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Smart prediction of liquefaction-induced lateral spreading 被引量:1
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作者 Muhammad Nouman Amjad Raja Tarek Abdoun Waleed El-Sekelly 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2310-2325,共16页
The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(... The prediction of liquefaction-induced lateral spreading/displacement(Dh)is a challenging task for civil/geotechnical engineers.In this study,a new approach is proposed to predict Dh using gene expression programming(GEP).Based on statistical reasoning,individual models were developed for two topographies:free-face and gently sloping ground.Along with a comparison with conventional approaches for predicting the Dh,four additional regression-based soft computing models,i.e.Gaussian process regression(GPR),relevance vector machine(RVM),sequential minimal optimization regression(SMOR),and M5-tree,were developed and compared with the GEP model.The results indicate that the GEP models predict Dh with less bias,as evidenced by the root mean square error(RMSE)and mean absolute error(MAE)for training(i.e.1.092 and 0.815;and 0.643 and 0.526)and for testing(i.e.0.89 and 0.705;and 0.773 and 0.573)in free-face and gently sloping ground topographies,respectively.The overall performance for the free-face topology was ranked as follows:GEP>RVM>M5-tree>GPR>SMOR,with a total score of 40,32,24,15,and 10,respectively.For the gently sloping condition,the performance was ranked as follows:GEP>RVM>GPR>M5-tree>SMOR with a total score of 40,32,21,19,and 8,respectively.Finally,the results of the sensitivity analysis showed that for both free-face and gently sloping ground,the liquefiable layer thickness(T_(15))was the major parameter with percentage deterioration(%D)value of 99.15 and 90.72,respectively. 展开更多
关键词 Lateral spreading Intelligent modeling Gene expression programming(GEP) Closed-form solution Feature importance
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Mineralogy and geochemistry of hydrothermal sulphide from a submarine volcanic high at 18°36.4'S Central Lau Spreading Center, Southwest Pacific
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作者 Durbar Ray Anil L.Paropkari 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第5期93-101,共9页
We report the mineralogy and geochemistry of hydrothermal sulphide from the crater of a volcanic high near 18°36.4′S of the Central Lau Spreading Center.During 1990s,that volcanic structure was reported active a... We report the mineralogy and geochemistry of hydrothermal sulphide from the crater of a volcanic high near 18°36.4′S of the Central Lau Spreading Center.During 1990s,that volcanic structure was reported active and sulphide samples were collected by MIR submersible.A section of a chimney-like structure from the crater-floor was studied here.The Fe-depleted sphalerites,and Co-depleted pyrites in that chimney were similar to those commonly found in low to moderate temperature(<300℃)sulphides from sediment-starved hydrothermal systems.Bulk analyses of three parts of that chimney section showed substantial enrichment of Zn(18%–20%)and Fe(14%–27%)but depletion of Cu(0.8%–1.3%).In chondrite-normalized rare earth element-patterns,the significant negative Ce-anomalies(Ce/Ce*=0.27–0.39)and weakly positive Eu-anomalies(Eu/Eu*=1.60–1.68)suggested sulphide mineralisation took place from reduced low-temperature fluid.The depleted concentration of lithophiles in this sulphide indicates restricted contribution of sub-ducting plate in genesis of source fluid as compared to those from other parts of Lau Spreading Centre.Uniform mineralogy and bulk composition of subsamples across the chimney section suggests barely any alteration of fluid composition and/or mode of mineralisation occurred during its growth. 展开更多
关键词 Central Lau spreading Center hydrothermal sulphide MINERALOGY GEOCHEMISTRY
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Elemental Compositions of Clinopyroxenes from Southern Okinawa Trough Basalt:Implications for Magmatism and Structural Environment in an Initial Back-Arc Basin
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作者 GUO Kun ZHAI Shikui +3 位作者 FAN Di ZHANG Xia ZHANG Yu ZHU Zhimin 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期643-653,共11页
The major and trace elemental compositions of clinopyroxene from basalt were used to characterize the nature of the primitive magma and structural environment beneath the southern Okinawa Trough(SOT),which is an initi... The major and trace elemental compositions of clinopyroxene from basalt were used to characterize the nature of the primitive magma and structural environment beneath the southern Okinawa Trough(SOT),which is an initial back-arc basin at a continental margin.The clinopyroxenes in the basalt were augite with variable Mg^(#)contents(73.37-78.22).The regular variations in major oxide contents(i.e.,CaO,FeO,TiO_(2),and Cr)with decreasing Mg#implied that the clinopyroxenes evolved from being enriched in Mg,Ca,and Cr to being enriched in Fe and Ti.The clinopyroxenes had relatively