Aqueous calcium-ion batteries (ACIBs) are a prospective solution for electrochemical energy storage. The scarcity of cathode materials with high capacity and long cycling lifespan making CIBs' development still in infancy. Vanadium-based compounds have long been considered promising cathode materials due to their low cost, abundance and high theoretical capacity. However, the low conductivity of vanadium-based materials and the lattice volume expansion during charging and discharging processes have been limiting their development and potential applications. Herein, to tackle these fundamental challenges, we designed and synthesized core-shell calcium vanadate cathode nanoparticles that feature rich oxygen defects and carbon encapsulation (denoted as d-CaV2O5-X@C). Compared with the pure phase vanadium trioxide without calcium ions, calcium vanadate materials incorporating calcium ions exhibit enriched defect structures that provide additional active sites, thereby enhancing the reaction kinetics. The further carbon encapsulation protects of structural integrity and increases conductivity. The d-CaV2O5-X@C cathode material exhibits a high specific capacity of 188.4 mAh center dot g- 1 at a current density of 200 mA center dot g- 1 and long cycle stability with 96.6 mAh center dot g- 1 retention after 4500 cycles at a current density of 5000 mA center dot g- 1 for aqueous calcium ion storage. This work provides a novel design approach for the advancement of cathode materials for advanced CIBs.

This study examined the effects of Cr and N contents on the composition, corrosion resistance, and electrical conductivity of the passive film formed on stainless steel bipolar plates. The results revealed that increased Cr and N contents facilitated the formation of a passive film enriched with Cr2O3 and CrN, resulting in an elevated Cr/Fe ratio within the film from 0.88 to 1.59. This compact passive film effectively mitigated attack of F- and enhanced electron transport, thereby significantly improving both the corrosion resistance and electrical conductivity of stainless steel with higher Cr and N contents. The study underscored the considerable potential of high-nitrogen stainless steel to improve both the corrosion resistance and electrical conductivity of bipolar plates.

Mesoporous molecular sieve-supported metals have been widely investigated as catalysts for the removal of tetracycline (TC) from water via a "preconcentration-activation-degradation" catalytic system. However, the design and construction of bimetallic catalysts supported on MCM-41 for TC degradation remains a challeng. In this study, highly dispersed Al-Fe3N species within MCM-41(Al-Fe3N/Al-MCM-41) was successfully prepared, where Al originates from Al-MCM-41 subjected to high-temperature dealumination. In the presence of Al-Fe3N/Al-MCM-41 and PDS, 98.5% of TC was efficiently degraded within 60 min. The corresponding reaction rate constant (0.07262 min-1) was 2.92 times that of Fe3N/MCM-41 (0.02486 min-1). The excellent degradation performance is attributed to the enhanced electron cloud density of Fe induced by Al doping, thereby enhancing the activation efficiency of peroxydisulfate (PDS). At the same time, micro-mesoporous structure in Al-Fe3N/Al-MCM-41 is beneficial to preconcentration of target contaminants for the enhancement of degradation efficiency. In addition, the disinfection performance of Al-Fe3N/Al-MCM-41 system against antibiotic-resistant bacteria and its device-level application were explored. This work provides a novel strategy to fabricate MCM-41 with doping Fe3N species for the water treatment. This strategy provides a new perspective for the rational utilization of Al atoms via high-temperature dealumination method.

Manipulating the intrinsic activity of heterogeneous catalysts at the atomic level is an effective strategy to improve their electrocatalytic performances but remains a great challenge. Herein, we synthesized Ni3+-rich, Ru-doped NiO nanoparticles (Ru-NiO) through a two-step thermal treatment method. As an OER catalyst, the obtained Ru-NiO exhibited a low overpotential of 220 mV at a current density of 10 mA cm-2 and a Tafel slope of 78 mV dec-1 in alkaline media, outperforming NiO-based electrocatalysts prepared via the conventional sol-gel synthesis method and conventional calcination synthesis method. Employing this strategy, the introduction of trace amounts of Ru atoms in the NiO lattice, leading to lattice strain and electron redistribution, results in superior OER activity. Our results further illustrate that the Ru-O-Ni bonds in the precursor play a vital role in this strategy for the formation of Ru-NiO nanoparticles with lattice strain. At the same time, density functional theory (DFT) results further confirmed that the Ru-NiO nanoparticles have a low d-band center caused by the lattice strain effect to improve the adsorption energy of oxygen-containing intermediates, ultimately accelerating OER kinetics. Thus, this work provides a new pathway for the design of NiO-based OER catalysts.

