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First-principles study on persistent luminescence mechanism of LiYGeO_(4):Eu^(3+)

Journal of Rare Earths 2023年第10期41卷 1519-1524,I0002页

作者： Shihang Zhou Bibo Lou Chong-Geng Ma Min Yin Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials School of Physics and Electronic EngineeringXinjiang Normal UniversityUrumqi830054China CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics and School of Physical SciencesUniversity of Science and Technology of ChinaHefei230026China School of Optoelectronic Engineering&CQUPT-BUL Innovation Institute Chongqing University of Posts and TelecommunicationsChongqing400065China

LiYGeO_(4):Eu^(3+)is a red persistent luminescent material with a duration of more than 21 *** its persistent luminescence phenomenon has been fully studied,its detailed mechanism is still the subject of ***,we performed first-principles study on the intrinsic point defects and the charge transfer processes in LiYGeO_(4):Eu^(3+)to reveal the mechanism of persistent *** results show that,under charge transfer excitation,the electron is promoted from the valence band(oxygen ion ligand)to the central Eu^(3+)ion to form Eu^(2+)ion in LiYGeO_(4):Eu^(3+),leaving a hole *** charge transfer excitation can relax quickly to the excited state of the Eu^(3+)ion,which produces the characteristic^(5)D_(0)→^(7)F_(J)(J=0-6)*** Li vacancies(V_(Li))and the antisite defects of Li replacing Y site(Li_(Y))and Y replacing Li site(YLi)are main defects,while O vacancies(V_(O))are less important in concentration due to high formation *** and Liy can serve as hole-type traps,with the trap depths suitable for trapping the holes produced by *** delayed release holes can combine with the Eu^(2+)left behind by the illumination,leading to persistent *** VLi trap is shallower than Li_(Y),and the latter is responsible for the long duration of persistent luminescence.A schematic based on the calculation results is constructed to illustrate the mechanism of persistent luminescence.

关键词： Persistent Iuminescence Eu^(3+) Charge transfer Point defects First-principles Rare earths

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AN EMPIRICAL ORTHOGONAL FUNCTION ANALYSIS FOR THE WAVE TRAINS IN EAST ASIAN SUMMER

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Journal of Tropical Meteorology 2010年第3期16卷 231-237页

作者：王亚非何金海李琰祝丽娟 State Key Laboratory of Severe Weather Chinese Academy of Meteorological sciences Nanjing University of Information science & technology

This study examines the wave trains at 500 hPa occurring in East Asian summer by using the Empirical Orthogonal Function （EOF） analysis as a diagnostic tool. The results are summarized as follows：（1） A wave train pattern （OKJ pattern） originating from the upstream areas of the Sea of Okhotsk to the subtropical regions could display its strong signal in early and middle summer. The OKJ pattern is clearly recognized in the first EOF component in Eurasia. （2） The other wave train pattern originating fi＇om the Philippines via Japan to North America （the P-J pattern） shows quite strong signals in the whole summer. Although the P-J pattern is described as the second EOF component around the area from East Asia to Northeast Pacific Ocean, the variance contribution is the same as that of OKJ pattern in the first EOF component. （3） The composite analyses indicate that the OKJ and P-J wave trains could coexist to some extents.

关键词： wave trains East Asian summer EOF analysis teleconnection 500 hPa

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Hydrophobicity changes of polluted silicone rubber introduced by spatial and dose distribution of plasma jet

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Plasma science and technology 2022年第4期24卷 53-60页

作者： Shuang LI Xinzheng GUO Yongqiang FU Jianjun LI Ruobing ZHANG Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments Shenzhen International Graduate School(SIGS)Tsinghua UniversityShenzhen 518055People's Republic of China

The hydrophobicity of polluted silicone rubber was improved rapidly under plasma jet *** is an important phenomenon of the interaction between the plasma jet and the porous surface,and shows a wide application prospect in the power *** this process,the spatial characteristics and dose of plasma jet are very ***,the variation of hydrophobicity of polluted silicone rubber under plasma jet treatment was studied,and the spatial characteristics and dose of plasma jet on polluted silicone rubber were also investigated in the *** results show that the surface property(hydrophilic or hydrophobic)depended on the dose of plasma applied to the *** effective treated area was a circle,and the contact angles changed along the radial direction of the *** was attributable to the diffusion of plasma bullets on the surface and the distribution of plasma *** plasma dose could be characterized by the energy density of the plasma applied on the *** the increase of plasma dose,the surface contact angles first increased rapidly and then decreased gradually.

