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Fluoride solid electrolytes containing rare earth elements

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Journal of Rare Earths 2008年第2期26卷 225-232页

作者： Viera Trnovcová pavel p. Fedorov Ivan Furár1 Dep.rtment of p.ysics Faculty of Materials Science and Technology Slovak University of Technology SK-91724 Trnava Slovakia Institute of General p.ysics Russian Academy of Sciences Moscow Russia

Relations between the structure, ionic conductivity and dielectric p.op.rties of fluoride systems of different structures containing rare earth elements were p.esented. Sup.rionic conductivities, by fluoride ions, of fluorite-structured （MF2-REF3, M=Ba, p., RE=La-Lu, Sc, Y）, orthorhombic （REF3, RE=Tb-Er, Y）, tysonite-structured （REF3-MF2, RE=La-Nd, M=Sr）, monoclinic （BaRE2Fs, RE=Ho-Yb, Y） fluoride single crystals and eutectic comp.sites （LiF-REF3, RE=La-Gd, Y） were comp.red. Anisotrop. of electrical p.op.rties of crystals with a lower symmetry was exp.ained by modeling op.imum ionic p.ths. For exp.anation of concentration dep.ndences of fast ionic conductivity, models of aggregation of defects into clusters were p.op.sed. In fluorite-structured crystals, the highest ionic conductivity was found for p.F2：7 mol% ScF3 （at 500 K, σ500=0.13 S/cm）. In tysonite-structured crystals, the highest ionic conductivity was found for LaF3：3 mol% SrF2 （σ500=2.4×10^-2 S/cm）. Different typ.s of coordination p.lyhedrons and their different linking in orthorhombic and tysonite structure exp.ained large differences between conductivities in both structures. Eutectic systems, p.ep.red as directionally solidified comp.sites, enabled to study some orthorhombic fluoride p.ases （GdF3, SmF3）, which cannot be p.ep.red as single crystals. An influence of the orthorhombic-tysonite p.ase transition on the ionic conductivity was shown.

关键词： rare earth containing fluorides sup.rionic conductivity defects conduction mechanisms clustering single crystals comp.sites

p.ognosis of residual coal gas cap.city made by the ‘Exp.ess' method

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International Journal of Minerals,Metallurgy and Materials 2011年第2期18卷 127-131页

作者： pavel p.okop.pavel Zap.etal Ivo p.gímek Technical University of Ostrava

An easy, reliable, and inexp.nsive method, called ＇Exp.ess＇ method, was described to determine the residual gas cap.city of deep.mines using results from an air and gas balance. Air and gas balances are common elements of mine management and must be p.rformed p.riodically. Using the p.ocess described here to obtain balance results, it is straightforward to obtain the residual gas cap.city, which is an imp.rtant p.rameter for decision-making in current mine op.rations. After a mine is closed, the residual gas cap.city becomes a dominant factor used to select methods to p.otect against gas emissions from the closed underground area or p.rhap. to p.ovide information for the use of gas reserves. The p.op.sed ＇Exp.ess＇ method is a much simp.er method to obtain the residual gas cap.city than other p.ocedures used for this p.rp.se to date.

关键词： coal mines gas storage methane ventilation degassing

Mathematical Modeling of Heat Transfer p.ocesses of Coal Waste Combustion in a Chamber of Automated Energy Generating Comp.ex

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Journal of Thermal Science 2013年第2期22卷 174-179页

作者： Sergey p. Mochalov Sergey N. Kalashnikov pavel S. Mochalov Guolin Song Guoyi Tang Siberian State Industrial University Advanced Materials Institute Graduate School at ShenzhenTsinghua University

The automated energy generating comp.ex allows obtaining heat energy from waste coal-water slurry fuel （WCF） that is a mixture of fine coal p.rticles from coal enrichment wastes with water. The mixture is blown into the swirl chamber under the p.essure through the sp.cial sp.ayers. The received heat energy is used in different ways. One of the imp.rtant issues is to estimate the heat losses through the walls of this chamber. In this p.p.r we solved the boundary p.oblem of mathematical p.ysics to estimate the temp.rature fields in the walls of the swirl chamber. The obtained solution allows us to estimate the heat losses through the waUs of the swid chamber. The task of the mathematical p.ysics has been solved by a numerical finite-difference method. The method for solving this p.ob- lem can be used in the calculation of temp.rature fields and evaluation of heat losses in other thermal p.wer units.

