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Test measurements for accuracy of absolute and relative GPS positioning

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中国有色金属学会会刊：英文版 2005年第S1期15卷 299-303页

作者： i. Havasi University of Miskolc Hungary

The paper, after the introduction, briefly outlines the principles of both absolute and relative GPS positioning. it deals with factors and error resources affecting the accuracy of these surveying procedures. it reviews the geodetic determination of a reference point and a base line used for the test measurements. The study describes the completed test measurements, and on the basis of results, it draws the conclusions for the accuracy of the investigated surveying methods. Finally, considering these accuracy measures, their possible application in mine surveying is also mentioned very shortly.

关键词： GPS surveying methods factors and errors test measurements accuracy

Comment on the paper “Hydromagnetic thin film flow of Casson fluid in non-Darcy porous medium with Joule dissipation and Navier's partial slip”

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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 1057-1058页

作者： i.POP Department of Mathematics Babes-Bolyai University

The present comment concerns some doubtful results included in the abovepaper.

关键词： local inertia parameter magnetic parameter Eckert number

Electro-tribological properties of diamond like carbon coatings

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Friction 2020年第2期8卷 451-461页

作者： iñigo BRACERAS iñigo iBÁNEZ Santiago DOMiNGUEZ-MEiSTER Xabier VELASCO Marta BRiZUELA iñaki GARMENDiA Tecnalia Research&innovation Mikeletegi Pasealekua 2Donostia-San Sebastian 20009Spain Mechanical Engineering Department University of the Basque Country UPV/EHUPlaza de Europa1Donostia-San Sebastian 20018Spain

Diamond like carbon(DLC)coatings typically present good self-lubricating tribological properties that could be of interest in sliding dielectric contacts in multiple electrical *** this work electro-tribological studies have been performed on several DLC coatings against aluminum in different humidity conditions,in which the coefficients of friction(CoFs)and electrical contact resistance(ECR)were continuously *** show that CoF and ECR data can be linked to the properties of the coatings(thickness,finishing,microstructure,residual stresses,and wettability)and the degradation modes of their tribological and electrical ***,electro-tribological data can provide valuable information about the performance of dielectric coatings,the reasons behind it,and assist in the development of the *** also shows potential for on-line monitoring of coated parts in operation.

关键词： DLC electro-tribology ECR-electrical contact resistance coefficient of friction

Synthesis and characterization of bulk composite Fe-Si-B alloys with small concentration of Nb and Mo

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Acta Metallurgica Sinica(English Letters) 2010年第6期23卷 401-408页

作者： S.Bez i.Betancourt i.A.Figueroa institute for Materials Research National Autonomous University of Mexico (UNAM)

The preparation and some mechanical, thermal and magnetic properties of the as cast bulk composite ***4 （M=Nb, Mo） alloys obtained by suction casting are presented and discussed. The microstructrural results showed the existence of a crystalline a-Fe（Si） phase embedded in a glassy matrix. The values of microhardness （/iv） and yield strength （ay） for the Nb-containing alloy are exceptionally high, i.e. （12.65~0.3） GPa and （4.22~0.10） GPa, respectively. The saturation polarization values are found to be as high as 1.24 T for both composite ~11oys. it is thought that the interplay between the secondary crystalline phases and amorphous matrix could be responsible for the mechanical and magnetic behaviour of these alloys.

关键词： Bulk composite alloys Magnetic properties Mechanical proper- ties Thermal stability and suction casting

Numerical investigation and potential tunability scheme on e^+e^- and π^+π^- stimulated pair creation from vacuum using high intensity laser beams

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High Power Laser Science and Engineering 2016年第4期4卷 1-7页

作者： i.Ploumistakis S.D.Moustaizis i.Tsohantjis Technical University of Crete Laboratory of Matter Structure and Laser Physics National and Kapodistrian University of Athens Faculty of PhysicsDepartment of Nuclear and Particle Physics

Numerical estimates for electrons and mesons particle–antiparticle creation from vacuum in the presence of strong electromagnetic fields are derived, using the complete probability density relation of Popov's imaginary time method(Popov, JETP Lett. 13, 185(1971); Sov. Phys. JETP 34, 709(1972); Sov. Phys. JETP 35, 659(1972); Popov and Marinov, Sov. J. Nucl. Phys. 16, 449(1973); JETP Lett. 18, 255(1974); Sov. J. Nucl. Phys. 19, 584(1974));(Popov,Phys. Let. A 298, 83(2002)), and within the framework of an experimental setup like the E144(Burke et al., Phys. ***. 79, 1626(1997)). The existence of crossing point among pair creation efficiency curves of different photon energies and the role of odd/even multiphoton orders in the production rates are discussed. Finally a kind of tunability process between the two creation processes is discussed.

