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腔内超声、MSCT联合血清CA125对卵巢囊腺肿瘤的诊断价值探讨 被引量:1
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作者 范晴 任转勤 +1 位作者 沈天波 万秦芸 《中国CT和MRI杂志》 2024年第4期125-128,共4页
目的探讨腔内超声、MSCT影像特征及CA125联合检查在卵巢囊腺肿瘤诊断的应用价值。方法回顾性分析116例女性(130个病灶)卵巢囊腺肿瘤患者超声、MSCT、CA125检查及病理资料,比较单独检查及联合检查在良、恶性囊腺肿瘤间诊断效能差异及影... 目的探讨腔内超声、MSCT影像特征及CA125联合检查在卵巢囊腺肿瘤诊断的应用价值。方法回顾性分析116例女性(130个病灶)卵巢囊腺肿瘤患者超声、MSCT、CA125检查及病理资料,比较单独检查及联合检查在良、恶性囊腺肿瘤间诊断效能差异及影像学特征分析。结果病理结果显示囊腺瘤93个,囊腺癌37个;腔内超声图像特征如包膜、囊内回声、壁结节、腹腔积液、腹膜及淋巴结转移、血流显示在两组间均具有统计学差异(P<0.05);MSCT图像特征如CT值、边界、形态、腹盆腔积液、腹膜及淋巴结转移、强化程度在两组间均具有统计学差异(P<0.05);良性组患者CA125水平显著低于恶性组患者,具有统计学差异(P<0.05);腔内超声、MSCT、CA125联合检查对卵巢囊腺肿瘤的诊断效能均高于各项单独检查,具有统计学差异(P<0.05)。结论卵巢囊腺肿瘤的腔内超声、MSCT、CA125检查具有显著差异,联合检查对两者检出率均高于单独检查,对肿瘤性质判断具有更高的准确性,可为临床诊疗工作提供可靠依据。 展开更多
关键词 卵巢囊腺肿瘤 腔内超声 msct 血清糖类抗原125
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M^(3)Res-Transformer:新冠肺炎胸部X-ray图像识别模型 被引量:1
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作者 周涛 刘赟璨 +3 位作者 侯森宝 常晓玉 叶鑫宇 陆惠玲 《电子学报》 EI CAS CSCD 北大核心 2024年第2期589-601,共13页
新冠肺炎(COVID-19)自爆发以来严重影响人类生命健康,近年来残差神经网络广泛应用于COVID-19识别任务中,辅助医生快速地诊断COVID-19患者,但是COVID-19图像病变区域形状复杂、大小不一,与周围组织的边界模糊,导致网络难以提取有效特征.... 新冠肺炎(COVID-19)自爆发以来严重影响人类生命健康,近年来残差神经网络广泛应用于COVID-19识别任务中,辅助医生快速地诊断COVID-19患者,但是COVID-19图像病变区域形状复杂、大小不一,与周围组织的边界模糊,导致网络难以提取有效特征.本文针对上述问题,提出一种M^(3)Res-Transformer的新冠肺炎胸部X-ray图像识别模型,采用Res-Transformer作为模型的主干网络,结合ResNet和ViT,有效地整合局部病变特征和全局特征;设计混合残差注意力模块(mixed residual attention Module,mraM),同时考虑通道和空间位置的相互依赖性,增强网络的特征表达能力;为了增大感受野,提取多尺度特征,通过叠加具有不同扩张率的扩张卷积构造多尺度扩张残差模块(multiscale dilated residual Module,mdrM),根据不同层次特征尺度的差异,使用3个逐渐收缩尺度的mdrM进行多尺度特征提取;提出上下文交叉感知模块(contextual cross-awareness Module,ccaM),使用深层特征中的语义信息来引导浅层特征,然后将浅层特征中的空间信息嵌入深层特征中,采用交叉加权注意力机制高效聚合深层和浅层特征,获得更丰富的上下文信息.为了验证本文所提模型的有效性,在新冠肺炎胸部X-ray图像数据集上进行实验,与先进的CNN分类模型、融合不同注意力机制的ResNet50模型、基于Transformer的分类模型对比以及消融实验.结果表明,本文所提模型的Acc、Pre、Rec、F1-Score与Spe指标分别为96.33%、96.36%、96.33%、96.35%与96.26%,在COVID-19胸部X-ray图像识别任务中有效提升了识别精度,并通过可视化方法对其进行进一步验证,为COVID-19的辅助诊断提供重要的参考价值. 展开更多
关键词 COVID-19 胸部x-ray图像 残差神经网络 vision transformer 注意力机制
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X-ray在鱼体组织及微量元素检测中的应用
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作者 宋一帆 张胜茂 +4 位作者 张衡 唐峰华 张寒野 石永闯 崔雪森 《应用光学》 CAS 北大核心 2024年第1期166-176,共11页
鱼类硬质组织物,特别是骨骼支持鱼体和保护其体内器官的组织,对其进行特征检测分析是研究鱼类游泳运动、鱼类解剖、鱼体建模等的数据基础。随着X-ray技术的发展和国产设备的广泛应用,其仪器设备成本明显降低,使得X-ray在渔业研究与自动... 鱼类硬质组织物,特别是骨骼支持鱼体和保护其体内器官的组织,对其进行特征检测分析是研究鱼类游泳运动、鱼类解剖、鱼体建模等的数据基础。随着X-ray技术的发展和国产设备的广泛应用,其仪器设备成本明显降低,使得X-ray在渔业研究与自动化生产中的应用成为可能。首先介绍了X-ray技术的基本原理与其在鱼体组织检测中的应用,X-ray技术在鱼体组织及微量元素检测中的应用主要分为鱼类组织器官的无损检测和鱼体微量元素检测两部分,其中分别介绍了包括照相法、数字成像法、衍射技术和吸收光谱法等X-ray技术;然后综述其在鱼体组织器官建模、鱼骨检测、鱼类化石研究、鱼耳石分析和鱼体微量元素检测方面的应用,总结了Xray在渔业领域应用中存在的问题;最后对X-ray的渔业应用方向进行展望。 展开更多
关键词 x-ray 鱼体骨骼 鱼类耳石 鱼体建模 鱼体微量元素
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Global hybrid simulations of soft X-ray emissions in the Earth’s magnetosheath 被引量:2
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作者 Jin Guo TianRan Sun +6 位作者 San Lu QuanMing Lu Yu Lin XueYi Wang Chi Wang RongSheng Wang Kai Huang 《Earth and Planetary Physics》 EI CSCD 2024年第1期47-58,共12页
Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging ... Earth’s magnetopause is a thin boundary separating the shocked solar wind plasma from the magnetospheric plasmas,and it is also the boundary of the solar wind energy transport to the magnetosphere.Soft X-ray imaging allows investigation of the large-scale magnetopause by providing a two-dimensional(2-D)global view from a satellite.By performing 3-D global hybrid-particle-in-cell(hybrid-PIC)simulations,we obtain soft X-ray images of Earth’s magnetopause under different solar wind conditions,such as different plasma densities and directions of the southward interplanetary magnetic field.In all cases,magnetic reconnection occurs at low latitude magnetopause.The soft X-ray images observed by a hypothetical satellite are shown,with all of the following identified:the boundary of the magnetopause,the cusps,and the magnetosheath.Local X-ray emissivity in the magnetosheath is characterized by large amplitude fluctuations(up to 160%);however,the maximum line-of-sight-integrated X-ray intensity matches the tangent directions of the magnetopause well,indicating that these fluctuations have limited impact on identifying the magnetopause boundary in the X-ray images.Moreover,the magnetopause boundary can be identified using multiple viewing geometries.We also find that solar wind conditions have little effect on the magnetopause identification.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will provide X-ray images of the magnetopause for the first time,and our global hybrid-PIC simulation results can help better understand the 2-D X-ray images of the magnetopause from a 3-D perspective,with particle kinetic effects considered. 展开更多
关键词 MAGNETOPAUSE x-ray emissivity x-ray imaging SMILE global hybrid-PIC simulation
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MSCT与X线诊断患者气胸的价值观察
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作者 李宏荣 谢晶美 王永宏 《中国CT和MRI杂志》 2024年第1期66-67,共2页
目的观察多层螺旋CT(MSCT)与X线诊断患者气胸的价值。方法选取2021年5月至2022年5月陕西省榆林市第二医院收治的气胸患者100例为研究对象,均行MSCT及X线检查,分析其各自影像学特点,并以MSCT为诊断气胸的金标准,分析X线与MSCT诊断结果的... 目的观察多层螺旋CT(MSCT)与X线诊断患者气胸的价值。方法选取2021年5月至2022年5月陕西省榆林市第二医院收治的气胸患者100例为研究对象,均行MSCT及X线检查,分析其各自影像学特点,并以MSCT为诊断气胸的金标准,分析X线与MSCT诊断结果的一致性。结果MSCT下,原发性自发性气胸表现为胸廓扁平、肋骨内突、肺气肿样改变及胸膜孔,21例患者检出38个胸膜窗,其中左侧15例,右侧6例,多见于肺尖,其次为前胸壁、纵膈面,MSCT可见小量气胸72例、大量气胸28例;X线胸片可见气胸患者双肺透光度增强,两肺见斑片状高密度影,肺组织压缩聚拢,其中9例未见血性气胸,小量气胸68例、大量气胸23例;MSCT测定小量、大量气胸的肺压缩比较X线更高(P<0.05),对于小量气胸的肺压缩比,X线与MSCT的相关度达0.904(P<0.05),对大量气胸的相关性为0.918(P<0.05);一致性检验显示,X线与MSCT诊断患者大量气胸的Kappa值为0.705,一致性较高。结论MSCT与X线对患者气胸均有一定诊断价值,其中MSCT的诊断价值更高。 展开更多
关键词 msct X线 气胸 价值
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The Soft X-ray Imager(SXI)on the SMILE Mission 被引量:4
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作者 S.Sembay A.L.Alme +83 位作者 D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bicknell C.Bouldin G.Branduardi-Raymont T.Crawford J.P.Breuer T.Buggey G.Butcher R.Canchal J.A.Carter A.Cheney Y.Collado-Vega H.Connor T.Crawford N.Eaton C.Feldman C.Forsyth T.Frantzen G.Galgóczi J.Garcia G.Y.Genov C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson J.Hasiba O.Hetherington A.Holland S-Y.Hsieh M.W.J.Hubbard H.Jeszenszky M.Jones T.Kennedy K.Koch-Mehrin S.Kögl S.Krucker K.D.Kuntz C.Lakin G.Laky O.Lylund A.Martindale J.Miguel Mas Hesse R.Nakamura K.Oksavik N.Østgaard H.Ottacher R.Ottensamer C.Pagani S.Parsons P.Patel J.Pearson G.Peikert F.S.Porter T.Pouliantis B.H.Qureshi W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sachdev A.Samsonov M.Soman D.Sibeck S.Smit J.Søndergaard R.Speight S.Stavland M.Steller TianRan Sun J.Thornhill W.Thomas K.Ullaland B.Walsh D.Walton C.Wang S.Yang 《Earth and Planetary Physics》 EI CSCD 2024年第1期5-14,共10页