关键词： plasma jet polluted silicone rubber hydrophobicity plasma dose energy density spatial distribution

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Identification and functional characterization of ApisOr23 in pea aphid Acyrthosiphon pisum

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Journal of Integrative Agriculture 2022年第5期21卷 1414-1423页

作者： HUANG Tian-yu ZHANG Rui-bin YANG Lu-lu CAO Song Frederic FRANCIS WANG Bing WANG Gui-rong State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193P.R.China Guangdong Laboratory for Lingnan Modern Agriculture(Shenzhen Branch) Genome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518120P.R.China Functional and Evolutionary Entomology Gembloux Agro-Bio TechUniversity of LiegeGembloux 5030Belgium

Pea aphid,Acyrthosiphon pisum,is a serious pest of many different leguminous plants,and it mainly relies on its odorant receptors(Ors)to discriminate among host ***,less is known about the role that Ors play in the host plant *** this study,we identified a novel conserved odorant receptor clade by phylogenetic analysis,and conducted the functional analysis of ApisOr23 in *** results showed that the homologous Ors from ***,Aphis glycines and Aphis gossypii share 94.28% identity in amino acid ***,conserved motifs were analyzed using the annotated homologous Or23 from eight aphid species,providing further proof of the high conservation level of the Or23 *** to the tissue expression pattern analysis,ApisOr23 was mainly expressed in the *** functional study using a heterologous Xenopus expression system revealed that ApisOr23 was tuned to five plant volatiles,namely trans-2-hexen-1-al,cis-2-hexen-1-ol,1-heptanol,4’-ethylacetophenone,and hexyl *** them,trans-2-hexen-1-al,which is one of the main volatile organic compounds released from legume plants,activated the highest response of *** findings suggest that the conserved Or23 clade in most aphid species might play an important role in host plant detection.

关键词： Acyrthosiphon pisum odorant receptor phylogenetic analysis two-electrode voltage clamp trans-2-hexen-1-al

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Improved thermal conductivity of styrene acrylic resin with carbon nanotubes, graphene and boron nitride hybrid fillers

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Carbon Resources Conversion 2021年第1期4卷 190-196页

作者： Fuhua Jia Emmanuel Oluwaseyi Fagbohun Qianyu Wang Duoyin Zhu Jianling Zhang Bin Gong Yanbin Cui State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China College of Mechanical and Power Engineering Shenyang University of Chemical TechnologyShenyang 110142China University of Chinese Academy of sciences Beijing 100049 China

In the process of printing and copying,the volatilization of toner produces tiny particles and harmful gases that are detrimental to the human ***-temperature printing and copying can reduce harmful gas *** acrylic resin is the main component of toner and the thermal conductivity of toner can be improved by increasing the thermal conductivity of styrene acrylic *** this paper,hexagonal boron nitride(h-BN),carboxyl modified multi-walled carbon nanotubes(MWCNTs-COOH)and graphene hybrid fillers were added into styrene acrylic resin to improve the thermal conductivity of resin composite by forming a connected thermal conductivity network in *** experimental result shows that the thermal conductivity of the h-BN/styrene acrylic resin composite increases with the increase in h-BN filler content(0-20wt%).When 20.0 wt%h-BN is added into styrene acrylic resin,the thermal conductivity is increased by 83.63%.Hybrid fillers(MWCNTs-COOH/graphene and 3.0 wt%h-BN)were added in styrene acrylic resin and the thermal conductivity of the composite is almost the same or higher than that of 20.0 wt%h-BN/styrene acrylic resin *** thermal conductivity of styrene acrylic resin composites improved by 69.57%and 87.14%via adding 1.5wt%CNTs-3 wt%h-BN and 1.0wt%graphene-3 wt%***-COOH or graphene can bridge isolated h-BN aggregates to form a thermally conductive network in styrene acrylic resin,while the addition of graphene improves the thermal conductivity of resin composite higher than that of MWCNTs-COOH.

