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国际医学放射学杂志 2024年第4期 499-500页

作者： M.Ni Y.q.Zhao L.H.Zhang W.Chen q.Z.Wang C.Y.Tian 常雪

摘要目的建立一个自动化、多任务、基于MRI的深度学习系统，用于精细评估冈上肌腱（SST）损伤。方法根据关节镜检查结果，将3 087例病人分为SST正常组、退变组和

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Axisymmetric wetting of a liquid droplet on a stretched elastic membrane

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Applied Mathematics and Mechanics(English Edition) 2023年第6期44卷 997-1006页

作者： C.q.RU Department of Mechanical Engineering University of AlbertaEdmontonAB T6G 2G8Canada

Wetting of a liquid droplet on another liquid substrate is governed by the well-known Neumann *** present work aims to develop an explicit modified version of the Neumann equations for axisymmetric wetting of a liquid droplet on a highly stretched elastic membrane of non-zero bending *** explicit modified form of the Neumann equations is derived to determine the two contact angles,which is reduced to Young's equation for a liquid droplet on a rigid membrane or to the Neumann equations for a liquid droplet on another liquid *** implications of the modified Neumann equations are examined by comparison with some previous results reported in the recent literature,particularly considering the ranges of material and geometrical parameters of the liquid droplet-membrane system which have not been recently addressed in the literature.

关键词： Neumann equation Young's equation liquid droplet membrane pretension

Interfacial Instability of Two Bonded Elastic Bodies Driven by Interface or Bulk Residual Stress

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Acta Mechanica Solida Sinica 2023年第6期36卷 914-920页

作者： C.q.Ru Department of Mechanical Engineering University of AlbertaEdmonton T6G 2G8Canada

Inspired by recent research interest in the interface wrinkling of bonded materials in diverse areas of 3D printing,the present work studies the interfacial instability of two bonded elastic bodies driven by negative interfacial tension or compressible bulk residual *** interfacial instability modes decaying exponentially with distance from the interface,the present model is formulated for two bonded elastic half-spaces with a planar interface under plane *** explicit expression is given for the wavenumber of interfacial instability driven by negative interfacial tension,and a critical condition is derived for interfacial instability driven by compressive bulk residual *** derived results are validated with comparison to known results on surface instability of an elastic half-space,and the role of shear modulus ratio and Poisson’s ratios of two bonded elastic bodies in interfacial instability,an issue to be addressed in literature,is studied with specific reference to material parameters used in some areas of 3D printing.

关键词： Interfacial tension Surface tension Interfacial instability 3D printing Interface wrinkling

青藏高原及邻区岩石圈应力状态特征及其地质意义

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中国科学：地球科学 2024年第6期54卷 1863-1882页

作者：张倩文徐亚褚伟路书鹏中国科学院地质与地球物理研究所中国科学院油气资源研究重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049

青藏高原及邻区现今岩石圈应力状态受到岩石圈本身及下部地幔作用的共同控制,即受岩石圈内部密度分布变化造成重力势能差及地幔对流作用对岩石圈底部拖曳力共同影响.研究岩石圈应力状态对进一步认识青藏高原演化的动力学背景及机制具有... 详细信息

青藏高原及邻区现今岩石圈应力状态受到岩石圈本身及下部地幔作用的共同控制,即受岩石圈内部密度分布变化造成重力势能差及地幔对流作用对岩石圈底部拖曳力共同影响.研究岩石圈应力状态对进一步认识青藏高原演化的动力学背景及机制具有重要作用.本文利用Crust1.0地壳密度模型结合S40RTS地幔横波速度变化模型计算重力势能,利用EGM2008重力场模型计算地幔对流作用在岩石圈底部的拖曳力,通过求解薄板近似下的力平衡方程分别得到这两种力源的岩石圈应力场以及两种力源的联合应力场,综合分析青藏高原地区应力状态特征,并根据重力势能应力场、地幔拖曳力应力场、两种应力场的相对大小,以及两种应力场与地表形变的相关关系特征划分了6个区域.综合分析表明,塔里木盆地等稳定地块区的岩石圈应力场主要受重力势能差控制;印度板块与青藏高原碰撞带岩石圈应力场主要受控于深部地幔拖曳力;青藏高原内部岩石圈应力场受重力势能和地幔拖曳力共同控制.青藏高原东南缘岩石圈应力场与地表形变相关性较差,推测该地区由于存在有效黏度更低的下地壳流使壳幔解耦,地幔拖曳力对浅部地壳影响较弱,导致岩石圈平均应力场与地表形变不一致.

