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Fluorescent carbon dots synthesized in solid phase and air for application in LEDs

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nano Research 2024年第9期17卷 8495-8503页

作者： Wei-Jie Zheng Zhao-nan Sun Yi-Ming wang Huan-Ming Xiong Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200438China

Carbon dots(CDs)have been widely adopted as optical materials because of their excellent luminescent ***,most of the reported synthetic methods are conducted in solvents,especially hydrothermal/solvothermal reactions,leading to intractable problems such as toxic and flammable solvents,complex and inseparable by-products,and dangerously high pressures and ***-phase synthesis of CDs in air is an effective solution to overcome the above issues,but solid reactions always result in uncontrolled growth and agglomeration of *** this study,some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air,which also play as dispersants to hinder CDs *** the meantime,some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources,ground with the optimized catalyst,and then heated together in *** production yields are affected by the reaction time and reactant ratio,while the graphitization degrees of the CDs are determined by the reaction *** IG/ID value of their Raman spectra increases from 0.59 to 0.85,and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280℃.The as-prepared CDs show emission peaks ranging from 366 to 606 nm,with the photoluminescence(PL)quantum yield up to 53%.Their emission color variation mainly results from different carbon sources,which can be ascribed to the differences in the element composition,functional groups,and graphitic nitrogen content of these *** dispersing CDs of different concentrations into polyvinyl alcohol(PVA)and combining them with blue LEDs,cold,standard,and warm white light emitting devices(WLEDs)are prepared,with a color rendering index(CRI)up to *** the as-prepared CDs have antioxidant ability at high temperature,the as-prepared WLEDs have long lifespans,remaining the effective white luminescence after 72 h continuous work.

关键词： carbon dot solid-phase synthesis white LED photoluminescence inorganic salt catalysis

QoS Routing Optimization Based on Deep Reinforcement Learning in SDN

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Computers, Materials & Continua 2024年第5期79卷 3007-3021页

作者： Yu Song Xusheng Qian nan Zhang Wei wang Ao Xiong State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China Marketing Service Center State Grid Jiangsu Electric Power Co.Ltd.Nanjing220000China Customer Service Center State Grid Co.Ltd.Nanjing211161China

To enhance the efficiency and expediency of issuing e-licenses within the power sector, we must confront thechallenge of managing the surging demand for data traffic. Within this realm, the network imposes stringentQuality of Service (QoS) requirements, revealing the inadequacies of traditional routing allocation mechanismsin accommodating such extensive data flows. In response to the imperative of handling a substantial influx of datarequests promptly and alleviating the constraints of existing technologies and network congestion, we present anarchitecture forQoS routing optimizationwith in SoftwareDefinedNetwork (SDN), leveraging deep reinforcementlearning. This innovative approach entails the separation of SDN control and transmission functionalities, centralizingcontrol over data forwardingwhile integrating deep reinforcement learning for informed routing decisions. Byfactoring in considerations such as delay, bandwidth, jitter rate, and packet loss rate, we design a reward function toguide theDeepDeterministic PolicyGradient (DDPG) algorithmin learning the optimal routing strategy to furnishsuperior QoS provision. In our empirical investigations, we juxtapose the performance of Deep ReinforcementLearning (DRL) against that of Shortest Path (SP) algorithms in terms of data packet transmission delay. Theexperimental simulation results show that our proposed algorithm has significant efficacy in reducing networkdelay and improving the overall transmission efficiency, which is superior to the traditional methods.

关键词： Deep reinforcement learning SDN route optimization QoS

Recent progress on rapid diagnosis of COVID-19 by point-of-care testing platforms

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Chinese Chemical Letters 2024年第3期35卷 66-75页

作者： Ya-nan Tang Dingding Jiang Xuejun wang Yunqi Liu Dacheng Wei State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China Institute of Molecular Materials and Devices Fudan UniversityShanghai 200433China

The outbreak of COVID-19 has drawn great attention around the ***-CoV-2 is a highly infectious virus with occult transmission by many mutations and a long incubation *** particular,the emergence of asymptomatic infections has made the epidemic even more ***,early diagnosis and timely management of suspected cases are essential measures to control the spread of the *** simple,portable,and accurate diagnostic techniques for SARS-CoV-2 is the key to epidemic *** advantages of point-of-care testing technology make it play an increasingly important role in viral detection and *** review summarizes the point-of-care testing platforms developed by nucleic acid detection,immunological detection,and nanomaterial-based biosensors ***,this paper provides a prospect for designing future highly accurate,cheap,and convenient SARS-CoV-2 diagnostic technology.

