Hexagram-like CoS-MoS<Subscript>2</Subscript> composites with enhanced activity for hydrogen evolution reaction

Hexagram-like CoS-MoS₂ composites were prepared on indium tin oxide (ITO) conductive glasses via cyclic voltammetry electrodeposition using Co(NO₃)₂ and (NH₄)₂MoS₂ as precursors and tested for application in hydrogen evolution reaction (HER). The structure of CoS-MoS₂ composites was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectrum (XPS). Electrochemical characterizations indicate that CoS-MoS₂ composites exhibit more excellent catalytic activity and stability than MoS₂. Compared with pure MoS₂, the hexagram-like CoS-MoS₂ composites with increased specific surface area improved the density of exposed active sites, and the Co binding S edges in CoS-MoS₂ composites promote the number of highly catalytic edge sites and decreased the binding energy △G _H. Moreover, the effects of different substrates on the CoS-MoS₂ composites were also investigated. Our further understanding of this highly active hydrogen evolution catalyst can facilitate the development of economical electrochemical hydrogen production systems.     

Efficient visible-light photocatalysts by constructing dispersive energy band with anisotropic p and s-p hybridization states

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The analysis study on nonlinear iterative methods for inverse problems

In this paper, the nonlinear iterative methods, which are different from the classical algorithms, to solve inverse problems are presented. Our methods by denoting some parameters and some properties of the algorithm in both noise and noiseless cases are studied. Finally, the convergence of the sequence generated by the algorithm without noise is discussed.     

iGreen: green scheduling for peak demand minimization

Home owners are typically charged differently when they consume power at different periods within a day. Specifically, they are charged more during peak periods. Thus, in this paper, we explore how scheduling algorithms can be designed to minimize the peak energy consumption of a group of homes served by the same substation. We assume that a set of demand/response switches are deployed at a group of homes to control the activities of different appliances such as air conditioners or electric water heaters in these homes. Given a set of appliances, each appliance is associated with its instantaneous power consumption and duration, our objective is to decide when to activate different appliances in order to reduce the peak power consumption. This scheduling problem is shown to be NP-Hard. To tackle this problem, we propose a set of appliance scheduling algorithms under both offline and online settings. For the offline setting, we propose a constant ratio approximation algorithm (with approximation ratio \(\frac{1+\sqrt{5}}{2}+1\)). For the online setting, we adopt a greedy algorithm whose competitive ratio is also bounded. We conduct extensive simulations using real-life appliance energy consumption data trace to evaluate the performance of our algorithms. Extensive evaluations show that our schedulers significantly reduce the peak demand when compared with several existing heuristics.     

Universal inequalities on complete noncompact smooth metric measure spaces

In this paper, we obtain universal inequalities for the eigenvalues of the Dirichlet problem and clamped plate problem of drifting Laplacian on (\(n+1\))-dimensional (\(n\ge 4\)) complete noncompact simply connected smooth metric measure spaces which meet some conditions of the sectional curvature and radial weighted Ricci curvature.     

Fractional Order Systems Time-Optimal Control and Its Application

This paper deals with the time-optimal control problem for a class of fractional order systems. An analytic solution of the time-optimal problem is proposed, and the optimal transfer route is provided. Considering it is usually adopted in the discrete situation for actual control system, the sampling date may induce chattering phenomenon, an alternative sub-optimal solution is constructed. Additionally, the special and meaningful application of fractional order tracking differentiator is introduced to explain our main results. The effectiveness and advantages of the proposed method have been illustrated by numerical examples.     

Nonhomogeneous Hemivariational Inequalities with Indefinite Potential and Robin Boundary Condition

We consider a nonlinear, nonhomogeneous Robin problem with an indefinite potential and a nonsmooth primitive in the reaction term. In fact, the right-hand side of the problem (reaction term) is the Clarke subdifferential of a locally Lipschitz integrand. We assume that asymptotically this term is resonant with respect the principal eigenvalue (from the left). We prove the existence of three nontrivial smooth solutions, two of constant sign and the third nodal. We also show the existence of extremal constant sign solutions. The tools come from nonsmooth critical point theory and from global optimization (direct method).     

A Two-Equation Model for Heat Conduction in Porous Media (II: Application)

The formulism of a two-equation model for heat conduction in porous media, developed in a previous paper, is applied to the case of steady state one-dimensional heat transfer in a porous medium that is made up of geometrically similar units of similar size and of ordered spatial distribution. For this case study, the model-predicted locally volume-averaged temperature distributions for the solid and the fluid phase are compared to a numerical solution at a microscopic level, showing excellent agreement.     

A transverse crack tip field in bimaterial

The asymptotic field near an interface crack tip is analyzed with the fully nonlinear theory. By dividing the crack tip field into narrowing sectors and an expanding sector, the asymptotic equations for the crack tip field are derived and solved. The singular characters of stress and strain near the crack tip are revealed.     

螺旋槽干气密封微尺度流动场的近似计算及其参数优化

应用PH线性化方法、迭代法,近似求解了螺旋槽内稳态微尺度流动场的非线性雷诺方程,求得了气体动压和速度分布的解析解。继而利用多目标优化方法构建了气膜刚度与泄漏量之比的协调函数,并对该目标函数进行了近似求解,获得了最佳的螺旋槽几何参数值。