30 research outputs found
Magyar Néprajz I. 1. félkötet = Ethnology of the Hungarians Vol. I. 1.
A program a Magyar Néprajz I. Táj, nép, történelem c. kötet első felének megalkotását tűzte célul és négy fő témakörre fókuszált: A cél megvalósult, a tervezett kéziratok elkészültek cca 30 ív terjedelemben. Az őshazáktól napjainkig követi a magyar nép kulturális adaptációját a mindenkori természeti tájhoz, figyelemmel annak tükröződésére a kulturális tradíciókban és a szókészletben. Az ökológiai potenciál kihasználását, a kultúrtáj formálását, a tájépítés eredményeit a tájformálás történeti menetét követve, elemző módon írja le. A történeti Magyarország etnikumainak és etnikai tereinek történeti alakulását, azon belül a magyar népességszám és népterület változásait követi korszakról-korszakra. Elemzi az etnodemográfia tényszámait és térképeken rögzíti az egyes népek, etnikumok időben változó térfoglalását és térvesztését. A magyar nép történeti-táji tagolódását a földrajzi és a kulturális régiók, történeti tartományok viszonyrendszerében, új osztályozási szempontok szerint, s a vizsgált régió, vagy népcsoport jellemzésére alkalmas néprajzi jelenségeket is megemlítve tekinti át. Az etnográfia és a folklorisztika történetét Magyarországon, külön-külön elsőként leíró tanulmányok a periodizáció, az eszmetörténet, az intézménytörténet, sőt az irányadó tudósok tekintetében is számos új megállapítással szolgálnak (pl. a nemzetiségek néprajzi felfedezéséről, az evolucionizmus eszmei hatásáról, az európai etnológia kezdeteiről) | The program's aim was to complete the first part of the volume entitled Hungarian Ethnology I. Environment, People, History and it focused on four main topics. The cultural adaptation of the Hungarian people to the given natural environment is being followed, with respect to its reflection in the cultural traditions and the vocabulary, from the early homelands. An analytical description of the exploitation of the ecological potential, forming of the civilized land, as well as the results of region-building are given, following the historical flow of the forming of environment. The historical changes of the ethnic groups and ethnic spaces are being followed through different ages and periods. The realistic figures of ethnodemography are analyzed and the always changing gains and losses of territories of different peoples and ethnics minorities. The work looks through the historical-regional division of the Hungarian people within the structure of correlations of the geographical and cultural regions, historical provinces following the categorization according to new classification rates. The studies presenting for the first time the history of ethnography and, respectively, folklore studies in Hungary bring plenty of new statements concerning periodization, the history of intellectual movements, history of ideas and institutions, and, what?s more, the influential scholars (e.g. on the ethnographical discovery of ethnic minorities, the ideological impacts of the evolutionism)
Magnetoelectric memory function with optical readout
The ultimate goal of multiferroic research is the development of
new-generation non-volatile memory devices, the so-called magnetoelectric (ME)
memories, where magnetic bits are controlled via electric fields without the
application of electrical currents subject to dissipation. This low-power
operation exploits the entanglement of the magnetization and the electric
polarization coexisting in multiferroic materials. Here we demonstrate the
optical readout of ME memory states in the antiferromagnetic (AFM) and
antiferroelectric (AFE) LiCoPO, based on the strong absorption difference
of THz radiation between its two types of ME domains. This unusual contrast is
attributed to the dynamic ME effect of the spin-wave excitations, as confirmed
by our microscopic model, which also captures the characteristics of the
observed static ME effect. Our proof-of-principle study, demonstrating the
control and the optical readout of ME domains in LiCoPO, lays down the
foundation for future ME memory devices based on
antiferroelectric-antiferromagnetic insulators.Comment: 6 pages, 4 figures + Supplementary (10 pages and 4 figures
Electrochemical template synthesis of protein-imprinted magnetic polymer microrods
A novel method for the electrochemical template synthesis of surface-imprinted magnetic polymer microrods for protein recognition is proposed. The polymer was electrodeposited into sacrificial cylindrical microreactors, the internal walls of which were previously modified with a target model protein, avidin, by simple physisorption. The electropolymerization was performed from a mixture of 3,4-ethylenedioxythiophene, poly(styrenesulfonate) (PSS), and PSS-coated superparamagnetic nanoparticles resulting in the formation of inherently electroconductive polymers confined to the volume of the microreactor. Here we show that: (i) the template synthesis within cylindrical microreactors results in polymer rods with dimensions matching that of the reactor, (ii) the incorporation of superparamagnetic particles induces magnetic properties that allow for efficient collection and manipulation of the microrods released from the microreactors in magnetic field even from dilute solution, and (iii) the protein coating on the internal walls of the microreactors is shown to generate molecular imprints on the surface of the polymeric rods. This latter property was demonstrated by comparative binding experiments of a fluorescent avidin derivative to the surface-imprinted and non-imprinted magnetic polymer microrods
Összehasonlító kémiai vizsgálatok a Lamiaceae család és rokonsági körében (elsősorban a Verbenaceae családban) néhány taxonnál különös tekintettel a Salvia, Stachy, Vitex nemzetség másodlagos anyagcseretermékeire. = Comparative chemical investigations on the Lamiaceae and related families (mainly Verbenaceae) with special respect to the secondary metabolites of genera Salvia, Stachy and Vitex.
