摘要：通过电催化氧化葡萄糖等可再生生物质生产高附加值化学品为实现碳中和目标提供了一条有效途径.目前用于电催化生物质氧化反应的电催化剂主要分为贵金属基催化剂和非贵金属基催化剂.对于贵金属基电催化剂,文献报道了铂基催化剂的氧化态随电势变化,进而调控电催化葡萄糖氧化的活性和选择性.对于非贵金属基催化剂,钴基和镍基氧化物和氢氧化物被广泛应用于电催化生物质氧化反应,但铜基催化剂直到最近才引起关注.最近,金属铜、氧化亚铜和氢氧化铜在内的铜基材料被证实是一类有应用前景的电催化生物质氧化催化剂,但在电化学条件下的真实活性位结构仍难以鉴定.本文针对电催化葡萄糖等生物质平台分子的氧化反应,证明了氧化铜的催化活性相随电压升高从氢氧化铜演变为羟基氧化铜,阐明了结构和反应活性及选择性的构效关系,该工作加深了对铜基催化剂活性位动态重构的理解,有助于电催化生物质转化的催化剂理性设计,促进可再生资源利用和碳中和目标的实现.

摘要：We report an economical approach for the fabrication of laser-produced graphene(LPG)electrodes,which results in an improved electrochemical *** polymer was used as the starting material for LPG synthesis and was irradiated under ambient conditions with a CO_(2) *** prepared LPG samples were characterized by Raman spectroscopy and FTIR,which validated the formation of multilayer graphene containing sp2 hybridized C=C ***-SEM revealed three-dimensional(3D)sheet-like structures,while HR-TEM images showed lattice planes with an interplanar spacing of approximately 0.33 nm,corres-ponding to the(002)plane of *** electrochemical performance showed a remarkable areal specific capacitance(CA)of 51 mF cm^(−2)(170 F g^(-1))at 1 mA cm^(−2)(3.3 A g^(-1))in a three-electrode configuration with 1 mol L^(−1) KOH as the aqueous *** LPG electrodes produced an energy density of~3.5μWh cm^(−2) and a power density of~350μW cm^(−2),demonstrating signific-ant energy storage *** also had an excellent cycling stability,retaining 87%of their specific capacitance after 3000 cycles at 1 mA/cm^(2).A symmetric supercapacitor fabricated with LPG electrodes and the 1 mol L^(−1) KOH electrolyte had a specific capacit-ance of 23 mF cm^(−2) and showed excellent retention after 10000 cycles,showing LPG’s potential for use in supercapacitors.

摘要：MXene is a variety of new two-dimensional(2D)materials with early transition metal carbides,nitrides,and *** chemical studies have been carried out on the geometries,electronic structures,stability and catalytic properties of a non-noble metal single-atom catalyst(SAC)with single Co atom anchored on MXene materials of Mo_(2)CS_(2).The Co adatom anchored on top of the Mo atom of this MXene is found to be rather stable,and this SAC is appropriate for CO *** charge transfers from the surface to the adsorbed CO and O2 play a significant role in the activation of these molecules on Co_(1)/Mo_(2)CS_(2).With this catalyst,the Eley-Rideal(ER),Langmuir-Hinshelwood(LH),and Termolecular Eley-Rideal(TER)mechanisms are explored for CO *** find that,while all the three mechanisms are feasible at low temperature,Co_(1)/Mo_(2)CS_(2) possesses higher catalytic activity for CO oxidation through the TER mechanism that features an intriguing OC(OO)CO intermediate(IM)adsorbed on Co single *** calculated activation energy barriers of the rate-limiting step are 0.67 eV(TER),0.78 eV(LH)and 0.88 eV(ER),*** present study illustrates that it is promising to develop and design low-cost,non-noble metal SACs using MXene types of 2D materials.

摘要：Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and *** electrode materials combing the features of high specific capacitance,excellent rate performance,and outstanding mechanical stability is still a ***,a facile partial sulfurization strategy has been developed to modulate the electronic structure and crystalline texture of cobalt hydroxide nanosheets(denoted as Co(OH)2)at room *** resultant cobalt hydroxysulfide nanosheet(denoted as Co SOH)electrode with abundant low-valence cobalt species and amorphous structure,exhibits a high specific capacitance of 2110 F g^-1at1 A g^-1with an excellent capability retention rate of 92.1%at10 A g^-1,which is much larger than that of Co(OH)2 precursor(916 F g^-1at 1 A g^-1 and 80%retention at 10 A g^-1).Furthermore,the fabricated asymmetric supercapacitor device constructed with Co SOH and active carbon displays a considerable high energy density of 44.9 W h kg^-1at a power density of 400 W kg^-1,and exceptional stability after 8000cycles.

