排序方式: 共有40条查询结果,搜索用时 17 毫秒
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Dr. Alessandra Alberti Dr. Ioannis Deretzis Dr. Giovanna Pellegrino Dr. Corrado Bongiorno Dr. Emanuele Smecca Dr. Giovanni Mannino Dr. Filippo Giannazzo Prof. Guglielmo Guido Condorelli Dr. Nobuya Sakai Prof. Tsutomu Miyasaka Dr. Corrado Spinella Dr. Antonino La Magna 《Chemphyschem》2015,16(14):3064-3071
We investigate the degradation path of MAPbI3 (MA=methylammonium) films over flat TiO2 substrates at room temperature by means of X‐ray diffraction, spectroscopic ellipsometry, X‐ray photoelectron spectroscopy, and high‐resolution transmission electron microscopy. The degradation dynamics is found to be similar in air and under vacuum conditions, which leads to the conclusion that the occurrence of intrinsic thermodynamic mechanisms is not necessarily linked to humidity. The process has an early stage, which drives the starting tetragonal lattice in the direction of a cubic atomic arrangement. This early stage is followed by a phase change towards PbI2. We describe how this degradation product is structurally coupled with the original MAPbI3 lattice through the orientation of its constituent PbI6 octahedra. Our results suggest a slight octahedral rearrangement after volatilization of HI+CH3NH2 or MAI, with a relatively low energy cost. Our experiments also clarify why reducing the interfaces and internal defects in the perovskite lattice enhances the stability of the material. 相似文献
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Summary The ion-assisted regrowth of chemical-vapour deposited Si films onto (100) Si substrates is reported. The regrowth was induced
by a 600 keV Kr++ beam at doses in the range (2·1015÷6·1015)/cm2 and at a dose rate of 1·1012/cm2s. The target temperature was set at 450°C. During irradiations the crystal-amorphous interface velocity was measuredin situ by monitoring the reflectivity of a He-Ne laser light focused onto the sample surface. After irradiation some samples were
also analysed by Rutherford backscattering in combination with the channelling effect and by transmission electron microscopy.
The growth rate of deposited layers depends on the cleaning procedure performed prior to deposition,i.e on the total amount of oxygen present at the deposited layer/substrate interface. Moreover, twinned material is observed
in the recrystallized layers and its concentration is strongly dependent on substrate cleaning. These phenomena are explained
in terms of a decrease in the ion-assisted growth rate in the presence of high oxygen concentrations. The data are discussed
and compared with those obtained during pure thermal annealing.
To speed up publication, the authors of this paper has agreed to not receive the proofs for correction. 相似文献
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Summary Germanium, arsenic and krypton ions of 600 keV energy were implanted in <100> silicon substrate at 250°C. The hot implantation
results in the formation of extended defects (dislocation loops and cluster of point defects) as residual damage. Rapid thermal
annealing process at a temperature above 1000°C was used to remove the damage. Rutherford-backscattering channelling technique
was used to measure the amount of defects and their annealing. In some cases the channelling results were correlated to transmission
electron microscopy (TEM) analysis. The annealing process of the damage is governed by an activation energy of (4.4±0.2) eV
for both germanium and arsenic implants. During RTA processes broadening of the As and Ge distributions is quite negligible.
The Kr atoms interact instead with defects and the annealing even after a prolonged time at 1100°C is not complete, bubbles
surrounded by extended defects are left
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
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Giorgio Della Sala Antonietta Artillo Aldo Spinella 《Journal of organometallic chemistry》2007,692(8):1623-1627
A study on the oxidation of Fischer tungsten-carbene uracil complexes has been carried out. Several commonly used oxidants gave results strongly influenced by the presence of substituent on nitrogen atoms. In particular, usual oxidants failed in the oxidation of 3-alkyl uracil carbene complexes. Finally, we showed that t-butyl hydroperoxide is able to oxidize successfully also 3-alkyl uracil carbene complexes and can be used as a good alternative to the other methods. 相似文献
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G.F. Cerofolini C. Bongiorno M. Camalleri G.G. Condorelli I.L. Fragalà C. Galati S. Lorenti L. Renna C. Spinella O. Viscuso 《Applied Physics A: Materials Science & Processing》2002,75(5):585-590
Nitridation of hydrogen-terminated silicon in a diluted N2:N2O atmosphere was studied by X-ray photoemission spectroscopy and high-resolution electron microscopy. Our analysis showed
that the broad N(1s) peak of width 1.5 eV at 398–399 eV, usually reported in the literature, is preceded by the formation
of a narrow peak of width around 1.0 eV at 397.5 eV, attributed to the moiety Si3N in which silicon is only marginally oxidized, and two other peaks at 400.0 eV and 401.5 eV, attributed to the moieties Si2NOSi and SiNO, respectively.
Received: 11 July 2001 / Accepted: 19 September 2001 / Published online: 20 December 2001 相似文献
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Stephen I. McConnell Albert J. Uveges Dana M. Fowlkes Dominic G. Spinella 《Molecular diversity》1996,1(3):165-176
Summary We have constructed two phage display libraries expressing N-terminal pIII fusions in M13 composed of 37 and 43 random amino acid domains, respectively. The D38 library expresses 37 random amino acids with a central alanine residue, and the DC43 library contains 43 random amino acids with a central cysteine flanked by two glycine residues, giving the displayed peptide the potential to form disulfide loops of various sizes. We demonstrate that the majority of random sequences in both libraries are compatible in pentavalent display with phage viability. The M13 phage display vector itself has been engineered to contain a factor Xa protease cleavage site to provide an alternative to acid elution during affinity selection. An in-frame amber mutation has been inserted between the pIII cloning sites to allow for efficient selection against nonrecombinant phage in the library. These libraries have been panned against mAb 7E11-C5, which recognizes the prostate-specific membrane antigen (PSM). Isolated phage display a consensus sequence that is homologous to a region in the PSM molecule. 相似文献
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M. G. Grimaldi S. Coffa C. Spinella F. Marabelli M. Galli L. Miglio V. Meregalli 《Journal of luminescence》1998,80(1-4):467-471
The structural and optical properties of β-FeSi2 precipitates produced by ion beam synthesis have been investigated by transmission electron microscopy, photoluminescence (PL) analysis and near infrared transmission measurements. The PL spectrum of β-FeSi2 precipitates in a dislocation free sample has been observed to consist of a sharp line at 1.54 μm and a weak peak at 1.46 μm. Optical transmission measurements showed a direct band gap about 0.8 eV smaller than in continuous β-FeSi2 film. Calculation of the electronic bands of β-FeSi2 for different values of the lattice parameters indicates that this reduction can be ascribed to band distortion provided by the lattice strain. 相似文献
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[reaction: see text] Marine diatoms produce alpha,beta,gamma,delta-unsaturated aldehydes that have detrimental effects on the reproduction of their natural predators. The production of these defensive metabolites is suggested to involve enzymatic oxidation of polyunsaturated fatty acids. In this paper, feeding experiments with labeled precursor provide clear evidence in support of the origin of octadienals 1 and 2 from 6,9,12-hexadecatrienoic acid (5), thus proving the involvement of novel lipoxygenase/lyase activity for the oxidation of C(16) fatty acids. 相似文献