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991.
ABSTRACTWe compare the emission characteristics of a thin-film liquid crystal (LC) laser created using a polymer-stabilized, dye-doped chiral nematic LC to that of an LC laser that was fabricated using an achiral, dye-doped nematic refilled into a chiral polymer scaffold that was templated from the same chiral nematic host. Both lasers exhibit wavelength tuning upon the application of an external electric field. However, for the templated sample, tuning is found to occur across a broader wavelength-range for the same electric field amplitude. We discuss the benefits of the templated approach and how it can be used to circumvent dye bleaching that may occur during photo-polymerisation. 相似文献
992.
Antía Fdez-Sanromán Marta Pazos Emilio Rosales María Ángeles Sanromán 《Current Opinion in Electrochemistry》2021
Overall, investigations about the utilization of electrokinetic technology alone or in combination with other processes have attracted particular attention in recent years for remediation of soils contaminated with heavy metals and organic compounds. This fact is due to its peculiar benefits together with its capability of operating in a fine and low-permeability matrix. This review aimed to ascertain the most recent developments on the commonly proposed integrated technologies (electrokinetic soil washing, electrokinetics coupled with permeable reactive barriers, electrokinetic-advanced oxidation processes, and bioelectrokinetic remediation), by evaluating the gaps, challenges, and trends of these systems in the last years. Special attention is paid to the current approaches for overcoming the main bottlenecks of electrokinetics concerning scale-up and reduction of electric energy consumption by integration of renewable energies. 相似文献
993.
Pauline Lefrançois Fanny Girard-Sahun Vasilica Badets Franck Clément Stéphane Arbault 《Electroanalysis》2021,33(4):882-890
The reactivity of platinized ultramicroelectrodes (Pt-black UMEs) towards superoxide anion O2.−, an unstable Reactive Oxygen Species (ROS), and its relatives, H2O2 and O2, was studied. Voltammetric studies in PBS demonstrate that Pt-black UMEs provide: i) a well-resolved reversible redox signature for O2.− detected in both alkaline and physiological buffers (pH 12 and 7.4); ii) irreversible oxidation and reduction waves for H2O2 at pH 7.4. The oxygen reduction reaction (ORR) at Pt-black surfaces solely yields H2O2 (2 electrons/2 H+) at physiological pH. Consequently, Pt-black UMEs allow to sense different ROS including superoxide anion for future biomedical or physico-chemical investigations. 相似文献
994.
Ahmad Guji Yahaya Tomohiro Okuyama Jaroslav Kristof Marius Gabriel Blajan Kazuo Shimizu 《Molecules (Basel, Switzerland)》2021,26(9)
The direct and indirect bactericidal effects of dielectric barrier discharge (DBD) cold atmospheric-pressure microplasma in an air and plasma jet generated in an argon-oxygen gas mixture was investigated on Staphylococcus aureus and Cutibacterium acnes. An AC power supply was used to generate plasma at relatively low discharge voltages (0.9–2.4 kV) and frequency (27–30 kHz). Cultured bacteria were cultivated at a serial dilution of 10−5, then exposed to direct microplasma treatment and indirect treatment through plasma-activated water (PAW). The obtained results revealed that these methods of bacterial inactivation showed a 2 and 1 log reduction in the number of survived CFU/mL with direct treatment being the most effective means of treatment at just 3 min using air. UV–Vis spectroscopy confirmed that an increase in treatment time at 1.2% O2, 98.8% Ar caused a decrease in O2 concentration in the water as well as a decrease in absorbance of the peaks at 210 nm, which are attributed NO2− and NO3− concentration in the water, termed denitratification and denitritification in the treated water, respectively. 相似文献
995.
Elif Mine Öncü-Kaya Nilgün Şide Özer Gök Asiye Safa Özcan 《Journal of Dispersion Science and Technology》2017,38(8):1211-1220
The removal efficiency of Reactive Blue 19 (RB19) by using surfactant-modified bentonite (MB) from aqueous solutions, and also textile wastewater samples was examined. Natural bentonite (NB) was firstly modified with didodecyldimethylammonium bromide (DDDAB) in order to increase the removal capacity of bentonite. MB was then characterized by Fourier Transformed Infrared Spectrophotometer (FTIR), x-ray diffractometry (XRD), x-ray fluorescence (XRF), Scanning Electron Microscope (SEM)/EDX, zeta potential, elemental, and thermal analysis techniques. The high adsorption capacity of MB was 407.7?mg g?1 at pH?=?1.5 and 20°C. The adsorption of Reactive Blue 19 onto MB agreed with the pseudo-second-order kinetic and Langmuir isotherm models. 相似文献
996.