关键词：青藏高原重力势能地幔对流岩石圈偏应力场 GPS应变率场

不平衡电网下模块化多电平换流器的直流环流均衡策略

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电工技术学报 2024年第2期39卷 541-553页

作者：潘子迅杨晓峰赵锐崔晨阳郑琼林北京交通大学电气工程学院北京100044

不平衡电网下模块化多电平换流器(MMC)存在三相直流环流不均衡问题,易导致相间电流应力和热应力差异,降低其在不平衡工况下安全运行能力。该文从桥臂功率角度分析不平衡电网下三相MMC直流环流不均衡现象和基于零序电压注入的直流环流均... 详细信息

不平衡电网下模块化多电平换流器(MMC)存在三相直流环流不均衡问题,易导致相间电流应力和热应力差异,降低其在不平衡工况下安全运行能力。该文从桥臂功率角度分析不平衡电网下三相MMC直流环流不均衡现象和基于零序电压注入的直流环流均衡机理。提出一种零序电压注入的直流环流均衡方法,通过网侧电流与直流环流偏差量计算得到零序电压相位,经过比例谐振控制器生成零序电压注入量,进而实现直流环流的快速、有效均衡。在所提出的控制策略的基础上,研究该方法对MMC桥臂电流峰值、有效值及子模块电容电压纹波的影响规律。仿真与实验结果验证了该文理论分析与控制策略的有效性。

关键词：不平衡电网模块化多电平换流器直流环流零序电压注入桥臂电流子模块电容电压

Theoretical and Experimental Study of a Numerical Aperture for Multimode PCS Fiber Optics Using an Imaging Technique

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Chinese Physics Letters 2012年第11期29卷 119-122页

作者： Saman q.Mawlud Nahlah q.Muhamad Department of Physics Education CollageScientific DepartmentSalahaddin UniversityErbilKurdistan RegionIraq

We study theoretically and experimentally the properties of numerical aperture(NA)of multimode graded-index plastic core silica(PCS)fibers by using an image technique.A He-Ne laser at wavelength 632.8 nm and output power 1 mW is used as the transmitter light *** output beam images and intensity profiles of an optical fiber are investigated by using an imaging *** laser beam profiles captured by a sensitive digital Nikon camera are processed and analyzed by using a Gaussian intensity distribution in a 2D graph.A MathCAD 14 program is used for converting the image of the laser output beam into *** theoretical and experimental values of the numerical aperture for the used optical fiber in this study are found to be 0.5 and 0.4924,*** theoretical value of V-number is also calculated to be approximately 2482.

关键词： technique fiber PCS

Acasta片麻杂岩多期次热事件:来自锆石、榍石和磷灰石的原位微区年代学证据

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中国科学：地球科学 2024年第3期54卷 693-707页

作者：梅清风杨进辉孙金凤李秋立吴石头凌潇潇彭澎王浩中国科学院地质与地球物理研究所岩石圈演化国家重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院大学计算地球动力学重点实验室北京100049

本文使用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)和二次离子质谱(SIMS)对Acasta片麻杂岩样品碎片(大小约1cm2)中的锆石、磷灰石和榍石进行了原位微区定年,以制约Acasta片麻杂岩的热演化历史.这些样品碎片中的锆石显示多期年龄,反映了... 详细信息

