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A robust and unique approach for tuning the energy level of Ag_(2)Se quantum dots via“on-surface”manipulation of nitrogencontaining groups of surface-coordinated ligands

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Nano Research 2023年第11期16卷 12608-12617页

作者： meng-yao luo Bo Tang An-An Liu Jing-Ya Zhao Zhi-Ling Zhang Dai-Wen Pang The Institute for Advanced Studies and College of Chemistry and Molecular Sciences Wuhan UniversityWuhan 430072China State Key Laboratory of Medicinal Chemical Biology Tianjin Key Laboratory of Biosensing and Molecular RecognitionFrontiers Science Center for New Organic MatterResearch Center for Analytical SciencesCollege of ChemistryFrontiers Science Center for Cell ResponsesNankai UniversityTianjin 300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Effects of surface chemistry on energy levels or optical properties of semiconductor nanocrystals have attracted considerable attention and show great promise in broad ***,it remains challenging to controllably tune the photoluminescence(PL)of quantum dots(QDs)by manipulating surface ***,we investigated effects of the ligand,glutathione(GSH),on PL properties of near-infrared(NIR)Ag_(2)Se QDs by“on-surface”manipulation,that is,precisely manipulating the chelating group without dissociating the ligand from the *** anchoring of the amino group was found to be controlled by solution pH,whereas the binding of the thiol group to the Ag+was pH independent,maintaining the“on-surface”state of *** tuning the pH-controlled binding of amino groups,the energy level or the bandgap of Ag2Se QDs could be increased by up to 140 *** increased bandgap resulted in the blueshift of PL spectrum,which could be reversibly tuned by up to 75 *** pH-mediated tunable PL properties of QDs could also be extended to other nitrogen-containing pH-sensitive groups which could coordinate to the Ag+,not limited to the amino *** work would facilitate the study of nanocrystal surface chemistry and our model that the binding of amino groups affected energy levels of Ag2Se QDs might facilitate new insights into the electronic structure and energy level of other QD-ligand complexes.

关键词： quantum dot(QD) surface chemistry ligand energy level pH

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Zn-doping enhances the photoluminescence and stability of PbS quantum dots for in vivo high-resolution imaging in the NIR-II window

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Nano Research 2020年第8期13卷 2239-2245页

作者： Xiulei Shi Song Chen meng-yao luo Biao Huang Guozhen Zhang Ran Cui Mingxi Zhang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology430070WuhanChina Key Laboratory of Analytical Chemistry for Biology and Medicine(Ministry of Education) College of Chemistry and Molecular SciencesWuhan UniversityWuhan430072China iChEM(Collaborative Innovation Center of Chemistry for Energy Materials) Hefei National Laboratory for Physical Science at the MicroscaleUniversity of Science and Technology of ChinaHefei230026China

Lead sulfide(PbS)quantum dots(QDs)are important near infrared(NIR)luminescent materials with tunable and strong emission covering a broad NIR ***,their optical properties are quite sensitive to air,water,and high temperature due to the surface oxidation,thus limiting their applications in optoelectronic devices and biological ***,a cation-doping strategy is presented to make a series of high-quality Zn-doped PbS QDs with strong emission covering whole second near-infrared window(NIR-II,1,000-1,700 nm).First-principle calculations confirmed that Zn dopants formed dopant states and decreased the recombination energy gap of host ***,the Zn dopants significantly improved the quantum yield,photoluminescence lifetime and thermal stability of PbS ***,the PEGylated Zn-doped PbS QDs emitting in the NIR-llb window(1,500-1,700 nm)realized the noninvasive imaging of cerebral vascular of mouse with high resolution,being able to distinguish blood *** material not only provides a new tool for deep tissue fluorescence imaging,but is also promising for the development of other NIR related devices.

关键词： quantum dots doping second near-infrared window(NIR-II window) tunable emission in vivo imaging

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Superexchange and charge transfer in the nickelate superconductor La3Ni2O7 under pressure

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Science China(Physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 5-12页

作者： Wéi Wú Zhihui luo Dao-Xin yao meng Wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of Physics Sun Yat-sen University

Recently, a bulk nickelate superconductor La3Ni2O7is discovered at pressures with a remarkable high transition temperature Tc～ 80 K. Here, we study a Hubbard model with tight-binding parameters derived from ab initio calculations of La3Ni2O7,by employing large scale determinant quantum Monte Carlo and cellular dynamical mean-field theory. Our result suggests that the superexchange couplings in this system are comparable to that of cuprates. The system is a charge transfer insulator as the hole concentration becomes four per site at large Hubbard U. Upon hole doping, two low-energy spin-singlet bands emerge in the system exhibiting distinct correlation properties: while the one composed of the out-of-plane Ni-d3z2-r2and O-pzorbitals demonstrates strong antiferromagnetic correlations and narrow effective bandwidth, the in-plane singlet band consisting of the Ni-dx2-y2and O-px/pyorbitals is in general more itinerant. Over a broad range of hole doping, the doped holes occupy primarily the dx2-y2and px/pyorbitals, whereas the d3z2-r2and pzorbitals retain underdoped. We propose an effective t-J model to capture the relevant physics and discuss the implications of our result for comprehending the La3Ni2O7superconductivity.