The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese... The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in 2025.SXI is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE orbit.SXI is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s exosphere.SWCX provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field lines.The sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many hours.SXI is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States. 展开更多
关键词 Soft x-ray Imaging micropore optics large area CCD
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Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background 被引量:2
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作者 YingJie Zhang TianRan Sun +5 位作者 JenniferACarter WenHao Liu Steve Sembay ShuiNai Zhang Li Ji Chi Wang 《Earth and Planetary Physics》 EI CSCD 2024年第1期119-132,共14页
Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is propo... Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust and reliable,and should be considered based on the best available options. 展开更多
关键词 solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft x-ray x-ray imaging MAGNETOSPHERE
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Exploring battery material failure mechanisms through synchrotron X-ray characterization techniques 被引量:1
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作者 Lingzhe Fang Xiaozhao Liu Tao Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第7期128-135,共8页
Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synch... Rechargeable battery cycling performance and related safety have been persistent concerns.It is crucial to decipher the capacity fading induced by electrode material failure via a range of techniques.Among these,synchrotron-based X-ray techniques with high flux and brightness play a key role in understanding degradation mechanisms.In this comprehensive review,we summarize recent advancements in degra-dation modes and mechanisms that were revealed by synchrotron X-ray methodologies.Subsequently,an overview of X-ray absorption spectroscopy and X-ray scattering techniques is introduced for charac-terizing failure phenomena at local coordination atomic environment and long-range order crystal struc-ture scale,respectively.At last,we envision the future of exploring material failure mechanism. 展开更多
关键词 Battery failure Synchrotron-based techniques x-ray scattering x-ray absorption spectroscopy
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Finding the magnetopause location using soft X-ray observations and a statistical inverse method 被引量:1
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作者 Gonzalo Cucho-Padin Hyunju Connor +2 位作者 Jaewoong Jung Brian Walsh David G.Sibeck 《Earth and Planetary Physics》 EI CSCD 2024年第1期184-203,共20页
Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the magneto... Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the magnetosphere.The spatial and temporal properties of the magnetopause,under varying solar and magnetospheric conditions,remain largely unknown because empirical studies using in-situ observations are challenging to interpret.Global wide field-of-view(FOV)imaging is the only means to simultaneously observe the spatial distribution of the plasma properties over the vast dayside magnetospheric region and,subsequently,quantify the energy transport from the interplanetary medium into the terrestrial magnetosphere.Two upcoming missions,ESA/CAS SMILE and NASA’s LEXI will provide wide-field imagery of the dayside magnetosheath in soft X-rays,an emission generated by charge exchange interactions between high charge-state