检索结果-南通市图书馆

One-step controlled electrodeposition nickel sulfides heterointerfaces favoring the desorption of hydroxyl groups for efficient hydrogen generation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4377-4386页

作者： Ru-chun li Xin-Yue Zhang Ze-Yue Qu Feng-Yi liu Quan-Qing Xu Zhao-Xia Hu Jing-Wei li Mohamed-Nawfal Ghazzal Jin-li Yu Faculty of Chemistry and Chemical Engineering Yunnan Normal University Foshan Gaoke Hechuang Technology Co. Ltd. School of Chemistry and Chemical Engineering Guangzhou University Universite′Paris-Saclay UMR 8000 CNRSInstitut de Chimie Physique Department of Chemistry City University of Hong Kong

The heterointerface engineering involving different components or phases represents a desirable strategy for enhancing the sluggish kinetics of hydrogen evolution reaction （HER）.However,constructing desired heterointerfaces and elucidating the reaction mechanisms on the interface remains a considerable *** this work,we propose a straightforward electrochemical synthesis strategy to prepare the nickel sulfide-based heterointerfaces for *** mechanism of electrochemical synthesis is revealed,wherein metal-thiourea species can be formed at the cathode potential and subsequently oxidized to nickel sulfides at the anode *** this mechanism,a range of nickel sulfides,including NiS,Ni3S2/NiS,Ni/Ni3S2and Ni3S2,have been successfully synthesized by tuning the potential range of cyclic *** these,the obtained Ni3S2/NiS@CC（CC:carbon cloth） exhibits the smallest overpotential of84 mV at 10 mA·cm-2and high *** calculations further reveal that the combination of NiS and Ni3S2induces electron redistribution at the interface,and thus the Volmer process is effectively promoted with faster water dissociation and OH desorption ***,the simplicity method coupled with a clear synthesis mechanism and outstanding HER performance highlights its promising potential for practical applications.

关键词： Electrochemical synthesis Heterointerfaces Hydrogen evolution reaction OH desorption kinetics

Study on Catalytic Behavior of Iron-based Catalyst with IITP as Electron Donor in the Polymerization of Butadiene

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 612-619,I0007页

作者： Shi-liang Xu Ying-Nan Zhao Yao Yu Qi Yang li-Hua Na Heng liu chun-Yu Zhang Xue-Quan Zhang Key Laboratory of Advanced Rubber Material Ministry of EducationSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Shandong Provincial College Laboratory of Rubber Material and Engineering School of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China Key Lab of Rubber-Plastics Ministry of Education/Shandong Provincial Key Lab of Rubber-plasticsSchool of Polymer Science and EngineeringQingdao University of Science&TechnologyQingdao266042China

In this study,a novel iron-based catalyst system,Fe(acac)3/(isocyanoimino)triptenylphosphorane(IITP)/AlR3,was employed for the synthesis of syndiotactic 1,2-polybutadiene in *** catalyst system exhibits remarkably high catalytic activity,achieving a polymerization activity of 762 kgpolymer·molcatalyst^(-1)·h^(-1)at 50℃with a[BD]/[Fe]molar ratio of ***,living polymerization characteristic were observed during the investigation of the polymerization kinetics of 1,3-butadiene *** characteristics were well demonstrated by a narrow molecular weight distribution(PDI≈2.0)of the resulting polybutadiene and a linear relationship between-ln(1-c)and polymerization time as well as number average molecular weight and polymer *** resultant polymer showed a 1,2-selectivity of approximately 76%and stereoregularity ranging from 62%to 73%(rrrr).Additionally,through kinetic studies on polymerization reaction,an apparent activation energy Ea value of this catalytic system was calculated to be 84.98 kJ·mol^(-1),which suggests that high polymerization temperature favors efficient polymerization.

关键词： Iron catalyst Syndiotactic 1,2-polybutadiene Elastomers Donor Selectivity

Reconfigurable optical neural networks with Plug-and-Play metasurfaces

在线全文

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2024年第7期7卷 1-3页

作者： Yongmin liu Yuxiao li Department of Mechanical and Industrial Engineering Northeastern UniversityBostonMassachusetts 02115USA Department of Electrical and Computer Engineering Northeastern UniversityBostonMassachusetts 02115USA

In a very recent study,*** Huang and co-workers proposed and demonstrated reconfigurable optical neural networks based on cascaded *** fixing one metasurface and switching the other pluggable metasurfaces,the neural networks,which operate at near-infrared wavelengths,can perform distinct recognition tasks for handwritten digits and fashion *** innovative device opens up an avenue for all-optical,high-speed,low-power,and multifunctional artificial intelligence systems.

