检索结果-南通市图书馆

Strain-promoted S-arylation and alkenylation of sulfinamides using arynes and cyclic alkynes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 928-935页

作者： Xi Zou Boming Shen Gao-lin li qian liang Yanhua Ouyang binghe Yang Peiyuan Yu bing Gao State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringInstitute of Chemical Biology and NanomedicineHunan UniversityChangsha 410082China Department of Chemistry and Shenzhen Grubbs Institute Guangdong Provincial Key Laboratory of CatalysisSouthern University of Science and TechnologyShenzhen 518055China

The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIVfunctionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective SIV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center(N-R). The origin of the high SIV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.

关键词： arylation alkenylation sulfoximines sulfinamides arynes

同方期刊数据库

Long-range Pt-Ni dual sites boost hydrogen evolution through optimizing the adsorption configuration

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 3700-3706页

作者： Cong liu Pengfang Zhang bing liu qian Meng Xuzhao Yang Yakun li Jingli Han Yao Wang Henan Province Engineering Research Center of Catalysis and Separation of Cyclohexanol College of Materials and Chemical EngineeringZhengzhou University of Light IndustryZhengzhou 450001China Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology Liaocheng UniversityLiaocheng 252000China Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringInternational Joint Research Center for Photoresponsive Molecules and MaterialsJiangnan UniversityWuxi 214122China

Elaborated design of catalytic systems with a specifically tailored site distance to match the intermediates could substantially improve reaction kinetics and boost catalytic activity under unfavorable reaction *** the lower energy barriers of water splitting upon the synergy of dual sites,constructing synergistic Pt-M(M:transition metal)dual sites is an effective way to boost Pt with highly catalytic hydrogen evolution reaction(HER)*** unconventional“Ni(OH)_(2)-coated high-index Pt facets”was constructed to obtain long-range Pt-Ni dual sites,in which Ni composition as a water dissociation synergistic site can protect Pt from electrolyte corrosion and ensure efficient proton donation to Pt *** obtained long-range Pt-Ni dual sites present 3.84 mA·cm^(-1) of current density,which is 7.5 times specific activity higher than that of commercial Pt/C towards alkaline *** enhanced HER performance is attributed to synergistic catalysis on Pt-Ni dual sites accompanied by unconventional electron *** work illustrates a new strategy to construct the long-range dual sites by unconventional strategy for fundamental electrocatalytic study of alkaline HER.

关键词： long-range Pt-Ni dual sites electron transfer hydrogen evolution reaction sites synergy

Enhancing photoresponsiveness of metal-organic polyhedra by modifying microenvironment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5712-5717页

作者： Long Zheng Peng Tan qian Song Sheng-Tao Wang Min li Xiao-Qin liu lin-bing Sun State Key Laboratory of Materials-Oriented Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)College of Chemical EngineeringNanjing Tech UniversityNanjing 211816China

Photoresponsiveness of materials is critical to their tunability and efficiency in terminal *** metal-organic polyhedra(PMOPs)feature intrinsic pores and remote controllability,but aggregation of PMOPs in solid state hampers their photoresponsiveness ***,we report the construction of a new PMOP(Cu_(24)(C_(16)H_(12)N_(2)O_(4))_(12)(C_(18)H_(22)O_(5))12,denoted as MOP-PR-LA),where long alkyl(LA)chains act as the intermolecular poles,propping against adjacent PMOP molecules to create individual microenvironment benefiting the isomerization of photoresponsive(PR)*** ultraviolet(UV)-and visible-light irradiation,MOP-PR-LA is much easier to isomerize than the counterpart MOP-PR without *** propylene adsorption,MOP-PR has a low change of adsorption capacity(9.9%),while that of MOP-PR-LA reaches 58.6%.Density functional theory calculations revealed that PR in the cis state has a negative effect on adsorption,while the trans state of PR favors *** work might open an avenue for the construction of photoresponsive materials with high responsiveness and controllability.

