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Particuology 2024年第7期90卷 323-339页

作者： Fopeng Wen Liuyun Xu Yixiang Chen Zhaofu Deng Shen Zhang Wenming Song Yuge Li Liping Wei school of Chemical engineering Northwest UniversityXi’an710069China school of chemistry and Chemical engineering Yan'an UniversityYan'an716000China Machinery industry Shanghai Lanya Petrochemical Equipment Inspection Institute Co. Ltd.Shanghai201518China The Research Center of Chemical engineering Applying Technology for Resource of Shaanxi Xi’an710069China

The elbow erosion seriously jeopardizes the safe and stable operation of water–slag discharge pipeline of the coal gasification *** work simulated water–slag elbow characteristics with various slag injection positions by simulating five simplified and representative erosion categories,including A-type horizontal-vertical elbow with an upstream flow,B-type horizontal-vertical elbow with a downstream flow,C-type vertical-horizontal elbow with an upstream flow,D-type vertical-horizontal elbow with a downstream flow and E-type horizontal-horizontal *** with the C/D-type elbow,where particles were injected uniformly,the A-type elbow and E-type elbow were found to increase erosion rate,while the B-type elbow decreases erosion *** interesting discovery is that the elbow erosion rate is relatively low for small particles when particles are injected from the middle and bottom positions of the inlet section of the *** on the observation,a novel preceding rotating sheet structure was developed to regulate the particle injection *** shows an excellent anti-erosion performance by reducing the maximum erosion rate of particles with diameters of 50,100,and 200μm by 23%,35%,and 43%,respectively.

关键词： Erosion Slag-water Uneven particles Elbow pipe Erosion inhibition Preceding rotating sheet structure

Metasurface-assisted low-frequency performance enhancement of ultra-broadband honeycomb absorber based on carbon nanotubes

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Nano Research 2024年第9期17卷 8542-8551页

作者： Cai-Liang Wang Shuang Bai Pei-Yan Zhao Tao Zhou Hui-Ya Wang Jun-Peng Wang Luo-Xin Wang Guang-Sheng Wang school of chemistry Beihang UniversityBeijing 100191China Aerospace Science and industry Corporation of Wuhan Magnetoelectricity Co. Ltd.Wuhan 430070China College of Materials Science and engineering Key Laboratory for New Textile Materials and Applications of Hubei ProvinceWuhan Textile UniversityWuhan 430200China school of chemistry and Chemical engineering Lingnan Normal UniversityZhanjiang 524048China school of Materials Science and engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Here,we present a unique method to enhance the low-frequency absorption performance of a honeycomb absorber by integrating a *** geometrical dimensions of the proposed metasurface have been numerically *** introduction of the metasurface allows exploitation of its robust resonance and superior impedance matching in low-frequency bands,thereby improving microwave absorption *** incorporation of the metasurface does not impact the wave transmission performance of the honeycomb core absorber at high-frequency band,thus preserving its high-frequency *** broadens the absorption range,leading to an expanded *** results reveal that the composite absorber(CA)exhibits strong absorption performance with an incident angle stability up to 45°for both transverse electric(TE)and transverse magnetic(TM)*** absorption mechanism of the CA has been investigated by using an equivalent circuit model and electromagnetic field analysis.A prototype was designed,fabricated,and tested to validate the proposed *** simulation and measurement results demonstrate that the prototype can achieve an average absorption rate exceeding 90%across a 1.0-18.0 GHz *** study introduces an innovative technique for creating microwave absorbers for low-frequency wideband applications.

关键词： low frequency metasurface radar absorption impedance matching

Nitrogen-doped carbon dots as photocatalysts for organic synthesis:Effect of nitrogen content on catalytic activity

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Nano Research 2024年第6期17卷 4825-4833页

作者： Kai-Kai Niu Chao-Qun Ma Rui-Zhi Dong Hui Liu Sheng-Sheng Yu Ling-Bao Xing school of chemistry and Chemical engineering Shandong University of TechnologyZibo 255000China