关键词： surfaces networks neural

Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 199-207页

作者： Yaling Huang Yong liu Yang liu Chenyang Zhang Wenzhang li Jie li School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083HunanChina School of Minerals Processing and Bioengineering Central South UniversityChangsha 4003HunanChina

Precision engineering of catalytic sites to guide more favorable pathways for li_(2)O_(2) nucleation and decom-position represents an enticing kinetic strategy for mitigating overpotential,enhancing discharge capac-ity,and improving recycling stability of li-O_(2) *** this work,we employ metal-organic frameworks(MOFs)derivation and ion substitution strategies to construct atomically dispersed Mn-N_(4) moieties on hierarchical porous nitrogen-doped carbon(Mn SAs-NC)with the aim of reducing the over-potential and improving the cycling stability of li-O_(2) *** porous structure provides more chan-nels for mass transfer and exposes more highly active sites for electrocatalytic reactions,thus promoting the formation and decomposition of li_(2)O_(2).The li-O_(2) batteries with Mn SAs-NC cathode achieve lower overpotential,higher specific capacity(14290 mA h g^(-1) at 100 mAg^(-1)),and superior cycle stability(>100 cycles at 200 mA g^(-1))compared with the Mn NPs-NC and *** functional theory(DFT)cal-culations reveal that the construction of Mn-N_(4) moiety tunes the charge distribution of the pyridinic N-rich vacancy and balances the affinity of the intermediates(liO_(2) and li_(2)O_(2)).The initial nucleation of li_(2)O_(2) on Mn SAs-NC favors the O_(2)-→liO_(2)→li_(2)O_(2) surface-adsorption pathway,which mitigates the overpoten-tials of the oxygen reduction(ORR)and oxygen evolution reaction(OER).As a result,Mn SAs-NC with Mn-N_(4) moiety effectively facilitates the li_(2)O_(2) nucleation and enables its reversible *** work establishes a methodology for constructing carbon-based electrocatalysts with high activity and selectivity for li-O_(2)batteries.

关键词： Single-atom Mn MOFs-oriented architecture Rechargeable li-O_(2)battery N-doped carbon Density functional theory calculation

An unprecedented synthesis of axially chiral biaryls by rearrangement and aromatization of carbocations with central-to-axial conversion of chirality

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第9期67卷 2998-3003页

作者： Qi liu Xue-Dong li liang Cheng li liu Beijing National Laboratory for Molecular Sciences (BNLMS) CAS Key Laboratory of Molecular Recognition and Function CAS Research/Education Center for Excellence in Molecular Sciences Institute of Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences

The central-to-axial chirality conversion represents a fascinating class of chemical processes consisting of the destruction of stereogenic centers and the simultaneous installation of axial chiral elements, which provides efficient methods for the preparation of axially chiral compounds. However, developing catalytic asymmetric approaches for constructing these central chirality precursors and the efficient central-to-axial chirality conversion remains a challenge due to the requirement of aromatization or elimination process. In this work, we have developed an unprecedented enantioselective intramolecular FriedelCrafts alkylation with unactivated-ketone carbonyls from which a chiral tertiary alcohol was generated with high efficiency and excellent enantioselectivity. In addition, the central-to-axial chirality conversion strategy has been successfully applied to the synthesis of enantioenriched biaryls via a less-explored carbocation-initiated rearrangement and aromatization under the promotion of Lewis acid. This methodology provided a straightforward and sustainable access to a broad range of biaryl-2-carboxylic acid and in excellent yields(up to 92%) and excellent central-to-axial chirality conversion(up to 99% conversion percentage). This work could be a great model for developing new methods for synthesizing axially chiral biaryls and a general protocol for the rearrangement and aromatization of carbocations for further functionalization.

关键词： brønsted acid catalysis desymmetrization phosphoric acid axially chiral biaryls central-to-axial conversion

同方期刊数据库

Enhancing photodynamic inactivation via tunning spatial constraint on photosensitizer

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 652-663页

作者： Chong li Minghao Han Ji Gao Shuxian Wang Song-Bo Lu Yaxi li Zhao liu Chen Zhang Zhaojin Wang Fangliang Wang Yuang Sun chun Loong Ho Kai Wang Yun Shen Kai li Shenzhen Key Laboratory of Smart Healthcare Engineering Guangdong Provincial Key Laboratory of Advanced BiomaterialsDepartment of Biomedical EngineeringSouthern University of Science and TechnologyShenzhen518055China Department of Chemical and Environmental Engineering University of California RiversideRiverside92521USA Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhen518055China