关键词： high intensity lasers multiphoton processes pair production

improving the reconstruction efficiency of sparsity adaptive matching pursuit based on the Wilkinson matrix

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Frontiers of information Technology & Electronic Engineering 2018年第4期19卷 503-512页

作者： Rasha SHOiTAN Zaki NOSSAiR i.i.iBRAHiM Ahmed TOBAL Computer and Systems Department Electronic Research Institute Electronics Communicationsand Computer DepartmentHelwan University

Sparsity adaptive matching pursuit(SAMP)is a greedy reconstruction algorithm for compressive sensing *** reconstructs signals without prior information of sparsity and presents better reconstruction performance for noisy signals compared to other greedy ***,SAMP still suffers from relatively poor reconstruction quality especially at high compression *** the proposed research,the Wilkinson matrix is used as a sensing matrix to improve the reconstruction quality and to increase the compression ratio of the SAMP ***,the idea of block compressive sensing(BCS)is combined with the SAMP technique to improve the performance of the SAMP *** simulations have been conducted to evaluate the proposed BCS-SAMP technique and to compare its results with those of several compressed sensing *** results show that the proposed BCS-SAMP technique improves the reconstruction quality by up to six decibels(d B)relative to the conventional SAMP *** addition,the reconstruction quality of the proposed BCS-SAMP is highly comparable to that of iterative ***,the computation time of the proposed BCS-SAMP is less than that of the iterative techniques,especially at lower measurement fractions.

关键词： Block compressive sensing Sparsity adaptive matching pursuit Greedy algorithm Wilkinson matrix

Conditions for formation and trapping of the two-ion Coulomb cluster in the dissipative optical superlattice

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Chinese Physics B 2015年第6期24卷 305-313页

作者： i.V.Krasnov institute of Computational Modeling Siberian DivisionRussian Academy of Sciences

Conditions have been studied under which a polychromatic optical superlattice can form and trap the Coulomb cluster of two strongly interacting ions. in our previous work （Krasnov i V and Kamenshchikov L P 2014 Opt. Comm. 312 192） this new all-optical method of obtaining and confining the Coulomb clusters was demonstrated by numerical simulations for special values of the optical superlattice parameters and in the case of Yb ions. in the present paper the conditions are explicitly formulated, under which the long-lived two-ion cluster in the superlattice cell is formed. The peculiarity of these conditions is the renormalization of the ion-ion Coulomb interaction. Notably, the renormalized Coulomb force is determined by the effective charge which depends on the light field parameters and can strongly differ from the ＂bare＂ ion charge. This result can be accounted for by the combined manifestation of the quantum fluctuations of optical forces, nonlinear dependence of these forces on the velocity, and non-Maxwellian （Tsallis type） velocity distribution of the ions in the optical superlattice. Explicit analytical formulas are also obtained for the parameters of the optical two-ion cluster.

关键词： optical trap ion trap rectified gradient force Coulomb clusters

Analysis of highly efficient perovskite solar cells with inorganic hole transport material

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Chinese Physics B 2019年第12期28卷 393-399页

作者： i Kabir S A Mahmood Department of Electrical and Electronics Engineering Bangladesh University of Engineering and Technology

Organo-halide perovskites in planar heterojunction architecture have shown considerable promise as efficient light harvesters in solar cells. We carry out a numerical modeling of a planar lead based perovskite solar cell(PSC) with Cu2ZnSnS4(CZTS) as the hole transporting material(HTM) using the one-dimensional solar cell capacitance simulator(SCAPS-1 D). The effects of numerous parameters such as defect density, thickness, and doping density of the absorber layer on the device performance are investigated. The doping densities and electron affinities of the electron transporting material(ETM) and the HTM are also varied to optimize the PSC performance. it has been observed that a thinner absorber layer of220 nm with a defect density of 1014 cm-3 compared to the reference structure improves the device performance. When doping density of the absorber layer increases beyond 2×1016 cm-3, the power conversion efficiency(PCE) reduces due to enhanced recombination rate. The defect density at the absorber/ETM interface reduces the PCE as well. Considering a series resistance of 5 ?·cm2 and all the optimum parameters of absorber, ETM and HTM layers simultaneously, the overall PCE of the device increases significantly. in comparison with the reference structure, the PCE of the optimized device has been increased from 12.76% to 22.7%, and hence the optimized CZTS based PSC is highly efficient.

关键词： CH3NH3Pbi3 Cu2ZnSnS4(CZTS) SCAPS-1D absorption coefficient

Susceptibility to Hot Cracking and Weldment Heat Treatment of Haynes 230 Superalloy

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Journal of Materials Science & Technology 2006年第5期22卷 685-690页

作者： i.K.Lee Department of Mechatronic Technology National Taiwan Normal University TaipeiTaiwanChina

This study investigates the susceptibility of hot cracking and weldment heat treatment of Haynes 230 superalloy. The Varestriant test was conducted to evaluate this susceptibility. Welding was performed by gas tungsten arc welding （GTAW） and plasma arc welding （PAW） with stress relief heat treatment and solid solution heat treatment. A tensile test is then performed to measure the changes in the mechanical properties of the heattreated material. The results indicate that the number of thermal cycles does not affect the susceptibility of Haynes 230 superalloy to hot cracking. However, it does increase the strain. in weldment of heat treatment, stress relief annealing increases the yield strength and tensile strength of the welded parts. The section of the tensile specimens shows fibrous fractures on the welded parts, regardless of whether they are heat-treated.

关键词： Haynes 230 super alloy Varestriant test Hot cracking Susceptibility Stress relief annealing