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Prediction of the seismic behavior of an underground railway station and a tunnel in Napoli(Italy)

Underground Space 2017年第2期2卷 88-105页

作者： S.Fabozzi v.Licata S.Autuori E.Bilotta G.russo F.Silvestri University of Napoli Federico II NapoliItaly

The assessment of the seismic safety of underground structures,either tunnels or large station boxes,should not be overlooked especially in densely populated areas,even with low to moderate *** underground structures,an important issue is the estimation of the seismic actions acting on the structure;only few experimental evidences are available for multi-level propped *** tunnels,it is generally assumed that their seismic behavior in soft ground is governed by the surrounding soil,while the inertial load contribution of the underground structure itself is *** both cases,recent numerical studies proved that advanced dynamic analyses can provide satisfactory interpretation of non-linear soil-structure interaction during *** this paper,a real case study,represented by a large open multi-propped excavation and a circular segmented tunnel in a densely urbanized area of the city center in Napoli,has been used to investigate some of the mentioned *** geotechnical characterization and choice of the reference input motions lead to a first estimate of the free-field ground motion,which was subsequently used for pseudo-static decoupled *** the complexity of both excavation geometry and staged construction,a full dynamic analysis was considered neither affordable nor reliable for the multi-propped station box;thus two conventional pseudo-static analyses,applying either a displacement-based or a force-based approach,were carried *** the case of the tunnel,the seismic increments of internal forces in the lining could be calculated through both a simplified pseudostatic analysis and a full dynamic analysis,showing a satisfying ***,the results of the study demonstrated that the seismic increments of internal forces in the diaphragm walls of the station and in the segmented lining of the tunnel were quite *** case study encourages improving the reliability of simplified methods based on the more

关键词： Underground structures Tunnels Diaphragm walls Seismic behavior Pseudo-static analysis Dynamic analysis Soil-Structure interaction

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Si/Si C-based DD hetero-structure IMPATTs as MM-wave power-source:a generalized large-signal analysis

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Journal of Semiconductors 2015年第6期36卷 58-63页

作者： Moumita Mukherjee P.r.Tripathy S.P.Pati Centre for MM-wave Semiconductor Devices and Systems (CMSDS) DRDO Hi-Tech College of Engineering Former Professor of Sambalpur University

A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMPATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation （~ 2%, i.e. small-signal conditions） results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode＇s negative conductance （5 × 106 S/m2）, susceptance （10.4 × 107 S/m2）, average breakdown voltage （207.6 v）, and power generating efficiency （15%, rF power： 25.0 W at 94 GHz） are obtained as a function of oscillation amplitude （50% of DC breakdown voltage） for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal （〉 50%） voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMPATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMPATT for possible application in high-power MM-wave communication systems.

关键词： Si/SiC hetero-structure double drift diode full-scale large-signal modelling high-power parasiticeffects noise-analysis

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The Effect of Super volcanic Eruptions on Ozone Depletion in a Chemistry–Climate Model

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Advances in Atmospheric Sciences 2019年第8期36卷 823-836页

作者： Luyang XU Ke WEI Xue WU S. P. SMYSHLYAEv Wen CHEN v. Ya. GALIN Center for Monsoon System research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China russian State Hydrometeorological University Malookhtinskii pr.98St.Petersburg 195196Russia Institute of Numerical Mathematics Russian Academy of Sciencesul.Gubkina 8Moscow 11999Russia

With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 rCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption.

关键词： stratospheric ozone volcanic eruptions stratospheric aerosols chemistry–climate model

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Effects of meal size and proximal-distal segmentation on gastric activity

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World Journal of Gastroenterology 2010年第46期16卷 5861-5868页

作者： Madileine F Américo Marjorie v Ietsugu Fernando G romeiro Luciana A Corá ricardo B Oliveira José ricardo A Miranda Department of Physics and Biophysics IBBUNESP-Sao Paulo State University Institute of Biological Sciences and Health ICBSUFMT-University of Mato Grosso Department of Clinical Medicine FMBUNESP-Sao Paulo State University Department of Clinical Medicine FMRPUSP-University of So Paulo UNCISAL-Alagoas State University of Health Sciences

AIM:To evaluate the effects of meal size and three segmentations on intragastric distribution of the meal and gastric motility,by ***:Twelve healthy volunteers were randomly assessed,twice,by *** test meal consisted of 60 or 180 mL of yogurt labeled with 64 MBq 99m Tc-tin *** and posterior dynamic frames were simultaneously acquired for 18 min and all data were analyzed in *** proximal-distal segmentations using regions of interest were adopted for both ***:Intragastric distribution of the meal between the proximal and distal compartments was strongly influenced by the way in which the stomach was divided,showing greater proximal retention after the 180 *** important finding was that both dominant frequencies (1 and 3 cpm) were simultaneously recorded in the proximal and distal stomach;however,the power ratio of those dominant frequencies varied in agreement with the segmentation adopted and was independent of the meal ***:It was possible to simultaneously evaluate the static intragastric distribution and phasic contractility from the same recording using our scintigraphic approach.

