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Amplified Spontaneous Emission Properties of Solution Processed CsPbBr3 Perovskite Thin Films
2017
Metal halide perovskites are currently emerging as highly promising optoelectronic materials. It has been recently demonstrated that fully inorganic solution processed CsPbBr3 perovskite thin films show good electroluminescence properties combined with high thermal stability. In this work, we investigate in details the amplified spontaneous emission (ASE) properties of CsPbBr3 perovskite thin films, as a function of the temperature and the trap density, modified by changing the CsBr-PbBr2 precursor concentration. ASE is observed in samples from both CsBr-rich solution (low trap density) and equimolar solution (higher trap density), up to about 150 K, with a minimum threshold of 26 and 29 mu…
Structural analysis of copper(I) interaction with amyloid β peptide
2019
Abstract The N-terminal fragment of Aβ (β = beta) peptide is able to bind essential transition metal ions like, copper, zinc and iron. Metal binding usually occurs via the imidazole nitrogens of the three His residues which play a key role in the coordination chemistry. Among all the investigated systems, the interaction between copper and Amyloid β assume a biological relevance because of the interplay between the two copper oxidation states, Cu(II) and Cu(I), and their involvement in redox reactions. Both copper ions share the ability to bind Amyloid β. A huge number of investigations have demonstrated that Cu(II) anchors to the N-terminal amino and His6, His13/14 imidazole groups, while …
Experimental alteration of granitic rocks: Implications for the evolution of geothermal brines in the Upper Rhine Graben, Germany
2020
Abstract Geothermal energy exploitation in the Upper Rhine Graben (URG) chiefly has targeted faults and fractures within or connected with the crystalline basement, where hot fluids of c. 200 °C circulate at depths of c. 5 km. Formation fluids of the crystalline basement are highly saline, NaCl-dominated brines, whereas shallow crystalline basement water ( The trace element concentrations of the leachates are hereby related to the composition and stability of minerals in the rocks and can be directly linked to the proposed and observed dissolution processes at the different temperatures. In experiments with pure water at 70 °C, representing the recharge or infiltration conditions, water-roc…
Anti-inflammatory and analgesic activities of flavonoid and saponin fractions from Zizyphus lotus (L.) Lam.
2008
Abstract The effect of the flavonoid and saponin fractions from the leaves and root bark of Zizyphus lotus (200 mg/kg) was evaluated on carrageenan-induced paw edema in rats and on acetic acid-induced algesia in mice. In addition, two methanolic extracts from the plant (1 mg/ear) were tested on oxazolone-induced contact-delayed hypersensitivity (DTH) in mice. The effect of the different fractions was also evaluated in vitro on the nitrite production induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages. The results showed that both the flavonoid and saponin fractions significantly inhibited paw edema, algesia, and nitrite production without affecting cell viability. Furthermore, the …
Optical saturation thermal lens spectrometry in non-polar solvents
1997
Abstract A model for thermal lens spectrometry (TLS) in partial optical saturation conditions which was previously applied to polar solutes in aqueous media is now checked with non-polar organic dyes and metal dithizonates in carbon tetrachloride. Some literature data are also examined. Most data can be consistently explained on the basis of the molecular structures, the sensitivity increasing with the capability of the solute to rapidly communicate the absorbed energy to the solvent molecules.
TASCAを用いたCn, Nh, Fl化学実験のためのHg, Tl, PbのSiO2及びAu表面に対するオンライン化学吸着研究
2018
Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO$_{2}$ and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO$_{2}$ or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO$_{2}$ surface at room temperature. On the other hand, the Hg did no…
Photocatalytic activity of nanocrystalline TiO2 (brookite, rutile and brookite-based) powders prepared by thermohydrolysis of TiCl4 in aqueous chlori…
2008
Abstract Nanocrystalline TiO2 powders were synthesized by thermohydrolysis of TiCl4 in HCl or NaCl aqueous solutions. Rutile, mixtures of brookite and rutile or mixtures of anatase, brookite and rutile were obtained depending on the acidity of the medium. Crystalline phases and composition of the mixtures were identified by using XRD analysis. Pure brookite nanoparticles, separated from the mixtures of brookite and rutile by simple peptization with water, were stable against transformation to rutile up to 750 °C. The prepared TiO2 powders were characterized by thermal analysis, diffuse reflectance spectroscopy and BET surface area determinations. The band gap of bulky brookite was estimated…
Influence of metallic silver and of platinum-silver bimetallic deposits on the photocatalytic activity of titania (anatase and rutile) in organic and…
1998
Abstract The influence of deposited silver upon the photocatalytic activity of titania in the rutile and anatase allotropic forms has been studied in three different reactions. The common feature found for these three reactions was an electron transfer from illuminated TiO 2 to silver particles. In the first reaction (platinum photodeposition). it has been shown that the initial presence of metallic silver orientates the localization of subsequent Pt photodeposits with, in particular, a 100% selectivity to Pt deposition on top of silver particles or agglomerates previously deposited on anatase. In the second reaction (2-propanol oxidation), Ag deposit was found beneficial for the activity o…
Influence of Silver Deposits on the Photocatalytic Activity of Titania
1997
The objectives of depositing metals over semiconductor photocatalysts are to improve the electron-hole pair separation and to increase the rate of the reduction process due to the catalytic properties of the metal itself. Most of the deposited (noble) metals that have been studied belonged to group VIII. Very few studies concerned silver deposits. In the present work, the influence of deposited silver over anatase or rutile has been followed in three different types of reactions: (i) metal deposition, (ii) oxidation, and (iii) dehydrogenation. The final solids obtained in the last reaction (Pt/Ag/TiO{sub 2}) were also used as catalysts in two other test reactions to make comparison with TiO…
TiO2 photocatalysts prepared by thermohydrolysis of TiCl4 in aqueous solutions
2010
Abstract Nanostructured TiO 2 photocatalysts were synthesized by thermohydrolysis of TiCl 4 at 100 °C in various aqueous solutions. Anatase or rutile, binary mixtures of anatase and rutile or anatase and brookite, and ternary mixtures of anatase, brookite and rutile were obtained depending on the hydrolysis solution. The most efficient catalysts consisted of ternary mixtures of the three polymorphic TiO 2 phases.