通过全岩黏土矿物分析、生物产气模拟、主成分分析(PCA)、气相色谱—质谱联用(GC-MS)、宏基因及代谢组学等技术手段,系统研究了煤变质过程中生物产气潜力和影响微生物代谢的机制。研究结果表明:①随着变质程度的增加,煤中总有机碳含量和挥发分含量显著降低,而灰分和黏土矿物含量则增加,黏土矿物类型由高岭土逐渐向伊利石及伊/蒙混层转变;②相应地,两种高变质程度煤样产气量分别降至1.13 mL/g和1.07 mL/g,较低变质程度煤样产气量下降超过50%;③PCA分析结果显示,变质作用通过有机质和矿物组分变化影响生物产气潜力,灰分和黏土矿物含量的增加,限制了有机质的生物可利用性;④尽管高变质程度煤中富集了Petrimonas和Pseudomonas等电活性菌,但由于水解及产酸菌(如Proteobacteria和Synergistota)丰度偏低,甲烷生成仍受到抑制。结论认为:①不同变质程度煤在生物降解过程中具有显著代谢差异,差异代谢物如5-Aminolevulinic acid、Dihydroisophorol和4-Hydroxy-1-(3-pyridinyl)-1-butanone均以酸类代谢为主;②研究成果揭示了煤变质过程对生物产气潜力的多维影响机制,能够为生物成因煤层气资源评价与开发利用提供理论基础与技术支撑。 展开更多
关键词 不同变质程度煤 生物成因煤层气 矿物组成 总有机碳 黏土矿物 液相产物 菌群结构 代谢组学
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基于μCT和深度学习的煤裂隙智能提取方法 被引量:1
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作者 胡咤咤 张寻 +4 位作者 金毅 巩林贤 黄文辉 任建吉 Norbert Klitzsch 《煤田地质与勘探》 北大核心 2025年第2期55-66,共12页
【目的】煤储层裂隙的精细描述对于煤层气资源的勘探开发具有重要意义,裂隙的尺寸、走向、分布密度等直接影响煤层的渗透性,准确识别和提取煤层中的裂隙信息是揭示体积压裂过程中裂缝网络形成与扩展机理的关键。传统的裂隙提取方法往往... 【目的】煤储层裂隙的精细描述对于煤层气资源的勘探开发具有重要意义,裂隙的尺寸、走向、分布密度等直接影响煤层的渗透性,准确识别和提取煤层中的裂隙信息是揭示体积压裂过程中裂缝网络形成与扩展机理的关键。传统的裂隙提取方法往往依赖人工标注和基于一定图像处理技术的特征提取,这些方法在精度和效率上存在明显不足。【方法】提出一种基于Trans-UNet网络和μCT图像的煤裂隙提取方法,Trans-UNet结合了Transformer模块和卷积神经网络(CNN)的优点,不仅具备全局特征提取能力,还能够捕捉图像中的局部细节特征,大幅提高了分割精度和网络的鲁棒性。首先对煤样μCT图像进行预处理,包括使用差值法提高图像质量、使用数据增强技术扩大样本数量等。随后,利用Trans-UNet网络对处理后的图像进行分割,提取裂隙特征,并比较不同神经网络模型的分割结果。【结果和结论】结果表明,提出的方法在数据集上表现出优越性能,Trans-UNet模型在煤裂隙提取上的准确性(accuracy)、精确度(precision)、F1分数(F1-score)和交并比(IoU)分别达到91.3%、89.5%、89.8%和84.0%,相较于U-Net、U-Net++等其他多种智能模型有显著提升。结合μCT图像的细粒度特征,将Trans-UNet网络应用于煤裂隙提取任务,是一种高效且准确的解决方案,为煤层气勘探开发领域的相关图像处理任务提供了新的思路。 展开更多
关键词 Trans-UNet μCT图像 煤裂隙 图像分割 深度学习
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卷取温度对工业试制铁素体高扩孔钢显微组织和力学性能的影响
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作者 白燚潮 崔磊 +5 位作者 刘阳 卢茜倩 马聪 Alexander Gramlich 王晓辉 胡斌 《精密成形工程》 北大核心 2025年第12期85-94,共10页
目的针对高扩孔钢扩孔性能富余量不足的问题,以4种不同卷取工艺制备的工业试制铁素体基高扩孔钢为研究对象,研究卷取温度对高扩孔钢拉伸和扩孔性能的影响,进而总结出扩孔性能提升存在的问题。方法采用万能试验机、显微硬度计(HV-1002)... 目的针对高扩孔钢扩孔性能富余量不足的问题,以4种不同卷取工艺制备的工业试制铁素体基高扩孔钢为研究对象,研究卷取温度对高扩孔钢拉伸和扩孔性能的影响,进而总结出扩孔性能提升存在的问题。方法采用万能试验机、显微硬度计(HV-1002)、场发射扫描电镜(ZEISS GeminiSEM 300)、电子探针微区分析仪(JXA-8530F Plus)和俄歇电子(AES)-电子背散射衍射仪(EBSD,PHI 710)进行力学性能及显微组织研究。结果在630℃卷曲时,高扩孔钢的屈服强度和抗拉强度达到最大值,分别为722 MPa和798 MPa;然而,此时热轧板的厚度中心由于C/Mn偏析而析出粗大珠光体,在形变过程中,由于中心和近表面位置变形不均匀而易在中心分层开裂,从而导致扩孔率降低至34.1%。降低卷取温度至500~550℃和提升卷曲温度至700℃均能抑制热轧板厚度中心处珠光体的形成,提升扩孔率;但是由于卷取温度偏离碳化钒的鼻尖析出温度,因此强度降低,屈服强度和抗拉强度分别为530~640 MPa和620~730 MPa。结论当卷取温度为630℃和700℃时,厚度中心C元素的偏析会导致生成珠光体/渗碳体组织,进而导致中心与边缘硬度差异增大,从而发生开裂。除此之外,当卷取温度提升至630℃时,屈服强度和抗拉强度达到最大值,分别为722 MPa和798 MPa。为了在高强度下提升铁素体扩孔钢的扩孔率,需改善铸坯中心C/Mn的偏析程度,使其在VC析出鼻尖温度附近卷取时能有效抑制厚度中心珠光体的形成。 展开更多
关键词 铁素体高扩孔钢 强度 中心开裂分层 偏析 珠光体
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考虑非稳态渗流影响的深埋隧道弹塑性解
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作者 林贤哲 陈有亮 +3 位作者 刘耕云 李溢 拉菲格·阿扎姆 陈奇键 《工业建筑》 2025年第4期132-141,共10页
为研究在非稳态渗流条件下的深埋水工隧道围岩开挖力学响应,基于Mohr-Coulomb强度准则,推导了考虑非稳态渗流和剪胀效应的深埋水工隧洞弹塑性解。采用分离变量法和Bessel函数理论,推导了隧洞开挖引起的非稳态渗流场水头分布解析解。由... 为研究在非稳态渗流条件下的深埋水工隧道围岩开挖力学响应,基于Mohr-Coulomb强度准则,推导了考虑非稳态渗流和剪胀效应的深埋水工隧洞弹塑性解。采用分离变量法和Bessel函数理论,推导了隧洞开挖引起的非稳态渗流场水头分布解析解。由参数敏感性分析得知:与稳态渗流场相比,非稳态渗流场对围岩稳定性具有显著的影响,即塑性区扩大时,松动圈厚度和围岩塑性区变形增大;非稳态渗流对围岩塑性区变形的影响不可忽视,尤其在相同剪胀角条件下,洞壁处径向位移远大于稳态渗流引起的洞壁位移。 展开更多
关键词 深埋隧道 非稳态渗流 剪胀 弹塑性解 应力场 位移场
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Substrate topography as a powerful tool to modify glial cell biology and interactions
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作者 Pascal Achenbach Haktan Altinova Gary A.Brook 《Neural Regeneration Research》 SCIE CAS 2025年第5期1390-1391,共2页
