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基于时域同步平均的Circular图分析方法及齿轮故障智能诊断研究
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作者 胥永刚 张翼飞 +1 位作者 孙国栋 张坤 《机械强度》 北大核心 2025年第6期11-16,共6页
齿轮Circular图是用于与时域同步平均(Time Synchronous Averaging,TSA)相结合的一种结果呈现方法,可以将TSA提取到的齿轮啮合振动波形直观、清晰地展现出来。针对齿轮Circular图绘制参数设置和其缺少量化指标的问题,提出了用于波形边... 齿轮Circular图是用于与时域同步平均(Time Synchronous Averaging,TSA)相结合的一种结果呈现方法,可以将TSA提取到的齿轮啮合振动波形直观、清晰地展现出来。针对齿轮Circular图绘制参数设置和其缺少量化指标的问题,提出了用于波形边缘识别的F_(i)指标和基于Hu氏不变矩的Y_(i)指标。首先,使用TSA算法提取出齿轮啮合振动信号,通过计算最小F_(i)指标确定振动信号波形的上、下边缘;其次,利用上、下边缘参数绘制齿轮Circular图;再次,将齿轮Circular图分割为4个部分,通过计算分割后图片的Hu氏不变矩得到齿轮Circular图的Y_(i)指标;最后,基于从齿轮Circular图中提取出的Y_(i)和F_(i)指标,使用K最近邻(K-Nearest Neighbor,KNN)分类器对齿轮振动信号进行分类。仿真信号及齿轮断齿、裂纹故障信号的处理结果表明了该方法的有效性。 展开更多
关键词 齿轮箱 齿轮circular 特征指标 智能故障诊断
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Circular Economy in Municipal Solid Waste Management: Innovations and Challenges for Urban Sustainability
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作者 Richard Edmond Victor Sesay Ping Fang 《Journal of Environmental Protection》 2025年第2期35-65,共31页
Urban areas worldwide face escalating challenges in managing municipal solid waste (MSW) due to rapid urbanization, population growth, and changing consumption patterns. Inefficient waste management systems contribute... Urban areas worldwide face escalating challenges in managing municipal solid waste (MSW) due to rapid urbanization, population growth, and changing consumption patterns. Inefficient waste management systems contribute to environmental degradation, public health risks, and resource depletion, underscoring the need for innovative solutions. This review employing AI-driven sorting technologies in urban waste management as a transformative framework for sustainable MSW management, emphasizing waste reduction, resource recovery, and closed-loop systems. The paper synthesizes existing literature, case studies, and technological advancements to explore strategies for integrating CE principles into MSW management. Key areas of focus include the application of emerging technologies such as artificial intelligence, machine learning, and big data analytics;advancements in waste-to-resource technologies;the development of scalable and adaptable CE models tailored to diverse urban contexts;and fostering collaboration among governments, private sectors, and communities. Findings highlight the potential of CE frameworks to minimize waste generation, enhance resource efficiency, and create resilient urban systems. However, significant barriers remain, including technological, financial, and policy challenges. The review concludes by identifying future research directions and actionable recommendations for stakeholders, aiming to advance the global transition toward sustainable urban waste management. 展开更多
关键词 circular Economy Municipal Solid Waste Urban Sustainability Emerging Technologies
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Scattering of plane P waves by circular-arc layered alluvial valleys: An analytical solution 被引量:27
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作者 梁建文 严林隽 Vincent W.Lee 《地震学报》 CSCD 北大核心 2001年第2期167-184,共18页
An analytical solution for scattering of plane P waves by circular-arc layered alluvial valleys was derived by Fourier-Bessel series expansion technique, and the solution was utilized to analyze the effects of alluvia... An analytical solution for scattering of plane P waves by circular-arc layered alluvial valleys was derived by Fourier-Bessel series expansion technique, and the solution was utilized to analyze the effects of alluvial sequence and their relative stiffness on the scattering of incident waves. 展开更多
