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Effects of water molecules on luminescence in europium and terbium coordination polymers with p-fluorobenzoic acid as ligand

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Journal of Rare Earths 2024年第7期42卷 1258-1264,I0003页

作者： Xiaoqi Zhao Puyan Hao Yami Ling Mengzhen Jia Rui Zhu Jiawen Liu Qiang Xu Jianhong Zhou Collaborative Innovation Center of Rare-Earth Optical Functional Materials and Devices Development Baoji Key Laboratory of Micro-Nano Optoelectronics and Terahertz TechnologySchool of Physics and Opto-Electronic TechnologyBaoji University of Arts and SciencesBaoji721016China

Our previous experimental observations show that the crystal structure of lanthanide luminescent complexes synthesized in aqueous solution usually contains a large number of coordination water molecules or free water *** order to probe the influence of water molecules on luminescent processes of lanthanide complexes,the photoluminescence properties of Ln-FBA(Ln=Eu and Tb,FBA=p-fluorobenzoic acid)coordination polymers at different ambient temperatures,in different solvents and aqueous DMSO solutions with different volume concentrations were systematically *** experiment results show that the presence of water molecules can promote the energy transfer from FBA ligand to Ln3+,at the same time,can cause luminescent non-radiation quenching of lanthanide *** addition,the variation of emission intensity ratio of 615 nm/591 nm peaks of Eu^(3+)with increasing the volume concentration of H_(2)O can be potentially used for the quantitatively detection of water traces in organic *** order to suppress the non-radiation quenching caused by the water molecules,Ln-FBA(Ln=Eu and Tb)coordination polymers were embedded into the PVP matrix to prepare Ln-FBA@PVP hybrid *** photoluminescence investigation indicates that PVP can not only block the quenching effect of water molecules on luminescence,but also effectively sensitize Eu^(3+)and Tb^(3+)*** experimental conclusions are useful for probing the influence of water molecules on luminescent processes of lanthanide complexes,quantitatively detecting water traces in organic solvents and enhancing the photoluminescence intensity in lanthanide complexes.

关键词： Lanthanide complexes Photoluminescence Luminescent quenching Rare earths

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The response and anti-stress mechanisms of nitrifying sludge under long-term exposure to Cd Se quantum dots

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Journal of Environmental sciences 2024年第1期135卷 174-184页

作者： Linkai Guo Lei Yang Yongxiang Ren Shen Cui Xiaotong Li Jia Wang Jun Lan Haoqi Lu Yuchao Wang shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Lab of Northwest Water Resource Environment and EcologyMinistry of EducationXi’an University of Architecture and TechnologyXi’an 710055China

The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment *** study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrifying sludge under long-term exposure to CdSe *** showed CdSe QDs(≥1 mg/L)would decrease the activity of ammonia monooxygenase(AMO).Under the stress of 30 mg/L CdSe QDs,the activity of AMO was reduced by 66%,while the activities of hydroxylamine oxidase and nitrite oxidoreductase were enhanced by 19.1%and 26%,***,the final nitrification effects were not adversely affected,and the production rates of NO_(2)^(-)-N and NO_(3)^(-)-N were ***,CdSe QDs improved biomass concentration in sludge and maintained the stability of sludge *** throughput sequencing analysis showed that CdSe QDs evidently reduced the abundance and diversity of microbial community in nitrifying *** abundances of amino acid metabolism and lipid metabolism were ***,CdSe QDs decreased the fluorescence intensity of tryptophan-like protein from 2,326 to 1,179 *** loosely bound extracellular polymeric substances(EPSs)and from 3,792 to 3,117 *** tightly bound *** relieve CdSe QD stress,the polysaccharide content increased from0.31 to 0.61 mg/g MLSS and intracellular antioxidant defense was *** CdSe QD level increasing to 30 mg/L,the total antioxygenic capacity and the activities of catalase were enhanced up to 411%and 143.2%,***,CdSe QDs had little adverse effects on cell membrane integrity,microbial metabolism and the abundance of Nitrospirae.

