检索结果-南通市图书馆

nano Research 2024年第8期17卷 6951-6959页

作者： Mengxuan li linf.ng Yu Hai liu Chuanyi Zhang Jiazhan li liang Luo Xiaoming Sun State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Zn-air batteries(ZABs)as a potential energy conversion system suffer from low power density(typically≤200 mW·cm^(−2)).Recently,three-dimensional(3D)integrated air cathodes have demonstrated promising performance over traditional twodimensional(2D)plane ones,which is ascribed to enriched active sites and enhanced diffusion,but without experimental ***,we applied a bubble pump consumption chronoamperometry(BPCC)method to quantitatively identify the gas diffusion coefficient(D)and effective catalytic sites density(ρEC)of the integrated air cathodes for ***,the D andρEC values can instruct consequent optimization on the growth of Co embedded n-doped carbon nanotubes(ConCnTs)on carbon fiber paper(CfP)and aerophilicity tuning,giving 4 times D and 1.3 timesρEC over the conventional 2D Pt/C-CfP *** a result,using the ConCnTs with half-wave potential of merely 0.78 V ***(Pt/C:0.89 V ***),the superaerophilic ConCnTs-CfP cathode-based ZABs exhibited a superior peak power density of 245 mW·cm^(−2) over traditional 2D Pt/C-CfP counterparts,breaking the threshold of 200 mW·cm^(−2).This work reveals the intrinsic feature of the 3D integrated air cathodes by yielding exact D andρEC values,and demonstrates the feasibility of BPCC method for the optimization of integrated electrodes,bypassing trial-and-error strategy.

关键词： Zn-air batteries three-dimensional(3D)integrated air cathodes superaerophilic gas diffusion coefficient effective catalytic sites density

Synthesis of crystalline g-C_(3)n_(4) with rock/molten salts for efficient photocatalysis and piezocatalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第5期9卷 890-898页

作者： Tingting Xu Jung Hur Ping niu Shulan Wang Sangwook Lee Sang-Eun Chun li li Department of Chemistry College of ScienceNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China School of Metallurgy Northeastern UniversityShenyang110819China School of Materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea School of Industrial Technology Advances Kyungpook National UniversityDaegu41566Republic of Korea

Graphitic carbon nitride(g-C_(3)n_(4))is emerging as a promising visible-light photocatalyst while the low crystallinity with sluggish charge separation/migration dynamics signiﬁcantly restricts its practical ***,synthesizing highly crystalline g-C_(3)n_(4) with sufﬁcient surface activities still remains ***,different from using alkali molten salts which is commonly reported,we propose an approach for synthesis of highly crystalline g-C_(3)n_(4) with feCl3/KCl rock/molten mixed *** rock salt can serve as the structure-directing template while molten salt provides the required liquid medium for ***,the synthesized photocatalyst showed further enhanced crystallinity and improved surface area along with high p/p*excitation compared with crystalline C_(3)n_(4) prepared from conventional molten-salt *** catalytically advantageous features lead to its superior photocatalytic and piezocatalytic activities with a high reactivity for overall water splitting that is not commonly reported for C_(3)n_(4).This work provides an effective strategy for structural optimization of organic semiconductor based materials and may inspire new ideas for the design of advanced photocatalysts.

关键词： High crystallinity Carbon nitride Photocatalysis Piezocatalysis Overall water splitting

Rapid and chemoselective imidation of sulfides in aqueous buffer enabled by a novel guanidine-derived n-O reagent

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 1929-1934页

作者： Hanzheng li Long Xu Jiajia Dong Key Laboratory of Organofluorine Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai200032China Institute of Translational Medicine National Facility for Translational Medicine(Shanghai)Shanghai Jiao Tong UniversityShanghai200240China School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced StudyShanghai Jiao Tong UniversityShanghai200240China Shanghai Artificial Intelligence Laboratory Shanghai200232China

Herein we report the facile synthesis of a series of.novel n-O reagents and identify n′-di-Boc-n′′-[(mesitylsulf.nyl)oxy]-guanidine as an efficient imidating *** reagent is synthetically scalable and bench-stable,yet it shows unprecedented reactivity and chemoselectivity towards S(II)in buffer/hexafluoroisopropanol(HfIP)system,to generate a new class of.nguanyl *** transformation of.n-guanyl sulfilimines to n-guanyl sulfoximines provides us a chance to investigate these rarely reached compounds,which are shown to be versatile precursors to a variety of.n-heterocyclic and *** work provides an addition to the tool box of both sulfur imidation and guanidine synthesis,especially for the need of rapid and selective modifications of sulfur(II)center under biocompatible conditions.