关键词： Styrene acrylic resin Boron nitride Carbon nanotubes Graphene Thermal conductivity

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From fundamentals to chemical engineering on oxidative coupling of methane for ethylene production:A review

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Carbon Resources Conversion 2022年第1期5卷 1-14页

作者： Jiao Liu Junrong Yue Mei Lv Fang Wang Yanbin Cui Zhanguo Zhang Guangwen Xu Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China Institute of Industrial Chemistry and Energy technology Shenyang University of Chemical TechnologyShenyang 110142LiaoningChina School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China

A comprehensive overview is presented to summarize the research works since 1982 on oxidative coupling of methane(OCM),a complex reaction network combining heterogeneous and homogeneous reaction *** on reaction mechanisms and thermodynamics have revealed that the OCM process is highly exothermic and its C2+selectivity and yield is critical in evaluating its commercial *** strategies have been put to enhance C2+selectivity,improve C2+yield and lower reaction *** catalyst MnNa2WO4/SiO2 enables methane activation at a temperature of 800◦C and simultaneously a high C2+selectivity of 70–80%,while the nanowire and La2O3-based catalysts enable to lower the reaction temperature to 200–300◦C and 500◦C,*** engineering aspects have also been dealt in many investigations in order to make the process technically ***,research works on reaction kinetics,reactor selection and reactor operating mode choice have been *** cooling and distributed oxygen feed have been integrated into a multi-stage adiabatic fixed-bed reactor system to suppress the side oxidation reactions and improve the performance of the catalysts towards CH4 conversion and C2+*** review paper proposes employing a circulating reactor system coupled with catalyst fine particles but having little internal diffusion resistance to maximize one-pass C2+selectivity and yield of the OCM reaction and evaluate its industrial application potential.

关键词： Oxidative coupling of methane Methane C2+ Ethylene OCM Reactor

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Achieving 20% photovoltaic efficiency by manganese doped methylammonium lead halide perovskites

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Journal of Energy Chemistry 2021年第9期30卷 376-383页

作者： Liangliang Deng Hanjun Yang Ruiheng Pan Haomiao Yu Jinpeng Li Ling Xu Kai Wang Key Laboratory of Luminescence and Optical Information Ministry of EducationSchool of ScienceBeijing Jiaotong UniversityBeijing 100044China Institute of Optoelectronics technology Beijing Jiaotong UniversityBeijing 100044China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074HubeiChina

We report a transition metal such as manganese doped methylammonium lead halide perovskite(MA(Pb:Mn)I_(3)) solar cell with an power conversion efficiency(PCE) over 20%. The rational design and fabrication of MA(Pb:Mn)I3 lead to the enhancements of all the photovoltaic parameters. To incorporate Mn can effectively eliminate the trap-assist and bi-molecular recombination. The photo-absorption ability at shorter wavelengths(i.e., less than 500 nm) and charge carrier lifetime can be elaborated. More importantly, the existence of the Mn^(2+)-I~--Mn^(3+)motif contributes for the double exchange effect, giving rise to the charge/spin transport. By a combination of linearly and circularly polarized photo-excitations, we have explicitly determined the role of intrinsic spin–orbit coupling(SOC) in MA(Pb:Mn)I_(3). More dark states are expected to be available for the photocurrent generation. This study may pave the way for deep understandings of transition metals doped hybrid perovskites for highly efficient solar cell applications.