M. Sreedhar I. Neelakanta Reddy Parthasarathi Bera T. S. Shyju C. Anandan 《Surface and interface analysis : SIA》2017,49(4):284-290
Radio frequency magnetron sputtering technique has been used to deposit Cu‐doped ZnS thin films on glass and n‐type Si(100) substrates at room temperature. Crystalline structure, surface morphology, and elemental oxidation states have been studied by X‐ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy. Ultraviolet–visible spectroscopy has been employed to measure the transmittance, reflectance, and absorbance properties of coated films. The deposited thin films crystallize in zinc blende or sphalerite phases as proved by X‐ray diffraction analysis. The intensity of diffraction peaks decreases with increasing the dopant concentrations. The predominant diffraction peak related to (111) plane of ZnS is observed at 28.52° along with other peaks. The peak positions are shifted to higher angles with an increase of Cu concentrations. X‐ray photoelectron spectroscopy studies show that Cu is present in +1 oxidation state. Transmittance, reflectance, and absorbance properties of the deposited films have a slight variation with dopant concentrations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
997.
《化学:亚洲杂志》2017,12(3):314-323
Self‐standing TiO2 nanotube layers in the form of membranes are fabricated by self‐organizing anodization of Ti metal and a potential shock technique. The membranes are then decorated by sputtering different Pt amounts i) only at the top, ii) only at the bottom or iii) at both top and bottom of the tube layers. The Pt‐decorated membranes are transferred either in tube top‐up or in tube top‐down configuration onto FTO slides and are investigated, after crystallization, as photocatalysts for H2 generation using either front or back‐side light irradiation. Double‐side Pt‐decoration of the tube membranes leads to higher H2 generation rates (independently of tube and light‐irradiation configuration) compared to membranes decorated at only one side with similar overall Pt amounts. The results suggest that this effect cannot be only ascribed to the overall amount of Pt co‐catalyst as such but also to its distribution at both tube extremities. This leads to optimized light absorption and electron diffusion/transfer dynamics: the central part of the membranes acts as light‐harvesting zone and electrons therein generated can diffuse towards the Pt/TiO2 active zones (tube extremities) where they can react with the environment and generate H2. 相似文献
998.
《Electroanalysis》2017,29(5):1324-1331
Vanadium oxide/poly (3,4‐ ethylenedioxythiophene)(V2O5‐PEDOT) hybrid materials were prepared in a rotating quartz plasma reactor via capacitively coupled radio frequency (RF 13.56 MHz) plasma. Thin films of V2O5‐PEDOT hybrid and V2O5 were obtained by electron beam evaporation technique onto flexible PET substrate for electrochromic devices (ECDs) applications. As a counter electrode, both RF magnetron sputtered MoO3 onto ITO coated PET and only ITO coated PET electrodes were used. Characterizations of the films were carried out via using scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDX) and X‐ray diffraction (XRD). Hybrid ECDs results showed that synergistic effect depending on improved stability between V2O5 and PEDOT. As a result, we developed all solid complementary electrochromic devices including V2O5, V2O5‐PEDOT and MoO3 films. The electrochromic device characteristics such as electrochromic contrast, coloration efficiency, switching time were calculated from optical and electrochemical measurements. The highest coloration efficiency and optical contrast were obtained as 53 cm2/C and 17 % for V2O5‐PEDOT/MoO3‐based ECD. 相似文献
999.
Mesoporous Mn-doped Co3O4 catalysts were successfully prepared via a dry soft reactive grinding method based on solid state reaction, and their catalytic performances on CO oxidation were evaluated at a high space velocity of 49,500 mL g−1 h−1. A significant promoted effect was observed once the atomic ratios of Mn/(Co+Mn) were lower than 10%, for instance, the temperature for 50% conversion decreased to about −60 °C, showing superior catalytic performance compared to the single metal oxide. Especially, the Mn-promoted Co3O4 catalyst with a Mn/(Co+Mn) molar ratio of 10% could convert 100% CO after 3000 min of time-on-steam without any deactivation at room temperature. As prepared catalysts were characterized by XRD, N2-adsorption/desorption, TEM, H2-TPR, O2-TPD and CO-titration analysis. The significant enhancement of performance for oxidation of CO over Mn-Co-O mixed oxides was associated with the high active oxygen species concentrations formed during the pretreatment in O2 atmosphere. 相似文献
1000.
Seong Hee Bae Dr. Yong-Min Lee Prof. Dr. Shunichi Fukuzumi Prof. Dr. Wonwoo Nam 《Angewandte Chemie (International ed. in English)》2017,56(3):801-805
Redox-inactive metal ions are one of the most important co-factors involved in dioxygen activation and formation reactions by metalloenzymes. In this study, we have shown that the logarithm of the rate constants of electron-transfer and C−H bond activation reactions by nonheme iron(III)–peroxo complexes binding redox-inactive metal ions, [(TMC)FeIII(O2)]+-Mn+ (Mn+=Sc3+, Y3+, Lu3+, and La3+), increases linearly with the increase of the Lewis acidity of the redox-inactive metal ions (ΔE), which is determined from the gzz values of EPR spectra of O2.−-Mn+ complexes. In contrast, the logarithm of the rate constants of the [(TMC)FeIII(O2)]+-Mn+ complexes in nucleophilic reactions with aldehydes decreases linearly as the ΔE value increases. Thus, the Lewis acidity of the redox-inactive metal ions bound to the mononuclear nonheme iron(III)–peroxo complex modulates the reactivity of the [(TMC)FeIII(O2)]+-Mn+ complexes in electron-transfer, electrophilic, and nucleophilic reactions. 相似文献