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青藏高原地形重力波对东亚春季降水的重要作用

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中国科学:地球科学 2023年第11期53卷 2639-2647页

作者：李闰秋徐昕徐祥德 theodore g.shepherd 王元南京大学中尺度灾害天气实验室南京大学大气科学学院南京210023 中国气象科学研究院灾害天气国家重点实验室北京100081 Department of Meteorology University of ReadingReading RG66BBUK

春季持续性降水是东亚夏季风爆发前的主要雨季,对东亚地区乃至全球水循环都具有深刻影响.过去研究揭示了青藏高原大尺度地形的动力和热力作用对东亚春季降水的重要影响,但青藏高原小尺度地形的作用尚不明确.本研究发现,副热带西风流受... 详细信息

春季持续性降水是东亚夏季风爆发前的主要雨季,对东亚地区乃至全球水循环都具有深刻影响.过去研究揭示了青藏高原大尺度地形的动力和热力作用对东亚春季降水的重要影响,但青藏高原小尺度地形的作用尚不明确.本研究发现,副热带西风流受青藏高原小尺度地形扰动激发的地形重力波,同样对东亚春季降水具有重要贡献.垂直传播的地形重力波在对流层中层发生破碎,产生纬向拖曳,从而驱动跨越青藏高原的经向环流.在青藏高原南侧,经向环流上升支的动力抽吸作用使得对流层低层气压减弱,从而增强经向气压梯度力和西南季风,将更多水汽输送至下游东亚地区,最终导致春季降水的增多.该研究有助于更加全面地理解青藏高原多尺度地形对东亚春季降水的影响,为西风-季风协同作用提供了新的视角.

关键词：青藏高原地形重力波季风春季持续性降水

Electrochemical Analysis of Zirconiumin Aqueous and Organic Media

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American Journal of Analytical Chemistry 2024年第2期15卷 99-118页

作者： Paul Mendy Démo Koita theodore Tzedakis Cheikhou Kane Codou guèye Mar-Diop Ecole Supérieure Polytechnique Université Cheikh Anta DIOP Dakar Sénégal Laboratoire de génie Chimique Université de Toulouse III—Paul Sabatier Toulouse France

For the challenging nature of the zirconium environment analysis, this study consists to analyze the electrochemical behavior of Zirconium in both aqueous and organic media. To that end first the electrolytic media was selected on the basis of the Pourbaix potential-pH diagram, which provides informations on the predominance of Zr(IV) ion and Zr in aqueous media. In aqueous media, analyzes were first carried out in acidic media then in basic media. Studies have thus revealed that the acidic environment is not favourable for the electrochemical analysis of zirconium. Voltammograms obtained in an acidic environment show no zirconium detection signal;this is due to the strong presence of H+ ions in the solution. We have also observed in acidic media the phenomenon of passivation of the electrode surface. In aqueous alkaline media (pH = 13), we have drawn in reduction several Intensity-Potential curves by fixingsome technical parameterslike scanning speed, rotation speed of the electrode. The obtained voltammograms show cathodic waves, starting from -1.5 V/DHW and attributed to the reduction of Zr (IV) to Zr (0). The last phase of this study focused on the electrochemical analysis of zirconium in an organic media. In this media, several intensity-potential curves were plotted in reduction and in cyclic voltammetry with various parameters. Through several reduction analysis, the Zr (IV) was reduced to Zr (0) to the potential of -1.5 V/DHW. The electrochemical analysis of zirconium in organic media seems globally easier to achieve thanks to its large solvent window (i.e. dimethylformamide (DMF) solvent window > 6 V).

关键词： Zirconium Electrochemical Reduction Cyclic Voltammetry Voltammogram Dymethylformamide

Primary liposarcoma of esophagus:A case report

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World Journal of gastroenterology 2006年第7期12卷 1149-1152页

作者： theodore D Liakakos theodore g Troupis Charalambos Tzathas Konstantina Spirou Irene Nikolaou Spiridon Ladas gabriel M Karatzas Department d~Department

Liposarcoma is the most common soft tissue sarcoma in adult life while esophageal liposarcoma is an extremely rare tumor. In the world literature, only 14 cases of esophageal liposarcomas have been described. We report a 72-year old male patient who was urgently admitted to our hospital for acute epigastric pain with a burning retrosternal sensation, persistent nausea, vomiting and dysphagia. Barium swallow, upper gastrointestinal （gI） endoscopy, esophageal manometry and CT scan, failed to accurately diagnose the lesion. After surgical resection of an esophageal polypoid tumor, the histological examination revealed a well-differentiated grade Ⅰ liposarcoma. Diagnostic and therapeutic tools were discussed and the results of literature were reviewed.