关键词 散射 平面P波 圆弧形层状沉积谷地 解析解 地震波 沉积排列顺序 相对刚度
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LARGE DEFORMATION OF CIRCULAR MEMBRANE UNDER THE CONCENTRATED FORCE 被引量:11
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作者 陈山林 郑周练 《应用数学和力学》 CSCD 北大核心 2003年第1期25-28,共4页
Making use of basic equation of large deformation of circular membrane under the concentrated force and its boundary conditions and Hencky transformation, the problems of nonlinear boundary condition were solved. The ... Making use of basic equation of large deformation of circular membrane under the concentrated force and its boundary conditions and Hencky transformation, the problems of nonlinear boundary condition were solved. The Hencky transformation was extended and a exact solution of large deformation of circular membrane under the concentrated force has been obtained. 展开更多
关键词 圆薄膜 集中力 大变形 精确解 Hercky变换
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三臂回转式水稻钵苗移栽机构轻量化设计
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作者 胡淼 薛洪彬 +2 位作者 金敏 杜成成 叶秉良 《农机化研究》 北大核心 2026年第2期98-106,共9页
三臂回转式水稻钵苗非圆齿轮行星轮系移栽机构能够有效提高水稻钵苗移栽效率,但同时移栽机构质量增加会导致机构能耗、用材和成本增加,因此有必要对三臂回转式移栽机构进行轻量化设计。本文分析了三臂回转式移栽机构1个运动循环各工作... 三臂回转式水稻钵苗非圆齿轮行星轮系移栽机构能够有效提高水稻钵苗移栽效率,但同时移栽机构质量增加会导致机构能耗、用材和成本增加,因此有必要对三臂回转式移栽机构进行轻量化设计。本文分析了三臂回转式移栽机构1个运动循环各工作过程的受力情况,基于各构件受力分析建立了机构动力学模型,应用基于MatLab自主开发的移栽机构动力学分析软件计算得到各构件的受力变化曲线,获得实际工况下移栽机构有限元静力学分析施加的载荷;建立了移栽机构各非圆齿轮的有限元模型,对其进行静力学分析和模态分析,进而开展非圆齿轮结构拓扑优化减轻其质量,并对轻量化设计后的非圆齿轮进行强度校核与模态分析。轻量化后的太阳轮、第1中间轮、第2中间轮和行星轮满足强度要求且固有频率较高,质量分别减小了31.0%、18.8%、33.6%和15.5%。搭建移栽机构动力学试验台,开展轻量化设计前后移栽机构样机的动力学试验,测试得到机构转速为60 r/min时的支座反力变化曲线,结果为:轻量化后x、y方向支座反力的最大幅值分别从397.8、171.4 N减小为370.2、162.5 N,降低了6.9%和5.2%;其方差则分别从5783.1、974.9 N^(2)减小为4817.8、835.6 N^(2),降低了16.7%和14.3%。研究表明,移栽机构轻量化设计效果明显,动力学性能有所改善,具有较好的可行性。 展开更多
关键词 水稻钵苗移栽机构 轻量化设计 三臂回转式 非圆齿轮行星轮系 动力学分析 有限元分析
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Control of mean and fluctuating forces on a circular cylinder at high Reynolds numbers 被引量:3
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作者 Chuanping Shao Jianming Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2007年第2期133-143,共11页
A narrow strip is used to control mean and fluctuating forces on a circular cylinder at Reynolds numbers from 2.0 ×10^4 to 1.0 ×^ 10^5. The axes of the strip and cylinder are parallel. The control parameters... A narrow strip is used to control mean and fluctuating forces on a circular cylinder at Reynolds numbers from 2.0 ×10^4 to 1.0 ×^ 10^5. The axes of the strip and cylinder are parallel. The control parameters are strip width ratio and strip position characterized by angle of attack and distance from the cylinder. Wind tunnel tests show that the vortex shedding from both sides of the cylinder can be suppressed, and mean drag and fluctuating lift on the cylinder can be reduced if the strip is installed in an effective zone downstream of the cylinder. A phenomenon of mono-side vortex shedding is found. The strip-induced local changes of velocity profiles in the near wake of the cylinder are measured, and the relation between base suction and peak value in the power spectrum of fluctuating lift is studied. The control mechanism is then discussed from different points of view. 展开更多
关键词 Control .Vortex shedding .circular cylinder .Mean and fluctuating forces High Reynolds number
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废塑料回收与催化剂循环利用的耦合路径展望
