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Tungsten 2024年第2期6卷 454-464页

作者： Meng-Long Liu Xu Han wen-wen he Feng-Yu Jiang Fang Ji Wang-Wang Shen Tao Zhou Jing-Mei Xu Ya-Qian Lan School of Chemistry and Life Science Changchun University of TechnologyChangchun 130012China Advanced Institute of Materials Science Changchun University of TechnologyChangchun 130012China School of Chemistry South China Normal UniversityGuangzhou 510006China

Polyoxometalates(POMs)are classified as solid superacids which can exhibit notable proton conductivity,making them a promising functional inorganic filler for enhancing the proton conductivity of proton exchange membranes(PEMs).In this study,a series of hybrid membranes were obtained by molecular-level hybridization of Weakley-type POM Na_(7)H_(2)LaW_(10)O_(36)(LaW_(10))clusters into sulfonated poly(aryl ether ketone sulfone)(SPAEKS).All hybrid membranes exhibited greater proton conductivity than the pristine membrane in the 30–80℃temperature *** the doping amount of LaW 10 reached 7 wt.%,the proton conductivity of M-LaW 10^(-7)achieved 64 mS·cm^(−1)at 80℃.Lanthanide ions'high coordination number property and variable coordination environment can aid to attract more water molecules from the *** 10 and these bound water can construct denser hydrogen bonds with–SO_(3)H of *** intensive hydrogen bonds will facilitate the constitution of more continuous proton transport channels,and improve the proton conductivity of the hybrid *** work off ers a fresh approach to using POMs containing rare-earth components in PEMs.

关键词： Polyoxometalates Rare-earth elements Sulfonated poly(arylene ether ketone sulfone) Proton exchange membranes

Covalent triazine frameworks modified by ultrafine Pt nanoparticles for efficient photocatalytic hydrogen production

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Nano Research 2024年第6期17卷 4908-4915页

作者： Xu Han Xueying Ge wen-wen he Wangwang Shen Tao Zhou Jian-Sen Wang Rong-Lin Zhong Abdullah MAl-Enizi Ayman Nafady Shengqian Ma School of Chemistry and Life Science Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012China Laboratory of Theoretical and Computational Chemistry Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China Department of Chemistry University of North Texas1508 W.Mulberry St.DentonTX 76201USA Department of Chemistry College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia

Pt nanoparticles(PtNPs)as active species have always been considered as one of the best semiconductor materials for photocatalytic hydrogen *** this study,a Schottky heterojunction has been successfully constructed by evenly loading ultrafine PtNPs onto a triazine-based covalent organic frameworks(COFs).This strategy maintained the high activity of these ultra-small PtNPs while maximizing the utilization of the Pt active *** fabricated PtNPs@covalent triazine-based framework-1(CTF-1)composite accomplished a significantly high rate of hydrogen evolution(20.0 mmol·g^(−1)·h^(−1),apparent quantum efficiency(AQE)=7.6%,atλ=450 nm)with 0.40 wt.%Pt loading,giving rise to a 44-fold-increase in the efficiency of the photocatalytic hydrogen production compared to the pristine *** calculations revealed that the strong electron transfer(Q(Pt)=−0.726 qe,in the analysis of Bader charge,Q(Pt)is the charge quantity transferred from Pt cluster to CTF-1,and qe is the unit of charge transfer quantity)between PtNPs and CTF-1 triggers a strong interaction,which makes PtNPs being firmly attached to the structure of CTF-1,thereby enabling high stability and excellent hydrogen production ***,the hydrogen binding free energy(ΔGH*)of PtNPs@CTF-1 is much lower than that of the unmodified CTF-1,leading to a much lower intermediate state and hence a significant improvement in photocatalytic *** overall findings of this work provide a new platform to incorporate metallic NPs into COFs for the design and fabrication of highly efficient photocatalysts.

关键词： Pt nanoparticles covalent triazine-based framework-1(CTF-1) photocatalysts hydrogen evolution reaction

Low profile cavity-embedded ultra-wideband UHF array antenna with end-fire beams

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Journal of Electronic Science and Technology 2024年第2期22卷 24-35页

作者： Huan he wen-Song Wang Southwest China Institute of Electronic Technology Chengdu610036China School of Electrical and Electronic Engineering Department Nanyang Technological UniversitySingapore639798Singapore

A low-profile,vertically polarized,ultra-wideband array antenna with end-fire beams operating in an ultra-high frequency(UHF)band is developed in this *** array antenna consists of 1×16 log-periodic top-hat loaded monopole antenna arrays and is feasible to embed into a shallow cavity to further reduce the array *** is introduced in the proposed antenna element to reduce profile height and the rectangular top hats are carefully designed to minimize the transverse *** results show that when the antenna array operates in a frequency range of 300 MHz-900 MHz,the end-fire radiation pattern achieves±45°scanning range in the horizontal *** prototypes of the proposed end-fire antenna element and a uniformly spaced linear array(1×2)are fabricated and *** end-fire antenna array should be suitable for airborne applications where low-profile and conformal scanning phased antenna arrays with end-fire radiations are *** design is attractive for airborne platform applications that are used to search,discover,identify,and scout the aerial target with vertically polarized beams.