关键词： COVID-19 Point-of-care testing platforms Nucleic acid detection Asymptomatic infection Biosensors

Effects of BN on the Mechanical and Thermal Properties of PP/BN Composites

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 345-352页

作者：陈厚振王艳芝 nan Yu wang Xu YUE Xianyang ZHANG Yifei FAN Huiling School of Textiles Zhongyuan University of TechnologyZhengzhou 451191China Kaifeng Power Supply Company State Grid Henan Electric Power CompanyKaifeng 475000China School of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China Zhengzhou Hengtian Copper Co. Ltd.Zhengzhou 451100China

In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moulding and compression *** composites were filled with BN particles of 5 and 20 μm respectively,and their mass fractions in composites were *** of BN was varied from 0 to 25wt% in steps of 5wt%.The effects of BN filler on mechanical properties of the composites were *** thermal behaviors were studied using DSC and TGA,and the thermal conductivity was also investigated by Laser Flash Device and the Model of 3D Heat Conduction *** experimental results show that impact strength of PP/BN can be enhanced with the addition of BN,but that composites exhibit lower breaking elongation & tensile strength when compared to unfilled *** is found that mass fraction of BN influenced the final thermal stability and degree of crystallization of PP matrix,the degree of crystallization of PP with 15wt% of 20 μm BN can be improved by 25% than neat ***,crystallization temperatures of PP composites are elevated by about 10 ℃.The thermal conductivity results demonstrate that the maximum value of the thermal conductivity is achieved from PP/BN with 20wt% of 20 μm BN,higher than that of pure PP by 95.65%,close to the simulation one.

关键词： thermal properties polypropylene composites hexagonal boron nitride

Polyoxometalate as the assembly material to self-assembled Ni(OH)_(2) nanosheets with electrocatalytic performance

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nano Research 2024年第8期17卷 7061-7067页

作者： Danyang He Tianyang Li Luozhen Jiang Fei wang Zihao Xing nan wang Zhiyu Jia Guo-Yu Yang Key Laboratory of Cluster Science Ministry of EducationSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Shanghai Advanced Research Institute Chinese Academy of ScienceShanghai 201210China Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Facluty of ChemistryNortheast Normal UniversityChangchun 130024China

Developing non-noble metal-based electrocatalyst with high catalytic activity is essential for advancing hydrogen energy *** study introduces a hydrothermal method for synthesizing order Ni(OH)_(2) nanosheets,with H_(3)O_(40)PW_(12)(denoted as PW_(12))loaded onto reduced graphene oxide(rGO)coated on nickel foam(referred to as PW_(12)-Ni(OH)_(2)/rGO).This method contrasts with the electrodeposition of Ni(OH)_(2),where PW_(12) is added to the synthetic system to direct the assembly and morphology of the Ni(OH)_(2) through a hydrothermal *** this work,the nickel foam acts dual roles as both the substrate and the source of nickel for the formation of Ni(OH)_(2).The PW_(12)-Ni(OH)_(2)/rGO nanosheets,when successfully prepared and loaded onto the nickel foam(NF),exhibited superior electrocatalytic activity for the hydrogen evolution reaction(HER)in an alkaline electrolyte,achieving a current density of 10 mA·cm^(-2) at an overpotential of 69 ***,we endeavored to expand the application of this material towards the oxygen evolution reaction(OER)by preparing PW_(12)-(Fe/Co)Ni(OH)_(2)/rGO through the addition of metal *** nanocomposite displayed outstanding electrocatalytic activity in alkaline electrolytes,with a current density of 10 mA·cm^(-2)at an overpotential of 211 mV,and demonstrated excellent stability over a 50 h period in a 1 M KOH *** results presented in this paper offer an effective strategy for the preparation of polyoxometalate-based inorganic materials with diverse functionalities,applicable to both HER and OER.