MoO2 is an environmentally friendly electrocatalyst for overall water splitting. Due to weak adsorption towards intermediate products, such as adsorbed H(H*) in hydrogen evolution reaction (HER) and different oxygen species (*OH, *O, *OOH) in oxygen evolution reaction (OER), the activity of MoO2 requires further improvement. Elevation of O 2p orbital and d band center in MoO2 can enhance its adsorption towards above intermediate products. To achieve this goal, Co is doped in MoO2.Obtained Co-MoO2 only requires89 and 253 mV to gain 10 mA·cm-2current in HER and OER. Excellent photothermal effect of Co-MoO2 facilitates thermal harvesting from sun light. Under solar irradiation, temperature of Co-MoO2 enhances, which improves overall water splitting performance greatly. Besides temperature increasing, light irradiation also induces structural change and raises d band center. This also decreases water splitting voltage. In solar irradiation induced overall water splitting, Co-MoO2 also shows good stability.

Superhydrophobic surfaces with expanded wetting behaviors, like tunable adhesion, hybrid surface hydrophobicity and smart hydrophobic switching have attracted increasing attention due to their broad applications. Herein, the construction methods, mechanisms and advanced applications of special superhydrophobicity are reviewed, and hydro/superhydrophobic modifications are categorized and discussed based on their surface chemistry, and topographic design. The formation and maintenance of special superhydrophobicity in the metastable state are also examined and explored. In addition, particular attention is paid to the use of special wettability in various applications, such as membrane distillation, droplet-based electricity generators and anti-fogging surfaces. Finally, the challenges for practical applications and future research directions are discussed.

设计了一种基于低相干光干涉的相位成像实验系统,系统主要包括低相干光光源、光纤迈克尔逊干涉仪和光谱仪.由光谱仪采集探测光和参考光的干涉光谱,对其进行傅里叶变换得到卷绕相位,分别用数值解卷绕、合成波长法及干涉光谱逼近法进行解卷绕.对分辨率板和阶差规进行了相位成像,对比了数值解卷绕、合成波长法及干涉光谱逼近法的优缺点.实验结果显示,数值解卷绕和干涉光谱逼近法具有较高分辨率,干涉光谱逼近法适用于较大测量范围的相位解调.

: Sulfur hexafluoride (SF 6 ) is widely used in the power industry because of its excellent insulation and arc extinguishing performance. However, the high greenhouse effect of this material is being restricted by many countries around the world, thereby discouraging its usage. As a potential alternative to SF 6 , the compatibility of C 5 F 10 O with conductive copper materials used in electrical equipment is of great significance in ensuring the safe and stable operation of environmentally friendly gas-insulated equipment. In this paper, the interaction among C 5 F 10 O/N 2 , C 5 F 10 O/air gas mixture, and copper was studied via experiments and simulations. When the C 5 F 10 O/N 2 (or air) gas mixture comes in contact with copper at the gas–solid interface, a small portion of C 5 F 10 O is decomposed to form C 3 F 6 (or C 3 F 6 and C 3 F 6 O) at high temperatures. Meanwhile, at low temperatures (120 ◦ C), the C 5 F 10 O/air gas mixture becomes more compatible with copper than with the C 5 F 10 O/N 2 gas mixture. When the experiment temperatures range between 170 ◦ C and 220 ◦ C, the compatibility of the C 5 F 10 O/air gas mixture with copper is significantly inferior to its compatibility with copper. Under high temperatures, the C 5 F 10 O/air gas mixture shows severe corrosion on the copper surface due to the presence of O 2 , forms a thick cubic grain, and emits irritating gases. The simulations show that the carbonyl group in C 5 F 10 O is chemically active and can be easily adsorbed on the copper surface. An anti-corrosion treatment must be performed on copper materials in manufacturing equipment. The findings provide an important reference for the application of C 5 F 10 O gas mixture. molecular adsorption C 5 F 10 O 13 nanocluster reaction. F atom on the α -position carbon atom of the C 5 F 10 O molecule oxygen atom carbonyl group have chemical activity