关键词： Quantum dots Activated sludge Extracellular polymeric substances Microbial community Antioxidant effect

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Preparation of a Novel Green Fluorescent Carbon Quantum Dots and Application in Fe^(3+)-Specific Detection in Biological System

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Journal of Analysis and Testing 2024年第1期8卷 40-51页

作者： Xianfen Zhang Wenxian Wang Lijiao Guan Huajie Chen Dai Li Lipeng Zhang Saipeng Huang School of Chemical Engineering Northwest UniversityXi'an 710069China Chemical Technology Academy of Shandong Province Qingdao University of Science and TechnologyJinan250014China

Trace ferric ion(Fe^(3+))detection has attracted increasing attention as an essential and indispensable role in many physiological and pathological *** green-emitting carbon quantum dots(Green-CQDs)were obtained through a green and facile one-step hydrothermal method for the specific recognition and trace detection of Fe^(3+)in this *** optimal excitation and emission wavelengths of the CQDs were 395 nm and 490 nm,*** stokes shift was up to 95 nm,which can effectively reduce the background fluorescence *** addition,it also exhibited good water solubility,stability,and high *** fluorescence intensity of Green-CQDs was linearly related to the concentration of Fe^(3+)(range of 0-80μmol/L),and the detection limit was as low as 59 nmol/*** good properties were favorable and successful for Fe^(3+)detection in tap water,human serum samples and living *** addition,a fluorescence visual test paper(FP@CQDs)was prepared utilizing filter paper as carrier,which can quickly identify Fe^(3+)in real time,and is suitable for the visualization analysis of Fe^(3+)in *** an efficient nanoprobe,the Green-CQDs held great promise and bright prospects in practical application in prevention and early clinical diagnosis of Fe^(3+)-associated diseases.

关键词： Carbon quantum dots Fluorescent Hydrothermal Fe^(3+)-specific detection Cell imaging

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Preparation and Swelling Kinetic Analysis of Poly (HPMC-co-AA-co-AM) Super Absorbent Resin

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Journal of Wuhan University of Technology(Materials science) 2024年第3期39卷 790-799页

作者：马砺 WANG Xin LIU Xixi WEI Gaoming GUO Ying School of Safety science and Engineering Xi’an University of Science and TechnologyXi'an 710054China Key Laboratory of Coal Fire Disaster Prevention Xi’an University of Science and TechnologyXi'an 710054China School of Energy Engineering Xi’an Uni-versity of Science and TechnologyXi'an 710054China Yanzhou Coal Mining Co. Ltd.Zoucheng 237500China

Super absorbent resin(SAR)is prepared by aqueous high temperature polymerization using hydroxypropyl methylcellulose(HPMC)as monomer backbone material,acrylic acid(AA)and acrylamide(AM)as the graft copolymer monomer,potassium persulfate(KPS)as the initiator to generate free radicals,and N,N`-methylenebisacrylamide(MBA)as cross-linking agent for cross-linking ***,the influence of individual factors on the water absorption is investigated,and these factors are mainly AA,AM,KPS,MBA,HPMC,and reaction *** optimized conditions are obtained by the experiment repeating for several *** water absorption multiplicity and salt absorption multiplicity under the conditions are 782.4 and 132.5 g/g,***,the effects of different temperatures and salt concentrations on its water absorption,as well as the swelling kinetics of SAR are *** is indicated the water-absorbing swelling process is mainly caused by the difference in water osmotic pressure and Na+concentration inside and outside the cross-linked molecular structure of the resin,which is not only consistent with the quasi-secondary kinetic model,but also with the Fick diffusion model.

关键词： super absorbent resin swelling kinetics water absorption graft copolymerization hydroxypropyl methyl cellulose

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Difference in microstructural characteristics of stamp-charged coke and gravity-charged coke with approximate macroscopic performance

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Journal of Iron and Steel research International 2024年第5期31卷 1050-1062页

作者： Chong Zou Zheng-yan Huang Jian-yun Li Bin Li Shi-wei Liu Yuan She School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710311ShaanxiChina Technical Center of Shandong Iron and Steel Co. Ltd.(Laiwu Branch)Jinan271104ShandongChina

The microstructural characteristics including optical texture,porosity and pore structure and chemical structure of stamp-charged coke(SCC)and gravity-charged coke(GCC)with similar conventional macro-indicators were investigated,and the properties including micro-strength,reactivity of coke matrix and that after alkali enrichment were comparatively studied by various characterization *** anisotropic structure of SCC is composed of high content of fine mosaic texture,while the content of medium mosaic texture,coarse texture and fibrous texture is *** statistical average shows that the fine mosaic average of SCC(24.89%)is 3.78 times the GCC average(6.58%),and the coarse mosaic average(1.24%)is only about 1/3 of the GCC average(3.43%).The porosity of SCC is lower than that of GCC,but tamping process does not lead to the fact that the number of closed pores of SCC is significantly lower than that of *** the structure of SCC is compact,its pore number is large and the pore wall is *** of coke with diameter less than 150 nm seem unaffected by tamping *** aromatic structure of SCC was less ordered than that of GCC,which was speculated to be related to the addition of more low metamorphic coal in *** microscopic strength and structural strength of SCC are lower than those of *** reactivity of coke matrix is affected by the specific surface area,but it is not the determining factor of its *** improvement in dissolution reactivity of coke after potassium enrichment is independent of coke type.

