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Study of axial double layer in helicon plasma by optical emission spectroscopy and simple probe

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Plasma Science and Technology 2018年第7期20卷 106-111页

作者： Gao ZHAO Wanying ZHU Huihui WANGl Qiang CHEN Chang TAN Jiting OUYANG School of Physics Beijing Institute of TechnologyBeijing 100081People＇s Republic of China Laboratory of Plasma Physics ＆ Materials Beijing Institute of Graphic CommunicationBeijing 102600 People＇s Republic of China Shanxi Key Laboratory of Plasma Physics and Applied Technology Xi＇an Aerospace Propulsion InstituteXi＇an 710100People＇s Republic of China

In this work we used a passive measurement method based on a high-impedance electrostatic probe and an optical emission spectroscope （OES） to investigate the characteristics of the double layer （DL） in an argon helicon plasma. The DL can be confirmed by a rapid change in the plasma potential along the axis. The axial potential variation of the passive measurement shows that the DL forms near a region of strong magnetic field gradient when the plasma is operated in wave- coupled mode, and the DL strength increases at higher powers in this experiment. The emission intensity of the argon atom line, which is strongly dependent on the metastable atom concentration, shows a similar spatial distribution to the plasma potential along the axis. The emission intensity of the argon atom line and the argon ion line in the DL suggests the existence of an energetic electron population upstream of the DL. The electron density upstream is much higher than that downstream, which is mainly caused by these energetic electrons.

关键词： helicon discharge double layer plasma diagnosis plasma potential

Comparison of double layer in argon helicon plasma and magnetized DC discharge plasma

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Plasma Science and Technology 2022年第3期24卷 114-122页

作者： Yueqing WANG Ruilin CUI Ruoyu HAN Feng HE Tianliang ZHANG Jinsong MIAO Jiting OUYANG School of Physics Beijing Institute of TechnologyBeijing 100081People's Republic of China

We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge *** in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were *** comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured *** results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently *** strength(or potential drop of DL)increases with the magnetic field in two different *** is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic *** in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).

关键词： helicon plasma magnetized plasma double layer diverging magnetic field electrostatic probe OES

Spectral Characteristics of Mechanically Induced Long-Period Fibre Gratings by New double-layer Grating Templates

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Chinese Physics Letters 2005年第8期22卷 1951-1954页

作者：王新伟张振宇庄怀轩盛秋琴 InstituteofPhysics NankaiUniversityTianjin300071

We design a new double-layer grating template, which has the advantages ofperiod uniformity, period number adjustability and continuous period regulation. By studying thetransmission spectrum under the new template, we also End some new characteristics different fromtraditional fibre gratings: the resonant wavelength is mainly determined by the grating period; theintensity of transmission peak loss lies in the external pressures; the bandwidth of transmissionspectrum can be controlled by the period number. Therefore, various applications can be realized byoptimizing the transmission spectrum by reasonably selecting the matched parameters.

关键词： Bandwidth Fiber gratings TRANSMISSION SPECTROSCOPY double layer long-period fiber grating jigs(templates) spectral characteristic

double-layer Hydrogels with Tunable Mechanofluorochromic Response for Smart Display

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Chinese Journal of Polymer Science 2023年第4期41卷 547-555,I0007页

作者： Hui-Hui Shi Shuang-Shuang Wu Rui-Jia Wang Yi Zhang Shu-Hui An Wei Lu Tao Chen Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China School of Chemical Sciences University of Chinese Academy of SciencesBeijing100049China

Mechanofluorochromic materials that render sensitive fluorescence color/pattern change upon mechanical stimuli have drawn extensive ***,traditional mechanofluorochromism relies on the chemical transformations of mechanophores,but their types are quite *** remains challenging to develop mechanofluorochromic materials with customized fluorescence color changing ***,a generally applicable strategy is proposed to present a class of double-layer mechanofluorochromic hydrogels based on the facile integration of two different-colored fluorescent *** to the UV transmittance change of top layer under Poisson’s effect,the emission intensity ratio of the upper and lower hydrogels exhibits a strain-dependent change,resulting in a force-triggered overlapping color *** the UV transmittance of top layer and the fluorescence emission of bottom layer can be readily modulated to enrich the variety of ***,the bottom layer is available to be printed by ion inks to fabricate patterned double-layer fluorescent hydrogel,holding great potential to design flexible mechanofluorochromic platforms for smart display and information encryption.

关键词： Mechanofluorochromism Fluorescent hydrogel double layer Smart display

EFFECT OF COVERING PLATES ON BUCKLING BEHAVIOUR OF double-layer GRIDS

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EFFECT OF COVERING PLATES ON BUCKLING BEHAVIOUR OF DOUBLE-LA...

Thermal stability and data retention of resistive random access memory with HfOx/ZnO double layers

Asia-Pacific Conference on Shell and Spatial Structures

作者： YOSHIYA TANIGUCHI TOSHITSUGU SAKA Department of Architecture and Building Engineering Faculty of EngineeringOsaka City UniversityOsaka 558Japan Department of Architecture and Building Engineering Faculty of EngineeringOsaka City UniversityOsaka 558Japan

＜正＞Covering plates as roof structures of double-layer grids may affect the buckling behaviour of *** effect of the composite action between covering plates and double-layer grids is experimentally *** double-layer grids treated are“diagonal-on-square”ones that are composed of diagonal meshes in the top layer and square meshes in the bottom *** model experiments are carried out for the grids with a covering *** models are simply supported at the perimeter nodes and subjected to a vertical load at the nodes in the bottom layer. The experimental results are compared with those of the grids without a covering plate to investigate the effect of roof structures on the buckling behaviour of grids.

