Results 31 to 40 of about 25,621 (167)
Finite Element Analysis for Maxwell's Eigenvalue Problems [PDF]
, 2016 在微波工程中，波导和谐振腔都是十分重要的微波器件，这些微波器件广泛地用于 我们的现实生活中.在波导问题中，如果电磁波的频率给定，那么传播常数就是一个非常重要的物理参数.在谐振腔问题中，谐振频率是一个十分重要的物理参数.当波导横截面不规则或者填充有非均匀介质时，此时波导问题的解析解是很难找到的;当腔体的几何结构十分复杂或者填充有非均匀介质时，此时谐振腔问题的谐振频率的精确解也是很难找到的.但是我们往往需要知道这些微波工程器件的这些物理参数，所以通常采用数值方法去近似求解它们 ...
姜威
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Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT The detection of volatile organic compounds (VOCs) holds significant implications in environmental monitoring and disease diagnosis. Traditional gas detection technologies are constrained by complex operation and high cost, thereby failing to satisfy real‐time detection demands.
Yuening Wang +11 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2019 目的研究三维彩色多普勒超声在甲状腺功能亢进症(Graves病)诊断中的应用价值。方法选取本院2017年1月-2018年1月间确诊的65例Graves病患者作为研究资料,选取同期在本院接受健康体检的65位健康受检者作为对照组,对比两组患者甲状腺彩色多普勒超声(彩超)参数、三维彩色多普勒超声(三维彩超)参数的差异性;以确诊结果为金标准,分析彩超、三维彩超诊断结果与金标准间的一致性,计算诊断效能指标;以受试者工作特征(ROC)曲线参数曲线下面积(AUC)分析彩超、三维彩超的诊断价值。结果疾病组甲状腺动脉管径 ...
黄浦
doaj
3D Change Detection of Tumor in Shape and Texture Based on Liver CT [PDF]
, 2016 肝癌是我国最为常见的一种恶性肿瘤，严重威胁到了人类生命健康，如何预防和治疗肝癌成为人类医疗领域的极大挑战。通过CT序列可以得到丰富的肿瘤信息，将这些信息以各种直观的形式展现出来可以帮助临床医生更好的分析病情。本文基于CT图片序列，着重从三维形态和三维纹理两个方面进行肿瘤变化分析，从而进一步推断肿瘤疗效： 首先，在进行肿瘤变化分析之前，需要从CT序列中分割出肿瘤区域并进行三维重建，排除其他组织对后续分析的影响。在分割阶段，为了能够得到理想的分割结果，为后续疗效分析铺垫基础，采用了先预处理 ...
熊婷
core
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Multimodal luminescent materials are crucial for advanced information encryption, real‐time dosimetry, and high‐resolution bioimaging, yet integrating orthogonal stimulus‐responsiveness into a single‐component system is challenging. Herein, we report a Pr3+‐doped Ca3Ga2Ge3O12 (CGGO: Pr3+) garnet phosphor that exhibits orthogonally addressable ...
Qi Chen +10 more
wiley +1 more source
Zhongshan Daxue xuebao. Yixue kexue ban, 2001 【目的】对比研究常规X 线、二维CT 和三维CT 对颌骨肿瘤显示的优缺点。【方法】对51 例颌骨肿瘤患者行常 规X 线、二维CT 和三维CT 检查, 比较分析三种检查方法对颌骨肿瘤显示的特征, 并与手术病理结果相对照。【结果】对下颌 骨肿瘤三种检查方法均能有效地显示, 以三维CT 显示得最为直观明了。对上颌骨肿瘤, 三维CT 通过旋转与切割, 能够立体 直观地显示肿瘤的部位、大小、形状及毗邻关系, 尤其对腭板、眶下壁以及颅底骨质破坏的显示更具优越性;二维CT 对肿瘤的 囊性或实性改变 ...
崇锦, 冉 炜
doaj
3D reconstruction of train accident scene based on monocular image [PDF]
, 2017 To help with making an emergency rescue plan for train accidents, a rapid 3D reconstruction method of train accident scene based on a monocular image was proposed.
Chang, J. +4 more
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Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT In conventional piezoceramics, the coordinated change between the dielectric constant (εr) and the piezoelectric charge constant (d33) usually limits the piezoelectric voltage constant g33 (g33 = d33/εr), a critical figure of merit for piezoelectric sensors.
Xiaoying Feng +7 more
wiley +1 more source
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Two‐dimensional (2D) nonlayered niobium nitrides have attracted considerable interest for electrochemical energy storage. However, the synthesis of these materials is hampered by their nonlayered crystal structures, which are characterized by strong three‐dimensional chemical bonding.
Rui Huo +7 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2014 目的探讨二维超声和三维超声检查在产前胎儿畸形筛查中的应用价值,评价其在产前诊断中的应用效果。方法选择56例接受二维和三维超声产前检查并经引产或随访证实有胎儿畸形的孕妇作为研究对象,观察记录56例孕妇共58个畸形胎儿的畸形情况,比较观察二维超声和三维超声检查结果。结果 56例孕妇共检出58个胎儿,最终随访结果发现75处胎儿畸形,其中腹部畸形最多,共27处,占36.0%。三维超声在评价颅面部、脊柱四肢以及体表处的畸形效果优于二维超声,但差异无统计学意义（P>0.05）;三维超声总的畸形检出率为92.0 ...
韩锁凤
doaj