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作者 潘琼 张晓华 +1 位作者 邢定峰 吕清龙 《石油炼制与化工》 北大核心 2026年第1期159-163,共5页
在“双碳”目标和经济增长背景下,石油化工行业对资源高效利用与绿色循环需求日益迫切。催化剂作为核心单元,其高效使用与循环再生可降低成本、助力碳减排。但传统催化剂再生能耗高、碳排放量大,需寻求低碳高效路径。我国塑料垃圾超过60... 在“双碳”目标和经济增长背景下,石油化工行业对资源高效利用与绿色循环需求日益迫切。催化剂作为核心单元,其高效使用与循环再生可降低成本、助力碳减排。但传统催化剂再生能耗高、碳排放量大,需寻求低碳高效路径。我国塑料垃圾超过60 Mt/a,回收率约为30%,焚烧填埋导致资源浪费和污染。废塑料热解技术能将难回收的塑料转化为液体燃料、可燃气体和炭,促进资源再利用。随着催化剂性能和工艺优化,热解效率提升,热解成为废塑料化学回收重要技术,但由于存在能耗高、受杂质影响及废气残渣难处理等问题,其产业化受到限制。将废塑料热解产物与催化剂循环利用进行耦合,探讨热解气、炭、油在催化剂再生、载体制备及催化裂化中的应用与协同机制,提出集成化低碳方案,可为石化行业绿色转型提供理论与实践支持。 展开更多
关键词 废塑料回收 热解 催化剂再生 循环利用
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圆形网格抽样和逆近邻优化的密度峰值聚类算法
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作者 赵嘉 何超凡 +2 位作者 肖人彬 曹浩 樊棠怀 《工程科学学报》 北大核心 2026年第1期161-176,共16页
密度峰值聚类(DPC)算法是一种简单高效的聚类算法,因其可直观和快速发现数据集中的类簇而得到广泛关注.但DPC算法需计算所有样本间的欧氏距离,算法的时间复杂度较高;局部密度定义未考虑类簇间密度差异影响,易误选类簇中心;使用链式分配... 密度峰值聚类(DPC)算法是一种简单高效的聚类算法,因其可直观和快速发现数据集中的类簇而得到广泛关注.但DPC算法需计算所有样本间的欧氏距离,算法的时间复杂度较高;局部密度定义未考虑类簇间密度差异影响,易误选类簇中心;使用链式分配策略,易产生错误连带效应.因此,本文提出一种圆形网格抽样和逆近邻优化的密度峰值聚类算法.该算法采用圆形网格抽样得到代表以减少需要计算的样本数,降低算法计算的时间开销,并引入近似K近邻策略加强代表和初始样本的联系,减少抽样导致的聚类精度丢失;利用逆近邻优化局部密度定义策略,根据样本所处环境调节其局部密度的大小,准确找到密度峰值;通过共享逆近邻计算相似性,由相似性矩阵分配代表,避免样本分配策略产生的错误连带效应.设置了复杂形态合成数据集、真实数据集和较大规模数据集进行分组实验.实验结果表明,本文算法在复杂形态、真实及较大规模数据集上聚类优势显著,精度与效率较DPC算法及其他基于DPC的改进算法均有较大提升. 展开更多
关键词 密度峰值聚类 圆形网格抽样 近似K近邻 逆近邻 共享逆近邻
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骨髓微环境中不同细胞对多发性骨髓瘤骨病外泌体环状RNA的贡献及相互作用
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作者 于漫亚 崔兴 《中国组织工程研究》 北大核心 2026年第1期101-110,共10页
背景:多发性骨髓瘤骨病是多发性骨髓瘤的严重并发症,其发病机制与骨髓微环境失调密切相关。外泌体环状RNA因高稳定性、高丰度、高特异性、高保守性等特点,正逐渐成为液体活检的焦点。在多发性骨髓瘤骨病中,外泌体环状RNA的作用尚缺乏相... 背景:多发性骨髓瘤骨病是多发性骨髓瘤的严重并发症,其发病机制与骨髓微环境失调密切相关。外泌体环状RNA因高稳定性、高丰度、高特异性、高保守性等特点,正逐渐成为液体活检的焦点。在多发性骨髓瘤骨病中,外泌体环状RNA的作用尚缺乏相关研究。随着单细胞RNA测序技术的发展,明确骨髓微环境中各类型细胞对多发性骨髓瘤骨病相关外泌体环状RNA的贡献及相互作用,有助于为多发性骨髓瘤骨病的诊疗提供新的生物标志物。目的:初步明确多发性骨髓瘤骨病相关外周血外泌体环状RNA的骨髓微环境来源细胞,并在单细胞水平上探究骨髓微环境中各细胞相互作用对多发性骨髓瘤骨病的影响。方法:对6例多发性骨髓瘤骨病患者和5名健康志愿者的外周血外泌体进行高通量测序,筛选差异环状RNA,并进行GO和KEGG富集分析。从GEO数据库中获取多发性骨髓瘤骨病患者的骨髓单细胞RNA测序数据集GSE271107,对其中的4例多发性骨髓瘤骨病患者数据进行整合,完成质控和过滤后,利用Harmony法去除批次效应,UMAP进行亚群聚类,SingleR自动注释后手动矫正细胞群,CellChat对单细胞RNA测序数据中的细胞间通讯进行推断和可视化,分析配体、受体间的相互作用。结果与结论:①相较于健康志愿者,多发性骨髓瘤骨病患者外周血外泌体中1265个环状RNA表达水平显著上调;②GO和KEGG分析差异环状RNA的亲本基因主要富集在神经系统发育、癌症中的通路、PI3K-Akt信号通路、Hippo信号通路、致心律失常性右心室心肌病、扩张型心肌病等,这与骨髓瘤细胞的增殖、黏附、迁移、归巢,以及多发性骨髓瘤相关并发症(如多发性骨髓瘤骨病、周围神经病变、心脏事件)关系密切;③多发性骨髓瘤骨病相关差异环状RNA的亲本基因主要来源于骨髓微环境中的T细胞/自然杀伤细胞、B细胞和单核/巨噬细胞,通过调节多种细胞因子的分泌影响破骨细胞功能;④单核细胞/巨噬细胞作为破骨细胞前体细胞与骨髓瘤细胞及其他免疫细胞间均有相互作用,MIF通路是其参与的主要通路。以上结果初步明确了多发性骨髓瘤骨病相关外周血外泌体环状RNA的骨髓微环境来源细胞,并发现单核/巨噬细胞与骨髓瘤细胞及免疫细胞间的MIF通路配体-受体相互作用可能是多发性骨髓瘤骨病发生的重要因素。 展开更多
关键词 多发性骨髓瘤骨病 外泌体 环状RNA 单细胞RNA测序 骨髓微环境 破骨细胞 PI3K-AKT信号通路 Hippo信号通路 工程化外泌体
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Circular RNA_0015278与甲状腺乳头状癌及临床特征的相关性
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作者 丁华杰 杨绍石 +3 位作者 李莎 史华宁 龚雪 那磊 《河北医药》 CAS 2023年第19期2945-2947,2951,共4页
目的探讨Circular RNA_0015278(circ_0015278)与甲状腺乳头状癌(PTC)及其临床病理特征的相关性。方法回顾分析手术切除的甲状腺乳头状癌患者200例,采用逆转录定量聚合酶链反应(RT-qPCR)检测Circular RNA_0015278在甲状腺乳头状癌(PTC)... 目的探讨Circular RNA_0015278(circ_0015278)与甲状腺乳头状癌(PTC)及其临床病理特征的相关性。方法回顾分析手术切除的甲状腺乳头状癌患者200例,采用逆转录定量聚合酶链反应(RT-qPCR)检测Circular RNA_0015278在甲状腺乳头状癌(PTC)及癌旁组织的表达。结果与癌旁组织比较,甲状腺乳头状癌(PTC)中Circular RNA_0015278表达显著降低(Z=-12.122,P<0.001),ROC分析显示,以相对表达量0.743为截断值,可较好的鉴别PTC肿瘤及癌旁组织(AUC:0.903,95%CI:0.873~0.933)。而PTC肿瘤中Circular RNA_0015278的高表达与患者年龄<45岁(Z=-2.319,P=0.020)、无甲状腺外侵犯(Z=-2.042,P=0.041)、无淋巴结转移(Z=-2.494,P=0.013)及低pTNM分期(Z=-3.719,P=0.001)相关(P<0.05)。而未发现与性别(Z=-1.323,P=0.186)、肿瘤大小(Z=-1.273,P=0.203)具有相关性(P>0.05)。结论PTC肿瘤中Circular RNA_0015278的表达显著降低,而其在PTC肿瘤中高表达与患者年龄<45岁、无甲状腺外侵犯、无淋巴结转移及低pTNM分期具有相关性。 展开更多
