Effect of cation(Li^+, Na^+, K^+, Rb^+, Cs^+) in aqueous electrolyte on the electrochemical redox of Prussian blue analogue(PBA) cathodes

Prussian blue analogue(PBA)material is a promising cathode for applications in Na-ion and K-ion batteries which can support high c-rates for charge and discharge.In this study,the material of composition[K2 CuIIFeII(CN)6]was synthesized and its structural and electrochemical redox behavior was investigated with 5 different alkali insertion cations(Li^+,Na^+,K^+,Rb^+,Cs^+).Galvanostatic measurements indicate that the redox potential strongly depends on the ionic radius of the inserted cation.The redox potential varies by 400 m V between using Li^+(0.79A)or Cs^+(1.73A)in the electrolyte.The underlying modification of the Fe2^+/Fe3^+redox potential in PBA is proposed to be due to the weakening of the Fe–C bond in the material.This hypothesis is supported by XRD measurements which reveal that the lattice parameter of the de-intercalated host structure follows the same trend of monotonic increase with the cation size.The relatively minor volume changes accompanying the redox(1.2%–2.4%)allow the PBA to accommodate differently sized cations,although the structural hindrances are quite pronounced at high c-rates for the larger ones(Rb^+and Cs^+).Cycle aging studies indicate that the minimum capacity fade rate is observed in case of K^+ and Rb^+ containing electrolyte.The peak intensity corresponding to the[220]crystallographic plane varies depending on the state of charge of PBA,since this plane contains the insertion cations.Owing to the sensitivity of the redox potential to the insertion cation coupled with the observed fast ion-exchange ability,the PBA material may find additional analytical applications such as ion sensing or filtration devices.

Carbide derived carbon electrode with natural graphite addition in magnesium electrolyte based cell for supercapacitor enhancements

Herein,we have presented a supercapacitor based on carbide derived carbon（CDC） electrode with natural graphite（NG） addition.The capacitor was analyzed at 22°C by cyclic voltammetry,galvanostatic charge-discharge and impedance techniques using a 0.5 mol/L of magnesium（II）bis（trifluoro methanesulfonyl） imide（Mg TFSI） in ethylene carbonate-propylene carbonate（EC ：PC = 1 ：1,v/v） as electrolyte.The results conclude that the CDC cell enhancements have been proven by the composite electrode（5%–30% NG to CDC） especially on the cell efficiency and voltage i.e.,the CDC cell around 2.5 V limit was improved.An obtainable specific capacitance,real power and energy density are 15 F g-1,1.2 k W kg-1and 15 Wh kg-1,respectively.

Control of disability glare by means of electrochromic filtering glasses:A pilot study

Purpose:To evaluate the potential clinical usability of a new prototype of ophthalmic blue light filters developed by using electrochromic technology in pseudophakic patients complaining of glare.Methods:A prototype of electrochromic device was developed,with a specific frame that enclosed an electronic driver that allowed personalizing its function for each patient.A pro-spective,observational case series study was performed to test it.Five patients who had un-dergone cataract surgery with clear intraocular lenses and complaining of glare were included in the study.Main outcome measures were the results obtained in the satisfaction questionnaire that was delivered to patients.Then,visual acuity,contrast sensitivity,and reading ability data were evaluated with and without the prototype under diferent lighting conditions and different modes of the prototype after a complete month of use.Lens transmittance was also measured.Results:Visual acuity,contrast sensitivity and reading function did not change significantly with prototype use.The main activity for which the prototype was used was walking.Only one patient found that the dimming level was insuficient.No patients reported variable discomfort when passing tunnels,not sufficiently clear indoors,or put on and remove discomfort.The lenses slightly decreased their transmittance at the end of the study.Conclusion:Glasses based on elect rochromic technology may be acceptable for outdoor/indoor use and for distance-near vision.Future studies with larger samples must be conducted to confirm the clinical usability of these glasses.

Comparison of Nine Membrane Pairs for Electrodialytic Removal of Nitrate Ions

Electrodialysis (ED) of NaNO3 solutions was performed to stress the role of the membrane pair as a unit i.e. the behavior as a whole of Anion Exchange Membrane (AEM) and Cation Exchange Membrane (CEM), in the process at room temperature. The membrane pair was also tested in the reclamation of nitric acid and sodium hydroxide. It was found that the membrane pair ranking in Limiting Current Density does not agree with that of ions leakage and both rankings are not the same as for Current Efficiency or Specific Power Consumption, each parameter for a specific membrane pair depends on the associated membrane and at a lesser degree on the flow rate. Results show that one cannot select a membrane or a membrane pair only by its limiting current density i.e. it is necessary to evaluate several parameters of the process by characterizing the whole membrane pair and to decide the parameter of interest, i.e. denitrification speed, ions leakage, proton back migration, current efficiency or specific power consumption.