low rare earth element concentrations(7.51×10^(-6) to 12.68×10^(-6))and negative Eu anomalies(δEu=0.67-0.95).The Kd_(cpx) values of clinopyroxenes(0.2-0.26),which were used to examine whether the clinopyroxene was equilibrated with its host basalt,demonstrate that these clinopyroxene phenocrysts were not captured crystals but were instead produced by crystallization differentiation of the magma.The calculated clinopyroxene crystallization temperatures showed a narrow range of 990-1061℃,and their crystallization pressures ranged from 2.0 to 3.2 kbar.The geochemistry features of these clinopyroxenes indicated that the parent magma belonged to the subalkaline tholeiitic magma series and suggested that the magma experienced crystallization differentiation of olivine,plagioclase,and clinopyroxene,where the crystallization of plagioclase occurred earlier than that of clinopyroxene.Combined with geophysical data,this research on primitive magma and its crystallization differentiation from clinopyroxene indicates that the SOT is in the stage of‘seafloor spreading’and that basaltic rocks produced from tholeiitic magma represent the generation of oceanic crust. 展开更多
关键词 trace elements CLINOPYROXENES southern Okinawa Trough seafloor spreading back-arc basin
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Individual dynamics and local heterogeneity provide a microscopic view of the epidemic spreading
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作者 朱友源 沈瑞哲 +1 位作者 董昊 王炜 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期656-663,共8页
The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the wid... The COVID-19 pandemic has caused severe global disasters,highlighting the importance of understanding the details and trends of epidemic transmission in order to introduce efficient intervention measures.While the widely used deterministic compartmental models have qualitatively presented continuous “analytical” insight and captured some transmission features,their treatment usually lacks spatiotemporal variation.Here,we propose a stochastic individual dynamical(SID)model to mimic the random and heterogeneous nature of epidemic propagation.The SID model provides a unifying framework for representing the spatiotemporal variations of epidemic development by tracking the movements of each individual.Using this model,we reproduce the infection curves for COVID-19 cases in different areas globally and find the local dynamics and heterogeneity at the individual level that affect the disease outbreak.The macroscopic trend of virus spreading is clearly illustrated from the microscopic perspective,enabling a quantitative assessment of different interventions.Seemingly,this model is also applicable to studying stochastic processes at the “meter scale”,e.g.,human society’s collective dynamics. 展开更多
关键词 Brownian motion epidemic spreading HETEROGENEITY
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An Important Spreading Event of the Neo-Tethys Ocean during the Late Jurassic and Early Cretaceous: Evidence from Zircon U-Pb SHRIMP Dating on Diabase in Nagarze, Southern Tibet 被引量:27
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作者 JIANG Sihong NIE Fengjun HU Peng LIU Yan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第4期522-527,共6页
Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. ... Widely distributed in Gyangzê-Chigu area, southern Tibet, NW- and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean. In order to constrain the emplacement age of these dykes, zircons of two samples from diabases in Nagarzê were dated by using the U-Pb SHRIMP method. Two nearly the same weighted mean ^206pb/^23SU ages were obtained in this paper, which are 134.9±1.8 Ma (MSWD=0.65) and 135.5 ± 2.1 Ma (MSWD=1.40), respectively. They not only represent the crystallization age of the diabase, but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous. This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau. 展开更多
关键词 DIABASE zircon U-Pb SHRIMP dating spreading event NEO-TETHYS Nagarzê southern Tibet
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A modified stiffness spreading method for layout optimization of truss structures 被引量:3
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作者 Mingjie Cao Haitao Ma Peng Wei 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2018年第6期1072-1083,共12页
The stiffness spreading method (SSM) was initially proposed for layout optimization of truss structures,in which an artificial elastic material of low modulus is uniformly distributed in the design domain to create co... The stiffness spreading method (SSM) was initially proposed for layout optimization of truss structures,in which an artificial elastic material of low modulus is uniformly distributed in the design domain to create connections between discrete members.In this paper,a modified stiffness spreading method is proposed by replacing the artificial elastic material with auxiliary bars to connect real members of the truss structure.Since the background continuum mesh for the elastic material is no longer required,the computational cost is significantly reduced.Like SSM,the new method is advantageous in that an initial design may consist of disconnected bars allocated in the design domain,and mathematical programming methods can be applied for the efficient solution of the formulated optimization problem.A number of solution strategies are also developed to achieve more practical designs with lower computational cost.Numerical examples of both 2-D and 3-D truss structures are presented to demonstrate the feasibility,robustness and effectiveness of the proposed method. 展开更多
