134 research outputs found
Quest for quantum superpositions of a mirror: high and moderately low temperatures
The Born-Markov master equation analysis of the vibrating mirror and photon
experiment proposed by Marshall, Simon, Penrose and Bouwmeester is completed by
including the important issues of temperature and friction. We find that at the
level of cooling available to date, visibility revivals are purely classical,
and no quantum effect can be detected by the setup, no matter how strong the
photon-mirror coupling is. Checking proposals of universal nonenvironmental
decoherence is ruled out by dominating thermal decoherence; a conjectured
coordinate-diffusion contribution to decoherence may become observable on
reaching moderately low temperatures.Comment: revised; the published versio
Post-selected weak measurement beyond the weak value
Closed expressions are derived for the quantum measurement statistics of
pre-and postselected gaussian particle beams. The weakness of the pre-selection
step is shown to compete with the non-orthogonality of post-selection in a
transparent way. The approach is shown to be useful in analyzing
post-selection-based signal amplification, allowing measurements to be extended
far beyond the range of validity of the well-known Aharonov-Albert-Vaidman
limit.Comment: The published version; with respect to previous one, note changes in
Eqs. (16),(17),(19)
Orientált ionvezetĹ‘ Ă©s fĂ©lvezetĹ‘ vĂ©konyrĂ©tegek kialakĂtása nem orientált hordozĂłkon
A projektben vegyĂĽletfĂ©lvezetĹ‘ Ă©s szuperionos vĂ©konyrĂ©tegek szerkezetkialakulási mechanizmusát, elektromos jellemzĹ‘it, alternatĂv előállĂtási lehetĹ‘sĂ©gĂ©t, egyes technolĂłgiai vonatkozásait vizsgáltuk. A vizsgált anyagok közĂĽl az Ag2Te, CdSe, ZnSe fotoelektromos cĂ©lokra, az Ag2Se pedig, lineáris GMR tulajdonságai miatt mágneses terek mĂ©rĂ©sĂ©re alkalmazhatĂł. A rĂ©tegeket topotaxiás mĂłdszerrel állĂtottuk elĹ‘. A rĂ©tegĂ©pĂĽlĂ©s mechanizmusát TEM mikroszkĂłpos mĂłdszerekkel tártuk fel (001) orientáciĂłjĂş, ill. polikristályos Ag rĂ©tegek Se gĹ‘zzel törtĂ©nĹ‘ kĂ©miai reakciĂłja során. A rĂ©tegek elektromos ellenállás-változását nĂ©gypontos mĂłdszerrel, in situ mĂ©rtĂĽk, Ă©s matematikai modellel szimuláltuk. A komplex vizsgálat alapvetĹ‘ fizikai folyamatokat tárt fel: Egykristály (hibamentes) rĂ©tegekben a Se diffĂşziĂłja ill. a kĂ©miai reakciĂł homogĂ©n mĂłdon megy vĂ©gbe. A reakciĂłs front sĂk, amely lassan áthalad a mintán a teljes szelĂ©nezĂ©sig. Polikristályos mintában megmutatkozik a kristályhibák szerepe: A könnyű szemcsehatár menti diffĂşziĂł miatt a reakciĂł ott gyorsabb, az Ag szemcsĂ©k lekerekednek, Ă©s árkádos Ag2Se/Ag front alakul ki. A Se a szemcsehatárok mentĂ©n lejut a hordozĂłig ahol az Ag-val reagál Ă©s a reakciĂł kĂ©t iránybĂłl zajlik a teljes szelĂ©nezĂ©sig. A folyamat önszabályzĂł, a sztöchiometrikus összetĂ©telt állĂtja be. LehűlĂ©snĂ©l, allotrop fázisváltozás miatt a rĂ©teg kedvezĹ‘, (001) orientáciĂłt vesz fel. A mechanizmusok várhatĂłan más anyagrendszerekre is általánosĂthatĂłk, de ezt mĂ©g igazolni kell. | In the project, the structure evolution, electrical properties and alternative preparation techniques of compound and superionic semiconductor thin films were studied. The materials; Ag2Te, CdSe, ZnSe can be applied for photovoltaic purposes, while Ag2Se, due to its linear GMR properties, is a candidate for magnetic field sensors. For the preparation of the layers a topotactic method was developed. The mechanism of the structure formation was studied by TEM, in situ electrical measurements and numerical simulations in both (001) oriented and polycrystalline Ag films. The complex study revealed fundamental physical phenomena. In single crystal (defect free) layers the Se diffusion and the chemical reaction occurs homogeniously. A planar reaction front is formed, which propagates across the film until complete selenization. In polycrystalline samples, however, the influence of crystal defects shows up. Due to fast grain boundary (GB) diffusion, the reaction occurs preferentially at the GB-s, and an arch shaped interface of Ag2Se/Ag builds up. Simultaneously, the Se diffuses along the GB-s to the substrate and reacts with Ag. From that stage the reaction occurs on both sides of the Ag layer until completing the selenization. The self controlling process results in stoichiometric composition. On cooling, (001) crystal orientation is formed due to polymorphic phase transition. The mechanisms may be general for numerous two-component systems, but this needs further studies
