Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Abstract A laboratory study of CaCO3 scaling kinetics has been undertaken to obtain information useful for prediction of CaCO3 scale formation. Thermodynamic carbonate scale prediction models have only a limited use since the rate of CaCO3 precipitation can be very slow at lower temperatures (< 60°C). The induc…
ADVERTISEMENT RETURN TO ISSUECommunication to the...Communication to the EditorNEXTEmbedding of Noble Metal Nanoclusters into Polymers as a Potential Probe of the Surface Glass TransitionV. Zaporojtchenko, T. Strunskus, J. Erichsen, and F. FaupelView Author Information Lehrstuhl für Materialverbunde, Technische Fakult…
Abstract One of the flow assurance challenges facing the deepwater oil and gas field development and production is mineral scale control. In a deepwater production system, barium sulfate scale deposition may arise from two causes, namely: a) commingling of injected seawater with connate formation water, and b) tempera…
Starting from commercially available Ni(II)octaethylporphyrin (OEP), an efficient approach for the preparation of a series of fluorinated and nonfluorinated benzochlorins with variable lipophicity has been developed. Their spectroscopic properties, preliminary in vitro photosensitizing efficacy, and tumor selectivity…
Abstract One of the major concerns within the oil industry is how to deal with scale formation, whether it is in the wellhead equipment, downhole pipelines or the actual field formation. This is because as the scale forms, it begins to deposit itself on the linings of the pipelines, within the equipment and the pores…
Abstract The effect of solvents on radiation‐induced grafting of styrene onto commercial fluorinated polymer films such as poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene‐ co ‐hexafluoropropylene) (FEP) and poly(tetrafluoroethylene‐ co ‐perfluorovinyl ether) (PFA) was investigated by a simultaneous irradiat…
To design near-infrared (NIR) absorbing polyaromatic dyes, we have theoretically elucidated the electronic transition properties of the extended π-conjugation derivatives of 3,4,9,10-perylenetetracarboxylic dianhydride diimide (PTCAI). Framework extension along the molecular long axis, that is, to terrylene (TTCAI) an…
Memory of chirality in triplet 1,7-diradicals was detected for the first time and to a remarkably high degree in the decarboxylative photocyclization of the proline derivative of N-phthaloyl anthranilic acid 1 into 2 (X=H: 45 % yield, 86 % ee; X=Cl: 50 % yield, 79 % ee).
Involatile OsO4! A tetrasubstituted olefin is immobilized on SiO2 and reacts with OsO4 to form a stable osmate(IV) ester (see scheme), which is a leak-proof heterogeneous catalyst for the cis-dihydroxylation of olefins.
Passivation of the metal surface by dendrons bearing a focal 4-pyridone functionality (the second-generation dendron is shown; C: gray, N: blue, O: red) allows controlled nucleation and growth of gold nanoclusters. The particle size is a direct function of the generation number of the dendritic ligands, with higher ge…
From the acid-catalyzed condensation of aryl aldehyde and pyrrole a new type of fused expanded porphyrins, N-fused pentaphyrins NFP5-Y (24 π, yellow) and NFP5-R (22 π, red) were obtained in total yields of 2–19 %. The two normal-type porphyrins are quantitatively interchanged through a redox reaction (see scheme). DDQ…
A surface anisotropy has been shown previously to be induced in thin films of photoreactive coumarin side-chain polymers by polarized UV illumination. Consequently, the resultant cross-linked polymer layers can be used as photoalignment layers for liquid crystal displays. Homogeneous alignment of a nematic liquid crys…
Abstract Description of Paper This paper discusses various mechanisms that can lead to the formation of iron sulfide scale downhole, techniques that can be used to prevent its formation and methods to remove it. Iron sulfide scale is present in oil and gas producing wells, water injection and supply wells. There are v…
Primary metallic or small-gap semiconducting nanotubes are tubes with band gaps that arise solely from breaking the bond symmetry due to curvature. We derive an analytic expression for these gaps by considering how a general symmetry breaking opens a gap in nanotubes with a well-defined chiral wrapping vector. This ap…
This paper draws attention to selected experiments on enzyme-catalyzed reactions that show convex Arrhenius plots, which are very rare, and points out that Tolman's interpretation of the activation energy places a fundamental model-independent constraint on any detailed explanation of these reactions. The analysis pre…
We study the adsorption of chlorine on the Ag(111) surface with full potential gradient corrected density functional calculations. When considering a root3 x root3 R30degree pattern, we find that the fcc hollow is the most favorable adsorption site. We obtain an Ag-Cl bond length of 2.62 Angstrom which is intermediate…
We have investigated the role of the stress-induced by the presence of the substrate in thin films of colossal magnetoresistive manganites on structural, resistive and magnetic properties. Because of the strong coupling between the small structural distortions related to the charge-ordering (CO) and the resistive prop…
Chiral recognition in organogels occurs in the coassembly of the chiral gelator 1 with the chiral guest molecule 2. The diastereomeric aggregates formed from (R,R)-2 with (R,R)-1 or (S,S)-1 were found to be truly different in structure and strength. Cooperativity makes a major contribution to the chiral recognition in…
Uniformly dispersed copper oxide nanoparticles in poly(vinyl alcohol) (CuO−PVA) have been synthesized by the sonochemical method. The properties of the as-prepared composite material are characterized by XRD, DSC, thermogravimetric analysis (TGA), TEM, and diffuse reflection spectroscopy (DRS). A band gap of 2.1 eV is…
Nanoparticles with high photoluminescence quantum yield have been recently considered as possible biolabels and as emitters in optoelectronic devices. Now gram amounts of nontoxic, chemically stable LaPO4:Ce,Tb nanocrystals (see picture) have been obtained in a coordinating solvent. These nanoparticles can be easily r…