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Error bounds of a quadrature formula with multiple nodes for the Fourier-Chebyshev coefficients for analytic functions

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Science China mathematics 2019年第9期62卷 1657-1668页

作者： Aleksandar v.■ miodrag m.■ Department of mathematics Faculty of Mechanical Engineering University of Beograd

Three kinds of effective error bounds of the quadrature formulas with multiple nodes that are generalizations of the well-known micchelli-Rivlin quadrature formula, when the integrand is a function analytic in the regions bounded by confocal ellipses, are given. A numerical example which illustrates the calculation of these error bounds is included.

关键词： error bound quadrature formula with multiple nodes analytic function

Synthesis and performance of Zn–Ni–P thin films

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Chinese Physics B 2015年第3期24卷 259-268页

作者： v.Soare m.Burada I.Constantin m.Ghita v.Constantin F.miculescu A.m.Popescu New materials and Technologies Laboratory National Research and Development Institute for Nonferrous and Rare Metals-IMNR Institute of Physical Chemistry "Ilie murgulescu" Laboratory of Molten Salts University Polytehnica of Bucharest Center of Biomaterials (BIOMAT)

The electroplating of Zn–Ni–P thin film alloys from a sulfate bath containing phosphoric and phosphorous acid was investigated. The bath composition and the deposition parameters were optimized through Hull cell experiments, and the optimum experimental conditions were determined（p H = 2, temperature = 298–313 K, zinc sulfate concentration =30 g·L^-1, EDTA concentration = 15 g·L^-1, and current density = 1.0–2.0 A·dm^-2）. The SEm analysis of the coating deposited from the optimum bath revealed fine-grained deposits of the alloy in the presence of EDTA. Optical microscopy analysis indicated an electrodeposited thin film with uniform thickness and good adhesion to the steel substrate. The good adherence of the coatings was also demonstrated by the scratch tests that were performed, with a maximum determined value of 25 N for the critical load. Corrosion resistance tests revealed good protection of the steel substrate by the obtained Zn–Ni–P coatings, with values up to 85.89% for samples with Ni contents higher than 76%. The surface analysis of the thin film samples before and after corrosion was performed by X-ray photoelectron spectroscopy（XPS）.

关键词： thin film corrosion electrochemistry surface

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坝式水电工程施工和运行期的过流问题

人民长江 1990年第8期21卷 58-62页

作者： v.m.谢缅科夫刘忠清

在苏联,影响大坝和其它水工建筑物的安全和造价的设计流量和年径流量的估算,在政府部门批准的施工规范中已有规定.按照规范要求,根据大坝等级(取决于坝型和坝高,基础条件和发生事故的后果)确定年最大洪水流量概率(见表).

关键词：溢洪道设计过流水电工程弧形闸门消力池静水池消能建筑物(水利) 水电站发电厂运行期工程施工工程建设施工

Relativistic Landau quantization in the spiral dislocation spacetime

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Communications in Theoretical Physics 2021年第2期73卷 68-72页

作者： A v D m maia K Bakke Departamento de Fisica Universijade Federal da ParaibaCaixa Postal 500858051-900Joao PessoaPBBrazil

We analyse the interaction of a relativistic electron with a uniform magnetic field in the spiral dislocation *** show that analytical solutions to the Dirac equation can be obtained,where the spectrum of energy corresponds to the relativistic Landau *** also analyse the influence of the spiral dislocation on the relativistic Landau levels by showing that there exists an analogue of the Aharonov–Bohm effect for bound states.

关键词： spiral dislocation spacetime relativistic Landau quantization Aharonov-Bohm effect relativistic wave equations Dirac equation

microstructure,Tensile and Impact Toughness Properties of Friction Stir Welded mild Steel

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Journal of Iron and Steel Research International 2010年第10期17卷 68-74页

作者： A K Lakshminarayanan v Balasubramanian m Salahuddin Department of manufacturing Engineering Annamalai University Clean Technology Division Ministry of Environment and Forests

microstructure, tensile and impact toughness properties and fracture location of friction stir welded AISI 1018 mild steel were revealed. The AISI 1018 mild steel plates with thickness of 5 mm were friction stir welded by tungsten based alloy tool with tool rotational speed of 1 000 r/min and welding speed of 50 ram/rain. Tensile strength of stir zone is higher （8%） compared to that of the base metal. This may be due to the formation of finer grains in the weld nugget region under the stirring action of the rotating tool. The ductility and impact toughness of the joints are decreased compared to those of the base metal owing to the inclusion of tungsten particles in the weld region.