Degradation and Detoxification of Banana Postharvest Treatment Water Using Advanced Oxidation Techniques

The elimination and detoxification of water contaminated with the principal commercial fungi-cides—thia- bendazole (Textar 60 T) and imazalil sulphate (Fruitgard IS 7.5)—used in the postharvest treatment of bananas was successfully achieved through the use of advanced oxidation processes (AOPs). The techniques tested were heterogeneous photocatalysis with TiO2 and TiO2-activated carbon (TiO2-CA) and Fenton and photo-Fenton processes. The evolution of fungicide concentration during degradation was studied together with mineralization and toxicity levels. When treated with any of the methods under study, the water meets the conditions stipulated by the legislation currently in force for its reuse in irrigation. However, this study proposes that the Fenton process is the best option for treatment of this type of water due to the efficiency of its reactions and its low economic cost.

明显增强的镧掺杂锶铁氧体的磁光克尔效应

采用陶瓷法制备了稀土La^(3+)掺杂的锶铁氧体Sr_(1-x)La_xFe_(12)O_(19)(x=0,0.05,0.10,0.15,0.20)。系统地研究了La^(3+)取代对材料结构、磁性能的影响,特别是对磁光克尔效应的影响。实验结果表明,La^(3+)取代Sr^(2+)能显著增强锶铁氧体的磁光克尔效应,当x=0.20时,与SrFe_(12)O_(19)相比,磁光克尔效应增加到了1%。

Challenges and perspectives on high and intermediate-temperature sodium batteries

Energy storage systems are selected depending on factors such as storage capacity, available power, discharge time, self-discharge, efficiency, or durability. Additional parameters to be considered are safety, cost, feasibility, and environmental aspects. Sodium-based batteries （Na-S, NaNiC12） typically require operation temperatures of 300-350 ~C. The high operating temperatures substantially increase the operating costs and raise safety issues. This updated review describes the state-of-the-art materials for high-temperature sodium batteries and the trends towards the development and optimization of intermediate and low-temperature devices. Recent advances in inorganic solid electrolytes, glass-ceramic electrolytes, and polymer solid electrolytes are of immense importance in all-solid-state sodium batteries. Systems such as Na~ super ionic conductor （NASICON, Nal^xZr2PB-~SixOl2 （0 -〈 x _〈 3））, glass-ceramic 94Na3PS4＂6Na4SiS4, and polyethylene oxide （PEO）-sodium triflate （NaCF3SO3） are also discussed. Room temperature ionic liquids （RTILs） are also included as novel electrolyte solvents. This update discusses the progress of on-going strategies to enhance the conductivity, optimize the electrolyte/electrode interface, and improve the cell design of emerging technologies. This work aims to cover the recent advances in electrode and electrolyte materials for sodium- sulfur and sodium-metal-halide （zeolite battery research Africa project （ZEBRA）） batteries for use at high and intermediate temperatures.

Polarization-independent multimode interference coupler with anisotropy-engineered bricked metamaterial

Many applications, including optical multiplexing, switching, and detection, call for low-cost and broadband photonic devices with polarization-independent operation. While the silicon-on-insulator platform is well positioned to fulfill most of these requirements, its strong birefringence hinders the development of polarizationagnostic devices. Here we leverage the recently proposed bricked metamaterial topology to design, for the first time, to our knowledge, a polarization-independent 2 × 2 multimode interference coupler using standard 220 nm silicon thickness. Our device can be fabricated with a single etch step and is optimized for the O-band,covering a wavelength range of 160 nm with excess loss, polarization-dependent loss, and imbalance below 1 dB and phase errors of less than 5°, as demonstrated with full three-dimensional finite-difference time-domain simulations.

Erratum to:Quantification of the influence of rolling stock failures on track deterioration

The original version of this article unfortunately contained a mistake.In line 6,p.785,the data“0.06”should be“6.04×10^-6”,i.e.“The results showed that among these seven failures,the occurrence probabilities of the wheel out-of-round and the wheel flat are the highest,both are approximately 6.04×10^-6.”

