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Characteristics of turbulent flow in 3-D pools in the presence of submerged rigid vegetation in channel bed

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Journal of Hydrodynamics 2024年第1期36卷 158-169页

作者： Kourosh Nosrati Hossein Afzalimehr Jueyi Sui Hamid Reza Reisifar Natural Disasters prevention research center Faculty of Civil EngineeringIran University of Science and TechnologyTehranIran School of engineering University of Northern British ColumbiaPrince GeorgeCanada

In this study,the interaction between 3-D bedforms and submerged rigid vegetation has been *** laboratory experiments were conducted to study the distribution of flow velocity,Reynolds shear stress,turbulent kinetic energy,and skewness coefficients for a constant density of *** showed that the velocity profile in the pool section deviates from those in the upstream section of the *** has been found that the dip parameter varied between 0.6H and 0.9H depending on various factors including bed roughness,vegetation distribution,and pool entrance/exit ***,scattered vegetation in the pool and differences in slopes created non-uniform flow ***,in the wake region behind each vegetated element,flow velocity reduced significantly,and small-scale eddies are formed,causing increased *** decreasing the entrance slope and bed roughness,relatively uniform flow and weaker turbulence was resulted,but the random distribution of vegetated elements counteracted this balance and intensified *** the decrease in the pool entrance slope,the contribution of sweep event decreased and the contribution of ejection event increased.

关键词： Submerged rigid vegetation 3-D pool Reynolds shear stress skewness coefficients

Preparation of α-High Strength Gypsum from Flue Gas Desulfurization Gypsum Pretreated by Hydrothermal-aging Method

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Journal of Wuhan University of technology(Materials Science) 2024年第1期39卷 75-81页

作者：苏一鑫 GAO Lili 陈学青 LI Zhishui 李雲 CAO Jilin engineering research center of Seawater Utilization technology of Ministry of Education School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China Heze center for Disease Control and prevention Heze 274010China Tianjin Bohua Yongli Chemical Industry Co. Ltd.Tianjin 300452China

The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD)gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtainα-CSH with the satisfactory performances, a facile hydrothermal-aging pretreatment process for FGD gypsum raw materials was proposed, where FGD gypsum was firstly hydrothermally converted to α-CSH whiskers, and α-CSH whiskers were further hydrated to synthesize CaSO4·2H2O (CSD) by aging under the regulation of N,N'-methylenebisacrylamide (MBA). The effects of aging time, MBA addition, aging temperature, and pH on the morphology of the synthesized CSD were investigated. The synthesized CSD crystals exhibit highly uniform prismatic morphology with the length of ca 100μm and the whiteness of 91.56%. The regulation mechanism of MBA was also illustrated. The synthesized CSD crystals with prismatic morphology were further used as raw materials to synthesize the short columnar α-CSH. The absolute dry compressive strength of paste prepared from the short columnar α-CSH is 40.85 MPa, which reaches α40 strength grade.

关键词： flue gas desulphurization gypsum α-calcium sulfate hemihydrate hydrothermal-aging method N,N'-methylenebisacrylamide prismatic CSD

Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation

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Journal of Energy Chemistry 2024年第8期95卷 168-199,I0004页

作者： Qibing Dong Ximing Li Yanyan Duan Qingyun Tian Xinxin Liang Yiyin Zhu Lin Tian Junjun Wang Atif Sial Yongqian Cui Ke Zhao Chuanyi Wang School of Environmental Science and engineering Shaanxi University of Science and TechnologyXi’an 710021ShaanxiChina Guangdong engineering technology research center for Environmental Purification and Functional Materials Guangzhou Institute of Industrial IntelligenceGuangzhou 511400GuangdongChina jiangxi Key Lab of Flexible Electronics Flexible Electronics Innovation InstituteJiangxi Science and Technology Normal UniversityNanchang 330013JiangxiChina Helmholtz-Zentrum Berlin für Materialien und Energie Kekuléstraße 512489 BerlinGermany

Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy *** a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and *** existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF ***,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@***,there is an urgent need for a comprehensive review encompassing these three types of core-shell *** on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental ***,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were ***,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are ***,the main challenges and development prospects of core-shell organic framework photocatalysts were *** review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation.