A költségcsökkentés lehetőségei a magyar tejtermelésben = The possibility of the cost reduction in the Hungarian milk production
A kutatás zavartalan lefolyását egy sajnálatos tragĂ©dia árnyĂ©kolta be, fiatalon elhunyt Dr. Geszti Szilárd a kutatás vezetĹ‘je. Eredeti elkĂ©pzelĂ©skĂ©nt azt fogalmaztuk meg, hogy a tejtermelĂ©sben rejlĹ‘ belsĹ‘ tartalĂ©kokat kĂvánjuk feltárni, az EDF (European Dairy Farmers) ĂĽzemgazdasági szervezet segĂtsĂ©gĂ©vel. A kutatás során rendelkezĂ©sĂĽnkre állt az EDF adatbázis – magyar ĂĽzemekkel is – Ăgy rá tudtunk világĂtani számos olyan körĂĽlmĂ©nyre, amely esetlegesen javĂthatná a hazai helyzetet. Az elĹ‘re letervezett munkát az is nehezĂtette, hogy a 2008-as válság felgyorsĂtotta azokat az amĂşgy is meglĂ©vĹ‘ negatĂv tendenciákat, amelyek Ă©vek Ăłta jellemzĹ‘ek a hazai tejtermelĂ©sre. Az tejárak rövid távĂş hektikusságába egy erĹ‘teljes visszaesĂ©st, majd egy pozitĂv árkorrekciĂłt láthattunk. A belsĹ‘ fogyasztás gyakorlatilag Ă©vek Ăłta stagnál Ă©s nem jelent igazábĂłl szĂvĂłhatást a termelĂ©sre. Az állatállomány csökken, az ország kvĂłtát mĂ©lyen alulteljesĂtjĂĽk. A telepek egy rĂ©sze eladja az állományt, egy kisebb rĂ©szĂĽk viszont jelentĹ‘s beruházásokba kezd. A vizsgálat során belsĹ‘ tartalĂ©kokat mutatunk ki az állománypĂłtlás tekintetĂ©ben, a munkatermelĂ©kenysĂ©gre vonatkozĂłan. Ezek mindenkĂ©ppen olyan terĂĽletek, ahol lehet Ă©s kell is csökkenteni a kiugrĂłan magas Ă©rtĂ©keket. | Our research was interrupted by an unfortunate tragedy. Szilárd Geszti Ph.D the leader of the research has died in his young age. The original conception was to reveal - with the help of EDF (European Dairy Farmers) - the hidden internal reserves in the dairy production. The EDF database was available for us – with Hungarian enterprises – therefore we could reveal some conditions in order to improve the domestic situation. Furthermore the crises in 2008 was accelerated the existed negative tendencies which are typical in the domestic milk production for years. The milk price was hectic on short term and a strong decrease was experienced, and after a positive price correlation was observed. The internal consumption has stagnated for years and it does not count as a suction effect to the production. The livestock is decreasing and our milk quota is unutilised. Some of the farmers are selling the animals; a smaller part is starting investments. During the research we ascertained some internal livestock replacement reserves concerning labour productivity. These are areas where the extreme values should and need to be decreased
A kelet-nĂ©met, a lengyel Ă©s a magyar tejtermelĂ©s összehasonlĂtĂł, gazdasági Ă©rtĂ©kelĂ©se = Comparative Economic analysis of Milk Production in East-Germany, Poland and Hungary
A kutatás cĂ©lkitűzĂ©se az volt, hogy a magyar, a lengyel Ă©s kelet-nĂ©met tejtermelĹ‘ ĂĽzemek működĂ©sĂ©t gazdaságilag hasonlĂtsuk össze. Az adatgyűjtĂ©s az European Dairy Farmers Ă©s az International Farm Comparison Nework keretein belĂĽl törtĂ©nt. Az összehasonlĂtásra az alapot az adta, hogy a meghatározĂł kelet-nĂ©met ĂĽzemek hasonlĂł struktĂşrában működnek, mint a magyar tejtermelĂ©s 80%-át adĂł hazai nagyĂĽzemek. A lengyel ĂĽzemek bevonását a nagy országos potenciál indokolta elsĹ‘sorban. Az eredmĂ©nyek számos hátrányra hĂvták fel a figyelmet, amelyek kiaknázása elsĹ‘dleges feladata a magyar tejtermelĹ‘knek. Ezek közĂĽl ki kell emelni a rendkĂvĂĽl magas takarmányozási költsĂ©get, a munkatermelĂ©kenysĂ©g Ă©s a terĂĽleti termelĂ©kenysĂ©g alacsony fokát, valamint az amortizáciĂłs költsĂ©gek relatĂve kedvezĹ‘ helyzetĂ©t. | Main focus of the survey was to performa an economic comparison of Hungarian, Polish and East-German dairy farms. Data collection was carried out within the framework of European Dairy Farmers and the International Farm Comparison Network. Basis of the comparison was provided by the fact that leading East-German dairy farms are working within the same structure as the Hungarian large-scale farms producing 80% of milk production of the country. Involving Polish farms was based on the high production potential of Poland. Results highlight a number of gaps and lacks and treating them can provide developing potential for Hungarian producers. High feeding costs, low labour efficiency and area-based productivity as well as relatively favourable conditions of depreciation costs can be mentioned
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