关键词 circular RNA_0015278 甲状腺乳头状癌 临床特征
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胫骨横向骨搬移加速2型糖尿病模型兔足溃疡愈合:环状RNA的参与和调控
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作者 孙祖延 黄文良 +4 位作者 徐林 李豪杰 谢同亮 杨治航 邓江 《中国组织工程研究》 北大核心 2026年第22期5639-5649,共11页
背景:胫骨横向骨搬移术作为一种新兴外科技术,通过改善局部血液循环和促进血管生成,有助于加速糖尿病足溃疡的愈合。尽管胫骨横向骨搬移术显示出积极的临床效果,但具体分子机制尚不明确。近年来,环状RNA在血管生成和创面修复中的作用逐... 背景:胫骨横向骨搬移术作为一种新兴外科技术,通过改善局部血液循环和促进血管生成,有助于加速糖尿病足溃疡的愈合。尽管胫骨横向骨搬移术显示出积极的临床效果,但具体分子机制尚不明确。近年来,环状RNA在血管生成和创面修复中的作用逐渐被揭示。环状RNA可能通过调控相关基因的表达,影响创面愈合过程,但环状RNA在胫骨横向骨搬移术治疗糖尿病足溃疡中的作用仍不清楚。目的:探讨胫骨横向骨搬移术对兔糖尿病足溃疡的治疗作用及机制。方法:选取18只3月龄、体质量2.8-3.6 kg的雄性新西兰兔,给予高糖高脂饲料喂养1个月后,通过静脉注射四氧嘧啶诱导建立2型糖尿病模型。造模成功后,结扎右侧股动脉中上段,切除同侧足背全层皮肤,以模拟糖尿病足溃疡的病理特征。随后,将造模成功的兔随机分为4组(每组4只):空白组不进行任何额外处理;换药组建模后常规碘伏消毒;假手术组建模后安装胫骨横向骨搬移术支架但不进行骨搬移;手术组建模后安装胫骨横向骨搬移术支架并进行骨搬移。在术后7,14 d,观察各组兔足背溃疡创面的愈合情况;术后7,14,21 d,通过酶联免疫吸附方法检测血清中血管内皮生长因子A和CD31水平;术后14 d,取各组溃疡创面组织进行苏木精-伊红染色、CD31免疫荧光染色及Western blot检测血管内皮生长因子A和CD31蛋白表达;术后7,14,21 d,采集手术组静脉血进行全序列基因测序,分析环状RNA的差异表达。结果与结论:术后7,14 d,手术组糖尿病足溃疡的恢复效果明显优于其他3组,在表皮修复、胶原纤维沉积和血管生成方面表现出更优的促进作用。术后14,21 d,手术组血清中血管内皮生长因子A、CD31水平显著高于其他3组(P<0.01)。基因测序分析结果显示,术后21 d环状RNA的变化最为显著,尤其是环状RNA姐妹染色体过早分离基因5黏附相关因子B的表达随着时间的推移逐渐降低,提示环状RNA姐妹染色体过早分离基因5黏附相关因子B可能与血管生成和组织修复密切相关。结果表明:胫骨横向骨搬移术能够有效促进兔糖尿病足溃疡创面的愈合。基因测序结果显示环状RNA差异表达,尤其是环状RNA姐妹染色体过早分离基因5黏附相关因子B下调显著,提示胫骨横向骨搬移术可能通过激活相关的分子通路,促进创面修复和血管生成。 展开更多
关键词 胫骨横向骨搬移 糖尿病足溃疡 糖尿病 血管生成 环状RNA(circRNA) circPDS5B
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Construction of Eco-agricultural Tourist Product Mode from the Perspective of Circular Economy
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作者 陈晓红 《Journal of Landscape Research》 2012年第2期51-53,57,共4页
Concepts and connotations of circular economy and eco-agricultural tourism were introduced,and feasibility of applying circular economy in eco-agricultural tourism was further studied.It was stressed that development ... Concepts and connotations of circular economy and eco-agricultural tourism were introduced,and feasibility of applying circular economy in eco-agricultural tourism was further studied.It was stressed that development of eco-agricultural tourism complies with the theme of resource recycling,moreover,both eco-agricultural tourist products and circular economy value environment protection,and target at the win-win of ecological and economic benefits.From the perspective of circular economy,the construction of eco-agricultural tourist product mode was studied,construction of eco-agricultural tourist areas,catering and accommodation areas and traffic construction of eco-agricultural scenic areas were discussed.The study stressed that connotations of circular economy can be used to restrain eco-agricultural tourism,and realize recycling and sustainable development of resources. 展开更多
关键词 Eco-agricultural TOURISM circular ECONOMY Product mode
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基于Circular模型的大剪应变率点接触弹流界面滑移数值分析 被引量:5
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作者 刘奕壕 黄柏林 +2 位作者 付忠学 郭峰 胡松钰 《摩擦学学报》 EI CAS CSCD 北大核心 2018年第2期129-137,共9页
采用Circular流变模型,将假定的流体的极限剪应力特性模型拟合入Reynolds方程,编写Fortran语言程序,数值模拟界面滑移效应.计算从弹流润滑(EHL)延展到动压润滑(HL)区域.随着速度增加,摩擦系数曲线出现反常波动,表现为两个异常拐点.在中... 采用Circular流变模型,将假定的流体的极限剪应力特性模型拟合入Reynolds方程,编写Fortran语言程序,数值模拟界面滑移效应.计算从弹流润滑(EHL)延展到动压润滑(HL)区域.随着速度增加,摩擦系数曲线出现反常波动,表现为两个异常拐点.在中、高速度下,模拟获得的接触轮廓等值线图中观测到入口凹陷及中心区下凸.进一步讨论了载荷、速度、综合弹性模量、滑滚比等因素对滑移的影响.界面滑移效应被认为是产生反常接触轮廓和摩擦力波动的主因,与试验结果互为验证. 展开更多
关键词 弹流 STRIBECK曲线 摩擦系数 界面滑移 circular模型
