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Nonlinear phenomena in dielectric barrier discharges: pattern, striation and chaos

Plasma Science and Technology 2018年第10期20卷 23-50页

作者： Jiting OUYANG Ben LI Feng HE Dong DAI School of Physics Beijing Institute of TechnologyBeijing 100081People＇s Republic of China School of Electric Power South China University of TechnologyGuangzhou 510641People＇s Republic of China

The nonlinear phenomenon is very popular in dielectric barrier discharge （DBD） plasmas. There are at least three kinds of spatial and temporal nonlinear phenomena appearing synchronously or asynchronously in DBDs, i.e. self-organized patterns, striations and chaos. This paper describes the recent research and progress in understanding the nature of these nonlinear phenomena. Patterns are macroscopic structures with certain spatial and/or temporal periodicities generated through self- organization of microscopic parameters. The physics of patterns in DBDs is mainly associated with lateral dynamic behaviors or the lateral non-local effect of charged particles resulting in the lateral development or non-uniformity of discharge. striations are ionization waves with unique properties determined by transport phenomena, ionization processes and electron kinetics in current-carrying plasmas. The physics of striations in DBDs is mainly associated with the advances in non-local electron kinetics in spatially inhomogeneous plasmas. Chaos is a kind of random and non-periodic phenomenon occunfng in a determined dynamic system, following a series of certain rules while exhibiting random locomotion, and is regarded as an intrinsic and ubiquitous phenomenon in a nonlinear dynamic system. An evolution trajectory including period-doubling bifurcation to chaos was observed in DBDs or DBD-derived plasmas. In a common sense, it is believed that the formation of all the three nonlinear phenomena in a DBD system should be related to the non-local transversal and/or longitudinal dynamics of space charges （i.e. non-local effect） or the localized electric field interaction. Future work is still needed on the underlying physics and should be directed to pursuing the unification of these nonlinear phenomena in DBD.

关键词： nonlinear phenomenon dielectric barrier discharge pattern striation chaos

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Effect of Wall Charge on striation in Plasma Display Cells

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Plasma Science and Technology 2007年第2期9卷 198-201页

作者：何锋欧阳吉庭曹菁冯硕缪劲松王建琪 School of Science Beijing Institute of TechnologyBeijing 100081China Key Laboratory for Physical Electronics and Devices of Ministry of EducationXi'an Jiaotong UniversityXi'an 710049China School of Science Beijing Institute of TechnologyBeijing 100081China Key Laboratory for Physical Electronics and Devices of Ministry of Education Xi'an Jiaotong UniversityXi'an 710049China

Different configurations and driving voltages have been employed to investigate the effect of the wall charge on the striations in macroscopic plasma display panel （PDP） cells. The experimental results show that a discharge channel near the dielectric layer is indispensable to striation occurring in the anode area during a discharge, while the pre-accumulated charge on the dielectric layer and the surface state are not important. The origin of the striation is related only to the physical process in the cell. The dielectric layer acts as a charge collector during a PDP discharge.

关键词： striation wall charge plasma display panel

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Analysis of striation Formation and Suppression Strategy on Upper Edge of Cutting Surface in Laser Cutting

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World Journal of Engineering and Technology 2018年第1期6卷 201-213页

作者： Chao Li Dengfei You Shanghai Xinli Machinery Factory Shanghai China

Metal laser cutting belongs to mature laser material processing technologies in industry applications. However, without understanding of the mechanism underlying the overall process, the improvement of the cutting quality is restricted. In this paper, an instantaneous melt removal model is presented to describe the process of material removal and striation formation. In the temperature field calculation, melted metal layer is removed when it grows to an assumed thickness. The effects of cutting parameters including cutting speed, gas pressure and laser power on the shape of striation are discussed. A novel method of getting striation free cutting surface is presented. Finally, laser cutting experiments of mild steel is conducted to validate the model. The striation variation trend can be well predicted by the model presented here and the disagreement may be caused by the coupling effect of cutting speed and critical thickness value.