关键词： polyoxometalate Ni(OH)_(2) assembly hydrogen evolution reaction oxygen evolution reaction

Psychological interventions for depression in children and adolescents:A bibliometric analysis

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World Journal of Psychiatry 2024年第3期14卷 467-483页

作者： nan wang Jia-Qi Kong nan Bai Hui-Yue Zhang Min Yin School of Nursing Lanzhou UniversityLanzhou 730000Gansu ProvinceChina

BACKGROUND Depression has gradually become a common psychological disorder among children and *** in children and adolescents affects their physical and mental *** is considered to be one of the main treatment options for depressed children and ***,our understanding of the global performance and progress of psychological interventions for depression in children and adolescents(PIDCA)research is *** To identify collaborative research networks in this field and explore the current research status and hotspots through *** Articles and reviews related to PIDCA from January 2010 to April 2023 were identified from the Web of Science Core Collection *** Charticulator website,CiteSpace and VOSviewer software were used to visualize the trends in publications and citations,the collaborative research networks(countries,institutions,and authors),and the current research status and *** Until April 16,2023,1482 publications were *** number of documents published each year and citations had increased rapidly in this *** United States had the highest productivity in this *** most prolific institution was the University of *** Cuijpers was the most prolific *** the context of research related to PIDCA,both reference co-citation analysis and keywords co-occurrence analysis identified 10 research hotspots,including thirdwave cognitive behavior therapy,short-term psychoanalytic psychotherapy,cognitive behavioral analysis system of psychotherapy,family element in psychotherapy,modular treatment,mobile-health,emotion-regulation-based transdiagnostic intervention program,dementia risk in later life,predictors of the efficacy of psychological intervention,and risks of psychological *** This bibliometric study provides a comprehensive overview of PIDCA from 2010 to *** intervention characterized as psychological-pr

关键词： Child Adolescent Depression Psychological intervention Bibliometrics

Zeolites for the separation of ethylene,ethane,and ethyne

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 137-146页

作者： Binyu wang Qiang Li Haoyang Zhang Jia-nan Zhang Qinhe Pan Wenfu Yan State Key Laboratory of Inorganic Synthesis&Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450012China Key Laboratory of Advanced Materials of Tropical Island Resources(Ministry of Education) School of Chemistry and Chemical EngineeringHainan UniversityHaikou 570228China

The cost-effective separation of ethylene(C_(2)H_(4)),ethyne(C_(2)H_(2)),and ethane(C_(2)H_(6))poses a significant challenge in the contemporary chemical *** contrast to the energy-intensive high-pressure cryogenic distillation process,zeolite-based adsorptive separation offers a low-energy *** review provides a concise overview of recent advancements in the adsorptive separation of C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)using zeolites or zeolite-based *** commences with an examination of the industrial significance of these compounds and the associated separation ***,it systematically examines the utilization of various types of zeolites with diverse cationic species in such separation *** then it explores how different zeolitic structures impact adsorption and separation capabilities,considering principles such as cation-πinteraction,π-complexation,and steric separation concerning C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)***,it discusses methods to enhance the separation performance of zeolites and zeolite-based adsorbents,encompassing structural design,modifications,and ion exchange ***,it summarizes current research trends and future directions,highlighting the potential application value of zeolitic materials in the field of C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)separation and offering recommendations for further investigation.