Regulating the doping of carbon dots(CDs)and the generation of reactive oxygen species(ROS)is essential to selectively control their application in photocatalytic organic *** study successfully synthesized five newly developed nitrogen-doped carbon dots(CDs 1-5)with varying nitrogen content,which have the ability to generate ROS when exposed to light radiation,specifically superoxide anion radicals(O_(2)•-)and singlet oxygen(^(1)O_(2)).The utilization of the aforementioned nitrogen-doped CDs as photocatalysts enables the realization of their potential in facilitating efficient photocatalytic organic ***,it was observed that the photocatalytic efficiency exhibited a gradual decrease when the nitrogen content in the CDs *** order to provide more evidence for this claim,we employed a set of five CDs in the context of photocatalytic dehalogenation ofα-bromoacetophenone,photocatalytic oxidative coupling reaction of amines to imines,photooxidation reaction of sulfides to sulfoxides,and cross-dehydrogenation coupling(CDC)reaction,in which it was further observed that there was a steady decrease in the yields of photocatalytic organic reactions as the nitrogen content in CDs ***,CDs 1 exhibited the best photocatalytic efficiency,thereby reinforcing the hypothesis that a higher nitrogen content corresponds to a decreased catalytic *** study not only investigates the impact of the nitrogen content on the catalytic performance of CDs,but also offers valuable insights for the future utilization of CDs for photocatalytic organic reactions in water.

关键词： carbon dots nitrogen-doped reactive oxygen species photocatalysis

Separation of La(Ⅲ),Ce(Ⅳ)and Ca(Ⅱ)from bastnaesite using acidic phosphonic chitosan and rotating disk membrane

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Journal of Rare Earths 2024年第5期42卷 995-1000,I0007页

作者： Dandan Lu Wenhui Li Linlin Fan Yunren Qiu school of chemistry and Chemical engineering Central South UniversityChangsha410083China

The separation of rare earths is difficult due to their similar properties and the complex characteristics of associated vein o ***-ultrafiltration(CUF)and shear induced o rderly dissociation coupling with ultrafiltration(SIODUF)were used to separate metal ions(M,M=La(Ⅲ),Ce(Ⅳ)and Ca(Ⅱ))from simulated bastnaesite leaching solution using acidic phosphonic chitosan(aPCS)and rotating disk *** of simultaneous removal of metallic ions was investigated by CUF,and suitable conditions were obtained for C/M 10.0(mass ratio of complexant to metal ions)and pH *** shear stabilities of aPCS-M complexes were explored at different pH values and the results show that the complexes can dissociate at a certain rotational speed,the critical *** critical s hear rates of aPCS-La,aPCS-Ce and aPCS-Ca complexes at pH 5.0 were calculated as 1.42×10^(5).1.69×10^(5) and 9.75×10^(4) s^(-1),*** order of complexes shear stability is aPCS-Ca aPCS-Lalight of the difference of aPCSM complexes shear *** separation coefficientsβLa/Ce andβCa/La reach 31.2 and 53.9,respectively.

关键词： Bastnaesite Rare earths Complexation-ultrafiltration Acidic phosphonic chitosan Rotating disk membrane

Nano-flower spherical SnS2 combined with a special lithium storage mechanism as a multifunctional separator for lithium-sulfur batteries contributes to ultra-high initial discharge specific capacity

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Science China(Technological Sciences) 2024年第2期67卷 509-519页

作者： LIU HuaZhong XIONG YaPing HUANG MouZhi CHEN ZongMin YANG Xiao ZHANG Ze YANG ZhenYu CAI JianXin school of chemistry&Chemical engineering Nanchang UniversityNanchang 330031China

The critical factors that limit the electrochemical performance of lithium-sulfur(Li-S)batteries are mainly the“shuttle effect”of polysulfides and the slow redox reaction between lithium polysulfides(LiPSs).Herein,a nano-sphere-type material selfassembled from tin disulfide nanosheets is designed and applied to the Li-S cell separator in this *** SnS_(2)@PP modified separator not only acts as a dual restriction for LiPSs by chemisorption and physical *** the same time,it improves the catalytic activity of the redox reaction between *** SnS_(2)has extremely high electrochemical ***,a portion of the lithium ions can be inserted into SnS_(2)to form Li_(x)SnS_(2)and contribute to the capacity during the first discharge of the *** addition,Li_(x)SnS_(2)possesses a high degree of stability,and it does not undergo further de-alloying reactions even at the high potential of the Li-S *** benefit is that the steady-state Li_(x)SnS_(2)acts as a lithium-containing *** can form special Li^(+)channels on the surface of the separator,thus greatly improving the efficiency of Li+*** results showed that the SnS_(2)@PP-based cell exhibited extremely high initial discharge specific capacity(1477 m Ah g^(-1)at 0.1 C)and excellent rate performance(631 m Ah g^(-1)at 5 C).Even after 1000 cycles at 2 C,the cell exhibited a low decay rate of 0.06%per cycle on *** addition,the superior electrochemical performance was obtained even with a high sulfur loading of 5.1 mg cm^(-2)and low electrolyte of E/S=8μL mg^(-1).