关键词： Fusion Cutting striation Instantaneous Removal Laser Power Modulation

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Glaciation-induced features or sediment gravity flows——An analytic review

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Journal of Palaeogeography 2023年第4期12卷 487-545页

作者： Mats O.Molen Umea FoU AB Vallmov 61S-90352 Ume aSweden

For more than 150 years, geologic characteristics claimed to be evidence for pre-Pleistocene glaciations have been debated. Advancements in recent decades, in understanding features generated by mainly glacial and mass flow processes, are here reviewed. Detailed studies of data offered in support of prePleistocene glaciations have led to revisions that involve environments of mass movements. Similarities and differences between Quaternary glaciogenic and mass movement features are examined, to provide a more systematic methodology for analysing the origins of more ancient deposits. Analyses and evaluation of data are from a) Quaternary glaciogenic sediments, b) formations which have been assigned to pre-Pleistocene glaciations, and c) formations with comparable features associated with mass movements(and occasionally tectonics). Multiple proxies are assembled to develop correct interpretations of ancient strata. The aim is not per se to reinterpret specific formations and past climate changes, but to enable data to be evaluated using a broader and more inclusive conceptual *** occurring pre-Pleistocene features interpreted to be glaciogenic, have often been shown to have few or no Quaternary glaciogenic equivalents. These same features commonly form by sediment gravity flows or other non-glacial processes, which may have led to misinterpretations of ancient deposits. These features include, for example, environmental affinity of fossils, grading, bedding, fabrics, size and appearance of erratics, polished and striated clasts and surfaces(“pavements”), dropstones, and surface *** decades of progress in research relating to glacial and sediment gravity flow processes have resulted in proposals by geologists, based on more detailed field data, more often of an origin by mass movements and tectonism than *** most coherent data of this review, i.e., appearances of features produced by glaciation, sediment gravity flows and a fe

关键词： Diamictite Tillite Sediment gravity flow(SGF) striation Groove Dropstone Paleoclimate Fossil vegetation Glaciogenic proxies Surface microtexture Late Paleozoic ice age

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Growth Defects in Langasite Crystals Observed with White Beam Synchrotron Radiation Topography

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Journal of Rare Earths 2006年第z1期24卷 159-161页

作者： Wang Xuping Wang Jiyang Hu Xiaobo Zhang Jianxiu Zhao Hongyang Huang Wanxia Zhu Peiping State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China Beijing Synchrotron Radiation Laboratory Institute of High Energy Physics Beijing 100039 China Beijing Synchrotron Radiation Laboratory Institute of High Energy Physics Beijing 100039 China

Langasite single crystal was grown by the Czochralski method and its perfection was assessed by white beam synchrotron radiation topography. It is found that the growth core and the growth striations are the primary growth defects and they show strong X-ray kinematical contrast in the topographs. Another typical defect in LGS crystal is dislocation. The formation mechanisms of these growth defects in LGS crystals were discussed.

关键词： Langasite (LGS crystal) growth striation growth core dislocation

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EXPERIMENTAL STUDIES ON THE EFFECT OF OVERLOAD ON FATIGUE CRACK GROWTH

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Acta Mechanica Sinica 1986年第2期2卷 146-157页

作者： Yang Bingxian Beijing Institute of Aeronautics and Astronautics Beijing Institute of Aeronautics and Astronautics Beijing China

The fatigue crack growth behavior resulting from a single overload *** order to clarify the mechanism of overload on fatigue crack growth, the processes of crack closureand opening and their stress levels are monitored by strain gages placed on the back surface ofspecimens, and the fracture surface morphologies are examined by the *** results may be used to explain quantitatively the mechanisms of retardation anddelayed retardation after a single overload.

关键词： overload retardation fracture surface morphology microfractography void dimple striation quasi-cleavage effective stress intensity factor range.

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Study on the Role of Supersonic Nozzle in Fiber Laser Cutting of Stainless Steel

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Materials Sciences and Applications 2017年第1期8卷 85-93页

作者： Yijun Zhou Jilan Kong Jin Zhang Yang Zhou Polytechnic College Jiangsu China

striation-free laser cutting, especially for thick section steel, is hard to obtain due to several factors. The inside shape of the gas nozzle is considered to be one of the most vital factors in striation-free fiber laser cutting. 0.8 mm normal nozzle and a supersonic nozzle are used to cut 0.8 mm AISI316L stainless steel (022Cr17Ni12Mo2) separately. The orthogonal experiment takes nozzle standoff distance, cutting speed, Laser power and gas pressure as its impacting factors. The same orthogonal table is adopted in different condition, using normal nozzle and using supersonic nozzle. In the mean time, Ar gas is used as assisted cutting gas in the experiment. The data from this experiment show that supersonic nozzle seems to be a strong helper for fiber laser cutting. Feed rate’s effect seems stable and inconspicuous under the condition of using supersonic nozzle.

