Synergism of preintercalated manganese ions and lattice water in vanadium oxide cathodes for high-capacity and long-life Zn-ion batteries

Aqueous Zn-ion batteries(AZIBs)are recognized as a promising energy storage system with intrinsic safety and low cost,but its applications still rely on the design of high-capacity and stable-cycling cathode materials.In this work,we present an intercalation mechanism-based cathode materials for AZIB,i.e.the vanadium oxide with pre-intercalated manganese ions and lattice water(noted as MVOH).The synergistic effect between Mn^(2+)and lattice H_(2)O not only expands the interlayer spacing,but also significantly enhances the structural stability.Systematic in-situ and ex-situ characterizations clarify the Zn^(2+)/H^(+)co–(de)intercalation mechanism of MVOH in aqueous electrolyte.The demonstrated remarkable structure stability,excellent kinetic behaviors and ion-storage mechanism together enable the MVOH to demonstrate satisfactory specific capacity of 450 mA h g^(−1)at 0.2 A g^(−1),excellent rate performance of 288.8 mA h g^(−1)at 10 A g^(−1)and long cycle life over 20,000 cycles at 5 A g^(−1).This work provides a practical cathode material,and contributes to the understanding of the ion-intercalation mechanism and structural evolution of the vanadium-based cathode for AZIBs.

Erratum to “Semiclassical and Quantum-Mechanical Formalism Applied in Calculating the Emission Intensity of the Atomic Hydrogen” [Journal of Modern Physics 7 (2016) 1004-1020]

The original online version of this article (Stanislaw Olszewski (2016) Semiclassical and Quantum-Mechanical Formalism Applied in Calculating the Emission Intensity of the Atomic Hydrogen. Journal of Modern Physics, 7, 1004-1020. http://dx.doi.org/10.4236/jmp.2016.79091) unfortunately contains a mistake. The author wishes to correct the errors in Section 2.

Relationship between the Fundamental Constants of Physics Obtained from the Uncertainty Principle for Energy and Time

An attempt is done to calculate the value of the elementary electron charge from its relation to the Planck constant and the speed of light. This relation is obtained, in the first step, from the Pauli analysis of the strength of the electric field associated with an elementary emission process of energy. In the next step, the uncertainty principle is applied to both the emission time and energy. The theoretical result for e is roughly close to the experimental value of the electron charge.

Can the Physics of Time Be Helpful in Solving the Differential Eigenequations Characteristic for the Quantum Theory?

The main differential equations of quantum theory are the eigenequations based on the energy operator;they have the energy as eigenvalues and the wave functions as eigenfunctions. A usual complexity of these equations makes their accurate solutions accessible easily only for very few physical cases. One of the methods giving the approximate solutions is the Schrödinger perturbation theory in which both the energies and wave functions of a more complicated eigenproblem are approached with the aid of similar parameters characteristic for a less complicated eigenproblem. No time parameter is necessary to be involved in these calculations. The present paper shows that the Schrödinger perturbation method for non-degenerate stationary quantum states, i.e. the states being independent of time, can be substantially simplified by applying a circular scale of time separately for each order of the perturbation theory. The arrangement of the time points on the scale, combined with the points contractions, gives almost immediately the series of terms necessary to express the stationary perturbation energy of a given eigenproblem. The Schrödinger’s method is compared with the Born-Heisenberg-Jordan perturbation approach.

High piezo/photocatalytic efficiency of Ag/Bi_(5)O_(7)I nanocomposite using mechanical and solar energy for N2 fixation and methyl orange degradation

In this work,Ag/Bi_(5)O_(7)I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange(MO)degradation.Bi_(5)O_(7)I was synthesized via a hydrothermal-calcination method and shows nanorods morphology.Ag nanoparticles(NPs)were photo deposited on the Bi_(5)O_(7)I nanorods as electron trappers to improve the spatial separation of charge carriers,which was confirmed via XPS,TEM,and electronic chemical analyses.The catalytic test indicates that Bi_(5)O_(7)I presents the piezoelectric-like behavior,while the loading of Ag NPs can strengthen the character.Under ultrasonic vibration,the optimal Ag/Bi_(5)O_(7)I presents high efficiency in MO degradation.The degradation rate is determined to be 0.033 min
1,which is 4.7 folds faster than that of Bi_(5)O_(7)I.The Ag/Bi_(5)O_(7)I also presents a high performance in piezocatalytic N2 fixation.The piezocatalytic NH3 generation rate reaches 65.4 μmol L^(-1)g^(-1)h^(-1)with water as a hole scavenger.The addition of methanol can hasten the piezoelectric catalytic reaction.Interestingly,when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi_(5)O_(7)I catalyst,higher performance in NH3 generation and MO degradation is observed.However,due to the weak adhesion of Ag NPs,some Ag NPs would fall off from the Bi_(5)O_(7)I surface under long-term ultrasonic vibration,which would greatly reduce the piezoelectric catalytic performance.This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst.The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.