关键词： Li-S batteries modified separators polysulfides catalytic conversion high electrochemical activity

Metal–phenolic coordination crystals derived magnetic hollow carbon spheres for ultrahigh electromagnetic wave absorption

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Nano Research 2024年第3期17卷 1616-1624页

作者： Hanxiao Xu Zizhuang He Yiruo Wang Xiangru Ren Panbo Liu school of chemistry and Chemical engineering Northwestern Polytechnical UniversityXi’an 710129China

Owing to the tunable compositions and versatile functionality,the development of eco-friendly metal–phenolic coordination crystals derivatives is highly anticipated for electromagnetic wave *** this study,three kinds of magnetic hollow carbon spheres(HCSs)with macro-meso-microporous characteristics,including Fe/HCS,Co/HCS,and CoNi/HCS,are successfully fabricated via the co-operative hard template and self-assembling process,in which magnetic particles are encapsulated in carbon shell matrix after the pyrolysis of metal–polyphenol coordination crystals and further subsequent template *** the one hand,hierarchical macro-meso-micropores effectively balance the impedance gap between absorbers and air and introduce structural defects or distortion,leading to matched impedance and enhanced dipolar/defect *** the other hand,wrapped magnetic particles provide uncountable hetero-interfaces and induce ferromagnetic resonance,resulting in strengthened interfacial polarization and additional magnetic *** particular,enhanced minimum reflection loss(RL,min)and broadband effective absorption bandwidth(EAB)are achieved with only 10 wt.%filler ***,the RL,min and EAB values are-57.5 dB and 7.2 GHz for Fe/HCS,-50.0 dB and 5.8 GHz for Co/HCS,and-52.1 dB and 6.7 GHz for CoNi/HCS,***,this work provides us a modular-assembly strategy to regulate the hollow cavity of absorbers and simultaneously manipulates the chemical components of absorbers to regulate electromagnetic wave absorption performance.

关键词： hollow engineering hierarchical pores hetero-interfaces synergetic effect electromagnetic wave absorption

Compositional evolution for mixed aerosols containing gluconic acid and typical nitrate and the effect of multiply factors on hygroscopicity

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Journal of Environmental Sciences 2024年第5期139卷 206-216页

作者： Yue Zhu Shufeng Pang Yunhong Zhang school of chemistry and Chemical engineering Beijing Institute of TechnologyBeijing 100081China

The aging process of atmospheric aerosols usually leads to a mixture of inorganic salts and organic compounds of anthropogenic *** organic compounds,polyhydroxy organic acids are important components,however,the study on composition and hygroscopic properties of the mixture containing inorganics and polyhydroxy organic acids is *** this study,gluconic acid,the proxy of polyhydroxy organic acids,is mixed with the representative nitrate(Mg(NO_(3))_(2),Ca(NO_(3))_(2))to form ***-FTIR and optical microscopy are employed to study the component changes and hygroscopicity as a function of relative *** relative humidity fluctuates,the FTIR-ATR spectra display that the internal mixed gluconic acid(CH_(2)(CH)_(4)(OH)_(5)COOH)and nitrate can react to release acidic gases,forming relevant gluconate and further affecting the *** specific presentation is particles cannot be recovered to their original size after the dehydration-hydration process and there will be some disparities in GF for mixed *** the gluconic acid-Ca(NO_(3))_(2)/Mg(NO_(3))_(2)mixtures with molar ratios of 1:1,higher degree of reaction resulting in the production of large amounts of gluconate should be responsible to the lower hygroscopicity compared to ZSR *** 1:2 gluconic acid-nitrate mixed systems(with higher nitrate content),the hygroscopicity of mixtures are higher than the ZSR prediction.A possible reason could be‘salt-promoting effect’on the organic fractions of the surplus inorganic salt in the *** data can improve the chemical composition list evaluation,in turn hygroscopic properties and phase state of atmospheric aerosol,and then the climate effect.

关键词： Hygroscopicity Gluconic acid Reaction ZSR simulation Size growth factors

Activity promotion of Rh_(1)Ca_(x)/Al_(2)O_(3) single-atom catalyst in 1-octene hydroformylation:a volcano curve exists between Ca adding ratio and catalytic activity

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Science China chemistry 2024年第4期67卷 1187-1192页

作者： Hao Zhang Xingcong Zhang Xilun Wang Qingdi Sun Hao Liu Hongbing Ji Xiaohui He Key Laboratory of Bioinorganic and Synthetic chemistry of Ministry of Education Fine Chemical Industry Research InstituteSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou 510275China Huizhou Research Institute Sun Yat-sen UniversityHuizhou 516081China State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology Institute of Green Petroleum Processing and Light Hydrocarbon ConversionCollege of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014China

Single-atom catalysts(SACs)are considered the best candidates for olefin hydroformylation due to their combined advantages of homogeneous and heterogeneous *** conventional organo-phosphine modification,Rh SAC is modified by introducing Ca,resulting in a significant increase in activity(maximum~5.7-fold)and ***,a volcano curve between Ca addition ratio and catalytic activity is *** Ca significantly increases activity by decreasing the energy barrier,but excessive Ca decreases activity due to hindering substrate adsorption and reaction.