关键词： Stamp-charged coke Optical texture Porosity Microstructure Reactivity

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Utilizing quantum coherence in Cs Rydberg atoms for high-sensitivity room-temperature terahertz detection: a theoretical exploration

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Photonics research 2024年第7期12卷 1583-1592页

作者： LEI HOU JUNNAN WANG QIHUI HE SUGUO CHEN LEI YANG SUNCHAO HUANG WEI SHI Department of Physics Xi’an University of TechnologyXi’an 710048China School of Electrical Engineering Xi’an University of TechnologyXi’an 710048China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 610101Singapore

In recent years,terahertz (THz) technology has made significant progress in numerous applications;however,the highly sensitive,room-temperature THz detectors are still rare,which is one of the bottlenecks in THz *** this paper,we proposed a room-temperature electrometry method for THz detection by laser spectroscopy of cesium(^(133)Cs) Rydberg atoms,and conducted a comprehensive investigation of the five-level system involving electromagnetically induced transparency (EIT),electromagnetically induced absorption (EIA),and Autler–Townes (AT) splitting in^(133)Cs *** solving the Lindblad master equation,we found that the influence of the THz electric field,probe laser,dressing laser,and Rydberg laser on the ground state atomic population as well as the coherence between the ground state and the Rydberg state,plays a crucial role in the transformation and amplitude of the EIT and EIA *** and the atomic vapor cell’s dimensions affect the number of^(133)Cs atoms involved in the detection,and ultimately determine the *** predicted the proposed quantum coherence THz detection method has a remarkable sensitivity of as low as 10^(-9)V m^(-1)Hz^(-1/2).This research offers a valuable theoretical basis for implementing and optimizing quantum coherence effects based on Rydberg atoms for THz wave detection with high sensitivity and room-temperature operation.

关键词： quantum Rydberg dimensions

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Electrostatic Encapsulation of Cobalt Ions into Crystalline Framework Derived Polymer Aerogel:Ultra-light,Pressure Resistant,Hydrophobic,Photothermal Conversion,Heat Insulation and Infrared Stealth

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Chinese Journal of Polymer science 2024年第7期42卷 946-957,I0007页

作者： Yi-Fan Kang Jin-Lu Tang Ming Song Wei Wang Jia-Cheng Ma Zhan-You Ji Tong Liu Wen-Huan Huang China Key Laboratory of Chemical Additives for China National Light Industry College of Chemistry and Chemical EngineeringShaanxi University of Science and TechnologyXi’an710021China College of New Energy Xi’an Shiyou UniversityXi’an710065China Xi’an Key Laboratory of Functional Supramolecular Structure and Materials College of Chemistry and Materials ScienceNorthwest UniversityXi’an710127China

A variety of electromagnetic wave absorption materials(EMWAs)have been reported,but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical ***,carbon-coated cobalt composites were prepared by adsorbing magnetic metal cations into an anionic crystalline framework through an electrostatic encapsulate *** reflection loss(RL_(min))of-40.49 d B and effective absorption bandwidth(EAB)of 5.36 GHz(RL<-10 d B,10.4-15.76 GHz)was achieved with an optimal radar cross section(RCS)reduction of 34.9 dB·m^(2) for the sample *** commercial applications,Co@CN-4 was integrated into sodium carboxymethyl cellulose(CMC)aerogel to create an ultra-lightweight composite aerogel that is compressive resistant and heat-holding while also having photothermal conversion *** hydrophobic modification makes it more widely *** study provides a new strategy for EWAMs to integrate versatility and improve their application prospects.