关键词： photoresponsive adsorption metal-organic polyhedra azobenzene long alkyl chains propylene capture

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第3期18卷 378-389页

作者： Zhao-ting SHANG Tang-ming li bing-qian HU Min liU Wang-ting LU Fan YU Yun ZHENG Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education College of Optoelectronic Materials and TechnologyJianghan UniversityWuhan 430056China Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China Department of Chemical Engineering University of WaterlooWaterlooOntario N2L 3G1Canada

The use of two-dimensional(2D)layered metal-organic frameworks(MOFs)as self-sacrificial templates has been proven to be a successful method to create high-efficiency Selenium(Se)-containing electrocatalysts for overall water ***,two strategies are then utilized to introduce Se element into the Co–Fe MOF,one being the etching of as-prepared MOF by SeO_(2) solution,and the other,the replacing of SCN−with SeCN−as the construction *** electrochemical activity of the pristine 2D MOF and their calcinated derivatives for catalyzing the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is evaluated and further *** is found that the effect of introducing Se on improving electrochemical catalytic activity is significant for the HER ***,the calcinated derivative in the replacing method exhibits an overpotential of 235 mV for HER and 270 mV for OER at a current density of 10 mA/*** comparing the two methods of introducing Se element into MOF,similar electrocatalytic activity can be achieved on the their calcinated *** high electrochemical performance of 2D CoFe-MOF derivatives may be resulted from the unique 2D hierarchical porous structure and strong synergistic effect between different components in the material.

关键词： 2D MOF selenium(Se)-containing materials hydrogen evolution reaction(HER) oxygen evolution reaction(OER)

Perspective of Calcium Imaging Technology Applied to Acupuncture Research

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第1期30卷 3-9页

作者： li Sha liU Yun ZHANG Nan li Wang XU Wen-jie XU Yi-qian CHEN Yi-yuan CUI Xiang ZHU bing GAO Xin-yan Institute of Acupuncture and Moxibustion China Academy of Chinese Medical SciencesBeijing(100700)China

Acupuncture, a therapeutic treatment defined as the insertion of needles into the body at specific points(ie, acupoints), has growing in popularity world-wide to treat various diseases effectively, especially acute and chronic pain. In parallel, interest in the physiological mechanisms underlying acupuncture analgesia, particularly the neural mechanisms have been increasing. Over the past decades, our understanding of how the central nervous system and peripheral nervous system process signals induced by acupuncture has developed rapidly by using electrophysiological methods. However, with the development of neuroscience, electrophysiology is being challenged by calcium imaging in view field, neuron population and visualization in vivo. Owing to the outstanding spatial resolution, the novel imaging approaches provide opportunities to enrich our knowledge about the neurophysiological mechanisms of acupuncture analgesia at subcellular, cellular, and circuit levels in combination with new labeling, genetic and circuit tracing techniques. Therefore, this review will introduce the principle and the method of calcium imaging applied to acupuncture research. We will also review the current findings in pain research using calcium imaging from in vitro to in vivo experiments and discuss the potential methodological considerations in studying acupuncture analgesia.

关键词： acupuncture research calcium imaging optical imaging nervous system

SAC-Based Computation Offloading for Reconfigurable Intelligent Surface-Aided Mobile Edge Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第6期21卷 261-270页

作者： li Bin qian Zhen Fei Zesong School of Computer Science Nanjing University of Information Science&TechnologyNanjing 210044China Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET) Nanjing University of Information Science&TechnologyNanjing 210044 School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

In this paper,we concentrate on a reconfigurable intelligent surface(RIS)-aided mobile edge computing(MEC)system to improve the offload efficiency with moving user equipments(UEs).We aim to minimize the energy consumption of all UEs by jointly optimizing the discrete phase shift of RIS,UEs’transmitting power,computing resources allocation,and the UEs’task offloading strategies for local computing and *** formulated problem is a sequential decision making across multiple coherent time ***,the mobility of UEs brings uncertainties into the decision-making *** cope with this challenging problem,the deep reinforcement learning-based Soft Actor-Critic(SAC)algorithm is first proposed to effectively optimize the discrete phase of RIS and the UEs’task offloading ***,the transmitting power and computing resource allocation can be determined based on the *** results demonstrate that the proposed algorithm can be trained more stably and perform approximately 14%lower than the deep deterministic policy gradient benchmark in terms of energy consumption.