关键词： sulfur imidation n-O reagent

Engineering tantalum nitride for efficient photoelectrochemical water splitting

在线全文

学校读者我要写书评

暂无评论

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

作者： Beibei Zhang Zeyu f.n Yanbo li Institute of f.ndamental 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,f.nding an efficient photoanode material with a suitable band gap and favorable band-edge positions is *** nitride(Ta_(3)n_(5))meets these f.ndamental 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

Single-atom catalysis:a promising avenue for precisely controlling reaction pathways

在线全文

学校读者我要写书评

暂无评论

frontiers of Chemical Science and Engineering 2024年第7期18卷 97-120页

作者： Xiaobo Yang Xuning li Yanqiang Huang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Single-atom catalysts (SACs), characterized by exceptionally high atom efficiency, have garnered significant attention across various catalytic reactions. Recent studies have showcased SACs with robust capabilities for precise catalysis, specifically targeting reactions along designated pathways. This review focuses on the advances in the precise activation and reconstruction of chemical bonds on SACs, including precise activation of C–O and C–H bonds and selective couplings involving C–C and C–n bonds. Our discussion begins with a thorough exploration of the factors that render SACs skilled in precise catalytic processes, encompassing the narrow d-band electronic state of single atom site resulting in the adsorption tendency, isolate site resulting in unique adsorption structure, and synergy effect of a single atom site with its neighbors. Subsequently, we elaborate on the applications of SACs in electrocatalysis and thermocatalysis including four prominent reactions, namely, electrochemical CO_(2) reduction, urea electrochemical synthesis, CO_(2) hydrogenation, and CH4 activation. Then the concept of rational design of SACs for precisely controlling reaction pathways is discussed from the aspects of pore structure design, support-metal strong interaction, and support hydrophilic/hydrophobic. f.nally, we summarize the challenges encountered by SACs in the field of precise catalytic processes and outline prospects for their further development in this domain.

关键词： single atom catalysts selective oxidation CO_(2)RR bond coupling

Efficient guiding and focusing of intense laser pulse using periodic thin slits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.Huang K.Jiang C.n.Wu H.Peng P.C.hen R.li H.B.Zhuo C.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** f.ndamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1334-1340页

作者： Jing Cheng Xingxing li Jinlong Yang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Hefei national Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Hefei national Laboratory University of Science and Technology of ChinaHefei 230088China

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique ***,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in ***,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly *** this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(MOfs)fe_(n)-(pyz)(n=1-6)by utilizing f.nmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic *** 2D cluster-based MOfs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine *** particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of fe_(n)clusters in fe_(n)-(pyz)(n=1-6)MOfs results in diverse f.nctional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half ***,these 2D assembled MOfs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

关键词： metal-organic framework two-dimensional material half metal bipolar magnetic semiconductor magnet

Effects of Sinusoidal Vibration of Crystallization Roller on Composite Microstructure of Ti/Al Laminated Composites by Twin-Roll Casting

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 196-205页

作者：李励杜凤山 national Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004China College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

A new,innovative vibration cast-rolling technology of “electromagnetic stirring+dendrite breaking+asynchronous rolling” was proposed with the adoption of sinusoidal vibration of crystallization roller to prepare Ti/Al laminated composites,and the effect of sinusoidal vibration of crystallization roller on composite microstructure was investigated in *** results show that the metallurgical bonding of titanium and aluminum is realized by mesh interweaving and mosaic meshing,instead of transition bonding by forming metal compound *** meshing depth between titanium and aluminum layers (6.6μm) of cast-rolling materials with strong vibration of crystallization roller (amplitude 0.87 mm,vibration frequency 25 Hz) is doubled compared with that of traditional cast-rolling materials (3.1μm),and the composite interfacial strength(27.0 n/mm) is twice as high as that of traditional cast-rolling materials (14.9 n/mm).This is because with the action of high-speed superposition of strong tension along the rolling direction,strong pressure along the width direction and rolling force,the composite linearity evolves from "straight line" with traditional casting-rolling to "curved line",and the depth and number of cracks in the interface increases greatly compared with those with traditional cast-rolling,which leads to the deep expansion of the meshing area between interfacial layers and promotes the stable enhancement of composite quality.

