A Photoactivated Cu–CeO2 Catalyst with Cu-[O]-Ce Active Species Designed through MOF Crystal Engineering

Fully utilizing solar energy for catalysis requires the integration of conversion mechanisms and therefore delicate design of catalyst structures and active species. Herein, a MOF crystal engineering method was developed to controllably synthesize a copper–ceria catalyst with well-dispersed photoactive Cu-[O]-Ce species. Using the preferential oxidation of CO as a model reaction, the catalyst showed remarkably efficient and stable photoactivated catalysis, which found practical application in feed gas treatment for fuel cell gas supply. The coexistence of photochemistry and thermochemistry effects contributes to the high efficiency. Our results demonstrate a catalyst design approach with atomic or molecular precision and a combinatorial photoactivation strategy for solar energy conversion.     

Origins of Boosted Charge Storage on Heteroatom-Doped Carbons

Although tremendous efforts have been devoted to understanding the origin of boosted charge storage on heteroatom-doped carbons, none of the present studies has shown a whole landscape. Herein, by both experimental evidence and theoretical simulation, it is demonstrated that heteroatom doping not only results in a broadened operating voltage, but also successfully promotes the specific capacitance in aqueous supercapacitors. In particular, the electrolyte cations adsorbed on heteroatom-doped carbon can effectively inhibit hydrogen evolution reaction, a key step of water decomposition during the charging process, which broadens the voltage window of aqueous electrolytes even beyond the thermodynamic limit of water (1.23 V). Furthermore, the reduced adsorption energy of heteroatom-doped carbon consequently leads to more stored cations on the heteroatom-doped carbon surface, thus yielding a boosted charge storage performance.     

Catalytic Systems Based on the Metal Complexes of 1-Alkyl-4-Aza-1-Azoniabicyclo[2.2.2]Octane Bromides

Kinetics and Catalysis - The catalytic activity of supramolecular systems based on the complexes of 1-alkyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide (Alk = CnH2n+ 1, n = 16, 18) with lanthanum...     

On the Development of a Method for Determining the Concentration of Hydrogen in Materials Based on Nuclear Backscattering Spectrometry

Metal hydrides and their alloys are widely used in nuclear power engineering and are regarded as promising hydrogen accumulators. Due to the nature of materials used in reactors, nondestructive methods are required to determine the concentration of hydrogen and its content in hydrides under the influence of a harsh environment. In this paper, a technique based on nuclear backscattering spectrometry is proposed, which allows determination of the hydrogen content in a sample at a depth of up to 100 μm. The profiles of the hydrogen distribution in Al, Mg, Ti, Zr, and their hydrides are measured. Estimation of the radiation damage to the sample is performed using the example of polymer impregnation of the protective coating.     

光寻址电位传感器的正交相位检波检测方法

光寻址电位传感器的幅度检测方法易受噪声干扰,灵敏度差,信噪比和精度低,且受调制光源的影响较大,影响检测结果的准确性.为此提出了一种基于正交相位检波的光寻址电位传感器检测方法.该方法是将光寻址电位传感器的输出光电流信号分别与两路正交信号相乘,通过低通滤波提取直流分量并相除,即可得到光寻址电位传感器的输出信号相位信息.与已有的光寻址电位传感器相位检测方法相比,该方法具有算法复杂度低、实时性高的优点.实验研究了调制光源光强对光寻址电位传感器幅度检测和相位检测的影响,对比分析了光寻址电位传感器的传统幅度检测方法与正交相位检波检测方法对pH检测的灵敏度、线性度及信噪比.结果表明,相比于幅度检测方法,调制光源光强对光寻址电位传感器的相位检测影响更小,在频率为10 kHz,pH的范围为1.68~10.01的情况下,相位检测方法比幅度检测方法测得的灵敏度增加了7 mV/pH,精度提高了14.9 mpH,非线性误差减小了0.003%,均方差减少了0.1051×10^-5,信噪比增加了8.2827 dB.该方法特别适用于弱光下的光寻址电位传感器检测.     

Generalized Ising Model in the Absence of Magnetic Field

Journal of Experimental and Theoretical Physics - The Ising model on an one-dimensional monoatomic equidistant lattice with different exchange interactions between atomic spins at the sites of...     

Cumulant t-Expansion for Strongly Correlated Electrons on a Lattice

Journal of Experimental and Theoretical Physics - A systematic nonperturbative scheme for calculating the ground state energy is adapted for studying systems of strongly correlated electrons on a...     

Spectral Analysis of Universal Conductance Fluctuations

Journal of Experimental and Theoretical Physics - Universal conductance fluctuations are usually observed in the form of aperiodic oscillations in the magnetoresistance of thin wires under...     

Surface Conductivity of the Ytterbium-Doped Topological Kondo-Insulator SmB6

Doklady Physics - The temperature dependence of the conductivity of the topological Kondo-insulator (TKI) Sm1 – xYbxB6 is investigated in the temperature range 2 < T < 300 K for...