关键词： Liposarcoma Esophagus Surgical treatment

Individual differences in transcranial electrical stimulation current density

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The Journal of Biomedical Research 2013年第6期27卷 495-508页

作者： Michael J Russell theodore goodman Ronald Pierson Shane shepherd Qiang Wang Bennett groshong David F Wiley Aaken Research Institute Inc. Sutter Center for Psychiatry Brain Image Analysis LLC Radiological Associates of Sacramento Inc. Stratovan Corp.

Transcranial electrical stimulation （TCES） is effective in treating many conditions, but it has not been possible to accurately forecast current density within the complex anatomy of a given subject＇s head. We sought to predict and verify TCES current densities and determine the variability of these current distributions in patient-specific models based on magnetic resonance imaging （MRI） data. Two experiments were performed. The first experiment estimated conductivity from MRIs and compared the current density results against actual measurements from the scalp surface of 3 subjects. In the second experiment, virtual electrodes were placed on the scalps of 18 subjects to model simulated current densities with 2 mA of virtually applied stimulation. This procedure was repeated for 4 electrode locations. Current densities were then calculated for 75 brain regions. Comparison of modeled and measured external current in experiment 1 yielded a correlation of r = .93. In experiment 2, modeled individual differences were greatest near the electrodes （ten-fold differences were common）, but simulated current was found in all regions of the brain. Sites that were distant from the electrodes （e.g. hypothalamus） typically showed two- fold individual differences. MRI-based modeling can effectively predict current densities in individual brains. Significant variation occurs between subjects with the same applied electrode configuration. Individualized MRI- based modeling should be considered in place of the 10-20 system when accurate TCES is needed.

关键词： RI modeling current density transcranial-stimulation tDCS

Subthreshold behavior of AlInSb/InSb high electron mobility transistors

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Chinese Physics B 2015年第7期24卷 360-364页

作者： S.theodore Chandra N.B.Balamurugan g.Lakshmi Priya S.Manikandan Department of Electronics and Communication Engineering Thiagarajar College of Engineering

We propose a scaling theory for single gate Al In Sb/In Sb high electron mobility transistors（HEMTs） by solving the two-dimensional（2D） Poisson equation. In our model, the effective conductive path effect（ECPE） is taken into account to overcome the problems arising from the device scaling. The potential in the effective conducting path is developed and a simple scaling equation is derived. This equation is solved to obtain the minimum channel potential Φdeff,minand the new scaling factor α to model the subthreshold behavior of the HEMTs. The developed model minimizes the leakage current and improves the subthreshold swing degradation of the HEMTs. The results of the analytical model are verified by numerical simulation with a Sentaurus TCAD device simulator.

关键词： scaling theory subthreshold behavior effective conducting path effect short channel effect

On solitary *** 2 A unified perturbation theory for higher-order waves

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Acta Mechanica Sinica 2005年第6期21卷 515-530页

作者： theodore Yaotsu Wu Xinlong Wang Wendong Qu California Institute of Technology Pasadena CA 91125 U.S.A. Fellow Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China State Key Laboratory of Modern Acoustics and Institute of Acoustics Nanjing University Nanjing 210093 China California Institute of Technology Pasadena CA 91125 U.S.A PIMCO Newport Beach CA 92660 U.S.A.

A unified perturbation theory is developed here for calculating solitary waves of all heights by series expansion of base flow variables in powers of a small base parameter to eighteenth order for the one-parameter family of solutions in exact form, with all the coefficients determined in rational numbers. Comparative studies are pursued to investigate the effects due to changes of base parameters on （i） the accuracy of the theoretically predicted wave properties and （ii） the rate of convergence of perturbation expansion. Two important results are found by comparisons between the theoretical predictions based on a set of parameters separately adopted for expansion in turn. First, the accuracy and the convergence of the perturbation expansions, appraised versus the exact solution provided by an earlier paper [1] as the standard reference, are found to depend, quite sensitively, on changes in base parameter. The resulting variations in the solution are physically displayed in various wave properties with differences found dependent on which property （e.g. the wave amplitude, speed, its profile, excess mass, momentum, and energy）, on what range in value of the base, and on the rank of the order n in the expansion being addressed. Secondly, regarding convergence, the present perturbation series is found definitely asymptotic in nature, with the relative error δ （n）（the relative mean-square difference between successive orders n of wave elevations） reaching a minimum, δm at a specific order, n = n both depending on the base adopted, e.g. nm,α= 11-12 based on parameter α （wave amplitude）, nm,δ = 15 on δ （amplitude-speed square ratio）, and nm.ε= 17 on ε （ wave number squared）. The asymptotic range is brought to completion by the highest order of n = 18 reached in this work.