heavy ions of solar wind origin and exospheric neutral atoms.High-cadence two-dimensional observations of the magnetosheath will allow the estimation of dynamic properties of its inner boundary,the magnetopause,and enable studies of its response to changes in the solar wind dynamic pressure and interplanetary magnetic field orientation.This work introduces a statistically-based estimation approach based on inverse theory to estimate the spatial distribution of magnetosheath soft X-ray emissivities and,with this,identify the location of the magnetopause over the Sun−Earth line.To do so,we simulate the magnetosheath structure using the MHD-based OpenGGCM model and generate synthetic soft X-ray images using LEXI’s orbit and attitude information.Our results show that 3-D estimations using the described statistically-based technique are robust against Poisson-distributed shot noise inherent to soft X-ray images.Also,our proposed methodology shows that the accuracy of both three-dimensional(3-D)estimation and the magnetopause standoff distance calculation highly depends on the observational point. 展开更多
关键词 MAGNETOPAUSE soft x-ray TOMOGRAPHY
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Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter 被引量:1
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作者 Hyangpyo Kim Hyunju K.Connor +9 位作者 Jaewoong Jung Brian M.Walsh David Sibeck Kip D.Kuntz Frederick S.Porter Catriana K.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nakamura Michael Collier 《Earth and Planetary Physics》 EI CSCD 2024年第1期173-183,共11页
The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective l... The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind conditions.To suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray images.In this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look direction of the instrument,and the angle at which the X-ray emission is maximized.Two assumptions are used in this method:(1)The look direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause curvature.We create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic background,the instrument point spread function,and Poisson noise.We then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look angles for the soft X-ray pea ks.From the filte red images,we calculate RS and its accuracy for different LEXI locations,look directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground truth.Our method estimates RS with an accuracy of<0.3 RE when the solar wind density exceeds>10 cm-3.The accuracy improves for greater solar wind densities and during southward interplanetary magnetic fields.The method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field turnings.Consequently,the technique will enable quantitative analysis of the magnetopause motion and help reveal the dayside reconnection modes for dynamic solar wind conditions.This technique will suppo rt the LEXI and SMILE missions in achieving their scientific o bjectives. 展开更多
关键词 soft x-ray MAGNETOPAUSE RECONNECTION low-pass filter LEXI SMILE
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SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation 被引量:1
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作者 S.Parsons D.J.Hall +4 位作者 O.Hetherington T.W.Buggey T.Arnold M.W.J.Hubbard A.Holland 《Earth and Planetary Physics》 EI CSCD 2024年第1期25-38,共14页
Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the sof... Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented. 展开更多