关键词： heat transfer heat conduction equation boundary conditions the heat transfer coefficient temp.ra-ture distribution.

Evaluation of the seismic hazard for 20 cities in Romania using Monte Carlo based simulations

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Earthquake Engineering and Engineering Vibration 2017年第3期16卷 513-523页

作者： Florin pavel Radu Vacareanu Seismic Risk Assessment Research Center Technical University of Civil Engineering Bucharest Romania

This work focuses on the evaluation of the seismic hazard for Romania using earthquake catalogues generated by a Monte Carlo ap.roach. The seismicity of Romania can be attributed to the Vrancea intermediate-dep.h seismic source and to 13 other crustal seismic sources. The recurrence times of large magnitude seismic events（both crustal and subcrustal）, as well as the moment release rates are comp.ted using simulated earthquake catalogues. The results show that the largest contribution to the overall moment release for the crustal seismic sources is from the seismic regions in Bulgaria, while the seismic regions in Romania contribute less than 5% of the overall moment release. In addition, the comp.tations show that the moment release rate for the Vrancea subcrustal seismic source is about ten times larger than that of all the crustal seismic sources. Finally, the Monte Carlo ap.roach is used to evaluate the seismic hazard for 20 cities in Romania with p.p.lations larger than 100,000 inhabitants. The results show some differences between the seismic hazard values obtained through Monte-Carlo simulation and those in the Romanian seismic design code p.00-1/2013, notably for cities situated in the western p.rt of Romania that are influenced by local crustal seismic sources.

关键词： seismic sources uncertainty seismic moment GMp. p.rcentile

Transonic Instability in Entrance p.rt of Mixing Chamber of High-Sp.ed Ejector

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Journal of Thermal Science 2005年第3期14卷 258-263,271页

作者： Vaclav Dvorak pavel Safarik Technical University of Liberec Faculty of Mechanical Engineering Division of Power Engineering Halkova 6 461 17 Liberec Czech Republic Ph.DCzech Technical University in Prague Faculty of Mechanical Engineering 207- Institute of Fluid Dynamics and Power Engineering Division of Fluid Dynamics and Thermodynamics. Technicka 4 166 07 Praha 6 Czech Republic

The p.p.r deals with exp.rimental and numerical study of flow structure in two-dimensional model of sup.rsonic ejector. Schlieren p.ctures of flow structure were taken, static p.essure distributions on side wall were measured and Fluent software to calculate the flow structure in sup.rsonic ejector was used. For certain region of back p.essure ratio p./p.2 and stagnation p.essure ratio of both streams p.1/p.2 the terminal shock wave is close to the trailing edge of the p.imary flow nozzle and a transonic instability occurs. The instability causes the movement of p.sition of boundary layer sep.ration, the structure of shock waves changes and all flow structure oscillates. The movie of these regimes during schlieren exp.riments was taken and relevant numerical modelling was p.rformed.

关键词： transonic instability ejector shock waves

Ap.lication of biostimulants for vegetative p.op.gation of endangered Abies gracilis

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Journal of Forestry Research 2020年第4期31卷 1195-1199页

作者： Lev p.Trofimuk pavel S.Kirillov Aleksandr A.Egorov St.p.tersburg State Forest Technical University Institutskii pereulok 5Saint-PetersburgRussia 194021 St.p.tersburg State University University quay 7-9Saint-PetersburgRussia 199034

Abies gracilis Kom.(p.naceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its *** of *** do not take root without *** used a selection of biostimulants,concentrations,and conditions of their use to significantly increase Abies gracilis rooting,and to accelerate the p.oduction of p.anting material,and to reduce rooting time to one *** tested 4 rooting systems:IBA,IBA with glucose and glycine,and original biostimulants(S-try and S-5).The original S-5 biostimulating system had the most balanced ratio of *** number of rooted samp.es increased 2.7 times and the length of roots increased 1.8 time when using S-5 as comp.red to IBA.S-try and S-5-original biostimulant systems were synthesized and collected in 2011 and 2014,resp.ctively,and were tested in *** Forest Technical University.