Facile preparation of Ag_(2)S/KTa_(0.5)Nb_(0.5)O_(3) heterojunction for enhanced performance in catalytic nitrogen fixation via photocatalysis and piezo-photocatalysis

In this work, a novel heterojunction composite Ag_(2)S/KTa_(x)Nb_(1-x)O_(3)was designed and synthesized through a combination of hydrothermal and precipitation procedures. The Ta/Nb ratio of the KTa_(x)Nb_(1-x)O_(3)and the Ag_(2)S content were optimized. The best 0.5% Ag_(2)S/KTa_(0.5)Nb_(0.5)O_(3)(KTN) sample presents an enhanced photocatalytic performance in ammonia synthesis than KTN and Ag_(2)S. Under simulated sunlight, the NH_(3)generation rate of 0.5% Ag_(2)S/KTN reaches 2.0 times that of pure KTN. Under visible light, the reaction rate ratio of the two catalysts is 6.0.XRD, XPS, and TEM analysis revealed that Ag2S was intimately decorated on the KTN nanocubes surface, which promoted the electron transfer between the two semiconductors. The band structure investigation indicated that the Ag_(2)S/KTN heterojunction established a type-Ⅱ band alignment with intimate contact, thus realizing the effective transfer and separation of photogenerated carriers. The change in charge separation was considered as the main reason for the enhanced photocatalytic performance. Interestingly, the Ag_(2)S/KTN composite exhibited higher NH3generation performance under the combined action of ultrasonic vibration and simulated sunlight. The enhanced piezo-photocatalytic performance can be ascribed that the piezoelectric effect of KTN improved the bulk separation of charge carriers in KTN. This study not only provides a potential catalyst for photocatalytic nitrogen fixation but also shows new ideas for the design of highly efficient catalysts via semiconductor modification and external field coupling.

Mechanistically Novel Frontal-Inspired In Situ Photopolymerization:An Efficient Electrode|Electrolyte Interface Engineering Method for High Energy Lithium Metal Polymer Batteries

The solvent-free in situ polymerization technique has the potential to tailor-make conformal interfaces that are essential for developing durable and safe lithium metal polymer batteries(LMPBs).Hence,much attention has been given to the eco-friendly and rapid ultraviolet(UV)-induced in situ photopolymerization process to prepare solid-state polymer electrolytes.In this respect,an innovative method is proposed here to overcome the challenges of UV-induced photopolymerization(UV-curing)in the zones where UV-light cannot penetrate,especially in LMPBs where thick electrodes are used.The proposed frontal-inspired photopolymerization(FIPP)process is a diverged frontal-based technique that uses two classes(dual)of initiators to improve the slow reaction kinetics of allyl-based monomers/oligomers by at least 50%compared with the conventional UV-curing process.The possible reaction mechanism occurring in FIPP is demonstrated using density functional theory calculations and spectroscopic investigations.Indeed,the initiation mechanism identified for the FIPP relies on a photochemical pathway rather than an exothermic propagating front forms during the UV-irradiation step as the case with the classical frontal photopolymerization technique.Besides,the FIPP-based in situ cell fabrication using dual initiators is advantageous over both the sandwich cell assembly and conventional in situ photopolymerization in overcoming the limitations of mass transport and active material utilization in high energy and high power LMPBs that use thick electrodes.Furthermore,the LMPB cells fabricated using the in situ-FIPP process with high mass loading LiFePO_(4)electrodes(5.2 mg cm^(-2))demonstrate higher rate capability,and a 50%increase in specific capacity against a sandwich cell encouraging the use of this innovative process in large-scale solid-state battery production.