关键词 STIFFNESS spreading METHOD MODIFIED STIFFNESS spreading METHOD Layout OPTIMIZATION TRUSS structure OPTIMIZATION strategy
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Numerical study of three-dimensional wave-induced longshore current's effects on sediment spreading of the Huanghe River mouth 被引量:4
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作者 LIANG Bingchen ZHAO Hongping +1 位作者 LI Huajun WU Guoxiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第2期129-138,共10页
A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface... A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN, damping function of sediment on turbulence, sediment model and depth-dependent wave radiation stress to COHERENS. The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River (Yellow River) mouth. Several different cases divided by setting different wave parameters of inputting boundary waves are carried out. The modeling results agree with measurement data. In terms of simulation results, it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m. Moreover, wave direction also affects the sediment spreading rules of the mouth strongly too. 展开更多
关键词 Huanghe River mouth three-dimensional wave radiation stress COHERENS COHERENS-SED sediment spreading
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Cenozoic Volcanism in South China Sea and Its Vicinity and South China Sea Spreading 被引量:4
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作者 Zhao Hailing Deng Jinfu Li Kaiming Di Yongjun Yu Junji Zhao Jianhua Li Yonghua Faculty of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100083 《Journal of China University of Geosciences》 SCIE CSCD 2002年第3期217-224,共8页
The rock series, rock types and Sr-Nd isotopic dating of the Cenozoicvolcanic rocks in the South China Sea are similar to those in its vicinity. On the basis of thespreading age of the South China Sea, the Cenozoic vo... The rock series, rock types and Sr-Nd isotopic dating of the Cenozoicvolcanic rocks in the South China Sea are similar to those in its vicinity. On the basis of thespreading age of the South China Sea, the Cenozoic volcanic rocks are divided into three stages: thepre-spreading stage, the spreading stage and the post-spreading stage. The deep processcharacteristics of the asthenosphere and lithosphere may be inferred from the study on primarybasaltic magma. The top layers of the asthenosphere both in the spreading stage and in thepre-spreading stage are closer to the earth surface than that in the post-spreading stage. From thepre-spreading stage to the spreading stage, the top layer of the asthenosphere decreased in depth,while the amount of interstitial partial melts increased. The evolution of the primary basalticmagma shows a progressive evolution sequence of the rifting volcanism and a faster lithosphericspreading velocity. From the spreading stage to the post-spreading stage, the top layer of theasthenosphere gradually increased in depth, but the amount of interstitial partial melts decreased.The evolution of primary basaltic magma shows a retrogressive evolution sequence of the riftingvolcanism and a gradual decrease in the lithospheric spreading velocity. The depth recognized by thestudy on the Cenozoic volcanism demonstrates the deep environment for the formation and evolutionof the South China Sea. 展开更多
关键词 cenozoic volcanism south china sea spreading ASTHENOSPHERE LITHOSPHERE VICINITY
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Rifting characteristics of eastern subbasin of South China Sea and its spreading pattern 被引量:3
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作者 Li Jiabiao Jin Xianglong Gao Jinyao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2002年第1期77-85,共9页
With processing and interpretation of 25 000 km full-coverage multibeam swath data fromthe eastern South China Sea, it is found that NE-trending and NW-trending linear morphological features such as scarps, horsts and... With processing and interpretation of 25 000 km full-coverage multibeam swath data fromthe eastern South China Sea, it is found that NE-trending and NW-trending linear morphological features such as scarps, horsts and grabens, govern the central part (14°-17° N) of eastern subbasin. Compared with reflection seismic profiles, these NE-trending linear morpho-structures are considered to be the representation of basement structures on seabed and can be divided into three linear structural zones. The trend of the central zone is NE45°-50° occurring around extinct spreading center, the trend of the second zone is NE70° - 78° on both sides of the central one and the trend of the third zone is about NE60° just on the north of the second one. These three NE-trending linear zones are formed in late-stage NW - SE-trending seafloor spreading of the eastern subbasin along NW-trending linear faults, and respectively correspond to three spreading episodes: 17.0- 19.0 Ma (5d-5e), 19.0 - 21.0 Ma (5e-6a) and 21.0 - 24.2 Ma (6a-6c) based on the contrast of morpho-structures to magnetic lineation anomalies. 展开更多