关键词 CCD soft x-ray imager characterisation SMILE
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Solar wind ion charge state distributions and compound cross sections for solar wind charge exchange X-ray emission 被引量:1
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作者 Dimitra Koutroumpa 《Earth and Planetary Physics》 EI CSCD 2024年第1期105-118,共14页
Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilitie... Solar Wind Charge eXchange X-ray(SWCX) emission in the heliosphere and Ea rth’s exosphere is a hard to avoid signal in soft Xray obse rvations of astrophysical targets.On the other hand,the X-ray imaging possibilities offered by the SWCX process has led to an increasing number of future dedicated space missions for investigating the solar wind-terrestrial inte ractions and magnetospheric interfaces.In both cases,accurate modelling of the SWCX emission is key to correctly interpret its signal,and remove it from obse rvations,when needed.In this paper,we compile solar wind abundance measurements from ACE for different solar wind types,and atomic data from literature,including charge exchange cross-sections and emission probabilities,used fo r calculating the compound cross-section a for the SWCX X-ray emission.We calculate a values for charge-exchange with H and He,relevant to soft X-ray energy bands(0.1-2.0 keV)for various solar wind types and solar cycle conditions. 展开更多
关键词 solar wind charge exchange x-rays MAGNETOSPHERE HELIOSPHERE
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MSCT三维重建联合磁共振诊断踝关节韧带损伤的价值 被引量:1
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作者 李文一 彭梦晗 张婧 《现代医用影像学》 2024年第2期322-325,共4页
目的:探讨MSCT三维重建联合磁共振(MRI)诊断踝关节韧带损伤的价值。方法:选取2021年7月至2023年6月本院收治的70例踝关节急性损伤手术患者为对象,采用MSCT三维重建及MRI检查,以关节镜检查为金标准,分析二者联合诊断踝关节韧带损伤的价... 目的:探讨MSCT三维重建联合磁共振(MRI)诊断踝关节韧带损伤的价值。方法:选取2021年7月至2023年6月本院收治的70例踝关节急性损伤手术患者为对象,采用MSCT三维重建及MRI检查,以关节镜检查为金标准,分析二者联合诊断踝关节韧带损伤的价值。结果:本文70例手术患者中65例明确诊断为韧带损伤。MSCT三维重建联合磁共振诊断踝关节韧带损伤的灵敏度、准确度为98.46%、97.14%;MSCT三维重建诊断踝关节韧带损伤的灵敏度、准确度分别为80.00%、78.57%;MRI诊断踝关节韧带损伤的灵敏度、准确度分别为81.54%、81.43%。MSCT三维重建+MRI诊断踝关节损伤的灵敏度、准确度高于二者单独检测(P<0.05)。结论:MSCT三维重建与MRI联合诊断踝关节韧带损伤的价值较高,可提高诊断的灵敏度及准确度,可在临床推广。 展开更多
关键词 msct三维重建 磁共振 踝关节韧带损伤
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Microstructures and micromechanical behaviors of high -entropy alloys investigated by synchrotron X-ray and neutron diffraction techniques: A review 被引量:1
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作者 Yubo Huang Ning Xu +3 位作者 Huaile Lu Yang Ren Shilei Li Yandong Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第6期1333-1349,共17页
High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Exten... High-entropy alloys(HEAs)possess outstanding features such as corrosion resistance,irradiation resistance,and good mechan-ical properties.A few HEAs have found applications in the fields of aerospace and defense.Extensive studies on the deformation mech-anisms of HEAs can guide microstructure control and toughness design,which is vital for understanding and studying state-of-the-art structural materials.Synchrotron X-ray and neutron diffraction are necessary techniques for materials science research,especially for in situ coupling of physical/chemical fields and for resolving macro/microcrystallographic information on materials.Recently,several re-searchers have applied synchrotron X-ray and neutron diffraction methods to study the deformation mechanisms,phase transformations,stress