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Graphene-confined ultrafast radiant heating for high-loading subnanometer metal cluster catalysts

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National Science Review 2023年第6期10卷 191-199页

作者： Ye-Chuang Han Jun Yi beibei pang Ning Wang Xu-Cheng Li Tao Yao Kostya S.Novoselov Zhong-Qun Tian State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical Engineering Graphene Industry and Engineering Research Institute School of Electronic Science and Engineering Xiamen University Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM) National Synchrotron Radiation Laboratory University of Science and Technology of China Faculty of Environment and Life Beijing University of Technology Institute for Functional Intelligent Materials National University of Singapore

Thermally activated ultrafast diffusion,collision and combination of metal atoms comprise the fundamental processes of synthesizing burgeoning subnanometer metal clusters for diverse ***,so far,no method has allowed the kinetically controllable synthesis of subnanometer metal clusters without compromising metal ***,we have developed,for the first time,a graphene-confined ultrafast radiant heating(GCURH) method for the synthesis of high-loading metal cluster catalysts in microseconds,where the impermeable and flexible graphene acts as a diffusion-constrained nanoreactor for high-temperature *** from graphene-mediated ultrafast and efficient laser-to-thermal conversion,the GCURH method is capable of providing a record-high heating and cooling rate of～109℃/s and a peak temperature above 2000 ℃,and the diffusion of thermally activated atoms is spatially limited within the confinement of the graphene *** a result,due to the kinetics-dominant and diffusion-constrained condition provided by GCURH,subnanometer Co cluster catalysts with high metal loading up to 27.1 wt% have been synthesized by pyrolyzing a Co-based metal-organic framework(MOF)in microseconds,representing one of the highest size-loading combinations and the quickest rate for MOF pyrolysis in the reported *** obtained Co cluster catalyst not only exhibits an extraordinary activity similar to that of most modern multicomponent noble metal counterparts in the electro catalytic oxygen evolution reaction,but is also highly convenient for catalyst recycling and refining due to its single metal *** a novel GCURH technique paves the way for the kinetically regulated,limited diffusion distance of thermally activated atoms,which in turn provides enormous opportunities for the development of sophisticated and environmentally sustainable metal cluster catalysts.

关键词： photothermal conversion ultrafast radiant heating graphene-confined high-loading metal clusters solid catalysts

Surface Oxygen Injection in Tin Disulfide Nanosheets for Efficient CO_(2) Electroreduction to Formate and Syngas

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Nano-Micro Letters 2021年第11期13卷 441-451页

作者： Tao Chen Tong Liu Tao Ding beibei pang Lan Wang Xiaokang Liu Xinyi Shen Sicong Wang Dan Wu Dong Liu Linlin Cao Qiquan Luo Wei Zhang Wenkun Zhu Tao Yao National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029People’s Republic of China State Key Laboratory of Environmentally Friendly Energy Materials School of National Defense Science and TechnologySouthwest University of Science and TechnologyMianyang 621010People’s Republic of China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601People’s Republic of China School of Materials Sun Yat-Sen UniversityGuangzhou 510275People’s Republic of China

Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing ***,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:*** operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic *** synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO**** result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.

关键词： Oxygen injection Tin disulfide CO_(2)electroreduction Formate Syngas

Engineering tantalum nitride for efficient photoelectrochemical water splitting

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Science China Chemistry 2024年第7期67卷 2171-2180页

作者： beibei Zhang Zeyu Fan Yanbo Li Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

Photoelectrochemical(PEC)water splitting is a promising energy conversion strategy for directly converting solar energy into green hydrogen *** an efficient PEC device,finding an efficient photoanode material with a suitable band gap and favorable band-edge positions is *** nitride(Ta_(3)N_(5))meets these fundamental requirements,and its theoretical maximum solar-to-hydrogen(STH)conversion efficiency can reach 15.9%.Consequently,it has been widely applied as a photoanode material for the PEC oxygen evolution reaction(OER).However,severe bulk and interface charge recombination,along with sluggish water oxygen kinetics,seriously limits its STH conversion efficiency for PEC water ***,this feature article briefly reviews recent advances by our research group in improving the STH conversion efficiency of the Ta_(3)N_(5)photoanode using various strategies,including defect engineering,construction of a gradient band structure,interface engineering,and surface modification of self-healing OER *** to now,the obtained half-cell STH efficiency has exceeded 4%,providing a solid foundation for the development of tandem PEC devices for unbiased solar-driven overall water splitting toward practical application.