A Lamiaceae család Erdtman szerinti két alcsaládja közötti kémiai különbségek kerültek megerősítésre. A Nepetoideae alcsaládra számos faj jelentős illóolajtartaloma (pl. Salvia-ban), az abietán típusú diterpének jelenléte, a fenilpropanoid glikozidok és iridoidok hiánya, a jelentős urzol-, oleanol-, és rozmaringsav tartalom a jellemző. Ezzel szemben, az iridoidok, feniletanolid glikozidok, a labdán vázas diterpének jelenléte, az alacsony illóolaj, urzol- oleanolsav tartalom, és a rozmaingsav hiánya a Lamioideae alcsalád sajátja. A hatóanyagok előfordulásában minden típusánál kivételek is jelentkeztek. Ezek alapján a két alcsalád közötti különbségeket tendenciózus és inkább kvantitatív jellegűeknek bizonyulnak. Iridoidokat izoláltunk a Stachys fajokból, diterpéneket a Salvia candelabrum-ból és Ballota nigra-ból, fenilpropanoid glikozidokat a Ballota fajokból. Gázkromatográfiás analitikai módszert dolgoztunk ki az urzol- és oleanolsav elválasztására, TLC/denzitometriás eljárást az iridoidok és a fenilpropanoid glikozidok mérésére. Ezeket a hatóanyagok változékonyságának tanulmányozására, mint pl. a B. nigra esetén, a vegetációs periódus alatt használtuk. Előzetes adatokat nyertünk az izolátumok biológiai hatására. Az iridoidok és más anyagok jelenléte a Verbenaceae (Verbena sp.) és a Lamiaceae családok (Stachys sp.) fajaiban összhangban van a két család közötti szoros rokonsággal. | The chemical differences, between the two subfamilies of Lamiaceae (in Erdtman's system) were confirmed. In the Subfamily Nepetoideae the high essential oil content in a lot of species (e.g. Salvia), the presence of diterpenes of abietane type, lack of phenylpropanoid glycosides and iridoids, the presence of ursolic, oleanolic and rosmarinic acids are typical. In contrast to it in the Subfamily Lamioideae the occurrence of iridoids, phenylpropanoid glycosides, diterpenes of labdane skeleton, law essential oil, ursolic and oleanolic acid contents and the lack of rosmarinic acid were confirmed. Beside these regularities in all type of ingredients exceptions were found. Iridoids of some Stachys species, diterpenoids of Salvia candelabrum and Ballota nigra and some phenylpropanoid glycosides from B. nigra were isolated. Analytical method for the rapid quantitative measurement of iridoids, a gas chromatographic one for parallel measurement of ursolic and oleanolic acids and a LC/densitometric method for the phenylethanolide glycosides have been developed and were applied in studying their variation e.g. in B. nigra during the vegetation period. Preliminary data were obtained on the effectiveness of the isolated compounds of several species. The presence of iridoids of the Verbenaceae species, available in Hungary was confirmed. The occurrence of iridoids and other chemicals in Verbena and Stachys species supports the close relationship between Verbenaceae and Lamiaceae families
Spin excitations of magnetoelectric LiNiPO in multiple magnetic phases
Spin excitations of magnetoelectric LiNiPO are studied by infrared
absorption spectroscopy in the THz spectral range as a function of magnetic
field through various commensurate and incommensurate magnetically ordered
phases up to 33\,T. Six spin resonances and a strong two-magnon continuum are
observed in zero magnetic field. Our systematic polarization study reveals that
some of the excitations are usual magnetic-dipole active magnon modes, while
others are either electromagnons, electric-dipole active, or magnetoelectric,
both electric- and magnetic-dipole active spin excitations. Field-induced
shifts of the modes for all three orientations of the field along the
orthorhombic axes allow us to refine the values of the relevant exchange
couplings, single-ion anisotropies, and the Dzyaloshinskii-Moriya interaction
on the level of a four-sublattice mean-field spin model. This model also
reproduces the spectral shape of the two-magnon absorption continuum, found to
be electric-dipole active in the experiment
Magnetoelectric effect and magnetic phase diagram of a polar ferrimagnet CaBaFe4O7
The magnetic phase diagram of a polar ferrimagnet
CaBaFe4O7 with a magnetic easy axis has been investigated by measurements of magnetization, specific heat, and magnetoelectricity. A ferrimagnetic transition takes place at TC1=275 K within the orthorhombic phase followed by a second magnetic transition at TC2=211 K. Below
TC2, successive metamagnetic transitions occur for magnetic fields applied perpendicular to the easy axis, implying a sequential emergence of magnetic states which are neither collinear nor coplanar. The observation of the static magnetoelectric effect was limited to temperatures below 120 K due to the conducting nature of the crystals at higher temperatures. The magnitude of the ferroelectric polarization shows large changes between the different field-induced magnetic phases. The low-field state is characterized by a large linear magnetoelectric coefficient of αcc=39 ps/m, while a gigantic polarization change of ΔP=850μC/m2 is observed for μoH=14 T applied along the easy axis
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Phonon thermal transport shaped by strong spin-phonon scattering in a Kitaev material Na2Co2TeO6
The report of a half-quantized thermal Hall effect and oscillatory structures in the magnetothermal conductivity in the Kitaev material α-RuCl3 have sparked a strong debate on whether it is generated by Majorana fermion edge currents, spinon Fermi surface, or whether other more conventional mechanisms are at its origin. Here, we report low temperature thermal conductivity (κ) of another candidate Kitaev material, Na2Co2TeO6. The application of a magnetic field (B) along different principal axes of the crystal reveals a strong directional-dependent B impact on κ, while no evidence for mobile quasiparticles except phonons can be concluded at any field. Instead, severely scattered phonon transport prevails across the B−T phase diagram, revealing cascades of phase transitions for all B directions. Our results thus cast doubt on recent proposals for significant itinerant magnetic excitations in Na2Co2TeO6, and emphasize the importance of discriminating true spin liquid transport properties from scattered phonons in candidate materials