关键词： friction stir welding tensile property impact toughness mildsteel

Preparation of crystalline mg(OH)2 nanopowder from serpentinite mineral

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International Journal of mining Science and Technology 2018年第3期28卷 499-503页

作者： v. Sirota v. Selemenev.m. Kovaleva I. Pavlenko K. mamunin v. Dokalov.m. Yapryntsev Belgorod State National Research University Belgorod 308015 Russia voronezh State University Voronezh 394006 Russia Belgorod State Technological University named after v.G. Shoukhov Russia

In this paper we describe a route to produce crystalline mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for mg（OH）2 precipitation was demonstrated. In this study, crystalline mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEm） and transmission electron microscopy （TEm）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of mg（OH）2 are 30-265 nm length or width.

关键词： Serpentinite Nitric acid leaching magnesium hydroxide Solvothermal reaction method Crystalline mg(OH)2 nanopowder

Spectral Characterization of Laser Induced Plasma from Titanium Dioxide

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Plasma Science and Technology 2007年第4期9卷 456-459页

作者： v.J.DANN m.v.m.THEW v.P.N.NAmPOORI C.P.G.vALLABHAN v.m.NANDAKUmARAN P.RADHAKRISHNAN International School of Photonics Cochin University of Science and TechnologyCochin 22India Centre of Excellence in Lasers and Optoelectronic SciencesCochin University of Science and TechnologyCochin 22India International School of Photonics Cochin University of Science and TechnologyCochin 22India Centre of Excellence in Lasers and Optoelectronic Sciences Cochin University of Science and TechnologyCochin 22India

Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.

关键词： laser induced plasma titanium dioxide optical emission spectroscopy local thermodynamic equilibrium

Influence of morse Potential on DNA Dynamics

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Chinese Physics Letters 2006年第1期23卷 65-68页

作者： ZDRAvKOvIC S SATARIC m. v. Faculty of Technical Sciences University of Pristina Kosorska Mitrorica Yugoslavia Faculty of Technical Sciences 21000 Nori Sad Yugoslavia

Based on the Peyrard-Bishop-Dauxois （i.e. the extended Peyrard-Bishop） model of DNA dynamics, the transversal hydrogen interaction is modelled by morse potential and the impact of the morse parameters on the DNA dynamics is investigated. In particular, we show how modulation of the signal, moving through the DNA chain, depends on those parameters. It is also shown that the DNA dynamics represents the interplay between dispersion and nonlinearity. Finally, we discuss the values of coupling constants κ and K.

关键词： NONLINEAR HELICOIDAL mODEL vISCOSITY BREATHER ImPACT

Additional risk in extreme precipitation in China from 1.5℃to 2.0℃global warming levels

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Science Bulletin 2018年第4期63卷 228-234页

作者： Wei Li Zhihong Jiang Xuebin Zhang laurent Li Ying Sun Key Laboratory of meteorological Disaster of ministry of Education Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisasterNanjing University of Information Science and TechnologyNanjing 210044China Joint International Research Laboratory of Climate and Environment Change.Collaborative Innovation Center on Forecast and Evaluation of meteorological Disaster Nanjing University of Information Science and Technology Nanjing 210044China Climate Research Division Environment and Climate Change CanadaTorontoOntario M3H 5T4Canada Laboratoire de meteorologie Dynamique CNRSSorbonne UniversitesUPMC Universite Paris 06ParisFrance National Climate Center Laboratory for Climate StudiesChina Meteorological AdministrationBeifing 100812China

To avoid dangerous climate change impact, the Paris Agreement sets out two ambitious goals: to limit the global warming to be well below 2 ℃ and to pursue effort for the global warming to be below 1.5 ℃ above the pre-industrial level. As climate change risks may be region-dependent, changes in magnitude and probability of extreme precipitation over China are investigated under those two global warming levels based on simulations from the Coupled model Inter-Comparison Projects Phase 5. The focus is on the added changes due to the additional half a degree warming from 1.5 ℃ to 2 ℃ . Results show that regional average changes in the magnitude do not depend on the return periods with a relative increase around 7% and 11% at the 1.5 ℃ and 2 ℃ global warming levels, respectively. The additional half a degree global warming adds an additional increase in the magnitude by nearly 4%. The regional average changes in term of occurrence probabilities show dependence on the return periods, with rarer events(longer return periods) having larger increase of risk. For the 100-year historical event, the probability is projected to increase by a factor of 1.6 and 2.4 at the 1.5 ℃ and 2 ℃ global warming levels, *** projected changes in extreme precipitation are independent of the RCP scenarios.

关键词： 1.5 ℃ and 2 ℃ global warmingExtreme precipitationChina