关键词： Fiber Laser Cutting Stainless Steel striation Supersonic Nozzle

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INVESTIGATION ON SURFACE FEATURE OF NEODYMIUM YTTRIUM ALUMINIUM TETRABORATE CRYSTAL

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Chinese Science Bulletin 1991年第24期36卷 2088-2092页

作者：张吉果潘恒福陆宝生 Institute of Crystal Materials Shandong UniversityJinan 250100 PRC

Ⅰ. INTRODUCTION Neodymium yttrium aluminium tetraborate [NdxY1-xAL （BO3）4, （NYAB）] is a functional material which is self-activated and self-frequent doubling. It belongs to an incongruent compound in the phase d... 详细信息

关键词： NdxY1-xAL(BO3)4 crystal straight steps and mat-like striation growth hillocks growth spirals crystal growth mechanisn

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A STUDY ON FATIGUE CRACK PROPAGATION PROPERTIES USING THE X-RAY DIFFRACTION METHOD

A STUDY ON FATIGUE CRACK PROPAGATION PROPERTIES USING THE X-...

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第五届国际材料与热加工物理模拟及数值模拟学术会议

作者： Md. Anowar Hossian ManBae Lim SunChul Huh WonJo Park Department of Mechanical and Precision Engineering Graduate School Gyeongsang Nat’l. Univ. Tongyoung Gyeongnam 650-160 Korea Department of Mechanical and Precision Engineering Gyeongsang Nat’l. Univ. Tongyoung Gyeongnam 650-160 Korea Research Center for Aircraft parts Technology Gyeongsang Nat’l. Univ. Jinju Gyeongnam 660-701 Korea Department of Mechanical and Aerospace Engineering Gyeongsang Nat’l. Univ. Institute of Marine Industry Tongyoung Gyeongnam 650-160 Korea

This study evaluated fatigue crack growth characteristics, Besides consider compressive residual stress effect and verified the most suitable shot peening velocity. Fatigue crack growth delay effect was compressive residual stress, but over peening did action projecting velocity that accelerate fatigue crack growth rate. X-ray diffraction technique according to crack length direction was applied to fatigue fractured surface. Fracture mechanics parameters could be estimated by the measurement of X-ray parameters, and the fractography observation was performed using a scanning electron microscope （SEM） for fatigue fracture surface. As the shot peening velocity increases, striation width increased. The changes in X-ray material parameters described above are directly related to the process of fatigue until the initiation of fatigue crack and X-ray diffraction pattern is thought that failure prediction with stress distribution is possible.

关键词： X-ray Diffraction Pattern Pole Figure Stress Intensity Factor Fatigue Fractured Surface Fatigue Crack Growth striation Compressive Residual Stress

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Late Tertiary faults and their paleostress along the boundary between the Kuqa Basin and the Tianshan Mountains

Late Tertiary faults and their paleostress along the boundar...

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中国科学院地质与地球物理研究所2004学术年会

作者： WANG Qingchen,ZHANG Zhongpei & LIN Wei Laboratory of Lithosphere Tectonic Evolution,Institute of Geology and Geophysics.Chinese Academy of Sciences,Beijing 100029,China

Field investigation shows that the boundary between the Kuqa Basin and the Tianshan Mountains can be divided into two sections with the Yanbulak area as the dividing *** the western section,the Mesozoic strata overlie unconformably on the Paleozoic *** basin -dipping faults developed in both Mesozoic and Paleozoic *** eastern section is characterized by basin-dipping normal faults separating the Paleozoic strata and Tertiary. The brittle structural analysis was carried out along the basin -range boundary.360 measurements of striations have been obtained at a total of 25 *** reconstruction indicates that the basin-range boundary was in an extensional condition,with some superimposed strike-slip,during the Late *** extension could be explained by the vertical block uplift of the Tianshan Mountains.

关键词： brittle fault striation paleostress Kuqa Basin Tianslian Mountains

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