关键词： Gastric motility Phasic contractions Proximal stomach Scintigraphy Meal size

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A new aluminum iron oxide Schottky photodiode designed via sol-gel coating method

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Chinese Physics B 2014年第5期23卷 563-567页

作者： A.Tataroglu A.A.Hendi r.H.Alorainy F.Yakuphanoglu Department of Physics Faculty of ScienceGazi University Physics Department Sciences Faculty for GirlsKing Abdulaziz University Department of Physics Faculty of ScienceF?rat University

A novel aluminum iron oxide （Al/AlFe2O4/p-Si） Schottky photodiode was successfully fabricated via the sol-gel coating process. The microstructure of the spinel ferrite （AlFe2O4） was examined by atomic force microscopy. The current-voltage characteristics of the fabricated photodiode were studied under dark and different illumination conditions at room temperature. By using the thermionic emission theory, the forward bias I-v characteristics of the photodiode are analyzed to determine the main electrical parameters such as the ideality factor （n） and barrier height （ФB0） of the photodiode. The values of n and ФB0 for all conditions are found to be about 7.00 and 0.76 ev, respectively. In addition, the values of series resistance （rs） are determined using Cheung＇s method and Ohm＇s law. The values of rs and shunt resistance （rsh） are decreased with the increase of illumination intensity. These new spinel ferrites will open a new avenue to other spinel structure materials for optoelectronic devices in the near future.

关键词： spinel ferrite Schottky photodiode I-v characteristics barrier height

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Sequential piezoresponse force microscopy and the‘small-data’problem

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npj Computational Materials 2018年第1期4卷 419-425页

作者： Harsh Trivedi vladimir v.Shvartsman Marco S.A.Medeiros robert C.Pullar Doru C.Lupascu Institute for Materials Science and Center for Nanointegration Duis order ferroic switching induced by sburg-Essen(CENIDE) University of Duisburg-EssenEssenGermany CICECO–Aveiro Institute of Materials University of AveiroAveiroPortugal Department of Materials and Ceramic Engineering University of AveiroAveiroPortugal

The term big-data in the context of materials science not only stands for the volume,but also for the heterogeneous nature of the characterization *** is a common problem in combinatorial searches in materials science,as well as ***,these data-sets may well be‘small’in terms of limited step-size of the measurement *** to this limitation,application of higher-order statistics is not effective,and the choice of a suitable unsupervised learning method is restricted to those utilizing lower-order *** an interesting case study,we present here variable magnetic-field Piezoresponse Force Microscopy(PFM)study of composite multiferroics,where due to experimental limitations the magnetic field dependence of piezoresponse is registered with a coarse *** efficient extraction of this dependence,which corresponds to the local magnetoelectric effect,forms the central problem of this *** evaluate the performance of Principal Component Analysis(PCA)as a simple unsupervised learning technique,by pre-labeling possible patterns in the data using Density Based Clustering(DBSCAN).Based on this combinational analysis,we highlight how PCA using non-central second-moment can be useful in such cases for extracting information about the local material response and the corresponding spatial distribution.

关键词： DBSCAN problem utilizing

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Nano inhomogeneity effects on small Ag/n-Si Schottky diode parameters at high temperature

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Journal of Semiconductors 2013年第8期34卷 8-14页

作者： M.A.Yeganeh r.K.Mamedov A.J.Novinrooz Islamic Azad University Bonab Branch Faculty of Electronic Engineering Faculty of Physics Baku State UniversityAcademic Zahid Khalilov Str.23AZ 1148Baku Islamic Azad University Takestan Branch Faculty of Physics

Schottky diodes with an Ag/n-Si/W/Cu structure and 100μm in diameter were *** the silver metal surface coating on the n-Si substrate using a scanning probe microscopy（SPM） device showed a large number of nano patches in the surface with dimensions of 0 to 100 *** potential distribution of the patches revealed that the potential of each patch with the neighboring patches was *** electrical characteristics of the devices were studied between temperature ranges of 300 and 380 *** the temperature ideality factor approximately increases,the potential barrier height *** potential barrier height was calculated separately from theⅠ-Ⅴand C-v *** main reasons for the significant difference between room temperature and higher temperatures were the differences in patch distribution,the different potentials of each patch,and the interactions between *** effective potential barrier height depended on the degree of inhomogeneity,and thus the operating potential barrier height in the contact surface was smaller than the average value,and the ideality factor was more than *** the increase in the potential value,the ideality factor becomes close to unitary, and with increasing temperatures,the ideality factor is *** this case,the maximum potential barrier height accrues at a greater distance from the metal *** this reason,at high temperatures the average value of the potential barrier height is ***,with increasing temperature,the ideality factor is increased.