Qualitative Considerations on the Influence of the Gases Water Vapor and Carbon Dioxide on the Global Environmental Temperature from the Point of View of Textbook Knowledge

The solar radiation that hits the Earth conditions the dynamic equilibrium that prevails on our planet. Consideration of basic physical-chemical knowledge shows that this equilibrium can be changed only by additional energy input or prolongation of the interaction time solar radiation—Earth matter. The contribution of H2O(g) and CO2 to the protection of the earth against excessive warming is experimentally and by basic laws of nature secured. For a greenhouse effect, a part of the earth radiation must be radiated back to the earth and then into space. If one understands the earth radiation as radiation of a black body with the average global environmental temperature, from all vibrations normal modes of the gases H2O(g) and CO2 only the bending mode of CO2 with 4% of the solar constant can contribute beside the rotational modes of the water to the greenhouse effect. The contributions of the normal modes of H2O(g) and CO2 to the heat capacity of the atmosphere are negligible. Therefore, in agreement with studies by K. Ångström, CO2 contributes only to the stabilization of the global environmental temperature. Whether the use of renewable energies can actually at least mitigate the increase of the environmental temperature is by no means certain but must be examined for each individual case. With certainty, this goal can only be achieved by reducing the energy consumption of mankind.

Protective and water-repellent properties of alkylcarboxylic and alkylphosphonic acid films on technically pure magnesium

The formation of superhydrophobic coatings using low-toxicity corrosion inhibitors is a promising method for corrosion protection of metals and alloys. In this study, the effects of surface roughness and the of the adsorbed substance structure on wettability and corrosion resistance of commercially pure magnesium were investigated. Surface roughness was created by three different methods: paper grinding,etching in nitric acid solution and laser treatment. Oleic, stearic and octadecylphosphonic acids were investigated as potential surface modifiers for the formation of corrosion resistant superhydrophobic coatings. It has been shown that the protective and hydrophobic properties of acid films on magnesium, as well as their stability, are determined by both the initial surface morphology and the nature of the inhibitors.Experimentally, the laser treatment was found to be preferable to mechanical and chemical surface preparation and the best hydrophobic agent among the studied acids is phosphonic acid. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray clamber are formed in a solution of 0.001 M octadecylphosphonic acid on the surface of magnesium with high roughness. In addition, the effect of vinyltrimethoxysilane on the protective and hydrophobic properties of stearic acid and octadecylphosphonic acid films was investigated. The results of direct corrosion tests and wetting contact angle degradation kinetics studies showed that the protective and hydrophobic properties of stearic acid can be enhanced by its layer-by-layer adsorption with silane.They practically reach the parameters of octadecylphosphonic acid.

微尺度声操控研究及其生物学应用

Acoustic waves-and ultrasound waves in particular-are biocompatible,with excellent transmission through biological tissues.Furthermore,the wavelength and intensity of acoustic waves can be tuned over several orders of magnitude.Most notably,the commonly used 10–300 MHz frequency range is attractive for biomedical applications,as its wavelength in water(5–150μm)corresponds to the cellular-length scale.

膜接触破乳——用于油包水乳液分离的超疏水ZIF-8@rGO膜

水-油界面不平衡是实现油水乳液破乳的关键。传统膜通常是依赖较高的跨膜压力破坏界面平衡而实现破乳。本文提出了可自然、快速地破坏水-油界面平衡的“接触破乳”的概念,开发了一种对有机组分具有高通量的新型破乳分离膜。具体制备过程分为两步,首先通过真空辅助抽滤法在聚四氟乙烯(PTFE)基底上组装ZIF-8@rGO微球(ZGS)层,再采用聚二甲基硅氧烷(PDMS)交联溶液中进行固定化处理。由于ZGS表面为微纳米阶层结构,所制备的ZIF-8@rGO@PDMS/PTFE(ZGPP)膜表面展现出超疏水性特性,当表面活性剂稳定的油包水乳液接触到膜表面时,微纳结构的超疏水膜表面会引起水-油界面不平衡。ZGPP膜对油包水乳液具有良好的分离破乳性能,在0.15 bar(15 kPa)的低跨膜压力下,分离效率可以达到99.57%,通量可达到2254 L·m^(-2)·h^(-1),且对于表面活性剂稳定的纳米级甲苯-水乳剂(平均液滴尺寸为57 nm)的体系也可以实现破乳分离。“接触破乳”概念的提出有望为开发新一代油包水乳液分离的破乳膜提供新的思路。

