Search results for "LENI"
showing 10 items of 756 documents
Structural and vibrational behavior of cubic Cu1.80(3)Se cuprous selenide, berzelianite, under compression
2020
[EN] We have performed an experimental study of the crystal structure and lattice dynamics of cubic Cu1.80(3)Se at ambient temperature and high pressures. Two reversible phase transitions were found at 2.9 and 8.7 GPa. The indexation of the angle-dispersive synchrotron x-ray diffraction patterns suggests a large orthorhombic cell and a monoclinic cell for the high-pressure phases. Raman measurements provide additional information on the local structure. The compressibility of the three ambient temperature phases has been determined and compared to that of other sulphides and selenides.
Precursor effects of the Rhombohedral-to-Cubic Phase Transition in Indium Selenide
2002
We report on the observation of precursor effects of the rhombohedral-to-cubic phase transition in Indium Selenide (InSe) with several experimental techniques. The pressure at which these precursor defects are first observed depends on the sensitivity of the experimental technique. In transport measurements, which are very sensitive to low defect concentrations, precursor effects are observed 5 to 6 GPa below the phase transition pressure whereas in X-ray diffraction measurements precursor effects are only observed 2 GPa below the phase transition pressure. We report optical absorption measurements, in which the precursor effects are shown by the growth and propagation of dark linear defect…
Posługa Kościoła wobec młodzieży na przykładzie diecezji opolskiej
2019
Synod Biskupów dotyczący duszpasterstwa młodzieży, który odbył się w 2018 roku, zauważa, iż posługa pastoralna prowadzona wśród ludzi młodych powinna odbywać się przede wszystkim na poziomie parafii w ramach duszpasterstwa zwyczajnego. Jednak działalność zbawcza Kościoła wśród młodzieży wymaga także obecności elementów duszpasterstwa nadzwyczajnego, co ma dokonywać się poprzez odpowiednie przygotowanie samego duszpasterza i pomagających mu animatorów. Takie działanie może przyczynić się do efektywności prowadzonych działań pastoralnych. Niewątpliwie konieczne wydają się również: wizja, strategia prowadzenia duszpasterstwa na szczeblu diecezji, dekanatu i parafii, a także znajomość kondycji …
La morale della storia. Osservazioni sul terzo libro di Diodoro
2013
Il profondo lavoro di revisione che, in modo molto incisivo a partire dagli anni ’80 ma con interventi importanti già in anni precedenti, ha modificato il giudizio storiografico su Diodoro consente di gettare una luce nuova su un’opera in realtà centrale per la comprensione di ampi periodi della storia greca e per l’analisi della sua ricezione nel I secolo a.C.
Bond stretching and redox behavior in coinage metal complexes of the dichalcogenide dianions [(SPh2P)2CEEC(PPh2S)2]2- (E=S, Se): diradical character …
2011
The metathetical reactions of a) [Li(tmeda)](2)[(S)C(PPh(2)S)(2)] (Li(2)·3c) with CuCl(2) and b) [Li(tmeda)](2)[(SPh(2)P)(2)CSSC(PPh(2)S)(2)] (Li(2)·4c) with two equivalents of CuCl both afford the binuclear Cu(I) complex {Cu(2)[(SPh(2)P)(2)CSSC(PPh(2)S)(2)]} (5c). The elongated (C)S-S(C) bond (ca. 2.54 and 2.72 A) of the dianionic ligand observed in the solid-state structure of 5c indicate the presence of diradical character as supported by theoretical analyses. The treatment of [Li(tmeda)](2)[(SPh(2)P)(2)CSeSeC(PPh(2)S)(2)] (Li(2)·4b) and Li(2)·4c with AgOSO(2)CF(3) produce the analogous Ag(I) derivatives, {Ag(2)[(SPh(2)P)(2)CEEC(PPh(2)S)(2)]} (6b, E=Se; 6c, E=S), respectively. The disele…
Mineralogical and petrographic analysis of early-Hellenistic mortars from a Punic-Roman residential area discovered at Palermo (Sicily)
2015
Lime based mortars dated back to 4th-3rd century BC were sampled in a Punic-Roman residential area recently brought to light in the historical centre of Palermo. The collected mortars have been analyzed by optical microscopy (PLM), X-ray powder diffraction analysis (XRPD) and scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS). The study was aimed to characterize these materials from the textural and compositional point of view in order to define the recipes. The mineralogical and petrographic investigations allowed to establish 4 different recipes used for the formulation of the studied floor and wall mortars in terms of both compositional and textural featur…
Uncommon localizations of hydatid cyst. Review of the literature
2016
Introduction Hydatid disease is an endemic anthropozoonosis with usual localization in liver and lungs. Rarely it localizes in uncommon sites as spleen, skeleton, kidney, brain, cardiac muscle, peritoneum, sub cutis. Complications of uncommon localizations are the same that for usual ones. Material and methods Review of the literature on rare and atypical localization of hydatid cysts in soft tissues. Key-words used on Pub-Med [(echinococ OR hydatid) AND (soft tissue OR subcutaneous OR cutaneous)] without time limit. There were found 282 articles; 242 were excluded because of muscular or bone localizations. 40 were coherent. Results Different variables are taken into account: age, sex, geog…
Tin-related double acceptors in gallium selenide single crystals
1998
Gallium selenide single crystals doped with different amounts of tin are studied through resistivity and Hall effect measurements in the temperature range from 30 to 700 K. At low doping concentration tin is shown to behave as a double acceptor impurity in gallium selenide with ionization energies of 155 and 310 meV. At higher doping concentration tin also introduces deep donor levels, but the material remains p-type in the whole studied range of tin doping concentrations. The deep character of donors in gallium selenide is discussed by comparison of its conduction band structure to that of indium selenide under pressure. The double acceptor center is proposed to be a tin atom in interlayer…
High‐temperature behavior of impurities and dimensionality of the charge transport in unintentionally and tin‐doped indium selenide
1993
A systematic study of the electron transport and shallow impurity distribution in indium selenide above room temperature or after an annealing process is reported by means of far‐infrared‐absorption and Hall‐effect measurements. Evidences are found for the existence of a large concentration of deep levels (1012–1013 cm−2), related to impurities adsorbed to stacking faults in this material. Above room temperature impurities can migrate from those defect zones and then become shallow in the bulk. The subsequent large increase of 3D electrons can change the dimensionality of the electron transport, which in most cases was 2D. The temperature dependence of the resistivity parallel to the c axis…
Trapping of three-dimensional electrons and transition to two-dimensional transport in the three-dimensional topological insulator Bi2Se3under high p…
2012
This paper reports an experimental and theoretical investigation on the electronic structure of bismuth selenide (Bi2Se3) up to 9 GPa. The optical gap of Bi2Se3 increases from 0.17 eV at ambient pressure to 0.45 eV at 8 GPa. The quenching of the Burstein-Moss effect in degenerate samples and the shift of the free-carrier plasma frequency to lower energies reveal a quick decrease of the bulk three-dimensional (3D) electron concentration under pressure. On increasing pressure the behavior of Hall electron concentration and mobility depends on the sample thickness, consistently with a gradual transition from mainly 3D transport at ambient pressure to mainly two-dimensional (2D) transport at hi…