关键词： Solitary waves on water Unified perturbation theory Base functions Base parameters Asymptotic representation

Compact analytical model for single gate AlInSb/InSb high electron mobility transistors

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Journal of Semiconductors 2014年第11期35卷 46-50页

作者： S.theodore Chandra N.B.Balamurugan g.Subalakshmi T.Shalini g.Lakshmi Priya National Instruments Electronics Laboratory Department of ECEThiagarajar College of Engineering

We have developed a 2D analytical model for the single gate AllnSb/lnSb HEMT device by solving the Poisson equation using the parabolic approximation method. The developed model analyses the device perfomance by calculating the parameters such as surface potential, electric field distribution and drain current. The high mobility of the AlInSb/InSb quantum makes this HEMT ideal for high frequency, high power applications. The working of the single gate AllnSb/InSb HEMT device is studied by considering the variation of gate source voltage, drain source voltage, and channel length under the gate region and temperature. The carrier transport efficiency is improved by uniform electric field along the channel and the peak values near the source and drain regions. The results from the analytical model are compared with that of numerical simulations （TCAD） and a good agreement between them is achieved.

关键词： high electron mobility transistor AlInSb/InSb quantum well 2D analytical model Poisson's equation surface potential electric field

Interaction of genotype and environment effects on important traits of cassava(Manihot esculenta Crantz)

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The Crop Journal 2017年第5期5卷 373-386页

作者： Athanase Nduwumuremyi Rob Melis Paul Shanahan Asiimwe theodore University of KwaZulu-Natal African Center for Crop Improvement (ACCI) Rwanda Agriculture Board (RAB)

general and specific environmental adaptation of genotypes is the main goal of ***, genotype-by-environment(g x E) interaction complicates the identification of genotypes for release. This study aimed at analyzing the effects of g x E interaction on the expression of important cassava traits using two multivariate analyses: additive main effects and multiplicative interaction(AMMI) and genotype stability index(gSI). Total carotene content(TCC), postharvest physiological deterioration(PPD), and reaction to viral diseases were significantly affected by g x E interaction effects. The low percent(%)variation due to genotype for cassava brown streak disease(gBSD) explained the influence of environment on CBSD expression. The % variation due to genotype for TCC was higher(96%) than variation due to environment(1.7%) and g x E interaction(2.4%) indicating a low interaction effect of environment on TCC accumulation. The % variation due to genotype was higher than % variation due to environment for all traits but CBSD root necrosis and CBSD on stems, indicating the influence of environment on the severity of the viral diseases. These findings indicate that screening for disease resistance requires multi-environment trials, whereas a single-environment trial suffices to screen for total carotene content.

关键词： Additive main effects and multiplicative interaction genotype adaptation genotype stability index Physiological postharvest deterioration Total carotene content

Amyand's hernia: A case report

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World Journal of gastroenterology 2006年第29期12卷 4761-4763页

作者： Sofia Anagnostopoulou Dimitrios Dimitroulis theodore g Troupis Maria Allamani Alexandras Paraschos Antonios Mazarakis Nikolaos I Nikiteas Alkiviadis Kostakis Department of Anatomy School of Medicine University of Athens75 Mikras Asias streetAthens 11527Greece 2nd Department of Propedeutic Surgery School of Medicine "LAIKON" University Hospital14 Ag.Thoma StreetAthens 11527Greece

The presence of vermiform appendix in inguinal hernia is rare and is known as Amyand＇s hernia. We report an Amyand＇s hernia, where the appendix was found in a right inguinal hernia in one male cadaver aged ninety tw... 详细信息

关键词： Amyand's hernia Appendix Inguinal hernia