本文使用激光剥蚀电感耦合等离子体质谱(LA-ICPMS)和二次离子质谱(SIMS)对Acasta片麻杂岩样品碎片(大小约1cm2)中的锆石、磷灰石和榍石进行了原位微区定年,以制约Acasta片麻杂岩的热演化历史.这些样品碎片中的锆石显示多期年龄,反映了继承锆石的存在或者锆石结晶后的再生长过程.结合前人研究,本文锆石数据揭示, Acasta片麻杂岩经历的多期岩浆事件发生时间分别为:>3.96、约3.72和约3.57Ga.样品AY199中榍石的PbPb等时线年龄为(2911±22)Ma(95%置信水平, MSWD=1.5),与Acasta片麻杂岩记录的太古宙最后一次岩浆事件年龄一致.样品AC478和AY066中榍石U-Pb年龄分别为(1932±270)Ma(95%置信水平, MSWD=2.3)和(1813±45)Ma(95%置信水平, MSWD=2.3).样品P090803-C中磷灰石的Pb-Pb等时线年龄为(1833±26)Ma(95%置信水平,MSWD=1.4).样品AC478、AY199和AY066中磷灰石U-Pb年龄分别为(1850±20)Ma(95%置信水平, MSWD=1.3)、(1827±100)Ma(95%置信水平, MSWD=6.3)和(1807±58)Ma(95%置信水平, MSWD=3.9).样品AC478和AY066中的榍石U-Pb年龄以及本文所有样品中的磷灰石Pb-Pb或U-Pb年龄相同,均为约1.9~1.8Ga,指示Wopmay造山作用导致的矿物U-Pb体系重置,证明了Wopmay造山作用的峰期温度超过了磷灰石的U-Pb体系封闭温度,并接近或者超过榍石的U-Pb体系封闭温度.

关键词：锆石榍石磷灰石 Acasta片麻杂岩 Wopmay造山带

A TWO-LEVEL GENETIC ALGORITHM FOR SCHEDULING IN ASSEMBLY ISLANDS WITH FIXED-POSITION LAYOUTS

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Journal of Systems Science and Systems Engineering 2010年第2期19卷 150-161页

作者： George q.HUANG Department of Industrial and Manufacturing Systems Engineering The University of Hong Kong

This paper focuses on the scheduling problem in assembly islands environment with fixed-position layouts. In such configuration, the product normally remains in one location for its entire manufacturing period while machines, materials and workers are moved to an assembly site called an assembly island. This production layout has some unique features such as moving assembly workers, tools and materials; limited space at assembly site; considerable distance between islands. The authors first give the definition and mathematical model for the scheduling problem and then propose a two-level genetic algorithm to obtain a near optimal solution to minimize the makespan. Experimental results show that this algorithm is effective. The performance analysis of the proposed algorithm indicates that it is more efficient in the airline or shipbuilding industry than in the machine or tool final assembly companies.

关键词： Assembly islands scheduling genetic algorithm

GLOBAL SUPERCONVERGENCE ESTIMATES OF FINITE ELEMENT METHOD FOR SCHRODINGER EqUATION

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Journal of Computational Mathematics 1998年第6期16卷 521-526页

作者： Lin, q Liu, Xq Acad Sinica Inst Syst Sci Beijing 100080 Peoples R China Xiangtan Teachers Coll Dept Math Hunan 411201 Peoples R China

In this paper, we shall study the initial boundary value problem of Schrodinger equation. The second order gradient superconvergence estimates for the problem are obtained solving by linear finite elements.

关键词： finite element superconvergence estimates interpolation Schrodinger equation

HIGH ACCURACY ANALYSIS OF THE WILSON ELEMENT

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Journal of Computational Mathematics 1999年第2期17卷 113-124页

作者： Luo, P Lin, q Chinese Acad Sci Inst Math Beijing 100080 Peoples R China Chinese Acad Sci Inst Syst Sci Beijing 100080 Peoples R China

In this paper, the Wilson nonconforming finite element is considered for solving a class of second-order elliptic boundary value problems. Based on an asymptotic error expansion for the Wilson finite element, the glob... 详细信息

关键词： finite elements defect correction global superconvergence Wilson element