In-depth analysis of the influence of bio-silica filler(Didymosphenia geminata frustules)on the properties of Mg matrix composites

A novel metal matrix composites(MMC)with Mg matrix reinforced with natural filler in the form of Didymosphenia geminata frustules(algae with distinctive siliceous shells)are presented in this work.Pulse plasma sintering(PPS)was used to manufacture Mg-based composites with 1,5 and 10 vol.%ceramic filler.As a reference,pure Mg was sintered.The results show that the addition of 1 vol.%Didymosphenia geminata frustules to the Mg matrix increases its corrosion resistance by supporting passivation reactions,and do not affect the morphology of L929 fibroblasts.Addition of 5 vol.%the filler does not cause cytotoxic effects,but it supports microgalvanic reactions leading to the greater corrosion rate.Higher content than 5 vol.%the filler causes significant microgalvanic corrosion,as well as increases cytotoxicity due to the greater micro-galvanic effect of the composites containing 10 and 15 vol.%diatoms.The results of contact angle measurements show the hydrophilic character of the investigated materials,with slightly increase in numerical values with addition of amount of ceramic reinforcement.The addition of Didymosphenia geminata frustules causes changes in a thermo-elastic properties such as mean apparent value of coefficient of thermal expansion(CTE)and thermal conductivity(λ).The addition of siliceous reinforcement resulted in a linear decrease of CTE and reduction in thermal conductivity over the entire temperature range.With the increasing addition of Didymosphenia geminata frustules,an increase in strength with a decrease in compressive strain is observed.In all composites an increase in microhardness was attained.The results clearly indicate that filler in the form of Didymosphenia geminata frustules may significantly change the most important properties of pure Mg,indicating its wide potential in the application of Mg-based composites with a special focus on biomedical use.

选择离子流动管质谱对汽车尾气成分的分析

运用选择离子流动管质谱 (SIFT/MS)装置 ,以H3 O+ 、NO+ 、O+ 2 为初始离子对安装有催化转换装置的汽油车引擎启动 5min后的尾气进行了取样分析 ,结果表明 ,尾气中含有大量的 CH 化合物 (包括烷烃、烯烃、炔烃、二烯烃以及芳香烃 ) ,含氧有机物 (包括醛、酮、醇 )以及NH3 和NOx 等污染成分。其中 ,NO的含量最高 ,它的浓度比其它所有SIFT/MS装置所能测量到的各种物质的总和还多 ;在CH化合物中以芳香烃的含量最高 ,约占整个CH化合物含量的一半以上 ;在含氧有机物中以醛类物质的含量最高。初步讨论了这些成分的形成动力学过程 ,对引擎冷启动和热启动时的尾气成分进行了分析 ,结果表明 :冷启动尾气中CH化合物和NOx 的含量是热启动的 3～ 5倍 ,而含氧有机物的含量没有很大的变化 ,此结果也证明了尾气的催化转化装置是一种减少尾气中CH化合物和NOx 污染物的一种有效的控制方法。

用选择离子流动管质谱测定汽油和柴油蒸汽成分

采用选择离子流动管质谱(SIFT/MS)装置,以H3O+、NO+为初始离子对汽油和柴油蒸汽进行了研究,质谱分析表明,汽油和柴油主要由C-H化合物组成.包括烷烃、环烷烃、烯烃、炔烃、二烯烃以及芳香烃。在这几种成分中,烷烃都占有最大的比例;汽油蒸汽和柴油蒸汽最大的区别是柴油蒸汽中长链大分子的挥发性C-H化合物所占的比例远远高于汽油蒸汽。文中还给出了以H3O+、NO+为初始离子所得到的汽油蒸汽的质谱图,以及汽油、柴油蒸汽中各种成分的定量分析结果。

汽车尾气中NO_X再燃烧过程的动力学

为了阐明汽车尾气中 NOX再燃烧的动力学进程 ,以甲醛和 NO2 作为探针分子 ,通过 FT-IR跟踪研究了反应体系中所产生的 HCO自由基与 NO2 反应的动力学。结果表明 ,反应的主要产物中包括 CO、CO2 、NO、HONO和 H2 O等分子 ,经长时间的反应 ,当体系中的 NO2 基本耗尽时 ,才有少量的 N2 O生成。这些产物分子分别是在几个不同途径的连串反应中形成的。从体系中 CO和 CO2 的生成量 ,测定了主反应的歧化反应速率比 ,并对相应的动力学机理进行了讨论。