Solar spectral conversion based on plastic films of lanthanide-doped ionosilicas for photovoltaics:Down-shifting layers and luminescent solar concentrators

The mismatch between the photovoltaic(PV)cells absorption and the solar irradiance on earth is one of the major limitations towards more efficient PV energy conversion.This aspect was addressed by downshifting the solar irradiance on Earth through luminescent down-shifting layers based on lanthanidedoped surface-functionalized ionosilicas(ISs)embedded in poly(methyl methacrylate)(PMMA)coated on the surface of commercial Si-based PV cells.The IS-PMMA hybrid materials exhibit efficient solar radiation harvesting(spectral overlap of^9.5×10^19 photons/(s·m2))and conversion(quantum yield^52%).The direct solar radiation and the down-shifted radiation are partially guided and lost through total internal reflection to the layer edges being unavailable for PV conversion of the coated PV cell.By tuning the down-shifting layer thickness,it also acts as luminescent solar concentrator enabling the collection of the guided radiation by flexible PV cells applied on the borders of the down-shifting layer leading to an enhancement of the PV energy conversion from^5%(in the case of the single-use of the luminescent down-shifting layer)to^13%comparing with the bare PV cell.The overall electrical output of the device resulted in an absolute external quantum efficiency increase of^32%for the optimized Eu^3+-based films in the UV spectral region(compared with the bare PV device,which is among the best values reported so far).

Carbon coating of air-sensitive insulating transition metal fluorides:An example study on α-Li3FeF6 high-performance cathode for lithium ion batteries

Li_(3)FeF_(6)has been the focus of research of fluorine-based cathode materials for lithium-ion batteries.Because of the low electronic conductivity of Li3 FeF6,the decrease of particle size,by an energyconsuming long-time ball milling process with carbon,is necessary to achieve a high electrochemical performance.The most successful method to enhance electrochemical activity,carbon coating,seemed to be impracticable,so far,for sensitive fluorides like Li3 FeF6.In this work,carbon coating on Li3 FeF6 particles has been successfully achieved for the first time,while avoiding both extended hydrolysis and Fe(Ⅲ)-Fe(Ⅱ)reduction.The heat treatment and atmosphere,yielding the maximal transformation of organic carbon to both graphitised and disordered carbon,has been determined.Carbon coating,with a thickness of approximately 2.5 nm,has been achieved by controlled thermal decomposition of glucose,under air,at 300℃.Raman and X-ray photoelectron spectroscopy(XPS)experiments have proved the existence of carbon and Fe2O3 on the surface of Li3FeF6 nanoparticles.XPS spectroscopy indicates the presence of organic residues from glucose decomposition.Attempts to further reduce the orga nic carbon content results in a decrease of the amorphous carbon coating layer.Optimised carbon-coated Li3 FeF6 nanoparticles deliver 122 mA h g^(-1)(85%of theoretical capacity)significantly higher than that of a noncoated sample(58 mA h g^(-1)).Even more,a significant beneficial effect of carbon coating on both capacity retention and coulombic efficiency is observed.

Modulating the growth of cysteine-capped cadmium sulfide quantum dots with enzymatically produced hydrogen peroxide

Cysteine （CSH） readily stabilizes cadmium sulfide quantum dots （CdS QDs） that grow in aqueous buffered solutions. The oxidation of CSH by hydrogen peroxide （H202） at room temperature yields cystine （CSSC）, which is less efficient in stabilizing CdS QDs compared to CSH. Herein, we demonstrate that such oxidation causes a decrease in the formation rate of CSH-capped CdS QDs from Cd^2＋ and S^2- ions. For the first time, we combined the oxidation of CSH with the glucose oxidase （GOx）-assisted biocatalytic oxidation of D-glucose, which leads to a buildup of H2O2 in the reaction mixture. The enzymatically modulated in situ growth of CdS QDs was monitored using two techniques： fluorescence spectroscopy and photoelectrochemical （PEC） analysis. This system enables quantification of GOx and glucose in human serum.

西班牙桉树林下土小平盘菌复合群中两个独立的种——暗柔膜菌属一新组合及一新种:分类、分子生物学、生态与分布

土小平盘菌复合群原产澳大利亚,其中两个土生种在西班牙报道,很可能是在18世纪中叶引入西班牙。根据形态学特征和序列分析的结果,建立一个新组合和一个新种,分别定名为Phaeohelotium undulatum comb.nov.和Phaeoh.succineoguttulatum sp.nov.。对其宏观和微观形态特征进行了详尽的描述和图示,ITS rDNA序列分析的结果显示,它们以100%的支持率与Phaeohelotium monticola聚类在同一个分支。文中提供了该复合群Phaeohelotium属5个土生种的分种检索表,并对它们的生态习性与世界分布进行了深入讨论。