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A Perturbation Result for Dynamical Contact Problems

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Numerical Mathematics(Theory,Methods and Applications) 2009年第3期2卷 237-257页

作者： Corinna Klapproth Peter Deuflhard anton Schiela Zuse Institute Berlin(ZIB) Takustrasse7D-14195 Berlin-DahlemGermany

This paper is intended to be a first step towards the continuous dependence of dynamical contact problems on the initial data as well as the uniqueness of a solution. Moreover,it provides the basis for a proof of the convergence of popular time integration schemes as the Newmark *** study a frictionless dynamical contact problem between both linearly elastic and viscoelastic bodies which is formulated via the Signorini contact *** viscoelastic materials fulfilling the Kelvin-Voigt constitutive law,we find a characterization of the class of problems which satisfy a perturbation result in a non-trivial mix of norms in function *** characterization is given in the form of a stability condition on the contact stresses at the contact ***,we present perturbation results for two well-established approximations of the classical Signorini condition:The Signorini condition formulated in velocities and the model of normal compliance,both satisfying even a sharper version of our stability condition.

关键词： Dynamical contact problems stability (visco-)elasticity Signorini condition Newmarkmethod.

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Effect of Heattreatment on Directionally Solidified NB Containing Tlalallys

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Effect of Heattreatment on Directionally Solidified NB Conta...

作者： Getman anton 哈尔滨工业大学

学位级别：硕士

This paper talks about the effect of heat treatmant (HT) on the cast and direction solidified (DS) Ti-46Al-6Nb and Ti-46Al-6.3Nb-0.1B compositions. These materials were prodused by cold crucible electromagnetic process. Samples were heat treated with six different conditions with the Muffle Atmosphere Furnace XY-1600A. HT1: temperature at1270℃for2h+air cooling. HT2:temperature at1330℃for2h+air cooling. HT3:temperature at1330℃for2h+900℃for30min+air cooling. HT4: temperature at1330℃for2h+air cooling, and then was repeat heating at1330℃for10min. HT5:temperature at1330℃for10min+air cooling, and then was repeated the same HT process. HT6:temperature at1330℃for10min+air cooling, and then was repeated the same HT process four times. After HT process all samples were polished, etched and prepared for further analysis. Firstly samples were taken pictures by a digital camera. Analysis of microstructure was performed by the optical microscope (OM) and the scanning electron microscope (SEM). After microstructure analysis all samples were cut into several small cylinders for compressive stress (CS) tests. CS test were tested by Inston5960Dual Column Tabletop Universal Testing Systems. Analysis of fracture mechanism before and after heat treatment was done by SEM.HT1decreased of average grain size of cast alloy from1.4mm to0.3mm, but didn't change the grain morphology of DS samples. Also HTlincreased of the lamellar spacing from2.46μm to4.38μm. The compressive stress decreased after HT1. HT2-HT4had insignificant influence on changing average grain size macrostructure of cast materials, but cardinally changed morphology and microstructure of DS materials. HT2-HT4and HT6caused elimination of all segregations. HT2-HT6decreased the lamellar spacing. The best result of compressive stress property had showed HT5. Also HT5caused the smallest lamellar spacing. HT1and HT2changed fracture mechanisms a little, but HT5and HT6significant changed fracture mechanism from inter or trans-lame

关键词： direction solidification grain size lamelae spacing TI-46Al-6Nb Ti-46Al-6.3Nb-0.1B compressive stress

Hot Articles Forecasting System Based on the Headline Analysis with Deep Learning

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Hot Articles Forecasting System Based on the Headline Analys...

作者： anton VORONOV 上海交通大学

学位级别：硕士

Forecasting popularity of the articles become one hot task for the news media industry and the research community have provided several prediction systems,based on popular trends,metadata and users ***,when the headline has a fundamental relationship with the popularity of the article,there is no proper system,which can use only the title to predict the possible views *** theses work proposes a new Hot Articles Forecasting System based on the headline analysis with Online Deep Neural Network architecture and Bottleneck compression technique,which can make an efficient real-time prediction of the article popularity and automatically learn new ***,this work introduces three new datasets based on the Chinese and Russian languages,with over than 800 000 samples in *** advanced,this thesis provides the corporation of the formal and informal language style headlines in the case of the popularity prediction for the Chinese *** work also investigates the challenges and provides solutions related to the popularity prediction and the headline *** work will show that the HAFS can provide prediction results with different languages in the case of changing activity and trends.