关键词： Organic framework Core-shell structure Photocatalysis Energy conversion Environmental remediation

High adsorption selectivity of activated carbon and carbon molecular sieve boosting CO_(2)/N_(2) and CH_(4)/N_(2) separation

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Chinese Journal of Chemical engineering 2024年第3期67卷 282-297页

作者： Siang Chen Wenling Wu Zhaoyang Niu Deqi Kong Wenbin Li Zhongli Tang Donghui Zhang The research center of Chemical engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Flue gas and coal bed methane are two important sources of greenhouse *** swing adsorption process has a wide range of application in the field of gas separation,and the selection of adsorbent is *** this regard,in order to assess the better adsorbent for separating CO_(2) from flue gas and CH_(4) from coal bed methane,adsorption isotherms of CO_(2),CH_(4) and N_(2) on activated carbon and carbon molecular sieve are measured at 303.15,318.15 and 333.15 K,and up to 250 *** experimental data fit better with Langmuir 2 compared to Langmuir 3 and Langmuir-Freundlich models,and Clausius-Clapeyron equation was used to calculate the isosteric *** the order of the adsorbed amount and the adsorption heat on the two adsorbents are CO_(2)>CH_(4)>N_(2).The adsorption kinetics are calculated by the pseudo-first kinetic model,and the order of adsorption rates on activated carbon is N_(2)-CH_(4)>CO_(2),while on carbon molecular sieve,it is CO_(2)-N_(2)>CH_(4).It is shown that relative molecular mass and adsorption heat are the primary effect on kinetics for activated carbon,while kinetic diameter is the main resistance factor for carbon molecular ***,the adsorption selectivity of CH_(4)/N_(2) and CO_(2)/N_(2) were estimated with the ideal adsorption solution theory,and carbon molecular sieve performed best at 318.15 K for both CO_(2) and CH_(4) *** study suggested that activated carbon is a better choice for separating flue gas and carbon molecular sieve can be a strong candidate for separating coal bed methane.

关键词： Activated carbon Carbon molecular sieve Adsorbent evaluation Adsorption equilibrium and kinetics Heat of adsorption Selectivity

The Crystallization Behavior of L-Poly(lactic acid)/Polypropylene Blends:The Acceleration for Both L-Poly(lactic acid)and Polypropylene

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Chinese Journal of Polymer Science 2024年第6期42卷 775-786页

作者： Shuang-Cheng Li Wei-Jia Zhou Wen-Jie Wu Jun Shao Shui-Liang Chen Hao-Qing Hou Sheng Xiang College of Chemistry&Chemical engineering and Nanofiber engineering center of jiangxi Province Jiangxi Normal UniversityNanchang330022China National engineering research center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China Wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in *** this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were *** showed that the crystalline structures of PLLA and PP were not altered by the *** the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP *** the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular *** the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP *** investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene Blends Crystalization behavior Crystallization acceleration

Crystal engineering regulation achieving inverse temperature symmetry breaking ferroelasticity in a cationic displacement type hybrid perovskite system

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Chinese Chemical Letters 2024年第5期35卷 477-481页

作者： Na Wang Wang Luo Huaiyi Shen Huakai Li Zejiang Xu Zhiyuan Yue Chao Shi Hengyun Ye Leping Miao Chaotic Matter Science research center Department of MaterialsMetallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000China

Ferroelastic hybrid perovskite materials have been revealed the significance in the applications of switches,sensors,actuators,***,it remains a challenge to design high-temperature ferroelastic to meet the requirements for the practical ***,we reported an one-dimensional organicinorganic hybrid perovskites(OIHP)(3-methylpyrazolium)CdCl_(3)(3-MBCC),which possesses a mmmF2/m ferroelastic phase transition at 263 ***,utilizing crystal engineering,we replace-CH_(3) with-NH_(2) and-H,which increases the intermolecular force between organic cations and inorganic *** phase transition temperature of(3-aminopyrazolium)CdCl_(3)(3-ABCC),and(pyrazolium)CdCl_(3)(BCC)increased by 73 K and 10 K,***,BCC undergoes an unconventional inverse temperature symmetry breaking(ISTB)ferroelastic phase transition around 273 ***,it transforms from a high symmetry low-temperature paraelastic phase(point group 2/m)to a low symmetry high-temperature ferroelastic phase(point group ī)originating from the rare mechanism of displacement of organic cations phase *** means that crystal BCC retains in ferroelastic phase above 273 K until melting point(446 K).Furthermore,characteristic ferroelastic domain patterns on crystal BCC are confirmed with polarized optical *** study enriches the molecular mechanism of ferroelastics in the family of organic-inorganic hybrids and opens up a new avenue for exploring high-temperature ferroic materials.