关键词 Multibeam echosounding swath topography morpho-structures spreading pattern
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Functionalized alginate-based bioinks for microscale electrohydrodynamic bioprinting of living tissue constructs with improved cellular spreading and alignment 被引量:1
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作者 Zhennan Qiu Hui Zhu +3 位作者 Yutao Wang Ayiguli Kasimu Dichen Li Jiankang He 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2023年第2期136-149,共14页
Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resol... Bioprinting has been widely investigated for tissue engineering and regenerative medicine applications.However,it is still difficult to reconstruct the complex native cell arrangement due to the limited printing resolution of conventional bioprinting techniques such as extrusion-and inkjet-based printing.Recently,an electrohydrodynamic(EHD)bioprinting strategy was reported for the precise deposition of well-organized cell-laden constructs with microscale filament size,whereas few studies have been devoted to developing bioinks that can be applied for EHD bioprinting and simultaneously support cell spreading.This study describes functionalized alginate-based bioinks for microscale EHD bioprinting using peptide grafting and fibrin incorporation,which leads to high cell viability(>90%)and cell spreading.The printed filaments can be further refined to as small as 30μm by incorporating polyoxyethylene and remained stable over one week when exposed to an aqueous environment.By utilizing the presented alginate-based bioinks,layer-specific cell alignment along the printing struts could be observed inside the EHD-printed microscale filaments,which allows fabricating living constructs with cell-scale filament resolution for guided cellular orientation. 展开更多
关键词 Microscale electrohydrodynamic bioprinting Alginate-based bioinks Cell spreading Cell alignment
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Boosting image watermarking authenticity spreading secrecy from counting-based secret-sharing 被引量:1
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作者 Adnan Gutub 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第2期440-452,共13页
This study presents enhancing images authentication by securing watermarking hidden data via shares generated from counting-based secret sharing.The trustfulness of shares utilised secret-sharing as an applicable priv... This study presents enhancing images authentication by securing watermarking hidden data via shares generated from counting-based secret sharing.The trustfulness of shares utilised secret-sharing as an applicable privacy creation tool for the authentication of real-life complex platforms.This research adjusts embedding the watermarking data over the images by innovative redistribution of shares to be embedded spread over all the images.The anticipated watermarking technique guaranteed to scatter the share bits implanting at different least significant bits of image pixels as boosting up the trust overall authentication practicality.The paper experimentation performance analysis shows that this improved image watermarking authentication(capacity)is averagely better by 33%–67%than other related exclusive-OR oriented and octagon approaches.Interestingly,these measurement improvements did not degrade the robustness and security of the system,inspiring our research for opening novel track of related future counting-based secret-sharing authentication progresses to come. 展开更多
关键词 counting-based secret-sharing data hiding fair data spreading image watermarking information security secret sharing
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The association between radiological spreading pattern and clinical outcomes in necrotizing external otitis
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作者 W.Leentje van der Meer Ahmed B.Bayoumy +3 位作者 Josje J.Otten Jerome J.Waterval Henricus P.M.Kunst Alida A.Postma 《Journal of Otology》 CSCD 2022年第3期156-163,共8页