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Radio observations of the first three-months of Fermi AGN at 4.8 GHz

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Research in Astronomy and Astrophysics 2012年第2期12卷 147-157页

作者： Nicola Marchili Thomas P.Krichbaum Lars Fuhrmann anton Zensus Max-Plank-Institut fr Radioastronomie

Using the Urumqi 25 m radio telescope, sources from the first three months of the Fermi-large area telescope detected active galactic nuclei （AGN） catalog with a declination of 〉 0° were observed in 2009 at 4.8 GHz. The radio flux density ap- peared to correlate with the γ-ray intensity. Intra-day variability （IDV） observations were performed in March, April and May 2009 for 42 selected γ-ray bright blazars, and ~60% of them showed evidence of flux variability at 4.8 GHz during the IDV observations. The IDV detection rate was higher than that in previous flat-spectrum AGN samples. IDV appeared more often in the very long baseline interferometry-core dominant blazars, and the non-IDV blazars showed relatively ＂steeper＂ spectral in- dices than the IDV blazars. Pronounced inter-month variability was also found in two BL Lac objects： J0112＋2244 and J0238＋1636.

关键词： galaxies: active - quasars: general - radio continuum: galaxies -gamma-rays: observations

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Clinico-pathological aspects of colorectal serrated adenomas

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World Journal of Gastroenterology 2006年第17期12卷 2770-2772页

作者： Ashish Chandra Adnan A Sheikh anton Cerar Ian C Talbot Department of Pathology St Thomas' Hospital Lambeth Palace RoadLondonSE1 7EHUnited Kingdom Department of Surgery Royal Liverpool University Hospital Prescot RoadLiverpoolL7 8XPUnited Kingdom Institute of Pathology Medical Faculty Korytkova 21105 LjubljanaSlovenia Academic Department of Pathology St Mark's and Northwick Park Hospitals NHS Trust HarrowMiddlesexHA1 3UJUnited Kingdom

AIM： To study the association of colorectal serrated adenomas （SAs） with invasive carcinoma, local recurrence, synchronicity and metachronicity of lesions. METHODS： A total of 4536 polyps from 1096 patients over an eight-year period （1987-1995） were retrospectively examined. Adenomas showing at least 50% of serrated architecture were called SAs by three reviewing pathologists. RESULTS： Ninety-one （2%） of all polyps were called SAs, which were found in 46 patients. Invasive carcinomas were seen in 3 out of 46 （6.4%） patients, of whom one was a case of familial adenomatous polyposis （FAP）. A male preponderance was noted and features of a mild degree of dysplasia were seen in majority （n=75, 83%） of serrated adenomas. Follow-up ranged 1-12 years with a mean time of 5.75 years. Recurrences of SAs were seen in 3 （6.4%） cases, synchronous SAs in 16 （34.8%） cases and metachronous SAs in 9 （19.6%） cases. CONCLUSION： Invasive carcinoma arising in serrated adenoma is rare, accounting for 2 （4.3%） cases studied in this series.

关键词： Serrated adenoma Carcinoma Polyps Colorectum

Reduction of bend scour with an air-bubble screen-morphology and flow patterns

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International Journal of Sediment Research 2013年第1期28卷 15-23页

作者： Violaine DUGU Koen BLANCKAERT Qiuwen CHEN anton J.SCHLEISS Ecole Polytechnique Fédérale de Lausanne(EPFL) Laboratory of Hydraulic Constructions(LCH)Station 18CH-1015 LausanneSwitzerland State Key Laboratory of Urban and Regional EcologyResearch Center for Eco-Environmental SciencesChinese Academy of Sciences

The interplay between streamwise flow,curvature-induced secondary flow,sediment transport and bed morphology leads to the formation of a typical bar-pool bed morphology in open-channel *** associated scour at the outer bank and deposition at the inner bank may endanger the outer bank’s stability or reduce the navigable width of the *** preliminary laboratory experiments in a sharply curved flume with a fixed horizontal bed have shown that a bubble screen located near the outer bank can generate an additional secondary flow located between the outer bank and the curvature-induced secondary flow and with a sense of rotation opposite to the *** bubble-induced secondary flow redistributes velocities and bed shear *** reported study investigates the implications of a bubble screen on the flow and the morphology in configurations with mobile *** measurements show that the bubble-induced secondary flow shifts the curvature-induced secondary flow in inwards direction and reduces its *** bubble screen considerably reduces morphological *** bend scour is reduced by about 50%and occurs further away from the outer bank where it does not endanger the bank stability *** location of maximum scour coincides with the junction of the curvature-induced and bubble-induced secondary *** this same location,the maximum streamwise velocities and maximum vertical velocities impinging on the bed also occur,which indicates their importance with respect to the formation of bend *** bubble screen also substantially reduced deposition at the inner *** preliminary experiments show the potential of a bubble screen to influence and modify the bed morphology.

