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Optical coherence tomography enhanced depth imaging of chorioretinal folds in patients with orbital tumors
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作者 Zhi-Yu Peng Lu Gan +4 位作者 Kang Xue Akrit Sodhi Xiao-Feng Ye Hui Ren Jiang Qian 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第2期233-237,共5页
AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was... AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was conducted in 20 eyes of 20 patients,the uninvolved eye served as a control.All the patients underwent clinical fundus photography,computed tomography,EDI SDOCT imaging before and after surgery.Two patients with cavernous hemangiomas underwent intratumoral injection of bleomycin A5;the remaining patients underwent tumor excision.Patients were followed 1 to 14mo following surgery(average follow up,5.8mo).RESULTS:Visual acuity prior to surgery ranged from 20/20 to 20/200.Following surgery,5 patients’visual acuity remained unchanged while the remaining 15 patients had a mean letter improvement of 10(range 4 to 26 letters).Photoreceptor inner/outer segment defects were found in 10 of 15 patients prior to surgery.Following surgical excision,photoreceptor inner/outer segment defects fully resolved in 8 of these 10 patients.CONCLUSION:Persistence of photoreceptor inner/outer segment defects caused by compression of the globe by an orbital mass can be associated with reduced visual prognosis.Our findings suggest that photoreceptor inner/outer segment defects on EDI SD-OCT could be an indicator for immediate surgical excision of an orbital mass causing choroidal compression. 展开更多
关键词 chorioretinal folds orbital mass enhanced depth imaging optical coherence tomography choroidal thickness inner/outer segment defects
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Tectonic evolution of the Dabashan orocline, central China: Insights from the superposed folds in the eastern Dabashan foreland 被引量:13
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作者 Wei Shi Jianhua Li +1 位作者 Mi Tian Guoli Wu 《Geoscience Frontiers》 SCIE CAS CSCD 2013年第6期729-741,共13页
The Dabashan orocline is situated in the northwestern margin of the central Yangtze block,central China.Previous studies have defined the orthogonal superposed folds growing in its central-western segment thereby conf... The Dabashan orocline is situated in the northwestern margin of the central Yangtze block,central China.Previous studies have defined the orthogonal superposed folds growing in its central-western segment thereby confirming its two-stage tectonic evolution history.Geological mapping has revealed that more types of superposed folds have developed in the eastern segment of the orocline,which probably provides more clues for probing the structure and tectonic history of the Dabashan orocline.In this paper,based on geological mapping,structural measurements and analyses of deformation,we have identified three groups of folds with different trends (e.g.NW-,NE-and nearly E-trending folds) and three types of structural patterns of superposed folds in the eastern Dabashan foreland (e.g.syn-axial,oblique,and conjunctional superposed folds).In combination with geochronological data,we propose that the synaxial superposed folds are due to two stages of ~N-S shortening in the west and north of the Shennongjia massif,and that oblique superposed folds have been resulted from the superposition of the NW-and NE-trending folds onto the early ~ E-W folds in the east of the Shennongjia massif in the late Jurassic to early Cretaceous.The conjunctional folds are composed of the NW-and NE-trending folds,corresponding to the regional-scale dual-orocline in the eastern Sichuan as a result of the southwestward expansion of the Dabashan foreland during late Jurassic to early Cretaceous,coeval with the northwestward propagation of the Xuefengshan foreland.Integration of the structure and geochronology of the belt shows that the Dabashan orocline is a combined deformation belt primarily experiencing a twostage tectonic evolution history in Mesozoic,initiation of the Dabashan orocline as a foreland basin along the front of the Qinling orogen in late Triassic to early Jurassic due to collisional orogeny,and the final formation of the Dabashan orocline owing to the southwestward propagation of the Qinling orogen during late Jurassic to early Cretaceous intra-continental orogeny.Our studies provide some evidences for understanding the structure and deformation of the Dabashan orocline. 展开更多
关键词 Dabashan foreland belt Superposed folds OROCLINE Paleo-stress field Intra-continental orogeny Late Jurassic
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Choroidal folds associated with carotid cavernous fistula:a case report
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作者 Yasutsugu Akasaki Takenori Inomata +5 位作者 Jaemyoung Sung Megumi Ito Hiroaki Kobayashi Ryosuke Kuwana Hidenori Oishi Akira Murakami 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第11期1881-1884,共4页
Dear Editor,I am Yasutsugu Akasaki, from the Department of Ophthalmology, Juntendo University Hospital. I am writing this letter to present a case of choroidal folds associated with carotid cavernous fistula(CCFs).