关键词： Photoelectrochemical water splitting tantalum nitride defect engineering interface engineering oxygen evolution cocatalyst

Toxicity mechanisms of photodegraded polyvinyl chloride nanoplastics on pea seedlings

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Frontiers of Environmental Science & Engineering 2024年第4期18卷 111-124页

作者： Hao Wu beibei He Bocheng Chen An Liu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Nanoplasctics(NPs),which are very small in particle size,exert toxic effect to ***,compared to original NPs,photodegraded NPs would pose higher *** is because their relatively higher specific surface areas and the presence of additives which can more easily *** original NPs and aged NPs affect plant growth has not been widely *** work chose polyvinyl chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by 10.6%–22.5%),stem length(decreased by 2.8%–8.1%),dry weight(decreased by 6.3%–7.1%)and fresh weight(decreased by 6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosynthesis and absorption of nutrients and hence the decrease in chlorophyll and soluble sugar *** to transcriptomic investigation results,the presence of aged PVC-NPs primarily influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway)and phenylpropanoid biosynthesis(downregulated metabolic pathway)of pea *** results provide an in-depth understanding of how NPs influence the growth of plants.

关键词： Nanoplasctics Polyvinyl chloride Toxicity mechanisms Plant growth

Global well-posedness for 2D inhomogeneous asymmetric fluids with large initial data

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Science China Mathematics 2024年第3期67卷 527-556页

作者： Chenyin Qian beibei He Ting Zhang School of Mathematical Sciences Zhejiang Normal UniversityJinhua 321004China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China

In this paper, by using time-weighted global estimates and the Lagrangian approach, we first investigate the global existence and uniqueness of the solution for the 2D inhomogeneous incompressible asymmetric fluids wi... 详细信息

关键词： inhomogeneous asymmetric fluids Littlewood-Paley theory Besov spaces global well-posedness

Effect of Direct Aging on Corrosion Behavior of AlSi10Mg Alloy Fabricated by Laser Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 266-282页

作者： Zhen Zhang Zhanyong Zhao Xiaofeng Li beibei Wang Peikang Bai Shanxi Key Laboratory of Controlled Metal Solidification and Precision Manufacturing School of Materials Science and EngineeringNorth University of ChinaTaiyuan030051China Technical Center Taiyuan Iron and Steel(Group)Co.LtdTaiyuan030003China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Effect of direct aging of 170℃on corrosion behavior of laser powder bed fused AlSi10Mg(LPBF-AlSi10Mg)was studied by microstructure analysis,electrochemical analysis and X-ray photoelectron *** results show that direct aging of 170℃has little effect on melt pool and Si cellular structure,but promotes the precipitation of nano-Si particles and releases the residual *** increasing aging time from 0 to 4 h to 24 h,the corrosion property of the LPBF-AlSi10Mg is deteriorated,which is evidenced by increased corrosion current density and decreased pitting potential and polarization *** increasing the aging time,the thickness of the oxide film formed on surface of the LPBF-AlSi10Mg *** Si content of the oxide film of the sample aging for 4 h is the lowest,9.42 at.%,and it is the highest,18.62 at.%,for the sample aging for 24 *** electrochemical noise analysis reveals that the middle-frequency contribution of the Hilbert spectrum is responsible for the deteriorated corrosion performance,which corresponds to metastable pitting initiated by nano-Si particles.

关键词： Laser powder bed fusion AlSi10Mg Direct aging Corrosion

Active MoS_(2)-based electrode for green ammonia synthesis

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Chinese Journal of Chemical Engineering 2024年第1期65卷 268-275页

作者： Xin Liu Lei Yang Tao Wei Shanping Liu beibei Xiao School of Energy and Power Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Institute Charles Gerhardt Montpellier UMR-5253Universite de MontpellierCNRSENSCMPlace E.Bataillon34095 Montpellier Cedex 05France