关键词： Electrostatic incorporation Magnetic nanoparticle Co@CN composites Electromagnetic wave absorbing Metal-organic framework

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Formation and transformation of metastable LPSO building blocks clusters in Mg-Gd-Y-Zn-Zr alloys by spinodal decomposition and heterogeneous nucleation

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Journal of Magnesium and Alloys 2024年第2期12卷 673-686页

作者： Xin Zhao Zhong Yang Jiachen Zhang Minxian Liang Liying Wang School of Materials science and Chemical Engineering Xi’an Technological UniversityXi’an 710021China Xi’an Tianli Metal Composite Material Co.Ltd. Xi’an 710299China

To study the formation and transformation mechanism of long-period stacked ordered(LPSO)structures,a systematic atomic scale analysis was conducted for the structural evolution of long-period stacked ordered(LPSO)structures in the Mg-Gd-Y-Zn-Zr alloy annealed at 300℃~500℃.Various types of metastable LPSO building block clusters were found to exist in alloy structures at different temperatures,which precipitate during the solidification and homogenization *** stability of Zn/Y clusters is explained by the first principles of density functional *** LPSO structure is distinguished by the arrangement of its different Zn/Y enriched LPSO structural units,which comprises local fcc stacking sequences upon a tightly packed *** presence of solute atoms causes local lattice distortion,thereby enabling the rearrangement of Mg atoms in the different configurations in the local lattice,and local HCP-FCC transitions occur between Mg and Zn atoms occupying the nearest neighbor *** finding indicates that LPSO structures can generate necessary Schockley partial dislocations on specific slip surfaces,providing direct evidence of the transition from 18R to *** of the LPSO,devoid of any defects and non-coherent interfaces,was observed separately from other precipitated *** a result,the precipitation sequence of LPSO in the solidification stage was as follows:Zn/Ycluster+Mg layers→various metastable LPSO building block clusters→18R/24R LPSO;whereas the precipitation sequence of LPSO during homogenization treatment was observed to be as follows:18R LPSO→various metastable LPSO building block clusters→14H *** these,14H LPSO was found to be the most thermodynamically stable structure.

关键词： LPSO Spinodal decomposition Homogenization treatment Clusters Phase transformation

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Dual-wavelength pumped latticed Fermi-Pasta-Ulam recurrences in nonlinear Schrödinger equation

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Chinese Physics B 2024年第3期33卷 277-280页

作者：张倩姚献坤董恒 School of Physics Northwest UniversityXi'an 710127China shaanxi Key Laboratory for Theoretical Physics Frontiers Xi'an 710127China Peng Huanwu Center for Fundamental Theory Xi'an 710127China

We show that the nonlinear stage of the dual-wavelength pumped modulation instability(MI)in nonlinear Schrödinger equation(NLSE)can be effectively analyzed by mode truncation *** resulting complicated heteroclinic structure of instability unveils all possible dynamic trajectories of nonlinear ***,the latticed-Fermi-Pasta-Ulam recurrences on the modulated-wave background in NLSE are also investigated and their dynamic trajectories run along the Hamiltonian contours of the heteroclinic *** is demonstrated that there has much richer dynamic behavior,in contrast to the nonlinear waves reported *** novel nonlinear wave promises to inject new vitality into the study of MI.

关键词： modulation instability dual-wavelength pumps latticed-Fermi-Pasta-Ulam recurrences

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Effect mechanism of seepage force on the hydraulic fracture propagation

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International Journal of Coal science & Technology 2024年第3期11卷 223-240页

作者： Haiyang Wang Desheng Zhou Yi Zou Peng Zheng School of Petroleum Engineering Xi’an Shiyou UniversityXi’an710065China Engineering research Center of Development and Management for Low to Extra-Low Permeability Oil and Gas Reservoirs in West China Ministry of EducationXi’an Shiyou UniversityXi’an710065ShaanxiChina Xi’an University of science and Technology Xi’an710054ShaanxiChina

The flow of fluid through the porous matrix of a reservoir rock applies a seepage force to the solid rock *** the seepage force exerted by fluid flow through the porous matrix of a reservoir rock has a notable influence on rock deformation and failure,its effect on hydraulic fracture(HF)propagation remains ***,in this study,we improved a traditional fluid–solid coupling method by incorporating the role of seepage force during the fracturing fluid seepage,using the discrete element ***,we validated the simulation results of the improved method by comparing them with an analytical solution of the seepage force and published experimental ***,we conducted numerical simulations in both homogeneous and heterogeneous sandstone formations to investigate the influence of seepage force on HF *** results indicate that fluid viscosity has a greater impact on the magnitude and extent of seepage force compared to injection rate,and that lower viscosity and injection rate correspond to shorter hydraulic fracture ***,seepage force influences the direction of HF propagation,causing HFs to deflect towards the side of the reservoir with weaker cementation and higher permeability.

关键词： Hydraulic fracturing Seepage force Fracture propagation Discrete element method Reservoir heterogeneity

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