关键词 folds LETTER FISTULA
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Determine Stress Field of the Shirband Area by Geometric and Kinematic Analysis of Faults and Folds (North Damqan, Iran)
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作者 H. Roohafza R. Ramesani A. Taheri 《Journal of Geoscience and Environment Protection》 2017年第2期75-85,共11页
In this paper faults and folds of shirband area (north of damqan) investigated to determine the orient of the stress field. The study area is limited between the two faults with E-W strike and northward slip. Investig... In this paper faults and folds of shirband area (north of damqan) investigated to determine the orient of the stress field. The study area is limited between the two faults with E-W strike and northward slip. Investigations result show major faults of the area have sinisteral mechanism. Waterways displacement and slicken slip of faults approve this issue. Three main folds of area has approx-imately same trend along major faults (E-W). Orientation of stress field investigated and classified by using from some large and medium scale faults and folds. Analysis of stress field investigated by inversion method show that compression axis in the study area have approximately NE-SW strike. 展开更多
关键词 Structural Analysis Stress Field FAULTS folds Astaneh Fault Eastern ALBORZ Shirband Area
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Stroboscopic Evaluation of the Vocal Folds’ Morphometric Characteristics, between the Different Voice Categories on Professional Singers
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作者 Athina Zarachi Aikaterini Lianou +6 位作者 Angelos Liontos Konstantinos Garefis Eleni Litsou Dionysios Tafiadis Efthymis Dimakis Ioannis Kastanioudakis Georgios Exarchakos 《International Journal of Otolaryngology and Head & Neck Surgery》 2021年第5期345-358,共14页
<strong>Objective(s):</strong> The aim of this study is to explore if there is a correlation between the typical voice classification and the morphometric characteristics of the vocal folds, using video la... <strong>Objective(s):</strong> The aim of this study is to explore if there is a correlation between the typical voice classification and the morphometric characteristics of the vocal folds, using video laryngeal stroboscopy, on professional singers in Greece. <strong>Methods:</strong> 70 professional singers, 50% men (35 men) and 50% women (35 women), were recruited for this study. A stroboscopic evaluation was prepared for every participant. Additionally, the voice classification and features of individuals were correlated statistically. <strong>Results:</strong> Statistically significant difference were observed between the voice categories and the size of stomatopharynx, the shape of the hard palate, the length of the vocal folds, the width and thickness of the vocal folds, as well as the tone of speech, in male singers. Statistically significant differences were also observed between the voice categories and all the variables except the shape of epiglottis, the color of speech and the shape of the vocal folds, in female singers. <strong>Conclusions:</strong> There is correlation between the morphometric characteristics of the vocal folds and the voice categories. 展开更多
关键词 STROBOSCOPY Vocal folds Professional Singers Voice Category Morphometric Characteristics
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Penfolds为品牌保护之路敲响警钟
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作者 杨婷婷 《新食品》 2018年第3期64-65,共2页
刚刚过去的2017年对于Penfolds来说是众望所归的一年,却也是考验重重的一年。
关键词 品牌保护 folds PEN
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Fractal Simulation and Classification of Folds 被引量:7
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作者 HOU Guiting 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1998年第2期217-223,共7页