关键词： hydroformylation bimetallic single-atom catalysts rhodium heterogeneous catalyst

Recent advances in g-C_(3)N_(4)-based direct Z-scheme photocatalysts for environmental and energy applications

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Chinese Journal of Structural chemistry 2024年第2期43卷 66-84页

作者： Xiaoming Fu Haibo Huang Guogang Tang Jingmin Zhang Junyue Sheng Hua Tang school of Intelligent engineering and Technology Jiangsu Vocational College of Finance&EconomicsHuai'anJiangsu223003PR China school of Modem Equipment Manufacturing Changzhou Institute of light industry Technology ChangzhouJiangsu213164PR China school of Environmental Science and engineering Qingdao UniversityQingdao266071PR China school of Materials Science and engineering Hainan UniversityHaikou570228PR China

In the midst of the rapid advancement of photocatalysis,direct Z-scheme heterojunction photocatalysts have emerged as a powerful solution to address environmental challenges and the looming energy *** precise engineering of direct Z-scheme heterojunction photocatalysts proves highly beneficial in optimizing their elec-tronic structure,ultimately enhancing their photocatalytic ***,graphitic carbon nitride(g-C_(3)N_(4))has recently gained recognition as a leading candidate for the creation of direct Z-scheme heterojunctions,owing to its favorable attributes such as a moderate band-gap(2.7 eV),high reduction potential and abundant active *** this review,we offer a concise overview of the fundamental principles and recent advancements in g-C_(3)N_(4)-based direct Z-scheme photocatalytic ***,we delve into the various practical applica-tions of g-C_(3)N_(4)-based direct Z-scheme photocatalysts,specifically in the realms of energy conversion and envi-ronmental *** applications include the removal of contaminant pollutants through photocatalytic degradation,water splitting(comprising H_(2)-generation,O_(2)-evolution,and overall water splitting),and CO_(2)***,we present comprehensive characterization methods and strategies aimed at further enhancing the photocatalytic activity of g-C_(3)N_(4)-based direct Z-scheme photocatalytic *** conclude,this review offers summarizing insights and a brief discussion on future challenges and prospects pertaining to g-C_(3)N_(4)-based direct Z-scheme *** believe that this review will inspire continued exploration and foster a deeper understanding of the groundbreaking possibilities within photocatalytic *** also provides valuable guidance for the design and construction of innovative direct Z-scheme photocatalysts.

关键词： Carbon nitride Photocatalyst Z-scheme systems Environmental remediation Energy conversion

Photoinduced generation of alkyl and phthalimide nitrogen radicals from N-hydroxyphthalimide esters for the synthesis of benzophenone-type bioisosteres

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Science China chemistry 2024年第10期67卷 3389-3396页

作者： Fei Li Jianyang Dong Huijuan Liao Jiayi Dang Xuechen Zhou Yuying Wang Chenya Wang Qin Jiang Gang Li Dong Xue Key Laboratory of Applied Surface and Colloid chemistry Ministry of Education and School of Chemistry and Chemical EngineeringShaanxi Normal University

N-Hydroxyphthalimide（NHPI） esters have emerged as powerful sources of alkyl radicals generated by single-electron transfer,but homolysis of NHPI ester to produce an alkyl radical and a phthalimide nitrogen radical is still in its infancy. In this study, we developed a light-induced method for generation of alkyl and phthalimide nitrogen radicals from NHPI esters and subsequent reactions of the radicals with [1.1.1]propellane and aryl aldehydes for rapid generation of bicycle [1.1.1]pentane ketones. This method does not require metals or photosensitizers, features a broad substrate scope（90 examples） and excellent functional group tolerance, and can be used for the functionalization of structurally complex natural products and drugs. Mechanistic investigations indicate that the reaction involves photoinduced homolytic cleavage of the Cs2CO3-NHPI ester complex to produce alkyl and phthalimide nitrogen radicals and subsequent hydrogen atom transfer between the phthalimide nitrogen radical and the aldehyde to generate an acyl radical.

关键词： phthalimide nitrogen radicals aryl aldehydes hydrogen atom transfer bicycle[1.1.1]pentane ketones bioisosteres