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41.
Bekzat ABDIKADYR Alp KILI Onur ALEV Serkan BÜYÜKK
SE Zafer Ziya
ZTÜRK 《Turkish Journal of Chemistry》2021,45(2):295
Pristine and WO3 decorated TiO2 nanorods (NRs) were synthesised to investigate n-n-type heterojunction gas sensing properties. TiO2 NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass (FTO) substrates. Then, tungsten was sputtered on the TiO2 NRs and thermally oxidised to obtain WO3 nanoparticles. The heterostructure was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. Fabricated sensor devices were exposed to VOCs such as toluene, xylene, acetone and ethanol, and humidity at different operation temperatures. Experimental results demonstrated that the heterostructure has better sensor response toward ethanol at 200 °C. Enhanced sensing properties are attributed to the heterojunction formation by decorating TiO2 NRs with WO3. 相似文献
42.
Unexpected dimerization of 1,3‐dimethyl‐5‐methylenebarbituric acid revealed by a combined experimental and computational study
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Bernd Doser Kamal Sweidan Norbert Kuhn Christian Ochsenfeld 《Journal of Physical Organic Chemistry》2015,28(5):354-357
A comparison of experimental and calculated 13C‐nuclear magnetic resonance chemical shifts reveals the molecular structure of a dimer that was obtained by an unexpected dimerization of 1,3‐dimethyl‐5‐methylenebarbituric acid. Furthermore, the puckering angle of the cyclobutane unit linking the six‐membered rings is discussed in detail. The influence of substituents on 1,3‐position of the cyclobutane ring on the puckering angle is demonstrated based on 1,1,3,3‐tetramethylcyclobutane. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
43.
Inside Back Cover: Site‐Selective Synthesis of Janus‐type Metal‐Organic Framework Composites (Angew. Chem. Int. Ed. 15/2014)
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44.
Gerardo Salinas Alice L. Dauphin Camille Colin Elena Villani Stphane Arbault Laurent Bouffier Alexander Kuhn 《Angewandte Chemie (International ed. in English)》2020,59(19):7508-7513
Miniaturized autonomous chemo‐electronic swimmers, based on the coupling of spontaneous oxidation and reduction reactions at the two poles of light‐emitting diodes (LEDs), are presented as chemotactic and magnetotactic devices. In homogeneous aqueous media, random motion caused by a bubble‐induced propulsion mechanism is observed. However, in an inhomogeneous environment, the self‐propelled devices exhibit positive chemotactic behavior, propelling themselves along a pH or ionic strength gradient (?pH and ?I, respectively) in order to reach a thermodynamically higher active state. In addition, the intrinsic permanent magnetic moment of the LED allows self‐orientation in the terrestrial magnetic field or following other external magnetic perturbations, which enables a directional motion control coupled with light emission. The interplay between chemotaxis and magnetotaxis allows fine‐tuning of the dynamic behavior of these swimmers. 相似文献
45.
Remote Actuation of a Light-Emitting Device Based on Magnetic Stirring and Wireless Electrochemistry
Alice L. Dauphin Dr. Stéphane Arbault Prof. Dr. Alexander Kuhn Prof. Dr. Neso Sojic Dr. Laurent Bouffier 《Chemphyschem》2020,21(7):600-604
We propose a straightforward access to a rotating light-emitting device powered by wireless electrochemistry. A magnetic stirrer is used to rotate a light-emitting diode (LED) due to the intrinsic magnetic properties of the tips that contain iron. At the same time, the LED is submitted to an electric field and acts as a bipolar electrode. The electrochemical processes that are coupled on both extremities of the LED drive an electron flow across the device, resulting in light emission. The variation of the LED alignment in time enables an alternating light emission that is directly controlled by the rotation rate. The stirring also enables a continuous mixing of the electrolyte that improves the stability of the output signal. Finally, the LED brightness can readily reveal a change of chemical composition in the electrolyte solution. 相似文献
46.