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Increased circulating circular RNA103516 is a novel biomarker for inflammatory bowel disease in adult patients 被引量:10
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作者 Yu-Lan Ye Juan Yin +3 位作者 Tong Hu Li-Ping Zhang Long-Yun Wu Zhi Pang 《World Journal of Gastroenterology》 SCIE CAS 2019年第41期6273-6288,共16页
BACKGROUND Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level,circular RNAs(circRNAs)participate in the pathogenesis of ... BACKGROUND Increasing evidence demonstrates that by acting as microRNA sponges modulating gene expression at the transcriptional or post-transcriptional level,circular RNAs(circRNAs)participate in the pathogenesis of a variety of diseases and are considered ideal biomarkers of human disease.AIM To examine the expression of circRNA_103516 in inflammatory bowel disease(IBD)and its associations with clinical phenotypes and inflammatory cytokines.METHODS Peripheral blood mononuclear cells(PBMCs)were obtained from patients with IBD,healthy controls(HCs),and patient controls(PCs).Expression of circRNA_103516 and hsa-miR-19b-1-5p was assessed by quantitative reverse transcription-polymerase chain reaction.Crohn's disease activity index(CDAI),Mayo score,C-reactive protein(CRP)level,and erythrocyte sedimentation rate(ESR)were measured.To assess the inflammatory cytokines tumour necrosis factorα(TNF-α),interferon-γ(IFN-γ),and interleukin-10(IL-10),blood samples were analysed by flow cytometry.RESULTS Ninety Crohn’s disease(CD)and 90 ulcerative colitis(UC)patients,80 HCs,and 35 PCs were included in the study.CircRNA_103516 was upregulated in CD and UC patients compared with HCs and PCs(P<0.05).The area under the curve of circRNA_103516 for diagnosing CD and UC was 0.790 and 0.687,respectively.In addition,circRNA_103516 levels were increased in active CD and UC compared with remittent groups(P=0.027,P=0.045).Furthermore,in CD,circRNA_103516 correlated positively with CDAI(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),and IFN-γ(P<0.001)and negatively correlated with IL-10(P=0.006).In UC patients,circRNA_103516 correlated with Mayo score(P<0.001),CRP(P<0.001),ESR(P<0.001),TNFα(P<0.001),IFN-γ(P=0.011),and IL-10(P=0.002).Additionally,circRNA_103516 correlated positively with stricturing(P=0.018)and penetrating(P=0.031)behaviour.Moreover,hsamiR-19b-1-5p correlated negatively with circRNA_103516 in CD.CONCLUSION CircRNA_103516 levels in PBMCs can be considered an ideal candidate biomarker for diagnosing IBD.Dysregulation of circRNA_103516 may participate in the molecular mechanism of IBD through hsa-miR-19b-1-5p sponging. 展开更多
关键词 circular RNA circular RNA_103516 INFLAMMATORY BOWEL diseases BIOMARKER
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Circular RNA circ-LDLRAD3 as a biomarker in diagnosis of pancreatic cancer 被引量:33
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作者 Fan Yang Dong-Yan Liu +6 位作者 Jin-Tao Guo Nan Ge Ping Zhu Xiang Liu Sheng Wang Guo-Xin Wang Si-Yu Sun 《World Journal of Gastroenterology》 SCIE CAS 2017年第47期8345-8354,共10页