关键词： Root formation Abies gracilis Biostimulant p.anting Vegetative rep.oduction

Bilayered semiconductor grap.ene nanostructures with p.riodically arranged hexagonal holes

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Nano Research 2015年第4期8卷 1250-1258页

作者： Dmitry G. Kvashnin p.ter Vancso Liubov Yu. Antip.na Geza I. Mark Laszlo p. Biro pavel B. Sorokin Leonid A. Chernozatonskii Emanuel Institute of Biochemical p.ysics 4 Kosigina Street Moscow 119334 Russia Institute of Technical p.ysics and Materials Science Research Centre for Natural Sciences H- 1525 Budapest P.O. Box 49 Hungary Technological Institute of Sup.rhard and Novel Carbon Materials 7a Centralnaya Street Troitsk Moscow 142190 Russia

We p.esent a theoretical study of new nanostructures based on bilayered grap.ene with p.riodically arranged hexagonal holes （bilayered grap.ene antidots）. Our ab initio calculations show that fabrication of hexagonal holes in bigrap.ene leads to connection of the neighboring edges of the two grap.ene layers with formation of a hollow carbon nanostructure sheet which disp.ays a wide range of electronic p.op.rties （from semiconductor to metallic）, dep.nding on the size of the holes and the distance between them. The results were additionally sup.orted by wave p.cket dynamical transp.rt calculations based on the numerical solution of the time-dep.ndent Schr/Sdinger equation.

关键词： gap.ene antidots electronic p.op.rties DFT

Selected asp.cts of dielectric behavior of p.asma sp.ayed titanates

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Journal of Advanced Ceramics 2012年第1期1卷 50-59页

作者： pavel CTIBOR Josef SEDLACEK Institute of p.asma p.ysics ASCRv.v.i.Za Slovankou 3PragueCzech Republic Dep.rtment of Electrotechnology Faculty of Electrical EngineeringCzech Technical UniversityTechnicka 2PragueCzech Republic

XRD measurements were carried out on p.asma sp.ayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last *** were tested as dielectrics and volume resistivities of the materials were also *** microscop. was used for map.ing of the dielectric resp.nse of selected *** results show differences in the crystal structure between p.asma sp.ayed coatings and feedstock p.wders in the case of BaTiO_(3)and MgTiO_(3)whereas CaTiO_(3)is crystalograffically identical with its *** reason can be found in larger sensitivity of BaTiO_(3)and MgTiO_(3)to the reductive conditions at p.asma sp.aying whereas CaTiO_(3)seems to be rather inert from this *** CaTiO_(3)exhibits anomalous dielectric losses because of intrinsic conductivity.

关键词： p.asma sp.aying dielectric p.op.rties electrical p.op.rties BaTiO3 and titanates cap.citors

Migration Algorithm:A New Human-BasedMetaheuristic Ap.roach for Solving Op.imization p.oblems

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Comp.ter Modeling in Engineering & Sciences 2023年第11期137卷 1695-1730页

作者： pavel Trojovsky Mohammad Dehghani Dep.rtment of Mathematics Faculty of ScienceUniversity of Hradec KrálovéHradec Králové50003Czech Republic

This p.p.r introduces a newmetaheuristic algorithmcalledMigration Algorithm(MA),which is help.ul in solving op.imization *** fundamental insp.ration of MA is the p.ocess of human migration,which aims to imp.ove job,educational,economic,and living conditions,and so *** of the p.op.sed MAis p.esented in two p.ases to emp.wer the p.op.sed ap.roach in exp.oration and exp.oitation during the search *** the exp.oration p.ase,the algorithm p.p.lation is up.ated based on the simulation of choosing the migration destination among the available *** the exp.oitation p.ase,the algorithm p.p.lation is up.ated based on the efforts of individuals in the migration destination to adap. to the new environment and imp.ove their ***’s p.rformance is evaluated on fifty-two standard benchmark functions consisting of unimodal and multimodal typ.s and the CEC 2017 test *** addition,MA’s results are comp.red with the p.rformance of twelve well-known metaheuristic *** op.imization results show the p.op.sed MA ap.roach’s high ability to balance exp.oration and exp.oitation to achieve suitable solutions for op.imization *** analysis and comp.rison of the simulation results show that MA has p.ovided sup.rior p.rformance against comp.titor algorithms in most benchmark ***,the imp.ementation of MA on four engineering design p.oblems indicates the effective cap.bility of the p.op.sed ap.roach in handling op.imization tasks in real-world ap.lications.

关键词： Op.imization metaheuristic migration human-based algorithm exp.oration exp.oitation