Traumatic injuries to the central nervous system(CNS) result in disruption of the intricate network of axons which connect functionally related neurons that are widely distributed throughout the brain and spinal cord.... Traumatic injuries to the central nervous system(CNS) result in disruption of the intricate network of axons which connect functionally related neurons that are widely distributed throughout the brain and spinal cord.Under normal conditions,maintenance of this complex system is structurally and functionally supported by astrocytes (ACs)and other glial cells,the processes of which form a framework surrounding neuronal cell bodies,dendrites,axons,and synapses. 展开更多
关键词 INJURIES TOPOGRAPHY system
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Sensorless battery expansion estimation using electromechanical coupled models and machine learning 被引量:1
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作者 Xue Cai Caiping Zhang +4 位作者 Jue Chen Zeping Chen Linjing Zhang Dirk Uwe Sauer Weihan Li 《Journal of Energy Chemistry》 2025年第6期142-157,I0004,共17页
Developing sensorless techniques for estimating battery expansion is essential for effective mechanical state monitoring,improving the accuracy of digital twin simulation and abnormality detection.Therefore,this paper... Developing sensorless techniques for estimating battery expansion is essential for effective mechanical state monitoring,improving the accuracy of digital twin simulation and abnormality detection.Therefore,this paper presents a data-driven approach to expansion estimation using electromechanical coupled models with machine learning.The proposed method integrates reduced-order impedance models with data-driven mechanical models,coupling the electrochemical and mechanical states through the state of charge(SOC)and mechanical pressure within a state estimation framework.The coupling relationship was established through experimental insights into pressure-related impedance parameters and the nonlinear mechanical behavior with SOC and pressure.The data-driven model was interpreted by introducing a novel swelling coefficient defined by component stiffnesses to capture the nonlinear mechanical behavior across various mechanical constraints.Sensitivity analysis of the impedance model shows that updating model parameters with pressure can reduce the mean absolute error of simulated voltage by 20 mV and SOC estimation error by 2%.The results demonstrate the model's estimation capabilities,achieving a root mean square error of less than 1 kPa when the maximum expansion force is from 30 kPa to 120 kPa,outperforming calibrated stiffness models and other machine learning techniques.The model's robustness and generalizability are further supported by its effective handling of SOC estimation and pressure measurement errors.This work highlights the importance of the proposed framework in enhancing state estimation and fault diagnosis for lithium-ion batteries. 展开更多
关键词 Sensorless estimation Electromechanical coupling Impedance model Data-driven model Mechanical pressure
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Risks and governance of heavy metals in European soil applied phosphate fertilizers 被引量:1
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作者 Lian-kai Zhang Xiang Liu +5 位作者 Ya-jie Sun Bernd G.Lottermoser Roland Bol Heike Windmann Silvia H.Haneklaus Ewald Schnug 《China Geology》 2025年第3期560-572,共13页
Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of ... Phosphorus(P)poses a global challenge to the environment and human health due to its natural association with heavy metals.Sustainable use of P is crucial to ensure food security for future generations.An analysis of the 150 phosphate fertilizers stored at the Institute for Crop and Soil Science in Germany has been conducted,supplemented by previously published data.The elements Cd,Bi,U,Cr,Zn,Tl,As,B,Sb,Ni,and Se are found in higher concentrations in sedimentary derived phosphates compared to igneous derived phosphates.Mineral fertilizers contain more than ten times the amount of U,Cd,B,and As compared to farmyard manure.Principal component analyses(PCA)indicate that U,Cd,Be,and Cr are primarily present in sedimentary derived phosphates and their concentrations are 2 to 10 times higher than those in igneous derived phosphates.Regarding heavy metal contamination,over 1000 potential combinations were identified;36% of these were significant but weak(>0.1).It is estimated that approximately 707 t of uranium enter farmland annually through the application of mineral phosphate fertilizers in European countries.This contribution addresses environmental issues related to the utilization of rock phosphate as well as alternative production methods for cleaner and safer phosphate fertilizers while presenting a roadmap with measures for mitigation. 展开更多
关键词 Phosphorus fertilizer Heavy metals U-Cd-Cr-Tl SOIL Mitigation Sustainable measures EUROPE Sustainable Development Goals(SDG 3) Environmental geological survey engineering
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Proton pump inhibitors and all-cause mortality risk among cancer patients
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作者 Arunkumar Krishnan Carolin Victoria Schneider Declan Walsh 《World Journal of Clinical Oncology》 2025年第1期34-42,共9页
BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term... BACKGROUND Proton pump inhibitors(PPIs)are widely used,including among cancer patients,to manage gastroesophageal reflux and other gastric acid-related disorders.Recent evidence suggests associations between long-term PPI use and higher risks for various adverse health outcomes,including greater mortality.AIM To investigate the association between PPI use and all-cause mortality among cancer patients by a comprehensive analysis after adjustment for various confounders and a robust methodological approach to minimize bias.METHODS This retrospective cohort study used data from the TriNetX research network,with electronic health records from multiple healthcare organizations.The study employed a new-user,active comparator design,which compared newly treated PPI users with non-users and newly treated histamine2 receptor antagonists(H2RA)users among adult cancer patients.Newly prescribed PPIs(esomeprazole,lansoprazole,omeprazole,pantoprazole,or rabeprazole)users were compared to non-users or newly prescribed H2RAs(cimetidine,famotidine,nizatidine,or ranitidine)users.The primary outcome was all-cause mortality.Each patient in the main group was matched to a patient in the control group using 1:1 propensity score matching to reduce confounding effects.Multivariable Cox regression models were used to estimate hazard ratios(HRs)and 95% confidence interval(CI).RESULTS During the follow-up period(median 5.4±1.8 years for PPI users and 6.5±1.0 years for non-users),PPI users demonstrated a higher all-cause mortality rate than non-users after 1 year,2 years,and at the end of follow up(HRs:2.34-2.72).Compared with H2RA users,PPI users demonstrated a higher rate of all-cause mortality HR:1.51(95%CI:1.41-1.69).Similar results were observed across sensitivity analyses by excluding deaths from the first 9 months and 1-year post-exposure,confirming the robustness of these findings.In a sensitivity analysis,we analyzed all-cause mortality outcomes between former PPI users and individuals who have never used PPIs,providing insights into the long-term effects of past PPI use.In addition,at 1-year follow-up,the analysis revealed a significant difference in mortality rates between former PPI users and non-users(HR:1.84;95%CI:1.82-1.96).CONCLUSION PPI use among cancer patients was associated with a higher risk of all-cause mortality compared to non-users or H2RA users.These findings emphasize the need for cautious use of PPIs in cancer patients and suggest that alternative treatments should be considered when clinically feasible.However,further studies are needed to corroborate our findings,given the significant adverse outcomes in cancer patients. 展开更多