Abstract: The method of fractal simulation and classification of folds is firstly studied here to describe various types of complex fold patterns in quantitative analysis. Based on the characteristics of natural folds... Abstract: The method of fractal simulation and classification of folds is firstly studied here to describe various types of complex fold patterns in quantitative analysis. Based on the characteristics of natural folds with a fractal pattern, the fold patterns are simulated to describe various types of folds quantitatively by means of fractal interpolation. The major factors affecting the fold pattern are elucidated in fractal simulation of folds, i.e. positions of interpolation points (x, y) and the disturbance coefficient d of folds (-1<d<1). The bigger the value d for a fold simulation is, the more complex or disturbed the folds are and the better developed the relative secondary folds are. If d>0, folds are upconvex. IF d<0, they are down-convex. |d|=0, |d|=0.25 and |d|=0.5 represent three conspicuous turning states. If |d|=0, the points will be joined by a straight line. If |d|=0.25, the points will be joined smoothly. If |d|<0.25, there will be complex secondary folds between the points. If |d| >0.5, there will be more complex secondary folds between the points. The complex degrees of the fold pattern, therefore, can be classified by the disturbance coefficient d and by the discongruent degree Δ d. In nature, most folds are self-affine fractal folds. 展开更多
关键词 FRACTAL SIMULATION CLASSIFICATION FOLD discongruent degree
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Rheological Properties of Fractal Deformation in Multilayer Folds 被引量:1
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作者 HOU Guiting 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第3期544-549,共6页
The fractal dimensions of folds are related to layer thickness and viscosity of the multilayer. This paper discusses how the thickness, viscosity, and anisotropic degree affect the rheological deformation of fractal f... The fractal dimensions of folds are related to layer thickness and viscosity of the multilayer. This paper discusses how the thickness, viscosity, and anisotropic degree affect the rheological deformation of fractal folds in multilayers. The number of layers, their thicknesses, viscosities, and anisotropic degree of multilayers cooperate to affect the rheological deformation of folds, which is not controlled by a single rheological factor. A greater anisotropic degree of multilayers is favorable to develop the more complex and disharmonious fractal folds. 展开更多
关键词 multilayer fold fractal dimension RHEOLOGY viscosity thickness anisotropic degree
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Enlarged folds on endoscopic gastritis as a predictor for submucosal invasion of gastric cancers 被引量:2
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作者 Osamu Toyoshima Shuntaro Yoshida +7 位作者 Toshihiro Nishizawa Akira Toyoshima Kosuke Sakitani Tatsuya Matsuno Tomoharu Yamada Takashi Matsuo Hayato Nakagawa Kazuhiko Koike 《World Journal of Gastrointestinal Endoscopy》 2021年第9期426-436,共11页
BACKGROUND Accurate diagnosis of the depth of gastric cancer invasion is crucial in clinical practice.The diagnosis of gastric cancer depth is often made using endoscopic characteristics of the tumor and its margins;h... BACKGROUND Accurate diagnosis of the depth of gastric cancer invasion is crucial in clinical practice.The diagnosis of gastric cancer depth is often made using endoscopic characteristics of the tumor and its margins;however,evaluating invasion depth based on endoscopic background gastritis remains unclear.AIM To investigate predicting submucosal invasion using the endoscopy-based Kyoto classification of gastritis.METHODS Patients with gastric cancer detected on esophagogastroduodenoscopy at Toyoshima Endoscopy Clinic were enrolled.We analyzed the effects of patient and tumor characteristics,including age,sex,body mass index,surveillance endoscopy within 2 years,current Helicobacter pylori infection,the Kyoto classification,and Lauren’s tumor type,on submucosal tumor invasion and curative endoscopic resection.The Kyoto classification included atrophy,intestinal metaplasia,enlarged folds,nodularity,and diffuse redness.Atrophy was characterized by non-reddish and low mucosa.Intestinal metaplasia was detected as patchy whitish or grayish-white flat elevations,forming an irregular uneven surface.An enlarged fold referred to a fold width≥5 mm in the greater curvature of the corpus.Nodularity was characterized by goosebump-like multiple nodules in the antrum.Diffuse redness was characterized by uniform reddish nonatrophic mucosa in the greater curvature of the corpus.RESULTS A total of 266 gastric cancer patients(mean age,66.7 years;male sex,58.6%;mean body mass index,22.8 