关键词： MEC RIS soft actor-critic user mobility

Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2024年第1期14卷 48-58页

作者： lijun li Congying JIA qian MA Tianzong XU College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590.China State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and *** suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,*** method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis *** the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

Phosphorylated cellulose nanofibers establishing reliable ion-sieving barriers for durable lithium-sulfur batteries

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5期92卷 619-628页

作者： Zihao li Pengsen qian Hongyang li He Xiao Jun Chen Gaoran li School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials Fuzhou 350108FujianChina

The shuttle effect is among the most characteristic and formidable challenges in the pursuit of high-performance lithium-sulfur(li-S)***,phosphorylated cellulose nanofibers(pCNF)are intentionally engineered to establish an ion-sieving barrier against polysulfide shuttling and thereby improve battery *** phosphorylation,involving the grafting of phosphate groups onto the cellulose backbone,imparts an exceptional electronegativity that repels the polysulfide anions from penetrating through the ***,the electrolyte wettability and li^(+)transfer can be significantly promoted by the polar nature of pCNF and the facile li^(+)*** such,rational ion management is realized,contributing to enhanced reversibility in both sulfur and lithium *** a result,li-S cells equipped with the self-standing pCNF separator demonstrate outstanding long-term cyclability with a minimum fading rate of 0.013%per cycle over 1000 cycles at 1 C,and a decent areal capacity of 5.37 mA h cm^(-2) even under elevated sulfur loading of 5.0 mg cm^(-2) and limited electrolyte of 6.0 mL g^(-1).This work provides a facile and effective pathway toward the well-tamed shuttle effect and highly durable li-S batteries.

关键词： lithium-sulfur batteries Cellulose Phosphorylation Ion-sieving Shuttle effect

Copper-Free Click Chemistry-Mediated Assembly of Single Quantum Dot Nanosensor for Accurately Monitoring Locus-Specific m^(6)A in Cancer Cells

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第5期42卷 499-504页

作者： Yue-Ying li Ning-Ning Zhao Yi-Xuan Geng qian Han Jian-Ge Qiu bing-Hua Jiang Zi-Yue Wang Chun-Yang Zhang Translational Medicine Center The First Affiliated Hospital of Zhengzhou UniversityThe Academy of Medical SciencesHenan Institute of Medical and Pharmaceutical Sciences BGI CollegeZhengzhou UniversityZhengzhouHenan450052 China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinanShandong250014 China School of Chemistry and Chemical Engineering Southeast UniversityNanjingJiangsu211189 China

N6-methyladenosine(m^(6)A)plays an important role in embryogenesis,nuclear export,transcription splicing,and protein translation ***,we demonstrate a copper-free click chemistry-mediated assembly of single quantum dot(QD)nanosensor for accurately monitoring locus-specific m^(6)A in cancer *** m^(6)A-sensitive endoribonuclease MazF can digest the unmethylated A-RNA,and the intact m^(6)A-RNA then hybridizes with DNA probes a and b to produce a sandwich hybrid,initiating the click chemistry to generate probe a–b ligation product via first tandem ligation detection reaction(LDR)***,DNA probes c and d can hybridize with the probe a–b ligation product to generate the probe c–d ligation product via second LDR *** LDR cycles can be repeated through denaturation and annealing reaction to generate abundant biotin-/fluorophore-modified probe c–d ligation products that can easily assemble on the QD surface to induce distinct fluorescence resonance energy transfer(FRET)between QD and *** assay can be homogenously performed without the involvement of copper catalyst,m^(6)A-specific antibody,radioactive labeling,ligase enzyme,enzymatic reverse transcription,and next-generation ***,it can discriminate even 0.01% m^(6)A level in complex samples and accurately measure cellular m^(6)A-RNA expression,providing a promising avenue for clinical diagnostics and biomedical research.

关键词： RNA methylation Click chemistry Förster resonance energy transfer Biosensor Cancer