关键词 All-cause mortality CANCER Histamine-2 receptor antagonists MORTALITY MALIGNANCY Proton pump inhibitors CARCINOMA OUTCOME
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Comparative modelling of retrogressive landslide runout:2D and 3D random large-deformation analyses using coupled Eulerian-Lagrangian method 被引量:1
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作者 Xuejian Chen Shunping Ren +4 位作者 Xingsen Guo Yueying Wang Fei Liu Hoang Nguyen Rita Leal Sousa 《International Journal of Mining Science and Technology》 2025年第11期2011-2030,共20页
Retrogressive landslides in sensitive clays pose significant risks to nearby infrastructure,as natural toe erosion or localized disturbances can trigger progressive block failures.While prior studies have largely reli... Retrogressive landslides in sensitive clays pose significant risks to nearby infrastructure,as natural toe erosion or localized disturbances can trigger progressive block failures.While prior studies have largely relied on two-dimensional(2D)large-deformation analyses,such models overlook key three-dimensional(3D)failure mechanisms and variability effects.This study develops a 3D probabilistic framework by integrating the Coupled Eulerian–Lagrangian(CEL)method with random field theory to simulate retrogressive landslides in spatially variable clay.Using Monte Carlo simulations,we compare 2D and 3D random large-deformation models to evaluate failure modes,runout distances,sliding velocities,and influence zones.The 3D analyses captured more complex failure modes—such as lateral retrogression and asynchronous block mobilization across slope width.Additionally,the 3D analyses predict longer mean runout distances(13.76 vs.11.92 m),wider mean influence distance(11.35 vs.8.73 m),and higher mean sliding velocities(4.66 vs.3.94 m/s)than their 2D counterparts.Moreover,3D models exhibit lower coefficients of variation(e.g.,0.10 for runout distance)due to spatial averaging across slope width.Probabilistic hazard assessment shows that 2D models significantly underpredict near-field failure probabilities(e.g.,48.8%vs.89.9%at 12 m from the slope toe).These findings highlight the limitations of 2D analyses and the importance of multi-directional spatial variability for robust geohazard assessments.The proposed 3D framework enables more realistic prediction of landslide mobility and supports the design of safer,risk-informed infrastructure. 展开更多
关键词 Retrogressive landslide Coupled Eulerian-Lagrangian approach Spatial variability Runout dynamics Progressive failure Hazard assessment
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A NURBS-based, perfectly matched layer method for transient elastodynamics in unbounded domains
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作者 Arturo Méndez Salas Myung-Jin Choi Sven Klinkel 《Earthquake Engineering and Engineering Vibration》 2025年第3期723-742,共20页