关键词： buckling buckling behavior roof structure top layer double layer composite action vertical loads COVER PLATES double Ganglia

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Chinese Physics B 2017年第8期26卷 411-416页

作者：赖云锋陈凡曾泽村林培杰程树英俞金玲 School of Physics and Information Engineering Fuzhou University

As an industry accepted storage scheme, hafnium oxide（HfO_x） based resistive random access memory（RRAM）should further improve its thermal stability and data retention for practical applications. We therefore fabricated RRAMs with HfO_x/ZnO double-layer as the storage medium to study their thermal stability as well as data retention. The HfO_x/ZnO double-layer is capable of reversible bipolar switching under ultralow switching current（〈 3 μA） with a Schottky emission dominant conduction for the high resistance state and a Poole–Frenkel emission governed conduction for the low resistance state. Compared with a drastically increased switching current at 120℃ for the single HfO_x layer RRAM, the HfO_x/ZnO double-layer exhibits excellent thermal stability and maintains neglectful fluctuations in switching current at high temperatures（up to 180℃）, which might be attributed to the increased Schottky barrier height to suppress current at high temperatures. Additionally, the HfO_x/ZnO double-layer exhibits 10-year data retention @85℃ that is helpful for the practical applications in RRAMs.

关键词： resistive random access memory (RRAM) thermal stability data retention double layer

Impact of Annealing on the Melt Recrystallization of a-PDLA/α-PLLA double-layered Films

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Chinese Journal of Polymer Science 2024年第2期42卷 230-238,I0009页

作者： Yun-Peng Li Hao-Ran Shen Shao-Juan Wang Hao Zhang Jian Hu Rui Xin Xiao-Li Sun Shou-Ke Yan Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plasticsQingdao University of Science&TechnologyQingdao266042China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China

Poly(lactic acid)(PLA) as a bio-based polymer with biodegradability and biocompatibility has attracted much attention. To manipulate its properties for different applications, regulation of crystal structure and crystalline morphology becomes an attractive research topic. In this work, the structure evolution of layered samples containing an amorphous poly(D-lactide)(PDLA) layer and a crystalline poly(L-lactide)(PLLA)layer with highly oriented edge-on α lamellar crystals after annealing at 150 ℃ or/and after melt-recrystallization has been studied by AFM, FTIR,and TEM combined with electron diffraction. The results demonstrate that melt recrystallization of the as-prepared sample leads to the formation of abundant randomly oriented PLA stereo-complex(PLA SC) crystals. Annealing at 150 ℃ results in the formation of a small amount of oriented PLA SC crystals at the interface. These PLA SC crystals show great impact on the recrystallization behavior of sample after melting at 190 ℃ and then crystallizing at 90 ℃. First, they impede the mutual diffusion of the overlying PDLA and underlying PLLA, and thus reduce their stereocomplexation ability as manifested by the decreased amount of PLA SC crystals. Second, they act as substrate to initiate the epitaxial crystallization of the overlying PDLA and underlying PLLA, which ensures the production of a highly oriented structure of PDLA and PLLA after melt recrystallization again.

关键词： Poly(L-lactide) Poly(D-lactide) double layer Stereocomplex

Bearing Capacity and Critical Punch-Through Depth of Spudcan on Sand Overlying Clay

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China Ocean Engineering 2014年第1期28卷 139-147页

作者：刘君于龙周慧孔宪京 State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology

Spudcan may experience punch-through failure on strong over weak layered soils, such as sand overlying clay. A large deformation finite element method （LDFE） is used to simulate the penetration process of spudcan into sand overlying clay. The sand is simulated by smoothed hyperbolic Mohr-Coulomb model, and the clay is simulated by a simple elasto-plastic model which obeys Tresca yield criterion. According to the LDFE results of a large amount of cases, the effects of the strength, unit weight and thickness of the top sand layer, as well as the effect of the strength of the underlying clay on the spudcan punch-through behavior, are investigated. The critical depth occurring punch-through and the critical bearing capacity are presented in charts. Fitting equations to calculate the critical punch-through depth and the critical bearing capacity are proposed for the convenience of engineering practice.

关键词： spudcan foundation punch-through sand overlying clay double layer jack-up platform

Mechanics of Aquitard Drainage by Aquifer-System Compaction and Its Implications for Water-Management in the North China Plain

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Journal of Earth Science 2014年第3期25卷 598-604页

作者： Chen Su Zongyu Chen Jiang Chen Yuhong Fei Jingsheng Chen Baoqian Duan Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological Sciences

The deformation of aquitard is the main contribution to land subsidence in the North China Plain, and the water released from aquitard compaction may be a large portion of the exploited groundwater. In this study, the consolidation test was employed to understand the mechanics on the drainage and deformation of aquitard. The results suggested the strain of aquitard mainly resulted from the difference of hydraulic head between aquifers. And it was decreased with depth of aquitard at the same hydrodynamic pressure. In contrast with the interbed within aquifers, the aquitard was deformable when it was compressed. The weakly bound water was significantly released when the void ratio was about 0.44–0.45, and the EC of water released from the aquitard was decreased with the compacting process. The data from the consolidation test suggested that the pumping of groundwater from aquifer III might be less contribution to the land subsidence with respect to other aquifers in the future.

关键词： Quaternary aquifer clay consolidation test double layer land subsidence.