关键词： Bubble screen Erosion Scour Morphodynamics Open-channel bend

Soil Conservation and Sediment Control in Europe

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长江科学院院报 2010年第9期27卷 83-86页

作者： anton Charles Imeson Foundation 3D Environmental Change Curtiuslaan 14 1851 AM Heiloo The Netherlands

The objective of this paper is to provide an overview of soil conservation and sediment control in Europe from the perspectives of policy makers seeking solutions to current problems of soil loss and *** and information are derived from detailed reports written in support of the European Soils Directive,that addressed the threats facing European soils and from workshops organised to identify best practices and achieve sustainable land use in different EU *** were organised by the SCAPE(Strategies for Soil Conservation and Protection in Europe) supporting *** technical measures used to limit erosion and restore ecosystems,there is much similarity between Europe and *** main soil and land degradation problems that soil conservation practitioners and scientists have to address are caused by land use and management impacts that have proved difficult or impossible to resist because of political *** political leadership that regarded soil conservation and sediment control,as a cornerstone of sustainable economic development,which seemed to be present eight years,is urgently required once more.

关键词： soil conservation sustainable land management European soil policy

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Optimal cutting condition determination for milling thin-walled details

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Advances in Manufacturing 2018年第3期6卷 280-290页

作者： anton Germashev Viktor Logominov Dmitri Anpilogov Yuri Vnukov Vladimir Khristal Mechanical Engineering Department Zaporizhzhya National Technical University Zaporizhzhya 69063 Ukraine Zaporozhye Machine-building Design Bureau Progress State Enterprise Zaporizhya Ukraine

This paper presents an approach for determiningthe optimal cutting condition for milling thin-walled ele-ments with complex shapes. The approach is based on theinteraction between the thin-walled detail and its periodicexcitation by tooth passing, taking into account the highintermittency of such a process. The influence of theexcitation frequency on the amplitude of the detail oscil-lation during milling was determined by simulation andexperiments. It was found that the analytical results agreedwith experimental data. The position of the detail when thetooth starts to cut was evaluated through experiments. Theinfluence of this parameter on the processing state is pre-sented herein. The processing stability is investigated andcompared with the proposed approach. Thereafter, spectralanalyses are conducted to determine the contribution of thevibrating frequencies to the detail behavior during processing.

关键词： Thin-walled detail High-speed milling Stability Surface finish

A methodological framework for analyzing PPGIS data collected in 3D

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International Journal of Digital Earth 2023年第1期16卷 3435-3455页

作者： Kamyar Hasanzadeh Nora Fagerholm Hans Skov-Petersen anton Stahl Olafsson Department of Geography and Geology University of TurkuTurkuFinland Department of Geosciences and Natural Resource Management University of CopenhagenCopenhagenDenmark

Public participation geographic information system(PPGIS)is a facilitated Volunteered Geographic Information approach and data collection method that aims to capture the spatial experiences of *** we experience the space around us three-dimensionally,altitude,as the third dimension,has been often absent from PPGis research and *** is largely because of the complexity of implementing surveys in 3D but can also be attributed to a lack of analytical preparedness for using such *** study complements 3D PPGIS data collected from a pilot study of the Aninkainen block in Turku,Finland with synthetic,*** manufactured,data to propose an analytical framework for the study of 3D PPGIS *** analytical framework divides methods based on the geographical scale into two groups:micro-and macro-scale *** this framework,we propose the use of geospatial metrics to analyze 3D PPGIS *** argue that while this multidisciplinary area of research is in its infancy,use of intuitive 3D adapted geometric and landscape metrics can help overcome some of complexities associated with use of this emerging participatory *** conclude by outlining the limitations and envisioning areas for future research.

关键词： 3D GIS landscape metrics PPGIS