In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted co... In this study,the wave motion in elastodynamics for unbounded media is modeled using an unsplit-field perfectly matched layer(PML)formulation that is solved by employing an isogeometric analysis(IGA).In the adopted combination,the non-uniform rational B-spline(NURBS)functions are employed as basis functions.Moreover,the unbounded and artificial domains,defined in the PML method,are contained in a single patch domain.Based on the proposed scheme,the approximation of the geometry problem is set in a new scheme in which the PML’s absorbing and attenuation properties and the description of traveling waves can be represented.This includes a higher continuity and smoother approximation of the computed domain.As high-order NURBS basis functions are non-interpolatory,a penalty method is present to apply a time-dependent displacement load.The performance of the NURBS-based PML is analyzed through numerical examples for 1D and 2D domains,considering homogeneous and heterogeneous media.Further,we verify the long-time numerical stability of the present method.The developed method can be used to simulate hypothetical stratified domains commonly encountered in soil-structure interaction analyses. 展开更多
关键词 perfectly matched layer NURBS ELASTODYNAMICS unbounded domains transient analysis
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Care for the soul of science:Equity and virtue in reform and reformation
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作者 Mare Knibbe Sarah de Rijcke Bart Penders 《Cultures of Science》 2025年第1期12-23,共12页
Scientific reforms proposed in response to moral concerns about corrupted science are reminiscent of the Christian Reformation,which similarly formed a moral reorientation as a reaction to malpractices.In this study,w... Scientific reforms proposed in response to moral concerns about corrupted science are reminiscent of the Christian Reformation,which similarly formed a moral reorientation as a reaction to malpractices.In this study,we compare these moral reorientation processes to contextualize two different moral programmes of the scientific reform movement and their sociopolitical conditions.We argue that such an explication of moral programmes is vital to build legitimacy and reflect on value-prioritization.While epistemic programmes are foregrounded,moral programmes also play a crucial role in shaping science,and different moral programmes offer different promises for the sustained support of credible,reliable,fair and equitable science.We discuss the virtue and equity programmes,and through interrogating both programmes in relation to the Reformation,we display the relevance of sociopolitical contexts to how key values operate in science and generate orders of worth.These insights aim to stimulate debate about the conditions for opting for either of these moral programmes.In our view,not all moral programmes offer equal promise for the sustained support of credible,equitable and fair science. 展开更多
关键词 Scientific reform REFORMATION moral programme valuation VIRTUE EQUITY
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Understanding pyramidal slip-induced deformation bands and dynamic recrystallization in AZWX3100 magnesium alloy
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作者 Risheng Pei Fatim-Zahra Mouhib +3 位作者 Mattis Seehaus Simon Arnoldi Pei-Ling Sun Talal Al-Samman 《Journal of Magnesium and Alloys》 2025年第3期1088-1098,共11页
Dynamic recrystallization(DRX)in inhomogeneous deformation zones,such as grain boundaries,shear bands,and deformation bands,is critical for texture modification in magnesium alloys during deformation at elevated temper... Dynamic recrystallization(DRX)in inhomogeneous deformation zones,such as grain boundaries,shear bands,and deformation bands,is critical for texture modification in magnesium alloys during deformation at elevated temperatures.This study investigates the DRX mechanisms in AZWX3100 magnesium alloy under plane strain compression at 200℃.Microstructural analysis revealed necklace-type DRX accompanied