behaviors,and in situ processes of HEAs,such as variable-temperature,high-pressure,and hydrogenation processes.In this review,the principles and development of synchrotron X-ray and neutron diffraction are presented,and their applications in the deformation mechanisms of HEAs are discussed.The factors that influence the deformation mechanisms of HEAs are also outlined.This review fo-cuses on the microstructures and micromechanical behaviors during tension/compression or creep/fatigue deformation and the application of synchrotron X-ray and neutron diffraction methods to the characterization of dislocations,stacking faults,twins,phases,and intergrain/interphase stress changes.Perspectives on future developments of synchrotron X-ray and neutron diffraction and on research directions on the deformation mechanisms of novel metals are discussed. 展开更多
关键词 high-entropy alloys MICROSTRUCTURES micromechanical behaviors synchrotron x-ray diffraction neutron diffraction
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Using restored two-dimensional X-ray images to reconstruct the three-dimensional magnetopause 被引量:2
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作者 RongCong Wang JiaQi Wang +3 位作者 DaLin Li TianRan Sun XiaoDong Peng YiHong Guo 《Earth and Planetary Physics》 EI CSCD 2024年第1期133-154,共22页
Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosph... Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space physics.The Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray imaging.However,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the magnetopause.The analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration models.This makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical models.We propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the magnetosphere.The idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch estimator.The Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the estimator.Experimental results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural similarity.The restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving the reconstruction results.Hence,the proposed technology may be feasible for processing SXI-simulated observation images. 展开更多
关键词 Solar wind Magnetosphere Ionosphere Link Explorer(SMILE) soft x-ray imager MAGNETOPAUSE image restoration
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基于X-rayμCT技术的玉米干燥损伤定量研究
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作者 范奔 任柳阳 杨德勇 《农机化研究》 北大核心 2024年第4期167-172,共6页
应力裂纹是玉米干燥损伤的主要形式,一些微裂纹无法肉眼观察但影响玉米的机械强度、发芽率以及活力等。为此,利用X-rayμCT技术对不同干燥条件下玉米进行扫描,使用深度学习算法分割与胚乳密度相近的胚区域并结合软件对玉米内部物性特征... 应力裂纹是玉米干燥损伤的主要形式,一些微裂纹无法肉眼观察但影响玉米的机械强度、发芽率以及活力等。为此,利用X-rayμCT技术对不同干燥条件下玉米进行扫描,使用深度学习算法分割与胚乳密度相近的胚区域并结合软件对玉米内部物性特征参数进行提取,提出了一种新的玉米内部损伤定量评价方法。结合定量研究结果提出的玉米干燥损伤模型,可为玉米损伤预测提供新思路。 展开更多
关键词 玉米干燥 应力裂纹 定量评价 x-rayμCT
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On the apparent line-of-sight alignment of the peak X-ray intensity of the magnetosheath and the tangent to the magnetopause,as viewed by SMILE-SXI 被引量:2
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作者 Andrew Read 《Earth and Planetary Physics》 EI CSCD 2024年第1期155-172,共18页