关键词： superconductivity nickelate superconductors Hubbard model superexchange charge transfer insulator quantum Monte Carlo

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Research progress of slippage characteristic and gas film stability enhancement methods on biomimetic hydrophobic surfaces

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Journal of Hydrodynamics 2024年第1期36卷 87-101页

作者： meng-zhuo Zhang Hai-bao Hu Liu-zhen Ren Lu-yao Bao Jun Wen luo Xie School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518063China

The biomimetic hydrophobic surface is a potentially efficient underwater drag reduction method and the drag reduction mechanism of this kind of surface comes from the interfacial *** now,it is a hotspot to grasp the slippage characteristic and explore slippage enhancement *** paper not only summarizes our numerical simulation and experimental results of slippage characteristic at the solid-liquid interface(SLI)of hydrophobic surfaces(HS)and the gas-liquid interface(GLI)of superhydrophobic surfaces(SHS)in recent years,but also introduces some innovative methods that can effectively improve the gas film stability and drag reduction effect of ***,we used the molecular dynamics(MD)simulation method to figure out the effect of the solid-liquid interaction strength,the system temperature and the shear rate on the slippage of SLI,and expound their action mechanism from molecular ***,by MD and multibody dissipative particle dynamics(MDPD)method,the slippage behavior at the GLI was studied under the influence of the microstructure size and the flow driving *** proposed a new kind of hybrid slip boundary condition model to describe the slippage characteristic on *** addition,we found through experiment that a three-dimensional backflow will appear on the GLI under the interfacial adsorption of surfactants,and the backflow direction will reverse with the change of GLI ***,we put forward the wettability step structure and gas injection method to enhance the stability and drag reduction effect of the gas film on SHS.

关键词： Hydrophobic surface superhydrophobic surface interfacial slip underwater drag reduction

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In memoriam:Shizhu Wen(1932-2023)

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Friction 2024年第7期12卷 1341-1346页

作者： Jianbin luo Yonggang meng Yu TIAN State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Professor Shizhu Wen,the winner of the 2015 Tribology Gold Medal,passed away due to illness on November 3,2023,at the age of *** was a professor of Tsinghua University,an academician of the Chinese Academy of Sciences,and the Honorary President of the Chinese Tribology Institute(CTI)from 1997 to *** Wen was born in 1932 in Jiangxi Province of China and graduated from Tsinghua University in 1955,where he was awarded the Outstanding Graduate Gold Medal and then remained as an assistant professor at the *** Wen was promoted to full professor in *** had undertaken tribology research at the Imperial College London in 1979 and *** 1985,he presided over the establishment of the State Key Laboratory of Tribology(SKLT)of Tsinghua University and served as the first director of the SKLT.

关键词： sided professor zhu

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Multi-Objective Optimization Based on Life Cycle Assessment for Hybrid Solar and Biomass Combined Cooling,Heating and Power System

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Journal of Thermal Science 2024年第3期33卷 931-950页

作者： LIU Jiejie LI yao meng Xianyang WU Jiangtao Key Laboratory of Thermo-Fluid Science and Engineering Ministry of EducationXi’an Jiaotong UniversityXi’an710049China

The complementary of biomass and solar energy in combined cooling,heating and power(CCHP)system provides an efficient solution to address the energy crisis and environmental *** work aims to propose a multi-objective optimization model based on the life cycle assessment(LCA)method for the optimal design of hybrid solar and biomass *** life-cycle process of the poly-generation system is divided into six phases to analyze energy consumption and greenhouse gas *** comprehensive performances of the hybrid system are optimized by incorporating the evaluation criteria,including environmental impact in the whole life cycle,renewable energy contribution and economic *** non-dominated sorting genetic algorithmⅡ(NSGA-Ⅱ)with the technique for order preference by similarity to ideal solution(TOPSIS)method is employed to search the Pareto frontier result and thereby achieve optimal *** developed optimization methodology is used for a case study in an industrial *** results indicate that the best performance from the optimized hybrid system is reached with the environmental impact load reduction rate(EILRR)of 46.03%,renewable energy contribution proportion(RECP)of 92.73%and annual total cost saving rate(ATCSR)of35.75%,*** comparing pollutant-eq emissions of different stages,the operation phase emits the largest pollutant followed by the phase of raw material ***,this study reveals that the proposed multi-objective optimization model integrated with LCA method delivers an alternative path for the design and optimization of more sustainable CCHP system.