kg/m2)were enrolled.Ninety-three patients underwent esophagogastroduodenoscopy for surveillance within 2 years,and 140 had current Helicobacter pylori infection.The mean Kyoto score was 4.54.Fifty-eight cancers were diffuse-type,and 87 cancers had invaded the submucosa.Multivariate analysis revealed that low body mass index(odds ratio 0.88,P=0.02),no surveillance esophagogastroduodenoscopy within 2 years(odds ratio 0.15,P<0.001),endoscopic enlarged folds of gastritis(odds ratio 3.39,P=0.001),and Lauren’s diffuse-type(odds ratio 5.09,P<0.001)were independently associated with submucosal invasion.Similar results were obtained with curative endoscopic resection.Among cancer patients with enlarged folds,severely enlarged folds(width≥10 mm)were more related to submucosal invasion than mildly enlarged folds(width 5-9 mm,P<0.001).CONCLUSION Enlarged folds of gastritis were associated with submucosal invasion.Endoscopic observation of background gastritis as well as the lesion itself may help diagnose the depth of cancer invasion. 展开更多
关键词 Gastric cancer GASTRITIS Enlarged fold Endoscopy Kyoto classification
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Study on folds of monolayer sandwiched-in different thickness terranes
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作者 YE Bai-long YU Ai-nan HE Yan-lan 《Journal of Central South University》 SCIE EI CAS 2001年第3期203-207,共5页
The paper discussed the limitation of ’Dominant wavelengt h theory’. The theoretical model and nonhomogeneous differential equation of fold and deformation of a monolayer sandwiched-in limited and different thickn e... The paper discussed the limitation of ’Dominant wavelengt h theory’. The theoretical model and nonhomogeneous differential equation of fold and deformation of a monolayer sandwiched-in limited and different thickn ess terranes are proposed by using mechanics of elasticity. In addition, the ′D ominant wavelength theory’ is proved by the experimental folding in elastic ma terials. The folds of a monolayer sandwiched-in limited and different thickness terranes are studied inside and are explored in the field. 展开更多
关键词 DOMINANT WAVELENGTH theory MONOLAYER FOLD simulation ex periment
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QUATERNARY GROWTH FOLDS IN THE JIUXI BASIN AT THE NORTHEASTERN MARGIN OF THE QINGHAI—XIZANG PLATEAU
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作者 Chen Jie 1, Karl\|Heinz Wyrwoll 2, Annette George 3,Lu Yanchou 1 (1 Institute of Geology, China Seismological Bureau, P.O.Box 9803,Beijing 100029,China, E\|mail:chenjie@mail.263.net.cn 2.Department of Geography, University of Western Australia, N 《地学前缘》 EI CAS CSCD 2000年第S1期333-334,共2页
As a consequence of the collision of India with Asia, the Qilian Shan, rising 4000~5000m above the Gobi, marks the northeastern boundary of the Tibet—Qinghai Plateau. The Qilian Shan developed as a WNW—ESE fold\|an... As a consequence of the collision of India with Asia, the Qilian Shan, rising 4000~5000m above the Gobi, marks the northeastern boundary of the Tibet—Qinghai Plateau. The Qilian Shan developed as a WNW—ESE fold\|and\|thrust belt with most of the movement directed towards the NEN—NE. Its foreland margin, the Jiuxi Basin, accommodates thick sequences of Late Cenozoic alluvial sediments derived from the Qilian Shan. Thin\|skinned fold\|and\|thrust deformation in the Jiuxi basin flanking the Qilian Shan, feature Mesozoic and Cenozoic sedimentary rocks that have been detached from the underlying basal decollement and folded into a series of NW—WNW trending anticlines and synclines. Towards the south deformation in the Jiuxi basin is accommodated by a west\|north\|west fold train (Qingcaowan, Laojunmiao, and Shiyougou folds) developed during the Quaternary. These form a distinct topographic feature separating the Qilian Shan from the central Jiuxi Basin. The doubly plunging Laojunmiao anticline is 10km long and 5km wide. It is asymmetric in shape, having a steep to overturned northern limb, and a backlimb dips to the south at 20~30°. The Laojunmiao anticline is composed of two distinct stratigraphic sequences which are defined by a syntectonic unconformity. 展开更多
关键词 QILIAN Shan QUATERNARY GROWTH fold GROWTH strata erosion RATE UPLIFT RATE