关键词： Organic-inorganic hybrid perovskite Crystal engineering Inverse temperature symmetry breaking Displacement type phase transition Ferroelasticity

Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity

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Chinese Journal of Chemistry 2024年第14期42卷 1623-1629页

作者： Ling-Ling Chen Ren-Fei Cao Hua Ke Zhi-Min Chen School of Chemistry and Chemical engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai200240 China engineering technology research center for Environmental Protection Materials Pingxiang UniversityPingxiangJiangxi337055 China

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first *** selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z *** the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

关键词： Alkynes Electrophilic addition Chemoselectivity Lewis base catalysis Selenofunctionalization

Magnetic, dielectric and luminescence synergetic switchable effects in molecular material [Et_(3)NCH_(2)Cl]_(2)[MnBr_(4)]

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Chinese Chemical Letters 2024年第4期35卷 502-505页

作者： Yan Cheng Hua-Peng Ruan Yan Peng Longhe Li Zhenqiang Xie Lang Liu Shiyong Zhang Hengyun Ye Zhao-Bo Hu Chaotic Matter Science research center Faculty of Materials Metallurgy and ChemistryJiangxi University of Science and TechnologyGanzhou 341000China College of Materials and Chemical engineering Pingxiang UniversityPingxiang 337055China jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China Key Laboratory of jiangxi University for Functional Materials Chemistry School of Chemistry and Chemical EngineeringGannan Normal UniversityGanzhou 341000China

The application of multifunctional materials in various fields such as electronics and signal processors has attracted massive attention. Herein, a new organic-inorganic hybrid material [Et_(3)NCH_(2)Cl]_(2)[MnBr_(4)](1) is reported, which contains two organic amines cations and one [MnBr_(4)] tetrahedral ion. Compound 1 has a dielectric anomaly signal at 338 K, which proves its thermodynamic phase transition. The single crystal measurements at 200 K and 380 K show that the phase transition of compound 1 is caused by the thermal vibration of organic amine cations in the lattice. Moreover, compound 1 shows yellow-green luminescence under UV light irradiation. The magnetism measurements indicate that compound 1 shows switchable magnetic properties. This organic–inorganic material is a multifunctional material with dielectric, optical, and magnetic synergetic switchable effects, which expands a new direction for designing multifunctional materials.

关键词： Synergetic switchable effects Molecular materials Magnetism Dielectric Luminescence

Defects in the grain interiors of 3 mol%yttria-stabilized tetragonal zirconia polycrystal ceramics with 0.25 wt%alumina

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Journal of Advanced Ceramics 2024年第4期13卷 469-477页

作者： Yan Xiong Lian Luo Yao Cheng Zhi Liu Qi Liu Weimin Wang Wei Ji School of Materials&Chemical engineering Hubei Province Key Laboratory of Green Materials for Light IndustryHubei University of TechnologyWuhan 430068China Fujian Institute of research on the Structure of Mater Chinese Academy of SciencesFuzhou 350002China jiangxi Provincial engineering research center for Multifunction Zirconia Materials Jiangxi Size Materials Co.Ltd.Jiujiang 332500China State Key Laboratory of Advance technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

The presence of high-density defects is rarely observed in bulk 3 mol%yttria-stabilized tetragonal zirconia polycrystal(3Y-TZP)ceramics obtained through conventional pressureless *** the present work,fine-grained dense 147 nm 3Y-TZP ceramics were prepared by pressureless sintering of commercial 0.25 wt%alumina-doped zirconia powders at 1300℃.A novel discovery was reported in which large amounts of defects were present in the grain interiors of the *** phenomenon was further examined using three types of powder samples,and the reasons for defect formation were investigated by microstructural characterization using high-resolution transmission electron microscopy(HRTEM)analysis and Rietveld *** results confirmed the essential dependence of the defect formation on the alumina *** authors attributed the defect formation to the significant difference in ionic radii of the solvent and solute during the dissolution of alumina into the zirconia *** sintering kinetics were proposed to be enhanced by the presence of substantial defects,which consequently favored the low-temperature sintering of the alumina-doped zirconia ceramics.

关键词： 3 mol%yttria-stabilized tetragonal zirconia polycrystal(3Y-TzP)ceramics alumina addition microstructure defect