by evidence of local grain boundary bulging.Additionally,ribbons of recrystallized grains were observed withinfine deformation bands,aligned with theoretical pyramidal I and II slip traces derived from the matrix.The distribution of local misorientation within the deformed microstructure demonstrated a clear association between deformation bands and localized strain.Dislocation analysis of lamellar specimens extracted from two pyramidal slip bands revealed<c+a>dislocations,indicating a connection between<c+a>slip activation and the formation of deformation bands.Crystal plasticity simulations suggest that the orientation of deformation bands is responsible for the unique recrystallization texture of the DRX grains within these bands.The texture characteristics imply a progressive,glide-induced DRX mechanism.A fundamental understanding of the role of deformation bands in texture modification can facilitate future alloy and process design. 展开更多
关键词 Magnesium Channel die Dynamic recrystallization Texture modification Pyramidal slip
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Feasibility of telemedicine in civil protection:a prospective observational study during a music festival
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作者 Anna Müller Robert Arimond +3 位作者 Janosch Kunczik Rolf Rossaint Michael Czaplik Andreas Follmann 《World Journal of Emergency Medicine》 2025年第2期121-128,共8页
BACKGROUND:As disasters intensify and professional deficits persist,civil protection is reliant on medical volunteers.With limited physician availability,telemedicine is promising.No system currently empowers lower-qu... BACKGROUND:As disasters intensify and professional deficits persist,civil protection is reliant on medical volunteers.With limited physician availability,telemedicine is promising.No system currently empowers lower-qualified paramedics for physician-delegated telemedicine.Existing telemedicine technology unfits for civil protection.This study aimed to evaluate a modified system at a music festival to simulate disaster situations.METHODS:A tablet-based telemedicine system,integrating vital sign monitoring,was deployed at the "Summerjam" music festival characterized by various medical emergencies.A physician could be contacted via telemedicine or requested onsite.Medical feasibility was rated by patient condition changes,with National Advisory Committee of Aeronautics(NACA) score and Primary Ranking for Initial Orientation in the Rescue service(PRIOR) algorithm for triaging.Technical feasibility was assessed by connection stability,communication,and vital sign transmission.RESULTS:Of 404 treatments,34(8.4%) were performed using telemedicine,49(12.1%) were carried out with a physician onsite.Telemedicine treatments accounted for 40.9% of all treatment in which a physician was involved.Patient conditions varied up to NACA III(moderate disturbance).A variety of internal medical(76.5%) and surgical(23.5%) conditions were addressed,some of which required invasive measures or application of medication.No patients experienced a deterioration in their condition.Despite technical difficulties,treatment was not significantly impacted,confirming technical feasibility.CONCLUSION:The study shows that lower-qualified paramedics can effectively use telemedicine for physician-delegated treatment,suggesting potential applicability to civil protection.Nonetheless,further system robustness improvements and research are needed. 展开更多
关键词 Disaster medicine Tele-paramedic Civil protection TELEMEDICINE Tele-physician
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Integrating three-dimensional printing and bioprinting technologies to develop a stretchable in vitro model of the human airway