Objectives: Necrotizing external otitis(NEO) is a rare infectious disease of the skull base. The purpose of this study was to determine whether clinical outcomes of NEO can be correlated to different infectious spread... Objectives: Necrotizing external otitis(NEO) is a rare infectious disease of the skull base. The purpose of this study was to determine whether clinical outcomes of NEO can be correlated to different infectious spread patterns.Methods: Retrospective chart review from 2010 to 2019 with NEO patients, who were divided into two cohorts: single spreading patterns(group A) or complex spreading patterns(group B) as diagnosed by CT.Clinical symptoms, diagnostic and treatment delay, course of disease, complications, and duration of antibiotic exposure were retrospectively collected from patient records.Results: 41 NEO patients were included, of which 27 patients belonged to group A(66%). The diseaserelated mortality rate was 12.2% among the entire cohort, no differences were found between group A and B. Higher rates of N.VII(42.9% vs 14.8% P = 0.047) and N. IX palsies were found in group B compared to group A(28.6% vs 3.7%, P = 0.039). The median duration of antibiotic use was significantly different for a complex spreading pattern, clinical recovery and hospitalizations. Complications were associated with higher diagnostic delay and with a complex spread pattern. The median duration of follow-up was 12.0(IQR 6.0-19.5) months.Conclusion: NEO is a severe disease, with significant mortality and morbidity(cranial nerve palsies). The radiological spread pattern may assist in predicting clinical outcome. Furthermore, complex spread patterns are associated with higher rates of clinical nerve palsies(N. VII and N.IX), complications, surgery rates and longer duration of antibiotic use. Diagnostic delay was associated with mortality, complications and facial palsies. 展开更多
关键词 Necrotizing external otitis Malignant external otitis Skull base osteomyelitis Clinical manifestation spreading routes Antibiotic exposure Facial nerve palsy
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Simulation and Experimental Research on Liquid Spreading in a Wire-Sawn Kerf
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作者 Lin Lin Hui Huang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第6期247-260,共14页
The significance of liquids in abrasive wire sawing has been demonstrated in several studies.However,the perfor-mance of its spreading behavior is limited by the current development trend,where the wafer has a larger ... The significance of liquids in abrasive wire sawing has been demonstrated in several studies.However,the perfor-mance of its spreading behavior is limited by the current development trend,where the wafer has a larger area and the kerf is narrower.Moreover,there are very few studies on the liquid spreading behavior in wire-sawn kerfs.Therefore,a 3D CFD(computational fluid dynamics)model is presented in this paper and used to simulate the liquid spreading behavior in a kerf based on a VOF(volume of fluid)method with a CSF(continuum surface force)model,which is used to simulate multiphase flow,and an empirical correlation for characterizing the liquid dynamic contact angle using UDF(user defined functions).Subsequently,parametric simulations are performed on the kerf area,kerf width,liquid viscosity,liquid surface tension,and liquid velocity at the inlet area of the kerf,and verification experi-ments are conducted to determine the validity of the simulation model.From the simulation and experimental results,three typical liquid spreading regimes that exhibit different effects on wire sawing in the kerfs are found,and their limiting conditions are identified using non-dimensional analysis.Subsequently,a prediction model is pro-posed for the liquid spreading regime based on a set of Weber and Capillary numbers.For wire sawing,an increase in the wafer area does not change the liquid spreading regime in the kerf;however,a reduction in the kerf width sig-nificantly hinders the liquid spreading behavior.Thereby,the spreading regime can be effectively converted to facili-tate wire sawing by adjusting the physical properties and supply conditions of the liquid. 展开更多
关键词 spreading regime KERF CFD Non-dimensional analysis Prediction model
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Differences of polygonal faults related to upper Miocene channels:a case study from the Beijiao sag of Qiongdongnan basin,South China Sea
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作者 Yufeng LI Renhai PU +4 位作者 Xueqin ZHAO Gongcheng ZHANG Xiaowei FAN Jingjing BAO Jiong WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第1期84-99,共16页
Deep-water coarse-grained channels are embedded within a polygonal fault tier,and the polygonal faults(PFs)present non-polygonal geometries rather than classic polygonal geometry in plan view.However,PFs present diffe... Deep-water coarse-grained channels are embedded within a polygonal fault tier,and the polygonal faults(PFs)present non-polygonal geometries rather than classic polygonal geometry in plan view.However,PFs present differences when they encounter deep-water(coarse-grained vs.fine-grained)channels with different lithology,which has not been further studied to date.Three-dimensional(3D)seismic data and a drilling well from Beijiao sag of Qiongdongnanbasin,South China Sea were utilized to document the plan view and cross-sectional properties of the PFs and their differences and genetic mechanism were investigated.Results show that,first,PFs can be divided morphologically into channel-segmenting PFs and channel-bounding PFs in plan view.The former virtually cuts or segments the axes of channels in highand low-amplitudes,and the latter nearly parallels the boundaries of