摘要：The global increase in the prevalence of drug-resistant bacteria has necessitated the development of alternative treatments that do not rely on conventional antimicrobial *** bacteriophage-derived lytic enzymes in antibacterial therapy shows promise;however,a thorough comparison and evaluation of their bactericidal efficacy are *** study aimed to compare and investigate the bactericidal activity and spectrum of such lytic enzymes,with the goal of harnessing them for antibacterial ***,we examined the bactericidal activity of spanins,endolysins,and holins derived from 2 Escherichia coli model phages,T1 and *** these,T1-spanin exhibited the highest bactericidal activity against ***,we expressed T1-spanin within bacterial cells and assessed its bactericidal activity.T1-spanin showed potent bactericidal activity against all clinical isolates tested,including bacterial strains of 111 ***,2 Acinetobacter spp.,3 Klebsiella spp.,and 3 Pseudomonas *** contrast,T1 phage-derived endolysin showed bactericidal activity against *** and ***,yet its efficacy against other bacteria was inferior to that of ***,we developed a phage-based technology to introduce the T1-spanin gene into target *** synthesized non-proliferative phage exhibited strong antibacterial activity against the targeted *** potent bactericidal activity exhibited by spanins,combined with the novel phage synthetic technology,holds promise for the development of innovative antimicrobial agents.

摘要：对高速边界层转捩与湍流的理解、建模与控制不但具有广泛的学术兴趣,而且对高速飞行器的设计与节能有至关重要的意义,因为转捩和湍流会急剧增加壁面摩阻和热流.根据Morkovin假设,高速流动具有一些与不可压缩流动本质上相似的特征,但另一方面,由于存在热力学过程、激波、高焓效应等多物理场耦合,与不可压缩流动也有显著区别.本文综述了高速边界层转捩与湍流的物理和建模方面的最新研究进展,其中较大部分内容为湍流研究.为了物理过程描述的完整性,我们首先简要综述了高速流动转捩,主要关注气动加热原理和推迟转捩的被动控制策略.随后,我们总结了近期在湍流平均流向速度和温度的标度率方面的一些令人鼓舞的发现,这些标度率能够用于构建一系列新颖的壁面模型以提高模式精度.此外,作为湍流建模的基础之一,我们还总结了湍流结构方面的研究,尤其关注边界层对数区含能运动的标度率与建模.另外,我们综述了各种用于预测壁湍流的线性模型.尽管湍流通常被认为是高度非线性的,这些线性模型在过去二十年的研究中取得了较大的成功.最后,我们对综述进行总结,并简要展望未来研究.

摘要：由于环境相容性好、分子结构可定制和有机物资源丰富等优势,水系锌-有机物电池(AZOBs)成为构建新一代大规模储能系统的关键技术.然而,电导率差、有机物溶解和单一活性基团等问题严重限制了有机物正极材料的倍率性能、稳定性和比容量.因此,具备多氧化还原中心和稳定骨架的有机物正极材料对于实现高性能有机物正极材料至关重要.这些多官能团有机物可协同作用并激发基于多电子转移的氧化还原反应,进而促进H^(+)/Zn^(2+)共嵌以显著提升电池性能.本文探索了多官能团有机物电极的分子结构与其氧化还原反应机理之间的构效关系.本文综述了多官能团有机正极材料在提高氧化还原电位、比容量、动力学以及稳定性等方面面临的挑战和解决策略,为进一步开发先进AZOBs的关键正极材料提供了重要基础.

摘要：过渡金属氧化物具有丰富的功能性,但其错综复杂的内部自由度对相图绘制和结构设计提出了挑战.本文中,我们引入了描述相图物理起源的轨道能级序(ELO),并通过对La_(0.67)Sr_(0.33)MnO_(3)(LSMO)氧化物的研究证明了其在相图预测中的有效性.结合DFT计算和实验,我们构建了氧含量和应变关联的LSMO相图,结果表明LSMO结构稳定性与ELO密切相关.据此发现了一种由ELO演化而产生的四倍氧有序相.最后,我们提出了描述轨道分裂程度的轨道弹性定律,阐明了ELO演化的起源,助力功能氧化物的设计.这项研究拓宽了材料科学领域的性能调控手段,并为从轨道角度预测相图提供了思路.

摘要：理解铁电材料畴结构在低温条件下的翻转行为,对于铁电物理以及其在宽温域的应用都非常重要;然而,目前在低温条件下直接观测介观尺度下的畴翻转仍然面临着巨大的挑战.本论文利用铁酸铋(BiFeO_(3))作为模型来研究3.6–260 K温度范围内的铁电畴翻转行为.菱形相的BiFeO_(3)在温度为130 K时观测到了明显的铁电保持失效现象;这是因为BiFeO_(3)在130 K附近有较大的热释电系数,从而使其升温到该温度附近时释放了大量的热释电电荷,进而产生较强的退极化场,导致铁电极化翻转.另外,本论文还发现通过纳米尺度设计相界可以有效地抑制铁电保持失效.本研究为变温条件下,尤其是低温温域,研究铁电翻转提供了实验范式.