FTIR研究HCO自由基与NO_2反应的动力学

In this work,mixtures of HCHO-NO2-Ar were photolyzed under stationary conditions using a high-pressure Hg lamp atλ =300～ 340 nm and HCHO as a probe molecule.The HCO radicals were generated in the reaction system,and the kinetics of the reaction between HCO radicals and NO2 was investigated at room temperature in Ar gas at 5.7× 104 Pa pressure by FTIR spectroscopy.The main reaction products including CO,CO2,NO,HONO and H2O were detected.A small amount of N2O was found only at longer reaction times when NO2 consumption was complete.These product molecules were formed in consecutive reactions from several reaction channels.From the yields of CO and CO2,branching ratios were determined and their kinetic mec hanism was discussed.

对二氧环己酮与丙交酯共聚反应的~1H-NMR分析

由对二氧环己酮(PDO)和丙交酯(LA)单体,在不同温度下合成了PDO-co-LA共聚物,采用核磁共振(1H-NMR)研究了共聚反应动力学和共聚物分子链结构,提出了一种链段平均序列长度的计算方法。结果显示,丙交酯在共聚反应中的聚合能力要比对二氧环己酮强;实验条件下LA/PDO投料物质的量比为2/3时,共聚物中PDO与LA的物质的量比接近1/1,两种单体的链段以二单元组和三单元组为主。共聚反应中单体转化率和链段平均序列长度的计算结果具有一致性,表明基于1H-NMR谱对PDO-co-LA共聚反应的分析是合理的。

LiBr溶液从低浓度到高浓度的分子动力学模拟(英文)

在 L i Br与水的物质量比分别为 1∶ 64、1∶ 32、1∶ 16、1∶ 8、1∶ 4和 1∶ 3的情况下 ,对 L i Br溶液从低温到高温的分子动力学模拟进行了研究。随浓度增加 ,锂离子的水合数量呈减少趋势但同时又从 L i+- Br-接触离子对的数量增加中得到补偿 ,而 L i离子的第一配位壳层的配位数量保持不变。在高浓度 Li Br溶液中 ,Br- O之间的距离有所增加 ,Br-- O的径向分布的形状更趋于非对称 ,从而很好地确定了 Br离子水合壳层 L i+- Br-接触离子对可以在更稀的溶液中产生 ,但随浓度增加而增加。L i+- Br-距离明显短于溶液中 Li离子与 Br离子的离子半径之和 ,也短于 L i Br晶体中两者离子半径之和。高浓度溶液中水分子的结构几乎被破坏 ,水分子间的氢键明显增加 ,但没有消失。对 L i+。

BR-D96N薄膜共线全息图像存储实验研究

利用一种生物光致变色材料—基因突变菌紫质BR-D96N薄膜的光致变色特性,实现了可擦写式共线全息图像存储实验.对于光密度为3.0的BR-D96N薄膜,在700mW/cm2的记录光强下(波长为632.8nm,物光、参考光光强比为约1∶1.2),全息图建立的最佳曝光时间约为3s,最佳再现光强约为50mW/cm2,全息图寿命约为10min.实验表明:共线全息存储技术光学系统简单,系统体积小,受存储环境的影响低,并能够实现高密度存储;同时也实验验证了BR-D96N薄膜具有响应速度快,感光灵敏度高,擦写次数高,稳定耐用,使用方便等优点,可以作为一种较灵敏的可擦写共线全息记录介质.

A comparative study of formaldehyde and carbon monoxide complete oxidation on MnO_x-CeO_2 catalysts

MnOx-CeO2 composite catalysts were prepared by a coprecipitation method and tested for formaldehyde （HCHO） and carbon monoxide （CO） oxidation. X-ray photon spectroscopy （XPS） results indicated that the average oxidation state of surface Mn species in CeMn composite catalyst was higher compared to the pure MnOx. The enhancement of reactivity for HCHO oxidation was due to the activation of the lattice oxygen species in MnOx by the addition of CeO2, which was confirmed by the H2 temperature programmed reduction （HE-TPR） results. The remarkable enhancement of reactivity for CO oxidation by the addition of CeO2 was due to the active oxygen species generated on the CeO2 surface which directly participated in the reaction.