the channels.Both are approximately perpendicular to each other.Secondly,channel-bounding PFs that related to low-amplitude channels are much longer than those of high-amplitude ones;channel-segmenting PFs related to low-amplitude channels are slightly longer than the counterparts related to high-amplitude channels.Lastly,the magnitudes(e.g.,heights)of the PFs are proportional to the scales(e.g.,widths and heights)of low-amplitude channels,whereas the magnitudes of the PFs are inversely proportional to the scales of high amplitude channels.Coarse-grained(high amplitude)channels act as a mechanical barrier to the propagation of PFs,whereas fine-grained(low-amplitude)channels are beneficial to the propagation and nucleation of PFs.Additionally,the genetic mechanism of PFs is discussed and reckoned as combined geneses of gravitational spreading and overpressure hydrofracture.The differences of the PFs can be used to reasonably differentiate coarse-grained channels from fine-grained channels.This study provides new insights into understanding the different geometries of the PFs related to coarse-grained and fine-grained channels and their genetic mechanism. 展开更多
关键词 polygonal faults coarse-grained channels fine-grained channels gravitational spreading overpressure hydrofracture
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BIFURCATION CONTROL FOR A FRACTIONAL-ORDER DELAYED SEIR RUMOR SPREADING MODEL WITH INCOMMENSURATE ORDERS
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作者 叶茂林 蒋海军 《Acta Mathematica Scientia》 SCIE CSCD 2023年第6期2662-2682,共21页
A fractional-order delayed SEIR rumor spreading model with a nonlinear incidence function is established in this paper,and a novel strategy to control the bifurcation of this model is proposed.First,Hopf bifurcation i... A fractional-order delayed SEIR rumor spreading model with a nonlinear incidence function is established in this paper,and a novel strategy to control the bifurcation of this model is proposed.First,Hopf bifurcation is investigated by considering time delay as bifurcation parameter for the system without a feedback controller.Then,a state feedback controller is designed to control the occurrence of bifurcation in advance or to delay it by changing the parameters of the controller.Finally,in order to verify the theoretical results,some numerical simulations are given. 展开更多
关键词 rumor spreading FRACTIONAL-ORDER time delay bifurcation control
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Effects of non-liquefiable crust layer and superstructure mass on the response of 2×2 pile groups to liquefaction-induced lateral spreading
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作者 S.Mohsen Haeri Morteza Rajabigol +2 位作者 Saman Salaripour Hiwa Sayaf Milad Zangeneh 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第10期2701-2719,共19页
In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spr... In this research,two shake table experiments were conducted to study the effects of non-liquefiable crust layer and superstructure mass on the responses of two sets of 22 pile groups to liquefactioninduced lateral spreading.In this regard,an inclined base layer overlain by a very loose liquefiable layer was constructed in both models;while only in one model,a non-liquefiable crust layer was built.A lumped mass,being representative of a superstructure,was attached to the cap of one pile group in both models.The models were fully instrumented with various sensors,including acceleration,displacement,and pore water pressure transducers.Also,the piles were instrumented with pair strain gauges to measure pure bending moments induced by cyclic and monotonic loadings associated with ground shaking and lateral spreading,respectively.The results showed that the existence of the non-liquefiable crust layer increases both the maximum and residual soil displacements at the free field and also the maximum bending moments in the piles.The results of the experiments indicated that the crust layer induces a high kinematic lateral soil pressure and force on the piles which are not present in the crustless case.The crust layer increases the pile cap displacement before liquefaction,albeit decreases it after liquefaction,due to the elastic rebound of the piles in the liquefiable layer.The crust layer postpones both liquefaction triggering and dissipation of excess pore water pressure.The existence of the superstructure mass on the pile caps decreases the acceleration amplitude of the pile caps,while increases their maximum displacement. 展开更多
关键词 Soil liquefaction Lateral spreading 1g shake table test Pile group Crust layer SUPERSTRUCTURE
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Spreading speed of a food-limited population model with delay
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作者 TIAN Ge AN Ruo-fan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第2期264-273,共10页