The Soft X-ray Imager(SXI)on board the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)spacecraft will be able to view the Earth’s magnetosheath in soft X-rays.Simulated images of the X-ray emission visible f... The Soft X-ray Imager(SXI)on board the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)spacecraft will be able to view the Earth’s magnetosheath in soft X-rays.Simulated images of the X-ray emission visible from the position of SMILE are created for a range of solar wind densities by using 3 years of the SMILE mission orbit,together with models of the expected X-ray emissivity from the Earth’s magnetosheath.Results from global magnetohydrodynamic simulations and a simple model for exospheric neutral densities are used to compare the locations of the lines of sight along which integrated soft X-ray intensities peak with the lines of sight lying tangent to surfaces(defined here to be the magnetopause)along which local soft X-ray intensities peak or exhibit their strongest gradients,or both,for strongly southward interplanetary magnetic field conditions when no depletion or low-latitude boundary layers are expected.Where,in the parameter space of the various times and seasons,orbital phases,solar wind conditions,and magnetopause models,the alignment of the X-ray emission peak with the magnetopause tangent is good,or is not,is presented.The main results are as follows.The spacecraft needs to be positioned well outside the magnetopause;low-altitude times near perigee are not good.In addition,there are seasonal aspects:dayside-apogee orbits are generally very good because the spacecraft travels out sunward at high altitude,but nightside-apogee orbits,behind the Earth,are bad because the spacecraft only rarely leaves the magnetopause.Dusk-apogee and dawnapogee orbits are intermediate.Dayside-apogee orbits worsen slightly over the first three mission years,whereas nightside-apogee orbits improve slightly.Additionally,many more times of good agreement with the peak-to-tangent hypothesis occur when the solar wind is in a high-density state,as opposed to a low-density state.In a high-density state,the magnetopause is compressed,and the spacecraft is more often a good distance outside the magnetopause. 展开更多
关键词 x-rays MAGNETOSPHERE MAGNETOSHEATH MAGNETOPAUSE Solar wind Magnetosphere Ionosphere Link Explorer(SMILE) Earth solar wind charge exchange
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Hybrid-Vlasov simulation of soft X-ray emissions at the Earth’s dayside magnetospheric boundaries 被引量:2
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作者 M.Grandin H.K.Connor +5 位作者 S.Hoilijoki M.Battarbee Y.Pfau-Kempf U.Ganse K.Papadakis M.Palmroth 《Earth and Planetary Physics》 EI CSCD 2024年第1期70-88,共19页
Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing tech... Solar wind charge exchange produces emissions in the soft X-ray energy range which can enable the study of near-Earth space regions such as the magnetopause,the magnetosheath and the polar cusps by remote sensing techniques.The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)and Lunar Environment heliospheric X-ray Imager(LEXI)missions aim to obtain soft Xray images of near-Earth space thanks to their Soft X-ray Imager(SXI)instruments.While earlier modeling works have already simulated soft X-ray images as might be obtained by SMILE SXI during its mission,the numerical models used so far are all based on the magnetohydrodynamics description of the space plasma.To investigate the possible signatures of ion-kinetic-scale processes in soft Xray images,we use for the first time a global hybrid-Vlasov simulation of the geospace from the Vlasiator model.The simulation is driven by fast and tenuous solar wind conditions and purely southward