AIM To analyze the diagnostic value of a circular RNA(circR NA), circ-LDLRAD3, in pancreatic cancer.METHODS Expression levels of circ-LDLRAD3 were tested in both cells and clinical samples; the latter included 30 pair... AIM To analyze the diagnostic value of a circular RNA(circR NA), circ-LDLRAD3, in pancreatic cancer.METHODS Expression levels of circ-LDLRAD3 were tested in both cells and clinical samples; the latter included 30 paired pancreatic cancer tissues and adjacent non-tumorous tissues, 31 plasma samples from patients with pancreatic cancer, and 31 plasma samples from healthy volunteers. Real-time quantitative reverse transcriptionpolymerase chain reaction(q RT-PCR) was performed to measure expression levels of circ-LDLRAD3 in cells and clinical samples; then, the relationship between clinicopathological factors of patient samples and expression of circ-LDLRAD3 in pancreatic cancer was analyzed. The diagnostic value of circ-LDLRAD3 was verified by receiver operating characteristic(ROC) curve analysis.RESULTS Circ-LDLRAD3 was up-regulated in pancreatic cancer cell lines(P < 0.01), pancreatic cancer tissues(P < 0.01), and plasma samples from patients with pancreatic cancer(P < 0.01). High expression of circLDLRAD3 was significantly associated with venous invasion, lymphatic invasion, and metastasis. The area under the ROC curve of circ-LDLRAD3 alone or combination with CA19-9 was 0.67 and 0.87, respectively, with a sensitivity and specificity of 0.5738(alone) and 0.7049(alone), and 0.8033(combination) and 0.9355(combination), respectively.CONCLUSION These data suggest that circ-LDLRAD3 may be a biomarker in the diagnosis of pancreatic cancer. 展开更多
关键词 circular RNA Pancreatic cancer BIOMARKER
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Circular HDAC9/microRNA-138/Sirtuin-1 Pathway Mediates Synaptic and Amyloid Precursor Protein Processing Deficits in Alzheimer’s Disease 被引量:29
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作者 Yanjun Lu Lu Tan Xiong Wang 《Neuroscience Bulletin》 SCIE CAS CSCD 2019年第5期877-888,共12页
Synaptic dysfunction and abnormal processing of amyloid precursor protein(APP) are early pathological features in Alzheimer’s disease(AD). Recently, noncoding RNAs such as micro RNAs(mi RNAs) and circular RNAs(circ R... Synaptic dysfunction and abnormal processing of amyloid precursor protein(APP) are early pathological features in Alzheimer’s disease(AD). Recently, noncoding RNAs such as micro RNAs(mi RNAs) and circular RNAs(circ RNAs) have been reported to contribute to the pathogenesis of AD. We found an age-dependent elevation of mi R-138 in APP/PS1(presenilin-1) mice. Mi R-138 inhibited the expression of ADAM10 [a disintegrin and metalloproteinase domain-containing protein 10], promoted amyloid beta(Ab) production, and induced synaptic and learning/memory deficits in APP/PS1 mice, while its suppression alleviated the AD-like phenotype in these mice. Overexpression of sirtuin 1(Sirt1), a target of mi R-138, ameliorated the mi R-138-induced inhibition of ADAM10 and elevation of Ab in vitro. The circ RNA HDAC9(circ HDAC9) was predicted to contain a mi R-138 binding site in several databases. Its expression was inversely correlated with mi R-138 in both Ab-oligomertreated N2 a cells and APP/PS1 mice, and it co-localized with mi R-138 in the cytoplasm of N2 a cells. Circ HDAC9 acted as a mi R-138 sponge, decreasing mi R-138 expression, and reversing the Sirt1 suppression and excessive Ab production induced by mi R-138 in vitro. Moreover,circ HDAC9 was decreased in the serum of both AD patients and individuals with mild cognitive impairment.These results suggest that the circ HDAC9/mi R-138/Sirt1 pathway mediates synaptic function and APP processing in AD, providing a potential therapeutic target for its treatment. 展开更多
关键词 Alzheimer’s disease SYNAPSE Memory Sirtuin-1 MICRORNA circular RNA
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Circular RNAs and human glioma 被引量:16
