High-entropy transition metal chalcogenides as electrocatalysts for renewable energy conversion

High-entropy transition metal chalcogenides (HE-TMCs) are advantageous in electrocatalytic applications compared to other entropy-stabilized systems owing to the greater orbital extension and energetic match of p-orbitals in chalcogenides with d-orbitals of the transition metals providing additional space to tailor their electronic structure. The high-configurational entropy of HE-TMCs leads to stabilization of cubic rock salt, wurtzite-type and hexagonally packed 2D structures. Due to the multi-element nature of HE-TMCs, the synergy among different elements results in tunable d- and p-band positions. As a consequence, the adsorption energies of electrocatalytic reaction intermediates can be tailored to enhance catalytic performance in water splitting and CO₂ reduction. Furthermore, the entropy-stabilized disordered microstructural state of the material endows HE-TMCs with improved corrosion resistance. Despite recent advances in HE-TMC electrocatalysis, challenges such as identification and synthesis of efficient HE-TMCs as well as the identification of catalytically active sites and reaction mechanisms on HE-TMCs remain to be investigated.     

Free volume,molecular grains,self-organisation,and anisotropic entropy: machining materials

ABSTRACT

In this article, the relationship between molecular architecture and the formation of twist-bend phases is reviewed under the context of shape dependency. We conclude that the twist-bend phase is a universal phenomenon, which occurs in a wide variety of materials, for dimers through to main chain polymers. In the process, the chemical information on molecular design is effectively lost or irrelevant, and molecular topology takes precedence over electrostatic interactions in mesophase formation. As a consequence of this macro-scale material, engineering by shape alone becomes a possibility, potentially more phases may be realised, and entropy is anisotropic.     

基于熵权模糊综合评价模型的股票内在价值研究

针对股票内在价值评判方法中指标权重设定的主观性缺陷,提出在利用熵权确定各指标权重的基础上,运用模糊综合评价方法对股票会计信息的综合指标进行模糊处理,为投资者投资股票提供一种新的参考;并通过"一带一路"概念股中的五支工程基建行业类股票进行模拟实证分析,证明将会计信息进行相关量化处理,能够为投资者提供较为客观的选择,同时基于熵权的模糊综合评价模型在股票内在价值评价中具有可行性.     

Entropy Unilateral Solution for Some Noncoercive Nonlinear Parabolic Problems Via a Sequence of Penalized Equations

We give an existence result of the obstacle parabolic equations(b(x,u))/(t)-div(a(x,t,u,▽u))+div(φ(x,t,u))=f in Q_T,where b(x,u) is bounded function of u,the term-div(a(x,t,u,▽u)) is a Leray-Lions type operator and the function φ is a nonlinear lower order and satisfy only the growth condition.The second term f belongs to L~1(Q_T).The proof of an existence solution is based on the penalization methods.     

Bounds for Shannon and Zipf‐Mandelbrot entropies

Shannon and Zipf‐Mandelbrot entropies have many applications in many applied sciences, for example, in information theory, biology and economics, etc. In this paper, we consider two refinements of the well‐know Jensen inequality and obtain different bounds for Shannon and Zipf‐Mandelbrot entropies. First of all, we use some convex functions and manipulate the weights and domain of the functions and deduce results for Shannon entropy. We also discuss their particular cases. By using Zipf‐Mandelbrot laws for different parameters in Shannon entropies results, we obtain bounds for Zipf‐Mandelbrot entropy. The idea used in this paper for obtaining the results may stimulate further research in this area, particularly for Zipf‐Mandelbrot entropy.     

原子系统中偶极-偶极相互作用对量子存储支撑熵不确定度的调控研究

本文研究了Markovian过程和non-Markovian过程两种情况下,原子系统中偶极-偶极(D-D)相互作用和失谐量对两原子系统量子存储支撑(QMA)熵不确定度的调控作用.与Markovian过程相比,在non-Markovian过程中,由于库环境的记忆效应使得具有D-D相互作用的两原子系统QMA熵不确定度的演化行为呈现出振荡上升现象,且熵不确定度的上升趋势得到减缓,从而抑制了由系统量子噪声引起的退相干效应.此外,D-D相互作用对两原子系统QMA熵不确定度具有显著的调控能力,且D-D相互作用比失谐量的调控能力更强.     

基于时频分帧能量熵的陶瓷制品敲击声波信号特征识别

针对现有陶瓷制品敲击声波信号特征提取方法中提取的特征代表性降低的问题,该文提出结合最大重叠离散小波包变换(MODWPT)和时频分帧能量熵的特征提取方法。首先采用MODWPT将信号分解为4层,再对每个节点的子信号分帧后计算各个节点的时频分帧能量熵,然后根据能量分布特征选择了前6个节点的时频分帧能量熵特征,最后构建随机森林分类器完成识别。将该方法和MODWPT时频分段能量熵、MODWPT归一化能量特征两种方法进行比较。实验结果表明,相比MODWPT时频分段能量熵、MODWPT归一化能量两种特征提取方法,MODWPT时频分帧能量熵能提升特征的代表性,具有更优的陶瓷制品敲击声波信号特征识别性能,其识别的F₁值达到了98.46%,相比上述两种方法分别提升F₁值3.22%、1.86%。