关键词： zeolite ethylene ethane cation-πinteraction π-complexation

Dynamic membrane filtration accelerates electroactive biofilms in bioelectrochemical systems

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Environmental Science and Ecotechnology 2024年第4期20卷 208-217页

作者： Jinning wang Mei Chen Jiayao Zhang Xinyi Sun nan Li Xin wang MOE Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityNo.38 Tongyan RoadJinnan DistrictTianjin300350China School of Environmental Science and Engineering Tianjin UniversityNo.35 Yaguan RoadJinnan DistrictTianjin300350China

Bioelectrochemical systems(BES)have emerged as a dual-function technology for treating wastewater and recovering energy.A vital element of BES is the rapid formation and maintenance of electroactive biofilms(EABs).Previous attempts to accelerate EAB formation and improve electroactivities focused on enhancing the bacterial adhesion process while neglecting the rate-limiting step of the bacterial transport ***,we introduce membrane filtration into BES,establishing a dynamic membrane filtration system that enhances overall *** observed that optimal membrane flux considerably reduced the startup time for EAB ***,EABs established under a 25 L m^(-2)h^(-1)flux(EAB_(25)LMH)had a formation time of 43.8±1.3 h,notably faster than the 51.4±1.6 h in the static state(EAB_(0)LMH).Additionally,EAB_(25)LMH exhibited a significant increase in maximum current density,approximately 2.2 times higher than EAB_(0)*** correlation analysis indicated a positive relationship between current densities and biomass quantities and an inverse correlation with startup *** analysis revealed two critical findings:(i)variations in maximum current densities across different filtration conditions were associated with redox-active substances and biomass accumulation,and(ii)the incorporation of a filtration process in EAB formation enhanced the proportion of viable cells and encouraged a more diverse range of electroactive ***,the novel electroactive membrane demonstrated sustained current production and effective solid-liquid separation during prolonged operation,indicating its potential as a viable alternative in membrane-based *** approach not only provides a new operational model for BES but also holds promise for expanding its application in future wastewater treatment solutions.

关键词： Electroactive biofilm Membrane filtration Spatial structure Mass transfer Microbial community

Exploring formation mechanism and source attribution of ozone during the 2019 Wuhan Military World Games:Implications for ozone control strategies

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Journal of Environmental Sciences 2024年第2期136卷 400-411页

作者： Lei Zhang Lili wang Runyu wang nan Chen Yuan Yang Ke Li Jie Sun Dan Yao Yuesi wang Minghui Tao Yang Sun Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of the Chinese Academy of Sciences Beijing 100049China Hubei Ecological Environment Monitoring Center Station Wuhan 430072China Guizhou Research and Designing Institute of Environmental Sciences Guizhou Academy of Environmental Science and DesignGuiyang 550081China Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Environment Key Laboratory for Yellow River and Huai River Water Environment and Pollution ControlMinistry of EducationHenan Normal UniversityXinxiang 453007China Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

A series of emission reduction measures were conducted in Wuhan,Central China,to ensure good air quality during the 7th Military World Games(MWG)in October *** better understand the implications for ozone(O_(3))pollution control strategies,we applied integrated analysis approaches based on the de-weathered statistical model,parameterization methods,chemical box model,and positive matrix factorization *** the MWG,concentrations of O_(3),NO_x,and volatile organic compound(VOCs),OFP(O_(3)formation potential),L_(OH)(OH radical loss rate)were 83μg/m^(3),43μg/m^(3),26 ppbv,188μg/m^(3),and 3.9 s^(-1),respectively,which were 26%,18%,3%,15%,and 13%lower than pre-MWG values and 6%,39%,30%,33%,and 50%lower than post-MWG values,*** removing meteorological influence,O_(3)and its precursors during the MWG decreased largely compared with post-MWG values,and only O_(3),NO_(2),and oxygenated VOCs(OVOCs)declined compared with pre-MWG values,which revealed the emission reduction measures during the MWG played an important role for O_(3)*** six VOCs sources,the mass contributions of biomass burning and solvents usage during the MWG decreased largely compared with pre-MWG values.O_(3)production was sensitive to VOCs and the key species were aromatics,OVOCs,and alkenes,which originated mainly from solvents usage,biomass burning,industrial-related combustion,and vehicle *** O_(3)concentration during the strict control was mainly caused by OVOCs reduction due to biomass burning ***,the O_(3)abatement strategies of Wuhan should be focused on the mitigation of high-reactivity VOCs.

关键词： VOCs Ozone Wuhan Military World Games Source apportionment Relative incremental reactivity Random forest