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作者 Jinglei Liu Kun Zhao +1 位作者 Nunu Huang Nu Zhang 《Cancer Biology & Medicine》 SCIE CAS CSCD 2019年第1期11-23,共13页
As a newly discovered type of RNA, circular RNAs(circRNAs) are widespread throughout the eukaryotic genome. The expression of circRNAs is regulated by both cis-elements and trans-factors, and the expression pattern of... As a newly discovered type of RNA, circular RNAs(circRNAs) are widespread throughout the eukaryotic genome. The expression of circRNAs is regulated by both cis-elements and trans-factors, and the expression pattern of circRNAs is cell type-and diseasespecific. Similar to other types of non-coding RNAs, functions of circRNAs are also versatile. CircRNAs have been reported previously to function as microRNA(miRNA) sponges, protein sponges, coding RNAs or scaffolds for protein complexes.Recently, several circRNAs have been reported to play important roles in human malignancies, including glioma. Here, we reviewed several reports related to circRNAs and glioma, as well as the potential diagnostic and therapeutic applications of circRNAs in brain cancer. In general, some circRNAs, such as circSMARCA5 and circCFH, are found to be expressed in a gliomaspecific pattern, these circRNAs may be used as tumor biomarkers. In addition, some circRNAs have been found to play oncogenic roles in glioma(e.g., circNFIX and circNT5E), whereas others have been reported to function as tumor suppressors(e.g.,circFBXW7 and circSHPRH). Furthermore, circRNA is a good tool for protein expression because of its higher stability compared to linear RNAs. Thus, circRNAs may also be an ideal choice for gene/protein delivery in future brain cancer therapies. There are some challenges in circRNA research in glioma and other diseases. Research related to circRNAs in glioma is comparatively new and many mysteries remain to be solved. 展开更多
关键词 circular RNA GLIOMA MIRNA SPONGE translation protein SCAFFOLD MIRNA target
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Numerical Simulation on Hydraulic Performances of Quarter Circular Breakwater 被引量:10
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作者 蒋学炼 谷汉斌 李炎保 《China Ocean Engineering》 SCIE EI 2008年第4期585-594,共10页
Quarter circular breakwater (QCB) is a new-type breakwater developed from senti-circular breakwater (SCB). The superstructure of QCB is composed of a quarter circular front wall, a horizontal base slab and a verti... Quarter circular breakwater (QCB) is a new-type breakwater developed from senti-circular breakwater (SCB). The superstructure of QCB is composed of a quarter circular front wall, a horizontal base slab and a vertical rear wall. The width of QCB' s base slab is about half that of SCB, which makes QCB suitable to be used on relatively finn soil foundation. The numerical wave flume based on the Reynolds averaged Navier-Stokes equations for impressible viscosity fluid is adopted in this paper to simulate the hydraulic performances of QCB. Since the geometry of both breakwaters is similar and SCB has been studied in depth, the hydraulic performances of QCB are given in comparison with those of SCB. 展开更多
关键词 quarter circular breakwater Reynolds averaged Navier-Stokes equations semi-circular breakwater wave forces wave reflection numerical wave flume
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Clinical value of circular RNAs and autophagy-related mi RNAs in the diagnosis and treatment of pancreatic cancer 被引量:9