关键词： End-fire radiation Low-profile Vertical polarization Log-periodic array

Interaction of yttrium barrier and calcium-rich phase on production and properties of WC precursor powders and alloys

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Journal of Rare Earths 2024年第1期42卷 228-236,I0008页

作者： wen he Dunqiang Tan Zhiqiang Yi Zhiqiang Liu School of Materials Science and Engineering Nanchang UniversityNanchang330031China Instrumental Analysis Center of Nanchang Hangkong University Nanchang330063China

In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electron microscopy and transmission electron microscopy were employed to analyze the phase compositions,particle sizes and morphologies of them,*** results show that the second type of"yttrium barrier effect"is observed and the adverse influence of Ca-rich phase on tungsten powder can be eliminated by *** flexural strength and fracture toughness of YG6-0.01%Ca+0.09%Y alloy are 2199.5 MPa and 11.49 MPa·m^(1/2),showing improvement of 6.5% and 2.7% compared to YG6 alloy,*** evolutions of Ca-rich phase and Y-rich phase at the every alloy preparation stage of WO_(3),W,WC and cemented carbides are ***,the strengthening mechanism of WC-Co cemented carbide with co-addition of Ca and Y is proposed.

关键词： Yttrium barrier effect Ca-rich phase WC-Co cemented Carbide Microstructures Mechanisms Rare earths

Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China

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Petroleum Science 2024年第1期21卷 100-114页

作者： wen-Long Dang Gang Gao Xin-Cai You Ke-Ting Fan Jun Wu De-wen Lei wen-Jun he Yong Tang State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum(Beijing)Beijing102249China School of GeoSciences China University of Petroleum(Beijing)Beijing102249China Exploration&Development Institute Xinjiang Oil Field CompanyKaramay834000XinjiangChina

The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu *** oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu *** crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep *** migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source *** changes might alter source rock evaluations and oil-source *** on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu *** source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate *** rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped ***,biomarker composition parameters indicate a higher thermal maturity than in-situ source *** a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin *** finding reminds

关键词： Organic geochemistry Source rock Influence of migrated hydrocarbons Fengcheng Formation Southern Mahu Sag

pH Induced Self-assembly of AIE Fluorescent Probe for Tumor Imaging

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Chinese Journal of Polymer Science 2024年第1期42卷 7-13,I0005页

作者： Jing-Yuan Xiang wen-Long Zhang he-Ting Li Ya-Ning he Department of Chemical Engineering Key Laboratory of Advanced Materials(MOE)Tsinghua UniversityBejing 100084China

This work reported an AIE fluorescent probe for tumor imaging based on the p H induced self-assembly strategy. The fluorescent probe was composed of an acid-responsive soluble copolymer PEG-b-PAMA-DMMA with a maleic acid amide group and an anionic soluble aggregation-induced emission fluorogen(AIEgen) TPE-2SO_(3)^(-). The polymer could be transformed into a protonated amine-containing polymer after the hydrolysis of maleic acid amide in acidic tumor microenvironment, which would be further self-assembled with TPE-2SO_(3)^(-)to form aggregated nanoparticles. The transition of TPE-2SO_(3)^(-)from dispersed state to aggregated state led to an obvious increase in fluorescence intensity due to its AIE characteristics.

关键词： p H-responsive Self-assembly Fluorescent probe AIE Tumor imaging

Palladium Complexes with N,O-Bidentate Ligands Based on N-Oxide Units from Cyclic Secondary Amines:Synthesis and Catalytic Application in Mizoroki-heck Reaction

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Chinese Journal of Chemistry 2024年第3期42卷 294-300页

作者： Xuefeng Jia Yanyan wen Changhui he Xianqiang Huang Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuanShanxi030032 China Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology School of Chemistry & Chemical EngineeringLiaocheng UniversityLiaochengShandong252059 China

Palladium-catalyzed Mizoroki-heck reaction is a powerful and efficient method for construction of Csp2–Csp2 ***,four palladium complexes(I—IV)with N,O-bidentate ligands(L1—L4)based on N-oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki-heck reaction of aryl bromides with electron-deficient olefins.X-ray diffraction analyses indicated the palladium(II)atom of II took the distorted square planar geometry and was four-coordinated by nitrogen and oxygen atoms from two ligands(L2).Two free chloride ions were presented as counter anions in complex *** the palladium(II)center of IV was coordinated by nitrogen and oxygen atoms from one ligand(L4)as well as two chlorine atoms,which exhibited the nearly square-planar *** study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other *** coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2—5 mol%palladium complex II,giving the desired products in good to excellent *** advantages of this method such as good compatibility of functional groups,high yields,and short reaction times made it more attractive for constructing Csp2–Csp2 bonds in the synthesis of functional molecules and materials.