This paper is concerned with the spreading speed of a food-limited population model with delay.First,the existence of the solution of Cauchy problem is proved.Then,the spreading speed of solutions with compactly suppo... This paper is concerned with the spreading speed of a food-limited population model with delay.First,the existence of the solution of Cauchy problem is proved.Then,the spreading speed of solutions with compactly supported initial data is investigated by using the general Harnack inequality.Finally,we present some numerical simulations and investigate the dynamical behavior of the solution. 展开更多
关键词 food-limited population model reaction-diffusion equations DELAY spreading speed
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Topological phase transition in network spreading
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作者 年福忠 张霞 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期629-641,共13页
This paper investigates information spreading from the perspective of topological phase transition.Firstly,a new hybrid network is constructed based on the small-world networks and scale-free networks.Secondly,the att... This paper investigates information spreading from the perspective of topological phase transition.Firstly,a new hybrid network is constructed based on the small-world networks and scale-free networks.Secondly,the attention mechanism of online users in information spreading is studied from four aspects:social distance,individual influence,content richness,and individual activity,and a dynamic evolution model of connecting with spreading is designed.Eventually,numerical simulations are conducted in three types of networks to verify the validity of the proposed dynamic evolution model.The simulation results show that topological structure and node influence in different networks have undergone phase transition,which is consistent with the phenomenon that followers and individual influence in real social networks experience phase transition within a short period.The infection density of networks with the dynamic evolution rule changes faster and reaches higher values than that of networks without the dynamic evolution rule.Furthermore,the simulation results are compared with the real data,which shows that the infection density curve of the hybrid networks is closer to that of the real data than that of the small-world networks and scale-free networks,verifying the validity of the model proposed in this paper. 展开更多
关键词 social network information spreading network structure phase transition
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Large colonic lipoma with a laterally spreading tumor treated by endoscopic submucosal dissection:A case report
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作者 Jun Yong Bae Hun Kyu Kim +4 位作者 Yee Jin Kim Se Woong Kim Youngeun Lee Chang Beom Ryu Moon Sung Lee 《World Journal of Clinical Cases》 SCIE 2023年第26期6194-6199,共6页
BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic s... BACKGROUND Since fat does not transmit electrical energy well,delayed perforation and postpolypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma.The endoscopic submucosal dissection(ESD)technique concentrates electrical energy conducts to the submucosa,not the adipose tissue.This helps to minimize electrical thermal injury,especially in the case of large colonic lipomas.In rare cases,such as colonic lipomas accompanied by mucosal lesions,it is difficult for endoscopists to decide how to safely remove them.CASE SUMMARY A 78-year-old man underwent colonoscopy for colorectal cancer screening.During colonoscopy,a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm.A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma.The lipoma was so large that it occupied much of the inside of the colon,making it difficult to see the entire laterally spreading tumor(LST)at once.The LST was confined to the surface of the lipoma,which had a semipedunculated shape with a wide neck.The margin of the LST was not observed at the neck of the lipoma.ESD was performed and the colonic lipoma with the LST was successfully removed without complications.After 3 d of hospitalization,the patient was discharged without any symptoms.The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with lowgrade dysplasia.CONCLUSION ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury. 展开更多
关键词 Colonic lipoma Endoscopic submucosal dissection Laterally spreading tumor Tubulovillous adenoma Electrical injury Case report
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Impact of random and scattered coincidences from outside of field of view on positron emission tomography/computed tomography imaging with different reconstruction protocols
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作者 Mahak Osouli Alamdari Pardis Ghafarian +2 位作者 Arman Rahmim Mehrdad Bakhshayesh‑Karam Mohammad Reza Ay 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期40-52,共13页
Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi... Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm. 展开更多
关键词 Positron emission tomography/computed tomography(PET/CT) Random coincidences Scatter coincidences·Time of flight(TOF) Point spread function(PSF) Field of view(FOV) Noise equivalent count rate(NECR) Signal-toNoise ratio(SNR)
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