Through the integration of Zn-Co3O4 and Zn-air batteries at the cell level, a hybrid battery was assembled, which possessed a higher voltage and power density than a common Zn-air battery. In this hybrid battery, the cathode material is composed of oxygen-vacancy-rich Co3O4-x and N, S-co-doped carbon derived from a metal-organic framework; a Zn plate acts as the anode. With a current of 1 A g-1, the specific capacity of the cathode material achieves 144 mA h g-1. A four-electron process dominates the oxygen reduction reaction of the cathode material with a half wave potential of 0.78 V. In the oxygen evolution reaction, the η10 potential of the cathode material is merely 365 mV. When discharged at 1 mA cm-2, the hybrid Zn battery shows two discharge plateaus at 1.75 V and 1.11 V. Its specific capacity and energy density reach 711 mA h g-1 and 810 W h kg-1, respectively. This battery also inherits superior power density from the Zn-Co3O4 battery. Its peak power density occurs at 43.6 mW cm-2, and this value is obviously higher than that of the Zn-air battery built from the same cathode material. The hybrid battery also exhibits excellent stability with a capacity and charge-discharge voltage that are well maintained after long time periods. This study integrates two distinct batteries into one power source to develop a hybrid Zn battery, which possesses high voltage, specific capacity and superior power and energy densities.

Capacitive deionization technology is an efficient method for brackish water desalination, in which the pseudocapacitive material plays a vital role in determining the desalination performance of the electrode directly. Compared with a traditional double-layer capacitance deionization electrode, a mixed capacitive deionization electrode possesses obvious advantages, because it integrates pseudocapacitance and double-layer capacitance together. A brand-new mixed capacitive deionization electrode is fabricated by co-deposition of P2Mo18O626- and polypyrrole on a 3D exfoliated graphite matrix using an electrochemical technique. In this electrode, composite particles composed of P2Mo18O626- and polypyrrole distribute evenly on the 3D exfoliated graphite matrix. At 1 A g-1 current, the specific capacitance of this electrode is 156.2 mA h g-1. Its rate capability is also promising with more than 76.5% of the capacitance being retained when the current increases to 20 A g-1. At 1.2 V voltage, its desalination capacity and rate reach 17.8 mg g-1 and 1.12 mg g-1 min-1 in 600 mg L-1 NaCl. This satisfactory desalination performance is attributed to the unique electrochemical properties of P2Mo18O623- and polypyrrole and the binder free character of this electrode. Even after 100 cycles, its desalination ability does not decay, which confirms its excellent stability. This work confirms the prospects for polyoxometalate based electrodes in brackish water desalination.

A new cadmium metal-organic framework [Cd(NIPA)(CH3CH2OH)(3)] (NIPA = 5-nitroisophthalic acid) has been assembled and served as precursor to fabricate nanoporous nitrogen doped carbon material via carbonization process under 900 degrees C (NC900). The obtained NC900 shows high capacitance (367 F g(-1) at 1 A/g), good cycling life (95% of initial capacitance after 3000 cycles). Moreover, NC900//NC900 supercapacitor device is assembled and shows energy density of 6.3 Wh kg(-1) with a current density of 1 A/g and the capacitance retention maintains 65% at 0.5 A g(-1) after 3000 cycles). The results obtained provide a facile way to prepare carbon material (MOF is used as precursor) for energy-storage devices. For the first time, the heteroatom doped nanoporous carbon material based on a new Cd MOF is served as supercapacitor materials. (C) 2020 Elsevier Ltd. All rights reserved.

Magnetomotive optical coherence tomography (MMOCT) is a promising imaging method for noninvasive three-dimensional tracking of magnetic nanoparticle (MNP) motions in target tissues or organs. The external B-field is the driving force that provides MMOCT contrast. However, B-field modulation also introduces modulation noise, thereby decreasing the quality of the MMOCT image. In this paper, a common-path-based device is designed for modulation noise reduction. The device is capable of adjusting interference distance, reference light intensity, and imaging position (X-Y translation). The sensitivity of the MMOCT is increased by ∼20 times with the new device. Using the proposed device, the distribution of MNPs injected in zebrafish was imaged.

建立了一种非接触光声成像系统,该系统用光纤迈克尔逊干涉仪检测超声波导致的样品表面振动.为了消除外界的干扰,使用多重触发使干涉仪工作于最大灵敏度状态,用该系统对光学分辨率板及小鼠耳朵血管进行了非接触光声成像.实验结果表明,该系统具有高灵敏度和非接触的优点,有助于学生了解、掌握光声成像及干涉测量的技术.

建立了一种基于谱域光学相干层析的表面形貌成像实验系统,该实验系统可以实现纳米精度及微米精度的表面形貌成像.系统主要包括低相干光光源、光纤迈克尔逊干涉仪、光谱仪.由光谱仪采集探测光和参考光的干涉光谱,经过傅里叶变换得到幅度谱和相位谱,分别得到纳米级及微米级精度的深度信息.用光学分辨率板和硬币对本系统进行了实验验证,该系统用于纳米级及微米级精度成像时,其精度分别为0.075 nm和5.1μm.