Nitrogen electro-reduction under mild conditions is one promising alternative approach of the energyconsuming Haber-Bosch process for the artificial ammonia *** critical aspect to unlocking this technology is to discover the catalysts with high selectivity and *** this work,the N_(2)-to-NH_(3)conversion on the functional MoS_(2)is fully investigated by density functional theory calculations since the layered MoS_(2)provides the ideal platform for the elaborating copies of the nitrogenase found in nature,wherein the functionalization is achieved via basal-adsorption,basal-substitution or edge-substitution of transition metal *** results reveal that the edge-functionalization is a feasible strategy for the activity promotion;however,the basal-adsorption and basal-substitution separately suffer from the electrochemical instability and the NRR ***,MoS_(2)functionalized via edge W-substitution exhibits an exceptional *** energetically favored reaction pathway is through the distal pathway and a limiting potential is less than 0.20 ***,this work escalates the rational design of the high-effective catalysts for nitrogen fixation and provides the explanation why the predicated catalyst have a good performance,paving the guidance for the experiments.

关键词： Nitrogen reduction reaction Density functional theory calculations Molybdenum disulfide Electrochemistry Catalyst Thermodynamics

Deflagration characteristics of freely propagating flames in magnesium hydride dust clouds

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Defence Technology（防务技术） 2024年第1期31卷 471-483页

作者： Qiwei Zhang Yangfan Cheng beibei Zhang Danyi Li Zhaowu Shen School of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001AnhuiPR China Anhui Engineering Laboratory of Explosive Materials and Technology Anhui University of Science and TechnologyHuainan 232001AnhuiPR China School of Engineering Science University of Science and Technology of ChinaHefei 230027AnhuiPR China

The flame propagation processes of MgH_(2)dust clouds with four different particle sizes were recorded by a high-speed *** dynamic flame temperature distributions of MgH_(2)dust clouds were reconstructed by the two-color pyrometer technique,and the chemical composition of solid combustion residues were *** experimental results showed that the average flame propagation velocities of 23μm,40μm,60μm and 103μm MgH_(2)dust clouds in the stable propagation stage were 3.7 m/s,2.8 m/s,2.1 m/s and 0.9 m/s,*** dust clouds with smaller particle sizes had faster flame propagation velocity and stronger oscillation intensity,and their flame temperature distributions were more even and the temperature gradients were *** flame structures of MgH_(2)dust clouds were significantly affected by the particle sinking velocity,and the combustion processes were accompanied by micro-explosion of *** falling velocities of 23μm and 40μm MgH_(2)particles were 2.24 cm/s and 6.71 cm/s,*** the falling velocities of 60μm and 103μm MgH_(2)particles were as high as 15.07 cm/s and 44.42 cm/s,respectively,leading to a more rapid downward development and irregular shape of the ***,the dehydrogenation reaction had a significant effect on the combustion performance of MgH_(2)*** combustion of H_(2)enhanced the ignition and combustion characteristics of MgH_(2)dust,resulting in a much higher explosion power than the pure Mg *** micro-structure characteristics and combustion residues composition analysis of MgH_(2)dust indicated that the combustion control mechanism of MgH_(2)dust flame was mainly the heterogeneous reaction,which was affected by the dehydrogenation reaction.

关键词： Magnesium hydride dust Flame combustion mechanism Particle size Dust explosion Two-color pyrometer

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用于中子衍射的原位应力加载装置

强激光与粒子束 2013年第11期25卷 2865-2868页

作者：张莹庞蓓蓓席治国李建中国工程物理研究院核物理与化学研究所四川绵阳621900 中国工程物理研究院中子物理学重点实验室四川绵阳621900

一种小型化的应力加载系统,配合中子衍射应力谱仪可实现对多晶材料的原位测量,为进一步获得材料内部相、织构与应力演化的原位中子衍射实验结果,建立基于微观机制的材料宏观本构模型提供可能。该系统利用伺服电机提供动力,机架使用7050... 详细信息

一种小型化的应力加载系统,配合中子衍射应力谱仪可实现对多晶材料的原位测量,为进一步获得材料内部相、织构与应力演化的原位中子衍射实验结果,建立基于微观机制的材料宏观本构模型提供可能。该系统利用伺服电机提供动力,机架使用7050铝合金材料制造,系统的拉伸强度可达10kN,运动速度可调(1μm/s^1mm/s)。试样拉伸(压缩)时,S型传感器内部应变片变形产生电压信号,再经PLC处理后得到试样应力与应变之间关系。通过与英斯特朗5967实验拉伸机针对同一钢质试样进行对比实验发现,应力-应变曲线一致性良好。

关键词：中子衍射原位加载应力应变