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作者 Junned Chan Julian Gonzalez Rubio +7 位作者 Oscar O’Dwyer Lancaster-Jones Yashasvi Verma Charlotte Büchter Stefan Jockenhoevel Laura De Laporte Mirko Trilling Anja Lena Thiebes Daniela Duarte Campos 《Bio-Design and Manufacturing》 2025年第4期595-608,I0033-I0041,共23页
The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019(COVID-19)pandemic.Current state-of-the-art models use polymer membranes to separate epithelial cells from other c... The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019(COVID-19)pandemic.Current state-of-the-art models use polymer membranes to separate epithelial cells from other cell types,creating a nonphysiological barrier.In this study,we applied three-dimensional(3D)printing and bioprinting to develop an in vitro model where endothelial and epithelial cells were in direct contact,mimicking their natural arrangement.This proof-ofconcept model includes a culture chamber,with an endothelial bioink printed and perfused through an epithelial channel.In silico simulations of the air velocity within the channel revealed shear stress values ranging from 0.13 to 0.39 Pa,aligning with the desired in vivo shear stress observed in the bronchi regions(0.1–0.4 Pa).Biomechanical movements during resting breathing were mimicked by incorporating a textile mesh positioned away from the cell–cell interface.The epithelial channel demonstrated a capacity for compression and expansion of up to−14.7%and+6.4%,respectively.Microscopic images showed that the epithelial cells formed a uniform monolayer within the lumen of the channel close to the bioprinted endothelial cells.Our novel model offers a valuable tool for future research into respiratory diseases and potential treatments under conditions closely mimicking those in the lung. 展开更多
关键词 Airway-on-a-chip In vitro model BIOPRINTING HYDROGEL Tissue engineering Lung
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Critical operation range of electro-hydrostatic actuator pumps based on cylinder block tilting states
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作者 Junhui ZHANG Xuguang LI +5 位作者 Fei LYU Felix SCHLEGEL Katharina SCHMITZ Shihao LIU Weidi HUANG Bing XU 《Chinese Journal of Aeronautics》 2025年第12期516-530,共15页
The electro-hydrostatic actuator(EHA)pump is required to operate in a wide range of pressures and speeds to meet the variable output power demands.However,the reliable operation range of EHA pumps is restricted,and th... The electro-hydrostatic actuator(EHA)pump is required to operate in a wide range of pressures and speeds to meet the variable output power demands.However,the reliable operation range of EHA pumps is restricted,and the cylinder block tilting is considered a serious factor.This paper presents an analytical approach for evaluating the critical operation range of EHA pumps based on a criterion for cylinder tilting states.It explicitly reveals the fundamental principle of the cylinder block tilting limiting the operation range.The criterion is verified with the measured tilting angle and leakage flow.Results show that the calculated critical conditions accurately identify the inflection point of performance changes.Beyond the critical operation range,the severe cylinder block tilting leads to a sharp increase in leakage and may even result in a sudden failure.Furthermore,the impacts of the center spring force,the piston-slipper assembly mass,and the position of the spline reaction on the critical operation range are investigated. 展开更多
关键词 EHA pump Critical operation range Cylinder block tilting Tilting criterion Center spring force
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