关键词： Transition metals Manganese doped methylammonium lead halide perovskites(MA(Pb:Mn)I_(3)) Double exchange Intrinsic SOC Solar cells

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Head-to-tail cyclization for the synthesis of naturally occurring cyclic peptides on organophosphorus small-molecular supports

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Organic Chemistry Frontiers 2022年第4期9卷 946-952页

作者： Haidi Li Junyou Li Jie Chao Zixin Zhang Chuanguang Qin MIIT Key Laboratory of Special Functional&Intelligent Polymer materials MOE Key Laboratory of Supernormal Material Physics&ChemistryShaanxi Key Laboratory of Polymer Science&TechnologyDepartment of ChemistrySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an710072P.R.China

To achieve head-to-tail cyclic peptides via the liquid-phase on-support cyclization and synergistic self-cleavage strategy,4,4’-bis(diphenylphosphinyloxyl)diphenyl ketoxime(BDKO)and 4-diphenyl phospho-loxy benzyl alcohol(DPBA)were designed and prepared as small-molecular supports of greener peptide *** the process of the BDKO(or DPBA)support assisted Boc strategy for liquid-phase peptide chain extension,the last amino acid at the N-terminus of the peptide chain ends with a Fmoc protected amino acid.

关键词： synthesis cyclization synthesis

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The Large Scale Circulation of the Snow Disaster in Southern china in the Beginning of 2008

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Acta meteorologica Sinica 2009年第6期23卷 750-759页

作者：王亚非李琰李萍云刘英 State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Nanjing University of Information science&technology

This study analyzed the heaviest snowfalls or icy-rainfalls occurring in southern china from January to the beginning of February *** results are summarized as follows：the disaster was induced by the persistent front of warm/cold air masses in southern china,which displayed an interaction between the weather systems in higher and lower *** was an adjustment for circulation at hemisphere scale during mid January by a variation of sign of the Arctic Oscillation（AO）index from negative to *** long lasting precipitation well coincided with a blocking situation centered near 80°E from mid January to the beginning of February.A diagnostic analysis indicates that stationary waves with an energy dispersion accompanying the blocking high propagated from upstream region in high latitudes to the south of the Yangtze River,which formed a maintaining energy source for the cyclonic circulation in *** resulted in that the large mass of cold air in high latitudes could not easily invade into the south but slowly shifted *** the other hand,the sea surface temperature（SST）over the warm pool of the western Pacific increased with a new history record due to the effect of the strong La Nina episode,which also blocked the cold air mass from the *** blocking high collapsed around 30 January and the energy source for the local cyclonic circulation was cut ***,the precipitation in southern china ceased after 1 February.

关键词： Rossby wave large scale circulation snow disaster blocking high

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A Fractional-Order Ultra-Local Model-Based Adaptive Neural Network Sliding Mode Control of n-DOF Upper-Limb Exoskeleton With Input Deadzone

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 760-781页

作者： Dingxin He HaoPing Wang Yang Tian Yida Guo the School of Automation Nanjing University of Science and TechnologyNanjing 210094China IEEE Norinco Group Institute of Navigation and Control technology Beijing 100089China

This paper proposes an adaptive neural network sliding mode control based on fractional-order ultra-local model for n-DOF upper-limb exoskeleton in presence of uncertainties,external disturbances and input *** the model complexity and input deadzone,a fractional-order ultra-local model is proposed to formulate the original dynamic system for simple controller ***,the control gain of ultra-local model is considered as a *** fractional-order sliding mode technique is designed to stabilize the closed-loop system,while fractional-order time-delay estimation is combined with neural network to estimate the lumped ***,a fractional-order ultra-local model-based neural network sliding mode controller(FO-NNSMC) is ***,to avoid disadvantageous effect of improper gain selection on the control performance,the control gain of ultra-local model is considered as an unknown ***,the Nussbaum technique is introduced into the FO-NNSMC to deal with the stability problem with unknown ***,a fractional-order ultra-local model-based adaptive neural network sliding mode controller(FO-ANNSMC) is ***,the stability analysis of the closed-loop system with the proposed method is presented by using the Lyapunov ***,with the co-simulations on virtual prototype of 7-DOF iReHave upper-limb exoskeleton and experiments on 2-DOF upper-limb exoskeleton,the obtained compared results illustrate the effectiveness and superiority of the proposed method.

关键词： Adaptive control input deadzone model-free control n-DOF upper-limb exoskeleton neural network

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