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Geometries and mechanism of folds in sediments on the southern Huanghai Sea shelf
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作者 LI Xishuang LIU Baohua +1 位作者 ZHAO Yuexia LI Sanzhong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第4期23-31,共9页
Most descriptions and studies about folds have been associated with consolidated strata; fold deformation in loosely-consolidated sediments, however, has been rarely discussed. Since the Pleistocene, tectonic activiti... Most descriptions and studies about folds have been associated with consolidated strata; fold deformation in loosely-consolidated sediments, however, has been rarely discussed. Since the Pleistocene, tectonic activities have been intensive over the South Huanghai Sea (SHS) shelf, resulting in fold deformation features that are preserved in thick sediment layers. Four types of folds with different geometries have been identified on the basis of an analysis of single - channel seismic profiles from the SHS shelf region: (1) fault-propagation fold; (2) fault-drag fold; (3) transversal bending fold; and (4) multi-action-folding fold. Studies on the geometry and mechanism of the folds indicate that base faults and fault blocks control the folding patterns in loosely-consoli- dated sediments on the SHS shelf and a large quantity of pore water in sediments plays an important role in cansing the deformation of sediment layers. The continuity of deformations of fault-propagation fold and fault-drag fold indicates that there is a genetic relationship between these fold types. The potential of earthquakes induced by fault-propagation folding in the deformation zone should be taken into account in the assessment of the marine engineering geology conditions of the SHS shelf. 展开更多
关键词 FOLD loosely-consolidated sediment base fault marine engineering south Huanghai Sea shelf
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Recognition of Protein Native Folds Using a Continuous Potential Function
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作者 WANG Yu-hong, LU Zhi-bin and LI Wei(Department of Molecular Biology , Jilin University , Changchun, 130023 ) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1994年第2期134-140,共7页
e report a simple continuous potential function that can recognize proteinchains' native folds from tens of thousands of alternative ones. Empirical parame-ters for this potential function were obtained by a neura... e report a simple continuous potential function that can recognize proteinchains' native folds from tens of thousands of alternative ones. Empirical parame-ters for this potential function were obtained by a neural network learning oversamples generated from PDB structural data.Hydrophobic interactions were foundto be mainly responsible for stabilization of the protein' s native fold. The inter-chain interaction was found indispensable in stabilizing some protein chains' nativeconformation. 展开更多
关键词 RECOGNITION Protein native fold Function
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Study on Folds of Equal Thickness Multi-layerSandwiched in Different Thickness Media
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作者 Ye Bailong Yu Ainan Ouyang JiantaoCollege of Resources , Environment and Civil Engineering, Central South University, Changsha 410083 《Journal of China University of Geosciences》 SCIE CSCD 2002年第1期26-29,共4页
The theoretical model and non-homogeneous differential equation of equal thickness multi-layer folds sandwiched in different thickness and same character media are established by elastic and plastic mechanics. The spe... The theoretical model and non-homogeneous differential equation of equal thickness multi-layer folds sandwiched in different thickness and same character media are established by elastic and plastic mechanics. The special answer of the non-homogeneous differential equation and the common answer of the homogeneous differential equation are deduced by applying logistic equation and special function, and the dominant wavelength theory of equal thickness multi-layer folds sandwiched in different thickness and same character media. In addition, the experimental folding in both elastic and sticky materials proves the dominant wavelength theory. 展开更多
关键词 multi-layer fold dominant wavelength theory different thickness media imitation experiment.