Optical refractive index (ORI) is one of the most important physical parameters for the description of the characterization of optical material,and measurement of ORI is crucial for research and industrial applications.We demonstrate establish an experimental system for three-dimensional imaging of ORI by combining low-coherence interferometry in frequency domain and computed tomography.The experimental system mainly consists of a broadband light source,an optical fiber Michelson interferometer and a spectrometer.The interference spectra of the detection light and reference light are acquired with the spectrometer,and the parallel projection of optical refractive index is calculated from the acquired interference spectra by Fourier transformation.The three-dimensional distribution of refractive index is reconstructed by the filtered back-projection algorithm.We experimentally demonstrate this system by cross-sectional imaging of a plastic tube.The present system is suitable for three-dimensional imaging of samples with homogeneous and inhomogeneous ORI distributions,and the ORI sensitivity is 0.01.The imaging system is suitable to be used as a synthetic and designing experiment in physical experiment teaching for undergraduates.

Microscopic surface topography plays an important role in studying the functions and properties of materials. Microscopic surface topography measurement has been widely used in many areas, such as machine manufacturing, electronic industry and biotechnology. Optical interferometry is a popular technique for surface topography measurement with an axial resolution up to nanoscale. However, the application of this technique is hampered by phase wrapping, which results in a limited measurement range for this technique. Various digital algorithms for phase unwrapping have been proposed based on the phase continuity between two adjacent points. However, several significant challenges still exist in recovering correct phase with this technique. Optical coherence tomography (OCT) is a non-contact three-dimensional imaging modality with high spatial resolution, and it has been widely used for imaging the biological tissues. In this paper, we demonstrate a method for nanoscale imaging of surface topography by using common-path phase-resolved spectral domain OCT to reduce the influence of phase wrapping. The system includes a superluminescent diode with a central wavelength of 1310 nm and a spectral bandwidth of 62 nm, an optical fiber circulator, a home-made spectrometer, and a reference arm and a sample arm in common-path arrangement. The reference mirror and the sample under investigation are positioned on a same stage in order to further reduce the influence of ambient vibration. The phase difference between two adjacent points is calculated by performing Fourier transform on the measured interferometric spectrum. The phase difference distribution of the surface is obtained first. And then, the surface topography of the sample is constructed by integrating the phase difference distribution. In the traditional methods, phase wrapping occurs if the absolute value of the measured phase is greater than . However, in the present method, phase wrapping occurs if the absolute value of the phase difference between two adjacent points is greater than . The maximal detectable absolute value of the phase difference between two adjacent points increases from for the traditional methods to 2 for the present method. The experimental results indicate that the present system has a high stability and the maximum fluctuation is less than 0.3 nm without averaging. The accuracy of the system is tested with a piezo stage, and the mean absolute deviation of the measured results is 0.62 nm. The performance of the present system is also demonstrated by the surface topography imaging of an optical resolution test target and a roughness comparison specimen. The experimental result shows that the present system is a potential powerful tool for surface topography imaging with an axial resolution better than 1 nm.

Abstract Amino group-functionalized Fe3O4 is loaded on a coordination complex-modified polyoxometalate nanoparticle. In this composite material, Fe3O4 and coordination complex-modified polyoxometalate are connected with intense hydrogen bonds as suggested by FTIR. This composite material exhibits excellent methylene blue (MB) adsorption, with adsorption capacity of 175.5 mg g−1. It also possesses selective separation ability between cationic and anionic dye molecules. In binary solution of MB and methyl orange (MO), MB adsorption efficiency reaches 75%, but it exhibits almost no effect on the adsorption of methyl orange. The saturation magnetization value of this composite material is 18.89 emu g−1, allowing magnetic separation, which facilitates the recycle and reuse of this composite adsorbent.

We demonstrate a system for thickness measurement using echo technique based on Labview. The pulsed sound wave is excited by hitting the surface of the object with a small metal ball. The sound wave is ac-quired by a sound detector. The interval of the sound wave transmission in the object is calculated by FFT. This system is validated by experiments. This system is suitable for experimental teaching for undergraduates in physics.

A system for measuring micro-angle was built with electric speckle pattern interferome-try (ESPI) .The system included an optical imaging system and a simple and effective algorithm for reducing speckle noise and calculating the width of interference stripes according to the characteristics of the speckle noise .Interference stripes were integrated along different directions ,and their modula-tions were calculated .The width of the interference stripes was equal to the period of the projection when a modulation reached its maximum value .The experimental result indicated that the minimum angle was 10-5 rad using this system .