关键词： laminated composites sinusoidal vibration composite microstructure

Impact of.next-generation sequencing on antimicrobial treatment in immunocompromised adults with suspected infections

在线全文

学校读者我要写书评

暂无评论

World Journal of Emergency Medicine 2024年第2期15卷 105-110页

作者： Jia li Jiazhen Luo Tao Hu ling Cheng Weiwei Shang li Yan Department of Intensive Care Unit Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Department of Emergency Medicine Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China Tongji Medical College Huazhong University of Science and TechnologyWuhan 430030China Department of Geriatrics Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

BACKGROUnD:Prompt pathogen identification can have a substantial impact on the optimization of antimicrobial *** objective of the study was to assess the diagnostic value of.next-generation sequencing(nGS)for identifying pathogen and its clinical impact on antimicrobial intervention in immunocompromised patients with suspected ***:This was a retrospective *** January and August 2020,47 adult immunocompromised patients underwent nGS testing under the following clinical conditions:1)prolonged fever and negative conventional cultures;2)new-onset fever despite empiric antimicrobial treatment;and 3)afebrile with suspected infections on *** data,including conventional microbial test results and antimicrobial treatment before and after nGS,were *** were analyzed according to documented changes in antimicrobial treatment(escalated,no change,or deescalated)after the nGS ***:The median time from hospitalization to nGS sampling was 19 *** relevant pathogens were detected via nGS in 61.7% of patients(29/47),more than half of whom suffered from f.ngemia(n=17),resulting in an antimicrobial escalation in 53.2% of patients(25/47)and antimicrobial de-escalation in 0.2% of patients(1/47).Antimicrobial changes were mostly due to the identification of fastidious organisms such as Legionella,Pneumocystis jirovecii,and *** the remaining three cases,nGS detected clinically relevant pathogens also detected by conventional cultures a few days *** antimicrobial treatment was subsequently adjusted according to the susceptibility test ***,nGS changed antimicrobial management in 55.3%(26/47)of patients,and conventional culture detected clinically relevant pathogens in 14.9% of the patients(7/47).COnCLUSIOn:With its rapid identification and high sensitivity,nGS could be a promising tool for identifying relevant pathogens and enabling rapid appropriate treatment in immunocompromised patients w

关键词： Immunocompromised patients next-generation sequencing Antimicrobial management

Pogostemon cablin essential oil as feed additive promotes the repair of the rumen epithelial barrier in heat-stressed beef cattle

在线全文

学校读者我要写书评

暂无评论

Animal nutrition 2024年第3期18卷 433-440页

作者： Huan Chen Mingrui Yang Xianglong Shang Hao Chen Yi li Yanjiao li lin li Mingren Qu Xiaozhen Song Jiangxi Province Key Laboratory of Animal nutrition Engineering Research Center of Feed DevelopmentJiangxi Agricultural UniversityNanchang 330045China

Pogostemon cablin essential oil(PEO),extracted from ***,has anti-oxidant,anti-inflammatory,and anti-stress properties,as well as the ability to improve gastrointestinal *** study aims to evaluate the effects of PEO on the performance,rumen epithelial morphology,and barrier f.nction in heat-stressed beef ***-six male Jingjiang cattle at 18 months old were randomly assigned into four groups and fed a diet containing PEO at 0(control),50,100,or 150 mg/kg in the feed concentrate(n=9).All experimental cattle were fed under high temperature and humidity in summer for 60 *** results indicated that 50 mg/kg of PEO treatment enhanced the average daily gain of beef cattle compared with the control group(P=0.032).All PEO treatments reduced the diamine oxidase activity(P=0.004)and malondialdehyde content(P=0.008)in *** addition,the content of 70 kDa heat shock protein in the 100 mg/kg group was increased,and the activity of glutathione peroxidase and total antioxidant capacity in both 100 mg/kg and 150 mg/kg groups were enhanced compared to the control group(Pntly,PEO treatment with 50 mg/kg enhanced the mRnA relative expressions of occludin in ruminal epithelia but decreased the mRnA relative expressions of c-Jun n-terminal kinase,P38 mitogen-activated protein kinases,caspase-3,Beclin1(Pnd extremely significant declined the mRnA relative expressions of extracellular regulated protein kinases and ubiquitin-binding protein in contrast to the control group(Pf.ndings indicated that dietary PEO supplementation might be favorable to improve growth performance and repairing damaged rumen epithelium of heat-stressed cattle by down-regulating the mitogen-activated protein kinase signaling pathway.

关键词： Beef cattle Heat stress Rumen epithelial barrier Pogostemon cablin essential oil Growth performance MAPK signaling pathway