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作者 Pei-Cheng Jiang Shu-Rui Bu 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2019年第6期511-516,共6页
Background:Circular RNAs(circRNAs)are a special group of long-chain and non-coding RNAs characterized by a closed-loop structure without 3’and 5’polarity.In recent years,studies have demonstrated that circRNAs act a... Background:Circular RNAs(circRNAs)are a special group of long-chain and non-coding RNAs characterized by a closed-loop structure without 3’and 5’polarity.In recent years,studies have demonstrated that circRNAs act as microRNA(miRNA)sponges to regulate the function of miRNAs.Increasing evidence indicates that circRNAs and targeted miRNAs are involved in the development,progression and metastasis of various cancers and drug resistance.A number of miRNAs are known to be associated with the pathogenesis,development and treatment of pancreatic cancer by regulating the autophagic activity.Data sources:A comprehensive literature search was executed in PubMed and EMBASE using the medical subject headings(MeSH)terms“Pancreatic Neoplasms”,“autophagy”,“RNA,circular”and“microRNA”.We also used text terms such as“diagnosis”,“prognosis”and“biomarker”to supplement the results.Results:Autophagy-related miRNAs is closely related to pancreatic cancer.On basis of the retrieval results,we summarized the synthesis,features and functions of circRNAs and analyzed the association between autophagy-related miRNAs and pancreatic cancer.Conclusions:circRNAs act as the miRNA sponges and there is an association between miRNAs and autophagy,which provides a new concept to broaden the knowledge about the mechanisms underlying the development,progression and metastasis of pancreatic cancer.Additionally,clinical value of circRNAs and autophagy-related miRNAs in the diagnosis and treatment of pancreatic cancer would be further verified with in-depth researches. 展开更多
关键词 AUTOPHAGY circular RNAS miRNA SPONGE PANCREATIC cancer
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Wave Forces on Submerged Semi-Circular Breakwater and Similar Structures 被引量:17
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作者 XIE Shileng Prof. Senior Engineer, The First Design Institute of Navigation Engineering, Ministry of Communications of China, Tianjin 300222, P. R. China. 《China Ocean Engineering》 SCIE EI 1999年第1期63-72,共10页
The results of design and experiment of a submerged semi-circular breakwater at the Yangtze estuary show that the submerged structure will be unsafe when the general empirical wave force formula for semi-circular brea... The results of design and experiment of a submerged semi-circular breakwater at the Yangtze estuary show that the submerged structure will be unsafe when the general empirical wave force formula for semi-circular breakwater is used in design. Therefore, a new calculation method for the wave forces acting on a submerged semi-circular structure is given in this paper, in which the wave force acting on the inside circumference of semi-circular arch is included, and the phase modification coefficient in the general empirical formula is adjusted as well. The new wave force calculation method has been Verified by the results of seven related physical model tests and adopted in the design of the south esturary jetty of the first stage project of Deep Channel Improvement Project of the Yangtze River Estuary, the total jetty length being 17.5 km. 展开更多
关键词 semi-circular breakwater submerged structure estuary jetty wave force
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