关键词： Palladium complexes N,O-Bidentate ligands N-Oxide units Mizoroki-heck reaction Aryl bromide Electron-deficient olefins C—C coupling Homogeneous catalysis Substituent effects

Asymmetric Drying and Wetting Trends in Eastern and Western China

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Advances in Atmospheric Sciences 2024年第2期41卷 221-232页

作者： wen WU Fei JI Shujuan HU Yongli he College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China

As an important factor that directly affects agricultural production, the social economy, and policy implementation,observed changes in dry/wet conditions have become a matter of widespread concern. However, previous research has mainly focused on the long-term linear changes of dry/wet conditions, while the detection and evolution of the non-linear trends related to dry/wet changes have received less attention. The non-linear trends of the annual aridity index, obtained by the Ensemble Empirical Mode Decomposition(EEMD) method, reveal that changes in dry/wet conditions in China are asymmetric and can be characterized by contrasting features in both time and space in China. Spatially, most areas in western China have experienced transitions from drying to wetting, while opposite changes have occurred in most areas of eastern China. Temporally, the transitions occurred earlier in western China compared to eastern China. Research into the asymmetric spatial characteristics of dry/wet conditions compensates for the inadequacies of previous studies, which focused solely on temporal evolution;at the same time, it remedies the inadequacies of traditional research on linear trends over centennial timescales. Analyzing the non-linear trend also provides for a more comprehensive understanding of the drying/wetting changes in China.

关键词： aridity index EEMD dry/wet conditions asymmetric evolution

Precise modification of poly(aryl ether ketone sulfone)proton exchangemembranes with positively charged bismuth oxide clusters for high proton conduction performance

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SusMat 2022年第1期2卷 76-89页

作者： Yi-Zhuo Yin Zhen-Guo Zhang wen-wen he Jing-Mei Xu Feng-Yu Jiang Xu Han Wan-Ting Di ZheWang Shengqian Ma School of Chemistry and Life Science Advanced Institute of Materials ScienceChangchun University of TechnologyChangchunChina Advanced Institute of Materials ScienceChangchun University of Technology ChangchunChina Department of Chemistry University of North TexasDentonTexas

In the field of proton exchange membranes(PEMs),it is still a great challenge to explore new Nafion alternatives,maintaining the high proton conductivity and lowering the cost of practical *** this work,a series of low sulfonated poly(aryl ether ketone sulfone)(SPAEKS)membranes hybridized by[Bi_(6)O_(5)(OH)_(3)]_(2)(NO_(3))10⋅6H_(2)O(H_(6)Bi_(12)O_(16))have been successfully *** the doping amount of H6Bi12O16 reaches 5 wt%,the DS15-Bi12-5 showing the best proton conductive ability and mechanical *** proton conductivity can achieve 72.8 mS⋅cm−1 at 80℃ and the tensile strength can reach 43.57 *** by experimental data and activation energy(Ea)calculations,the existence of Bi cluster makes more hydrogen bonds,providing additional proton hopping sites and offers more proton transport vehicles,leading to a high proton conduction *** work proved that polyoxometalates(POMs)can replace the role of sulfonate groups in SPAEKS to a certain extent and work out the defects of high sulfonation,making a remarkable contribution to the practical application of low sulfonated SPAEKS.

关键词： polyoxometalates proton conductivity proton exchange membrane sulfonated poly(aryl ether ketone sulfone)

Thermodynamic theory of flotation for a complex multiphase solid -liquid system and high-entropy flotation

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1177-1197页

作者： Shuming wen State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China

The flotation of complex solid–liquid multiphase systems involve interactions among multiple components,the core problem facing flotation ***,the combined use of multicomponent flotation reagents to improve mineral flotation has become an important issue in studies on the efficient use of refractory mineral ***,studying the flotation of complex solid–liquid systems is extremely difficult,and no systematic theory has been developed to *** addition,the physical mechanism associated with combining reagents to improve the flotation effect has not been unified,which limits the development of flotation theory and the progress of flotation *** this study,we applied theoretical thermodynamics to a solid–liquid flotation system and used changes in the entropy and Gibbs free energy of the reagents adsorbed on the mineral surface to establish thermodynamic equilibrium equations that de-scribe interactions among various material components while also introducing adsorption equilibrium constants for the flotation reagents adsorbed on the mineral *** homogenization effect on the mineral surface in pulp solution was determined using the chemical potentials of the material components of the various mineral surfaces required to maintain *** flotation effect can be improved through synergy among multicomponent flotation reagents;its physical essence is the thermodynamic law that as the number of compon-ents of flotation reagents on the mineral surface increases,the surface adsorption entropy change increases,and the Gibbs free energy change of adsorption *** to the results obtained using flotation thermodynamics theory,we established high-entropy flotation theory and a technical method in which increasing the types of flotation reagents adsorbed on the mineral surface,increasing the adsorption entropy change of the flotation reagents,decreasing the Gibbs free energy change,and improving the adsorption efficiency

关键词： multicomponent flotation reagent adsorption entropy change equations of thermodynamic equilibrium adsorption equilibri-um constant high-entropy flotation