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Mechanical analysis of folds in compressive belt and its significance to earthquakes
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作者 谢新生 《Acta Seismologica Sinica(English Edition)》 EI CSCD 1999年第3期306-313,共8页
The paper proposes the conception of Beads type fold system. The mechanical analyses of the typical tectonic system are made by means of elastic stability theory, mathematical and mechanical method and rheology. The... The paper proposes the conception of Beads type fold system. The mechanical analyses of the typical tectonic system are made by means of elastic stability theory, mathematical and mechanical method and rheology. The relation among the deflections of folds and time, external forces, and distribution of stresses, strain energy density are analyzed to explain the causing mechanism of folding earthquake. 展开更多
关键词 Beads type fold system critical stress of buckling ratio of minor and major fold axesviscoelasticity folding earthquake
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Conformational dynamics as an intrinsic determinant of prion protein misfolding and neurotoxicity
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作者 Alessandro Cembran Pedro Fernandez-Funez 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第10期2095-2096,共2页
The prion protein(PrP) is the key molecular and pathological mediator of prion diseases,a heterogeneous group of brain disorders with fatal outcomes.Prion diseases are rare but deserve special attention because of the... The prion protein(PrP) is the key molecular and pathological mediator of prion diseases,a heterogeneous group of brain disorders with fatal outcomes.Prion diseases are rare but deserve special attention because of their unique familial,sporadic,and transmissible etiologies,all caused by a single agent:misfolded conformations of PrP. 展开更多
关键词 FOLDING INTRINSIC DYNAMICS
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MAUN:Memory-Augmented Deep Unfolding Network for Hyperspectral Image Reconstruction
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作者 Qian Hu Jiayi Ma +2 位作者 Yuan Gao Junjun Jiang Yixuan Yuan 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第5期1139-1150,共12页
Spectral compressive imaging has emerged as a powerful technique to collect the 3D spectral information as 2D measurements.The algorithm for restoring the original 3D hyperspectral images(HSIs)from compressive measure... Spectral compressive imaging has emerged as a powerful technique to collect the 3D spectral information as 2D measurements.The algorithm for restoring the original 3D hyperspectral images(HSIs)from compressive measurements is pivotal in the imaging process.Early approaches painstakingly designed networks to directly map compressive measurements to HSIs,resulting in the lack of interpretability without exploiting the imaging priors.While some recent works have introduced the deep unfolding framework for explainable reconstruction,the performance of these methods is still limited by the weak information transmission between iterative stages.In this paper,we propose a Memory-Augmented deep Unfolding Network,termed MAUN,for explainable and accurate HSI reconstruction.Specifically,MAUN implements a novel CNN scheme to facilitate a better extrapolation step of the fast iterative shrinkage-thresholding algorithm,introducing an extra momentum incorporation step for each iteration to alleviate the information loss.Moreover,to exploit the high correlation of intermediate images from neighboring iterations,we customize a cross-stage transformer(CSFormer)as the deep denoiser to simultaneously capture self-similarity from both in-stage and cross-stage features,which is the first attempt to model the long-distance dependencies between iteration stages.Extensive experiments demonstrate that the proposed MAUN is superior to other state-of-the-art methods both visually and metrically.Our code is publicly available at https://github.com/HuQ1an/MAUN. 展开更多
关键词 DEEP FOLDING ITERATION
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Petrogenesis and Tectonic Implications of the Early Triassic Nianzi Adakitic Granite Unit in the Yanshan Fold and Thrust Belt:New Constraints from U-Pb Geochronology and Sr-Nd-Hf Isotopes
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作者 ZHANG Huijun WU Chu +5 位作者 HE Fubing WANG Biren CUI Yubin LIU Zhenghua YOU Shina DONG Jing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期50-66,共17页
