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OSCILLATION AND VARIATION OF THE LAGUERRE HEAT AND POISSON SEMIGROUPS AND RIESZ TRANSFORMS

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Acta Mathematica Scientia 2012年第3期32卷 907-928页

作者： j.j.Betancor R.Crescimbeni j.L.Torrea Departamento de An'aisis Matema'ico Universidad de La Laguna38271-La LagunaTenerifeIslas CanariasSpain Departamento de Matema'ica Universidad Nacional del ComahueBuenos Aires 14008300 Neuqu'enArgentina Departamento de Matem'aticas Facultad de CienciasUniversidad Auto'noma de Madrid28049 MadridSpain

In this article, we study LP-boundedness properties of the oscillation and vari- ation operators for the heat and Poissson semigroup and Riesz transforms in the Laguerre settings. Also, we characterize Hardy spaces as... 详细信息

关键词： Oscillation variation heat Laguerre semigroup Riesz transforms

Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

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Plasma Science and Technology 2019年第6期21卷 52-57页

作者： H j YEOM D H CHOI Y S LEE j H KIM D j SEONG S j YOU H C LEE Korea Research Institute of Standards and Science(KRISS) Daejeon 34113 Republic of Korea Department of Physics Chungnam National University Daejeon 34134 Republic of Korea

In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff *** measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 *** plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing *** decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this *** etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and *** was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).

关键词： remote plasma source electron density cutoff probe downstream etch

Incremental forming of free surface with magnesium alloy AZ31 sheet at warm temperatures

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中国有色金属学会会刊：英文版 2008年第A1期18卷 165-169页

作者： Y.H.jI j.j.PARK Department of Mechanical and System Design Engineering Hongik University

The formabilityof AZ31 sheet begins to increase drastically at 150℃.The incremental forming technique was thus applied to AZ31 sheet at 150℃to utilize the formability to its fullest capacity at the lowest possible temperature for forming applications.A surface scanning technique was used followed by the tool path generation to incrementally form an egg *** thorough examination of various tool paths,the surface was most successfully produced by forming an intermediate shape followed by a series of tool *** scale stickers were devised to improve the accuracy in the measurement of grid deformation.

关键词：金属材料数控成形加工 AZ31镁合金板材

The role of GIS in Digital Earth education

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International journal of Digital Earth 2008年第4期1卷 326-346页

作者： j.j.Kerski Environmental Systems Research Institute BroomfieldColoradoUSA

A growing number of educators worldwide have become convinced that geotechnologiesincluding geographic information systems(GIS),global positioning systems(GPS),and remote sensingare key technologies to prepare students to be tomorrow’s decision *** with local,regional,and global issues of the 21st century requires people who think spatially and who can use *** educators teach geotechnologies as a discipline,emphasising *** educators use geotechnologies as a tool to teach content,such as geography,history,environmental studies,Earth Science,biology,mathematics,economics and other *** such as traffic,population growth,urban sprawl,energy,water,crime,human health,biodiversity and sustainable agriculture are growing in complexity,exist at every scale and increasingly affect people’s everyday *** of these issues has a spatial *** for geotechnology education include educational content standards,constructivism,the school-to-career movement,active learning,citizenship education,authentic practice and assessment,interdisciplinary education,community connections and a sustained,increasing demand for GIS *** Earth is an ideal framework for contextualising domains of *** Digital Earth community can have a significant impact on the growth of geotechnologies in education,and conversely,the growth of geotechnologies in education and society can foster the forward movement of Earth systems concepts.

关键词： digital earth and geotechnologies spatial thinking educational GIS digital earth and society

Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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journal of Rare Earths 2004年第Z2期22卷 153-156页

作者： D H jung B Park j j Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

Observation of the poloidally asymmetrical density perturbation of sawtooth collapse on j-TEXT

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Plasma Science and Technology 2023年第3期25卷 32-39页

作者：周乙楠庄革石鹏高丽杨州军张晓卿 the j-TEXT Team International joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China Department of Engineering and Applied Physics School of Physical Sciences University of Science and Technology of ChinaHefei 230026People’s Republic of China United Kingdom Atomic Energy Authority Culham Centre for Fusion EnergyCulham Science CentreAbingdonOxon OX143DBUnited Kingdom Southwestern Institute of Physics Chengdu 610041People’s Republic of China

The detailed density perturbations provided by the advanced polarimeter-interferometer system(Polaris) during sawtooth collapse on the joint Texas Experimental Tokamak(j-TEXT) are reported in this *** a sawtooth collapse and the crash of plasma pressure at the center,it is found that the increase in density in the region between the inversion radius and mixing radius is poloidally asymmetrical,while the increase in temperature is poloidally *** poloidal location where the density increases is dependent on the phase of the precursory m/n=1/1 kink *** is always out of phase with the hot core of the m/n=1/1 *** behaviors of density perturbations during sawtooth collapse observed in j-TEXT are beyond the expectations of the standard model,and this can shed new light on the understanding of sawtooth collapse.

关键词： tokamak sawtooth collapse polarimeter density perturbation

Basic 3-Transposittions of Unitary Group Un(2)

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Algebra Colloquium 2023年第1期30卷 31-42页

作者： j.Moori School of Mathematical and Physical Sciences North-West University(Mafikeng) Mmabatho 2735South Africa

We aim to study maximal pairwise commuting sets of 3-transpositions(transvections)of the simple unitary group U_(n)(2)over GF(4),and to construct designs from these *** maximal set of pairwise commuting 3-transpositions is called a basic set of *** G=U_(n)(2).It is well known that G is a 3-transposition group with the set D,the conjugacy class consisting of its transvections,as the set of *** L be a set of basic transpositions in *** give general descriptions of L and 1-(ν,κ,λ)designs D=(P,B),with P=D and B={L^(9)|g∈G}.The parameters k=|L|,λ and further properties of D are *** also,as examples,apply the method to the unitary simple groups U_(4)(2),U_(5)(2),U_(6)(2),U_(7)(2),U_(8)(2)and U_(9)(2).

关键词： designs simple groups unitary groups 3-transposition groups basic transposition commuting sets transvections

Possible Detection of a Flare-associated Coronal Mass Ejection on an M-dwarf

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Research in Astronomy and Astrophysics 2023年第9期23卷 207-212页

作者： j.Wang Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

We here report a probable detection of a stellar coronal mass ejection(CME)in active M dwarf KIC 8093473 by performing an analysis on its time resolved X-ray spectra observed by the XMM-Newton *** to the value at the quiescent state and the interstellar one,our spectral modeling returns a marginal(and probably evolving)excess of hydrogen column density in the flare state at a significance level of 1σ,which can be understood by an additional absorption due to a flare-associate *** CME mass is then estimated to be∼7×10^(18)–2×10^(20)g according to the ice cream cone model.

关键词： stars coronae-stars flare-stars late-type-X-rays stars

Supervision of two fundamental problems in modern fluid dynamics for sparing energy

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journal of Thermal Science 2009年第2期18卷 97-98页

作者： jürgen Zierep Institut für Strmungslehre Universitt Karlsruhe

The normal shock at a curved surface in transonic flow leads to a superdetermined boundary value problem. A bump behind the shock decreases the drag of the airfoil and reduces the necessary energy. Flows of non-Newtonian media lead in the contrary to subdetermined boundary initial problems. The energy balance for these fluids is of great interest for chemical engineering.

关键词： Transonic flow Shock at a curved wall Superdetermined problem Non- Newtonian media Subdeermined problem Energy balance.