interplanetary magnetic field.We first produce global X-ray images of the dayside near-Earth space by placing a virtual imaging satellite at two different locations,providing meridional and equatorial views.We then analyze regional features present in the images and show that they correspond to signatures in soft X-ray emissions of mirrormode wave structures in the magnetosheath and flux transfer events(FTEs)at the magnetopause.Our results suggest that,although the time scales associated with the motion of those transient phenomena will likely be significantly smaller than the integration time of the SMILE and LEXI imagers,mirror-mode structures and FTEs can cumulatively produce detectable signatures in the soft X-ray images.For instance,a local increase by 30%in the proton density at the dayside magnetopause resulting from the transit of multiple FTEs leads to a 12%enhancement in the line-of-sight-and time-integrated soft X-ray emissivity originating from this region.Likewise,a proton density increase by 14%in the magnetosheath associated with mirror-mode structures can result in an enhancement in the soft X-ray signal by 4%.These are likely conservative estimates,given that the solar wind conditions used in the Vlasiator run can be expected to generate weaker soft X-ray emissions than the more common denser solar wind.These results will contribute to the preparatory work for the SMILE and LEXI missions by providing the community with quantitative estimates of the effects of small-scale,transient phenomena occurring on the dayside. 展开更多
关键词 MAGNETOSPHERE MAGNETOSHEATH numerical simulation SMILE LEXI soft x-ray emissions hybrid-Vlasov model polar cusp flux transfer events mirror-mode waves
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基于MSCT三维扫描加重建对成人髋关节发育不良全髋关节置换术中髋臼假体的选择及截骨的准确性预测价值 被引量:1
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作者 崔晓荣 兰丽华 +1 位作者 李向阳 钟志锋 《实用医学杂志》 CAS 北大核心 2024年第9期1309-1313,共5页
目的探讨基于MSCT三维扫描加重建对成人髋关节发育不良(DDH)患者行全髋关节置换术(THA)时髋臼假体的选择及截骨准确性的预测价值。方法选择60例行全髋关节置换术的成人DDH患者,其中使用常规术前规划的30例患者作为对照组,而使用MSCT三... 目的探讨基于MSCT三维扫描加重建对成人髋关节发育不良(DDH)患者行全髋关节置换术(THA)时髋臼假体的选择及截骨准确性的预测价值。方法选择60例行全髋关节置换术的成人DDH患者,其中使用常规术前规划的30例患者作为对照组,而使用MSCT三维扫描加重建技术的30例患者作为观察组,规划完成后依据规划情况实行手术操作及假体置入,收集两组手术前后相关信息,比较两组患者手术时间、术中出血量、术中透视时间、髋臼假体选择匹配率、股骨劈裂骨折发生率、骨盆及髋臼复位质量、Majeed评分及Harris髋关节功能评分,比较两组患者规划前及实际情况中截骨距离、尖肩距情况,评估MSCT三维扫描加重建技术与髋臼假体选择准确度的相关性。结果结果分析显示,观察组患者术前评估使用的MSCT三维扫描加重建技术与髋臼假体选择的准确性具相关性(P<0.05),且规划前情况与实际相比,观察组患者截骨距离及尖肩距的绝对误差更小(P<0.05),此外,相较于对照组患者,观察组患者的手术时间、术中出血量、术中透视时间及股骨劈裂骨折发生率明显更低,髋臼假体选择匹配率、术后3个月时的Majeed评分及Harris评分明显更高(P<0.05),骨盆及髋臼复位质量则两组比较差异无统计学意义(P>0.05)。结论基于MSCT三维扫描+重建对成人DDH全髋关节置换术中髋臼假体的选择及截骨的准确性具较高预测价值,且使用该技术进行术前规划对实际治疗效果及患者恢复具有显著优化效果。 展开更多
关键词 多层螺旋CT 术前规划 髋关节发育不良 全髋关节置换术 截骨
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腹内型隐睾继发精原细胞瘤的MSCT诊断
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作者 柯君丽 陈卫东 《浙江实用医学》 2024年第5期408-411,共4页
目的探讨腹内型隐睾继发精原细胞瘤的MSCT特征。方法分析浙江省衢州市人民医院2014年8月~2021年8月收治的3例经病理证实的腹内型隐睾继发精原细胞瘤的MSCT表现,包括肿瘤位置、大小、密度、强化方式、供血动脉及引流静脉显示、腹内有无... 目的探讨腹内型隐睾继发精原细胞瘤的MSCT特征。方法分析浙江省衢州市人民医院2014年8月~2021年8月收治的3例经病理证实的腹内型隐睾继发精原细胞瘤的MSCT表现,包括肿瘤位置、大小、密度、强化方式、供血动脉及引流静脉显示、腹内有无肿大淋巴结、同侧精索是否存在。结果2例发生于右中下腹,呈单发肿块,其中囊实性1例,实性1例,发生于盆腔呈实性肿块伴腹内淋巴结转移1例。动态增强扫描病灶囊性成分无强化;实性成分呈不均匀轻中度渐进性强化,并见分隔样强化;转移淋巴结呈轻度均匀强化,可见血管“漂浮征”。肿块均由腹主动脉发出的小分支供血,静脉回流至下腔静脉或同侧肾静脉。同侧精索未见2例,存在1例。结论腹内肿块伴增粗的供血动脉及引流静脉、实性成分呈轻中度渐进性强化、分隔样强化、同侧精索未见,结合隐睾病史、血清总β人绒毛膜促性腺激素升高史,有助于腹内型隐睾继发精原细胞瘤的诊断。 展开更多
关键词 隐睾精原细胞瘤 腹内型 msct
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