关键词： Schottky contact nano patch high temperatures Schottky parameters AFM and SPM

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Density Modulation Experiments on HT-7 Tokamak

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Chinese Physics Letters 2004年第12期21卷 2458-2460页

作者： K.Tanaka 高翔揭银先 r.Sakamoto K.Toi NationalInstituteforFusionScience 322-6Oroshi-choTokiJapan InstituteofPlasmaPhysics ChineseAcademyofSciencesHefei230031

Density modulation experiments are successfully conducted on HT-7 ohmic discharge to investigate particle transport coefficients: diffusion coefficients D and convection velocity v. The particle transport is studied at low (1.5×1019m−3) and high (3×1019m−3) density regimes. The clear differences are observed that D is 0.42m2/s and 0.17m2/s, v is 4.7m/s (outward) and 1.6m/s (inward) for low and high density plasmas respectively, where spatially constant D and v(r) = (r/a)v0 were assumed for the analysis.

关键词： Modulation

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Improvement of tissue analysis and classification using optical coherence tomography combined with raman spectroscopy

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Journal of Innovative Optical Health Sciences 2015年第4期8卷 10-19页

作者： Chih-Hao Liu Ji Qi Jing Lu Shang Wang Chen Wu Wei-Chuan Shih Kirill v.Larin Department of Biomedical Engineering University of Houston 3605 Cullen Blvd. HoustonTexas 77204-5060USA Department of Electrical and Computer Engineering University of Houston 4800 Calhoun rd. HoustonTexas 77204USA Department of Molecular Physiology and Biophysics Baylor College of Medicine One Baylor Plaza HoustonTexas 77030USA

Optical coherence tomography(OCT)provides significant advantages of high resolution(approaching the histopathology level)realtime imaging of tsess without use of contrast *** on these advantages,the microstructural features of tumors can be visualized and detected ***,it is still not clinically accepted for tumor margin delin-eation due to poor specificity and *** contrast,raman spectroscopy(rS)can obtain tissue information at the molecular level,but does not provide real-time inaging ***,combining OCT and rS could provide *** this end,we present a tissue analysis and dassification method using both the slope of OCT intensity signal vs depth and the principle components from the rS spectrum as the indicators for tissuse *** goal of this study was to understand prediction accuracy of OCT and combined OCT/rS method for dassification of optically similar tisues and *** pilot experiments were performed on mouse kidneys,livers,and small intestines(SIs).The prediction accuracy with five-fold cross validation of the method has been evaluated by the support vector machine(SvM)*** results demonstrate that tissue characterization based on the OCT/rS method was superior compared to using OCT structural information *** combined OCT/rS method is potentially useful as a noninvasive optical biopsy technique for rapid and automatic tissue characterization during surgery.

关键词： OCT signal slope principle component analysis multi-support vector machine raman spectra

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validation of glaucoma-like features in the rat episcleral vein cauterization model

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Chinese Medical Journal 2014年第2期127卷 359-364页

作者： Bai Yujing Zhu Yingting Chen Qin Xu Jing Marinko v. Sarunic Uri H. Saragovi Zhuo Yehong Key Laboratory of vision Loss and restoration Ministry of Education Department of Ophthalmology Peking University People's Hospital Beijing 100044 China State Key Laboratory of Ophthalmology Zhongshan Ophthalmic Center Sun Yat-sen University Guangzhou Guangdong 510060 China Department of Ophthalmology First'Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu 210029 China Engineering Science Simon Fraser University Burnaby BC Canada V5A 1S6 Department of Pharmacology and Therapeutics Department of Oncology and the Cancer Center Bloomfield Centre for Research in Aging Lady Davis Institute-Jewish General Hospital McGill University Montreal Quebec Canada H3T 1E2

Background Glaucoma,an irreversible optic nerve neuropathy,always results in *** study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization （EvC） model by multiple in vivo and in vitro *** Wistar rat was used in this *** elevated intraocular pressure （IOP） was induced by cauterization of three episcleral *** was monitored with Tono-Pen XL ***-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence *** function of retina was evaluated by electroretinogram （ErG）.Survival of retinal ganglion cells （rGCs） was quantified by retrograde *** study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear *** and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha （TNF-α） and alpha-2 macroglobulin （α2m） were measured with Western *** EvC is a relatively facile intervention,with low failure rates （＜5％）.After surgical intervention,chronic mild lOP elevation （about 1.6-fold over normal,P ＜0.05） was induced for at least 6 weeks without requiring a second *** lOP causes chronic and progressive loss of rGCs （averaging about 4％ per week）,progressive thinning of neuronal retinal layers （3-5 μm per week）,and reduction of a-and b-wave in *** method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α*** EvC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.

关键词： glaucoma experimental animal model retinal neurons rat

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