The Nianzi granite unit,which includes the Nianzi,Xiaolianghou and Xiawopu granitic intrusions,is a significant component of the northern part of the North China Craton(NCC)and is situated in the Yanshan fold and thru... The Nianzi granite unit,which includes the Nianzi,Xiaolianghou and Xiawopu granitic intrusions,is a significant component of the northern part of the North China Craton(NCC)and is situated in the Yanshan fold and thrust belt(YFTB).However,there is still debate regarding the tectonic evolutionary history of the YFTB during the late Permian to Triassic period,specifically regarding the timing of subduction and collision between the NCC and the Paleo-Asian Ocean.The Nianzi granite unit exhibits unique petrological,geochronological and geochemical signatures that shed light on the tectonic evolutionary history of the YFTB.This study presents detailed petrology,whole-rock geochemistry,together with Sr-Nd isotopic,zircon U-Pb dating and Lu-Hf isotopic data of the granites within the Nianzi granite unit.Our findings demonstrate that the granites primarily consist of subhedral K-feldspar,plagioclase,quartz,minor biotite and hornblende,with accessory titanite,apatite,magnetite and zircon.Zircon U-Pb dating indicates that the Xiaolianghou granite was emplaced at 247.5±0.62 Ma.Additionally,the adakitic characteristics of the Nianzi,Xiawopu and Xiaolianghou granitic intrusions,such as high Sr and Ba contents and high ratios of Sr/Y and(La/Yb)N,combined with negative Sr-Nd and Lu-Hf isotopes(87Sr/86Sr)i=0.705681–0.7057433,εNd(t)=−21.98 to−20.97,zirconεHf(t)=−20.26 to−9.92,as well as the I-type granite features of high SiO_(2),Na_(2)O and K_(2)O/Na_(2)O ratios,enriched Rb,K,Sr and Ba,along with depleted Th,U,Nb,Ta,P and Ti,suggest that the Nianzi granitic unit was mainly derived from the partial melting of a thickened lower crust containing hydrous,calc-alkaline to high-K calc-alkaline,mafic to intermediate metamorphic rocks.In light of these parameters,we further integrate our data with previous studies and conclude that the Nianzi granitic unit was generated in a post-collisional extensional environment during the Early Triassic. 展开更多
关键词 tectonic evolution zircon geochronology Sr-Nd-Hf isotopes Nianzi granite unit Yanshan fold and thrust belt
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Breaking the optical efficiency limit of virtual reality with a nonreciprocal polarization rotator
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作者 Yuqiang Ding Zhenyi Luo +1 位作者 Garimagai Borjigin Shin-Tson Wu 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2024年第3期4-14,共11页
A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads t... A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the formfactor.However,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical loss.The theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization rotator.In our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy HM.The theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective polarizers.In addition,we evaluated the ghost images using a micro-OLED panel in our imaging system.Indeed,the ghost images can be suppressed to undetectable level if the optics are with antireflection coating.Our novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption. 展开更多
关键词 near-eye display virtual reality pancake optics folded optics nonreciprocal polarization rotator
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Wideband spectrum sensing using step-sampling based on the multipath nyquist folding receiver
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作者 Kai-lun Tian Kai-li Jiang +5 位作者 Sen Cao Jian Gao Ying Xiong Bin Tang Xu-ying Zhang Yan-fei Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期523-536,共14页
Wideband spectrum sensing with a high-speed analog-digital converter(ADC) presents a challenge for practical systems.The Nyquist folding receiver(NYFR) is a promising scheme for achieving cost-effective real-time spec... Wideband spectrum sensing with a high-speed analog-digital converter(ADC) presents a challenge for practical systems.The Nyquist folding receiver(NYFR) is a promising scheme for achieving cost-effective real-time spectrum sensing,which is subject to the complexity of processing the modulated outputs.In this case,a multipath NYFR architecture with a step-sampling rate for the different paths is proposed.The different numbers of digital channels for each path are designed based on the Chinese remainder theorem(CRT).Then,the detectable frequency range is divided into multiple frequency grids,and the Nyquist zone(NZ) of the input can be obtained by sensing these grids.Thus,high-precision parameter estimation is performed by utilizing the NYFR characteristics.Compared with the existing methods,the scheme proposed in this paper overcomes the challenge of NZ estimation,information damage,many computations,low accuracy,and high false alarm probability.Comparative simulation experiments verify the effectiveness of the proposed architecture in this paper. 展开更多
关键词 Wideband spectrum sensing Sub-Nyquist sampling Step-sampling Nyquist folding receiver(NYFR) Multisignal processing
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