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排序方式: 共有1411条查询结果,搜索用时 15 毫秒
951.
Sameh El Sayed Lluís Pascual Alessandro Agostini Ramón Martínez-Má?ez Félix Sancenón Ana M Costero Margarita Parra Salvador Gil 《ChemistryOpen》2014,3(4):142-145
The synthesis, characterization and sensing features of a novel probe 1 for the selective chromogenic recognition of diisopropylfluorophosphate (DFP), a sarin and soman mimic, in 99:1 (v/v) water/acetonitrile and in the gas phase is reported. Colour modulation is based on the combined reaction of phosphorylation of 1 and fluoride-induced hydrolysis of a silyl ether moiety. As fluoride is a specific reaction product of the reaction between DFP and the −OH group, the probe shows a selective colour modulation in the presence of this chemical. Other nerve agent simulants, certain anions, oxidant species and other organophosphorous compounds were unable to induce colour changes in 1. This is one of the very few examples of a selective detection, in solution and in the gas phase, of a sarin and soman simulant versus other reactive derivatives such as the tabun mimic diethylcyanophosphate (DCNP). 相似文献
952.
In this work, we studied the catalytic activity of LaMnO3 and (La0.8A0.2)MnO3 (A = Sr, K) perovskite catalysts for oxidation of NO and C10H22 and selective reduction of NO by C10H22. The catalytic performances of these perovskites were compared with that of a 2 wt% Pt/SiO2 catalyst. The La site substitution increased the catalytic properties for NO or C10H22 oxidation compared with the non-substituted LaMnO3 sample. For the most efficient perovskite catalyst, (La0.8Sr0.2)MnO3, the results showed the presence of two temperature domains for NO adsorption: (1) a domain corresponding to weakly adsorbed NO, desorbing at temperatures lower than 270 ℃ and (2) a second domain corresponding to NO adsorbed on the surface as nitrate species, desorbing at temperatures higher than 330 ℃. For the Sr-substituted perovskite, the maximum NO2 yield of 80% was observed in the intermediate temperature domain (around 285 ℃). In the reactant mixture of NO/C10H22/O2/H2O/He, (La0.8Sr0.2)MnO3 perovskite showed better performance than the 2 wt% Pt/SiO2 catalyst: NO2 yields reaching 50% and 36% at 290 and 370 ℃, respectively. This activity improvement was found to be because of atomic scale interactions between the A and B active sites, Sr2+ cation and Mn4+/Mn3+ redox couple. Thus, (La0.8Sr0.2)MnO3 perovskite could be an alternative free noble metal catalyst for exhaust gas after treatment. 相似文献
953.
Hyein Ryu Ji Hye Baek Myung Gil Choi Jong Chan Lee Suk-Kyu Chang 《Tetrahedron letters》2017,58(30):2927-2930
We developed a simple Cu2+-selective turn-on fluorescence signaling probe based on the hydrolysis of 1-pyrenecarbohydrazide (1) to 1-pyrenecarboxylic acid. Probe 1 exhibited prominent fluorescence signaling of Cu2+ ions in a 10% aqueous Tris-buffered (pH 7.0) DMSO solution with a detection limit of 5.93 × 10?8 M. Signaling with control compounds derived from pyreneacetic acid and pyrenebutyric acid showed that the fluorescence signal became less pronounced as the distance between the hydrazide functionality and the pyrene fluorophore increased. As a practical application, this probe was employed for the determination of Cu2+ in a simulated semiconductor wastewater. 相似文献
954.
Woo Ram Lee Hyuna Jo Li-Ming Yang Hanyeong Lee Dae Won Ryu Kwang Soo Lim Jeong Hwa Song Da Young Min Sang Soo Han Jeong Gil Seo Yong Ki Park Dohyun Moon Chang Seop Hong 《Chemical science》2015,6(7):3697-3705
An amine-functionalized metal–organic framework (MOF), dmen-Mg2(dobpdc) (dmen = N,N-dimethylethylenediamine), which contains a heterodiamine with both primary and tertiary amines, was prepared via a post-synthetic method. This material exhibits a significant selectivity factor for CO2 over N2 that is commensurate with top-performing MOFs. It is remarkable that the solid is fully regenerated under vacuum or flowing Ar at low desorption temperatures, and following this can take up CO2 at more than 13 wt%. An exceptionally high working capacity is achieved at low regeneration temperatures and after exposure to humid conditions, which are important parameters for a real post-combustion CO2 capture process. 相似文献
955.
AbstractMode-division multiplexing requires all-optical signal processing techniques that are able to deal with a new coding dimension, the spatial mode. In this context, optical microwires emerge as a potential highly non-linear and multi-modal waveguide envisioning the development of all-optical signal processing devices to mode-division multiplexing systems based on the four-wave mixing process. The inter- and intramodal phase-matching conditions for the four-wave mixing process are mapped as a function of the microwire diameter and the wavelength of signals. Moreover, the efficiency of four-wave mixing considering a strong guiding regime is investigated in the multi-modal regime. 相似文献
956.
957.
A. A. Novoselov F. Z. Gil’mutdinov V. Ya. Bayankin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(3):474-480
The effect of ion implantation on the composition and mechanical properties of rolled Ni-Cu foils is studied. The formation of a non-monotonic oscillating dependence of the chemical composition on depth associated with a presumable change in the defect structure of the material has been observed. Possible mechanisms of the observed phenomena are proposed. 相似文献
958.
V. K. Ivanov O. S. Polezhaeva A. B. Shcherbakov D. O. Gil’ Yu. D. Tret’yakov 《Russian Journal of Inorganic Chemistry》2010,55(1):1-5
A new microwave-hydrothermal process has been developed for preparing stable aqueous sols of nanocrystalline ceria. Transmission
electron microscopy, UV-Vis spectroscopy, and dynamic light scattering shows that CeO2 nanoparticle size remains unchanged during hydrothermal treatments. Sodium adenosine triphosphate and sodium citrate are
proposed for additional stabilization of the sols. 相似文献
959.
960.
Gi Won Shin Yang Sook Cho Hee Sung Hwang Mi‐Hwa Oh Hong Gil Nam Jin Hyun Park Gyoo Yeol Jung 《Electrophoresis》2009,30(15):2728-2736
Rapid diagnosis of bacterial infection is important for patient management and appropriate therapy during the early phase of bacteria‐induced disease. Among the existing techniques for identifying microbial, CE‐SSCP combined with 16S ribosomal RNA gene‐specific PCR has the benefits of excellent sensitivity, resolution, and reproducibility. However, even though CE‐SSCP can separate PCR products with high‐resolution, multiplex detection and quantification are complicated by primer‐dimer formation and non‐specific amplification. Here, we describe a novel technique for multiplex detection and quantification of pathogens by template‐tagging followed by multiplex asymmetric PCR and subsequent CE‐SSCP. More specifically, we reverse transcribed 16S ribosomal RNAs from seven septicemia‐inducing pathogens, tagged the templates with common end sequences, and amplified them using common primers. The resulting amplicons could be successfully separated by CE‐SSCP and quantified by comparison to an internal standard. This method yielded results that illustrate the potential of this system for diagnosing infectious disease. 相似文献