关键词： combined cooling heating and power system solar-biomass multi-objective optimization life cycle assessment optimal design

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Infinitely Many Solutions for a Class of Quasi-linear Elliptic Problem

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 728-743页

作者： Xiao-yao JIA Zhen-luo LOU School of Economics and Management Zhongyuan University of TechnologyZhengzhou 450007China Mathematics and Statistics School Henan University of Science and TechnologyLuoyang 471023China

In this paper,we study the following quasi-linear elliptic equation:■where Ω?R^(N) is a bounded domain,λ>0 is a *** function ψ(|t|)t is the subcritical term,and φ(|t|)t is the critical Orlicz-Sobolev growth term with respect to φ.Under appropriate conditions on φ,ψ and φ,we prove the existence of infinitely many weak solutions for quasi-linear elliptic equation,for λ∈(0,λ_(0)),where λ_(0)> 0 is a fixed constant.

关键词： quasi-linear elliptic equations variational methods Orlicz-Sobolev spaces

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Restoring cosmological concordance with axion-like early dark energy and dark matter characterized by a constant equation of state?

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Communications in Theoretical Physics 2024年第7期76卷 74-82页

作者： Yan-Hong yao Xin-He meng School of Physics and Astronomy Sun Yatsen University 2 Daxue RoadTangjiaZhuhaiChina School of Physics Nankai University 94 Weijin RoadNankaiTianjinChina

The Hubble tension persists as a challenge in *** early dark energy(EDE)models,initially considered the most promising for alleviating the Hubble tension,fall short of addressing the issue without exacerbating other tensions,such as the S_(8)*** that a negative dark matter(DM)equation of state(EoS)parameter is conducive to reduce the value of the σ_(8)parameter,we extend the axion-like EDE model in this paper by replacing the cold dark matter(CDM)with DM characterized by a constant EoS w_(dm)(referred to as WDM hereafter).We then impose constraints on this axion-like EDE extension model,along with three other models:the axion-like EDE model,ΛWDM,and Λ*** constraints are derived from a comprehensive analysis incorporating data from the Planck 2018 cosmic microwave background,baryon acoustic oscillations,and the Pantheon compilation,as well as a prior on H_(0)(i.e.H_(0)=73.04±1.04,based on the latest local measurement by Riess et al)and a Gaussianized prior on S_(8)(i.e.S_(8)=0.766±0.017,determined through the joint analysis of KID1000+BOSS+2dLenS).We find that although the new model maintains the ability to alleviate the Hubble tension to~1.4σ,it still exacerbates the S_(8)tension to a level similar to that of the axion-like EDE model.

关键词： Hubble tension early dark energy noncold dark matter S8 tension

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Integrating Neighborhood Geographic Distribution and Social Structure Influence for Social Media User Geolocation

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2513-2532页

作者： meng Zhang Xiangyang luo Ningbo Huang Key Laboratory of Cyberspace Situation Awareness of Henan Province Zhengzhou450001China State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450001China

Geolocating social media users aims to discover the real geographical locations of users from their publicly available data,which can support online location-based applications such as disaster alerts and local content *** relationship-based methods represent a classical approach for geolocating social ***,geographically proximate relationships are sparse and challenging to discern within social networks,thereby affecting the accuracy of user *** address this challenge,we propose user geolocation methods that integrate neighborhood geographical distribution and social structure influence(NGSI)to improve geolocation ***,we propose a method for evaluating the homophily of locations based on the k-order neighbor-hood geographic distribution(k-NGD)similarity among *** are notable differences in the distribution of k-NGD similarity between location-proximate and non-location-proximate *** this distinction,we filter out non-location-proximate social relationships to enhance location homophily in the social *** better utilize the location-proximate relationships in social networks,we propose a graph neural network algorithm based on the social structure *** algorithm enables us to perform a weighted aggregation of the information of users’multi-hop neighborhood,thereby mitigating the over-smoothing problem of user features and improving user geolocation *** results on real social media dataset demonstrate that the neighborhood geographical distribution similarity metric can effectively filter out non-location-proximate social ***,compared with 7 existing social relationship-based user positioning methods,our proposed method can achieve multi-granularity user geolocation and improve the accuracy by 4.84%to 13.28%.

关键词： User geolocation social media neighborhood geographic distribution structure influence

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Varieties of Involution J-Trivial Monoids with Continuum Many Subvarieties

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ALGEBRA COLLOQUIUM 2024年第3期31卷 467-480页

作者： Gao, meng Zhang, Wenting luo, Yanfeng Lanzhou Univ Sch Math & Stat Lanzhou 730000 Peoples R China

In this paper, we give a sufficient condition under which an involution monoid generates a variety with continuum many subvarieties. According to this result, several involution J-trivial monoids are shown to generate varieties with continuum many subvarieties. These examples include Rees quotients of free involution monoids, Lee monoids with involution, and Straubing monoids with involution.

关键词： monoid involution monoid variety subvariety lattice of varieties SEMIGROUPS

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