The critical factor of spatial constraint,provided by the external confinement(e.g.,matrix),is often overlooked during photodynamic inactivation,despite playing a crucial role in determining the molecular photophysical process and subsequent antipathogen ***,as a proof-of-concept model,we employed two types of polymers with varying interaction energies with dopants to investigate the intrinsic relationship between spatial constraint and the essential excited-state behaviors of doped photosensitizer(4-(2-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)ethyl)-1-methylquinolin-1-ium iodine,TPP).Through experimental investigation and theoretical calculations,we found that TPP tends to remain in the excited state for a shorter dwell time under weaker spatial constraints due to less restricted molecular motion in polyurethane(PU) ***,the singlet oxygen(^(1)O_(2)) generated from doped-TPP shows a 9.23-fold enhancement in PU than in the polyvinylchloride(PVC) *** light irradiation,the PU@TPP nanofiber can efficiently eliminate the coronavirus MHV-A59(≥99.9997%) at a 220,000-fold higher concentration than the infected *** antibacterial efficacy has also been demonstrated,with a killing rate of ≥99%.

关键词： photodynamic antibacterial singlet oxygen triphenylamine nanofiber

Experimental Investigation on Vertical Hydraulic Transport of Ores in Deepsea Mining

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第1期38卷 42-53页

作者： liu Lei liu Jian-cheng li Xin XU li-xin ZHANG Xiu-zhan State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Sanya Yazhou Bay Institution of Deep-sea Sci-Tech Shanghai Jiao Tong UniversitySanya 572000China China Merchants Marine And Offshore Research Institute Co. Ltd.Shenzhen 518067China China Merchants Deepsea Research Institute(Sanya)Co. Ltd.Sanya 572000China School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Deepsea mining has been proposed since the 1960s to alleviate the lack of resources on *** hydraulic transport of collected ores from the seabed to the sea surface is considered the most promising method for industrial *** the present study,an indoor model test of the vertical hydraulic transport of particles was conducted.A noncontact optical method has been proposed to measure the local characteristics of the particles inside a vertical pipe,including the local concentration and particle *** hydraulic gradient of ore transport was evaluated with various particle size distributions,particle densities,feeding concentrations and mixture flow *** transport,the local concentration is larger than the feeding concentration,whereas the particle velocity is less than the mixture *** qualitative effects of the local concentration and local fluid velocity on the particle velocity and slip velocity were *** local fluid velocity contributes significantly to particle velocity and slip velocity,whereas the effect of the local concentration is marginal.A higher feeding concentration and mixture flow velocity result in an increased hydraulic *** effect of the particle size gradation is slight,whereas the particle density plays a crucial role in the transport.

关键词： deepsea mining vertical hydraulic transport experiment flow characteristics

Sigmatropic rearrangements of B(MIDA)-propargylic alcohols towards the diverse synthesis of α-functionalized organoborons

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第2期67卷 568-575页

作者： Jiasheng Qian li-Cai liu Zhi-Hao Chen Yuan liu Yin li Qingjiang li Honggen Wang Guangdong Key Laboratory of Chiral Molecule and Drug Discovery School of Pharmaceutical SciencesSun Yat-Sen UniversityGuangzhou510006China

α-Functionalized organoborons are useful building blocks and key structural elements in functional *** previous synthesis relied on the famous Matteson reaction or the late-stage borylative modification of alkynes or ***,the synthetic transformation of borylated building blocks offers another useful strategy and is currently actively *** report herein that B(MIDA)-propargylic alcohols(BPAs) are a useful type of borylated building *** two complementary functional group handles(alkyne and hydroxyl) in close proximity,the redox-neutral [3,3] and [2,3] sigmatropic rearrangements of BPAs allow the efficient synthesis of several types of α-functionalized boronates,including α,β-unsaturated acylborons,α-S/P-substituted allenylborons,boryl-substituted thiazoles and a borylated α,β-unsaturated hydrazine,some of which are otherwise challenging targets using other synthetic methods.

关键词： organoboron diverse synthesis sigmatropic rearrangement heteroarene amide

Input-to-State Stability of Impulsive Switched Systems Involving Uncertain Impulse-Switching Moments

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1515-1517页

作者： Chang liu Wenlu liu Tengda Wei Xiaodi li School of Mathematical and Statistics Shandong Normal UniversityJinan 250014China

Dear Editor,This letter studies the input-to-state stability(ISS)for a class of impulsive switched systems,where uncertain impulse-switching moments are *** robustness of ISS with respect to the perturbations of the occurrence time of impulse-switching moments is revealed by several less conservative dwell-time conditions for the uncertain impulse-switching moments combined with Lyapunov ***,the Lyapunov conditions have multiple coefficients at discrete time so as to handle the hybrid effect of impulse-switching moments,and the case that time derivative of Lyapunov function is indefinite is also taken into ***,a numerical example is proposed to illustrate the effectiveness of the theoretical results.

关键词： letter conservative derivative