In modern chemistry, chiral (electro)catalysis is a powerful strategy to produce enantiomerically pure compounds (EPC). However, it still struggles with uncontrollable stereochemistry due to side reactions, eventually producing a racemic mixture. To overcome this important challenge, a well-controlled design of chiral catalyst materials is mandatory to produce enantiomers with acceptable purity. In this context, we propose the synergetic combination of two strategies, namely the elaboration of mesoporous Pt films, imprinted with chiral recognition sites, together with the spatially controlled formation of a self-assembled monolayer. Chiral imprinted metals have been previously suggested as electrode materials for enantioselective recognition, separation and synthesis. However, the outermost surface of such electrodes is lacking chiral information and thus leads to unspecific reactions. Functionalising selectively this part of the electrode with a monolayer of organosulfur ligands allows an almost total suppression of undesired side reactions and thus leads to a boost of enantiomeric excess to values of over 90% when using these surfaces in the frame of enantioselective electrosynthesis. In addition, this strategy also decreases the total reaction time by one order of magnitude. The study therefore opens up promising perspectives for the development of heterogeneous enantioselective electrocatalysis strategies.Highly enantioselective electrosynthesis with up to 90% ee and short reaction times can be achieved with alkanethiol protected chiral imprinted mesoporous Pt surfaces. 相似文献
47.
Benjamin Byerly Kevin Kuhn Lisa Colletti Lynn Foster Russ Keller Elmer Lujan Alex Martinez Donivan Porterfield Dan Schwartz Khal Spencer Floyd Stanley Mariam Thomas Lisa Townsend Ning Xu Lav Tandon 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(1):95-104
Thorough physical and chemical characterization of plutonium–beryllium (PuBe) neutron sources is an important capability with applications ranging from material accountancy to nuclear forensics. Characterization of PuBe sources is not trivial owing to range of existing source designs and the need for adequate infrastructure to deal with radiation and protect the analyst. This study demonstrates a method for characterization of three PuBe sources that includes physical inspection and imaging followed by controlled disassembly and destructive analysis. 相似文献
48.
In order to study the structural and dynamical aspects of the solubilization process of pentanol within a sodium octanoate micelle a molecular dynamics simulation is presented. In this initial study we discuss the results and detailed insights into the interactions between sodium octanoate, pentanol, and water. The total micellar radius and the hydrophobic core radius were determined. The calculated values are in fairly good agreement with experimental results. In contrast to pure sodium octanoate micelles the aggregate with dissolved pentanol attained a more spherical shape related to the time interval of the simulation. It is clear that the results of a molecular dynamics computer simulation are always limited by its total length and the total time used for data analysis. Nevertheless, from our simulation study it turned out that a part of the pentanol hydroxyl groups were located within the micellar core and some alcohol molecules were also observed at the surface region of the micelle. The corresponding partition coefficient was calculated and agreed well with the experiment. The evaluated radial distribution functions of the sodium ions, the octanoate oxygens, and the hydroxyl hydrogens reveal details of the interface region of the micelle and the bulk phase. Additionally, it was possible to calculate the trans-to-gauche ratios of the alkyl chains and to compare these results with the simulation of a pure octanoate micelle. 相似文献
49.
Gorzelle BM Hoffman AK Keyes MH Gray DN Ray DG Sanders CR 《Journal of the American Chemical Society》2002,124(39):11594-11595
Amphipathic polymers ("amphipols") were introduced several years ago (Tribet, C.; Audebert, R.; Popot, J.-L. Proc. Natl. Acad. Sci. U.S.A. 1996, 93, 15047-15050) as an alternative method for solubilizing integral membrane proteins in stable, nativelike conformations. However, direct maintenance of full membrane protein functionality in amphipol solutions has not previously been demonstrated in the absence of added lipid or detergent. In this contribution, the first zwitterionic amphipol "PMAL-B-100" is introduced. PMAL-B-100 not only maintains membrane protein structure and solubility, but also supports the full catalytic activity of an integral membrane enzyme, diacylglycerol kinase, in the complete absence of additional lipid or detergent. All of the roles which a lipid bilayer normally plays in maintaining diacylglycerol kinase's structure and in facilitating catalysis are satisfied by the environment and interactions supplied by PMAL-B-100. 相似文献
50.
A sequence of single photons is emitted on demand from a single three-level atom strongly coupled to a high-finesse optical cavity. The photons are generated by an adiabatically driven stimulated Raman transition between two atomic ground states, with the vacuum field of the cavity stimulating one branch of the transition, and laser pulses deterministically driving the other branch. This process is unitary and therefore intrinsically reversible, which is essential for quantum communication and networking, and the photons should be appropriate for all-optical quantum information processing. 相似文献