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A bifunctional POM-based Cu-viologen complex with mixed octamolybdate clusters for rapid oxidation desulfurization and effective photogeneration of hydrogen

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Rare Metals 2024年第1期43卷 236-246页

作者： Lin Yang Zhong Zhang Chao-Nan Zhang xiu-Li wang College of Chemistry and Materials Engineering Bohai UniversityJinzhou 121013China Professional Technology Innovation Center of Liaoning Province for Conversion Materials of Solar Cell Bohai UniversityJinzhou 121013China

The design and synthesis of catalysts for the oxidation desulfurization and production of hydrogen are extremely important for solving environmental pollution and energy ***,a novel bifunctional [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)-based Cu-viologen complex H_(4)[Cu_(2)~ⅠCl_(2)(Hbcbpy)_(4)] [α-Mo_(8)O_(26)] [β-Mo8O_(26)]·H_(2)O(BHU-2,Hbcbpy=1-(4-carboxybenzyl)-4,4'-bipyridinium) was synthesized and characterized by single-crystal X-ray diffraction(XRD),infrared radiation spectra,powder X-ray diffraction(PXRD) and X-ray photoelectron spectroscopy(XPS) *** structural characteristic of BHU-2 is the presence of two types of octamolybdate clusters [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)and a new binuclear Cu~Ⅰ-Hbcbpy complex linked by Cl-bridges[Cu_(2)ⅠCl_(2)(Hbcbpy)_(4)]^(4+).BHU-2 as a heterogeneous catalyst exhibits excellent activities to the oxidation desulfurization and photocatalytic hydrogen *** room temperature,BHU-2 can catalyze 96% conversion of methyl phenyl sulfide with 98% selectivity,and the process obeys the pseudo-first-order reaction kinetic with the half-life of9.6 *** notorious 2-chloroethyl ethyl sulfide can achieve 99% conversion with 98% selectivity within only1 min at the presence of BHU-2,and the turnover frequency(TOF) is up to 7400 h^(-1).BHU-2 also exhibits high catalytic activity for the oxidation of other aromatic and aliphatic thioethers within short time at room ***,BHU-2 shows a high catalytic activity for visible-light-driven hydrogen evolution with an H_(2) evolution rate of 1677.85 μmol·g^(-1)·h^(-1) within 10 ***,the catalytic activities do not decrease evidently after three cycles,revealing the prominent structural stability and recyclability.

关键词： Polyoxometalate Metal-organic complex Viologen Oxidation desulfurization Photocatalytic hydrogen production

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On the superconvergence of a WG method for the elliptic problem with variable coefficients

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Science China Mathematics 2024年第8期67卷 1899-1910页

作者： Junping wang Xiaoshen wang xiu Ye Shangyou Zhang Peng Zhu Division of Mathematical Sciences National Science FoundationAlexandriaVA 22314USA Department of Mathematics University of Arkansas at Little RockLittle RockAR 72204USA Department of Mathematical Sciences University of DelawareNewarkDE 19716USA College of Data Science Jiaxing UniversityJiaxing 314001China

This article extends a recently developed superconvergence result for weak Galerkin(WG)approximations for modeling partial differential equations from constant coefficients to variable *** superconvergence features a rate that is two orders higher than the optimal-order error estimates in the usual energy and L^(2)*** extension from constant to variable coefficients for the modeling equations is highly *** underlying technical analysis is based on a sequence of projections and *** results confirm the superconvergence theory for second-order elliptic problems with variable coefficients.

关键词： weak Galerkin finite element methods superconvergence second-order elliptic problems stabilizerfree

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Hypoglycemic effect and the mechanism of action of a polysaccharide from sweet corncob in a high-fat diet and streptozotocin-induced diabetic mice

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Food Science and Human Wellness 2024年第3期13卷 1543-1555页

作者： Xin wang Weiye xiu Ye Han Zhili wang Yu Luo Yongqiang Ma Heilongjiang Provincial Key Laboratory of Cereals and Comprehensive Processing of Cereal Resources College of Food EngineeringHarbin University of CommerceHarbin 150028China

Type 2 diabetes mellitus(T2DM)is a metabolic disease caused by a glycolipid metabolism disorder and isletβ-cell ***-80-I is a biologically active water-soluble polysaccharide isolated from sweet corncob,an agricultural *** hypoglycemic effects of SCP-80-I on T2DM mice and its mechanisms were investigated in this ***-80-I was found to significantly reduce blood glucose and lipid deposition levels in T2DM mice,as well as decrease serum leptin and increase adiponectin ***,real time-polymerase chain reaction(RT-PCR)and Western blotting results revealed that SCP-80-I could regulate the expression of several glycolipid metabolisms and insulin secretion genes and proteins,including 5'-AMP-activated protein kinase(AMPK),carnitine palmitoyltransferase I(CPTI),and acetyl coenzyme A carboxylase(ACC)in the liver and AMPK,sirtuin1(Sirtl),peroxisome proliferator-activated receptorycoactivator-1(PGC-1α),and uncoupling protein 2(UCP2)in the *** have a hypoglycemic effect,SCP-80-1 regulated glycolipid metabolism and islet cell function in the liver by regulating the AMPK/AC C/CPT1 signaling pathway and the AMPK/Sirt1/PGC-1αand AMPK/Sirtl/UCP2 signaling *** findings improve our understanding of polysaccharides derived from sweet corncob and the use of SCP-80-I in the production of hypoglycemic foods.

关键词： Sweet corn cob polysaccharide Type 2 diabetes Signal pathway 5’-AMP-activated protein kinase(AMPK)

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Unusual Single Electron Transfer Reactions between Alkenes and Iodine Electrophiles

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Chinese Journal of Chemistry 2024年第5期42卷 471-477页

作者： Zhengzhao Lou Jingyu Hu Chuanfa Ni xiu wang Jinbo Hu Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Ling Ling RoadShanghai200032 China School of Physical Science and Technology ShanghaiTech University100 Haike RoadShanghai201210 China

The electrophilic addition to an alkene with an electrophile has been widely studied and applied in organic *** organic chemistry textbook describes the classical reaction between an alkene and an iodine electrophile(such as elemental iodine and N-iodosuccinimide(NIS))as a typical ionic reaction,in which an iodonium ion is formed and then attacked by a ***,in this article,we report a new and unusual reaction mode between an alkene and NIS;that is,a single electron transfer(SET)process occurs between these two reactants by forming an electron-donor acceptor *** only does this unusual single electron transfer reaction between an alkene and NIS add fundamentally important knowledge to organic chemistry,it also provides a valuable synthetic method as the new SET reaction mode with opposite regioselectivity as compared with the traditional ionic mode.

关键词： Electrophilic addition Radical ions Reaction mechanisms Alkenes Fluorine

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Surface iodine and pyrenyl-graphdiyne co-modified Bi catalysts for highly efficient CO_(2) electroreduction in acidic electrolyte

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Nano Research 2024年第4期17卷 2381-2387页

作者： Min Zhang Juan wang Xin Rong xiu-Li Lu Tong-Bu Lu MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China

CO_(2) electroreduction to formic acid/formate would contribute to alleviating the energy and climate *** work reports a Bi-based catalyst derived from the in-situ electroreduction of Bi_(2)O_(2)CO_(3. modified with iodine and pyrenyl-graphdiyne(PGDY)on the surface for efficient electroreduction of CO_(2) in acidic electrolyte,with a high partial current density of 98.71 mA·cm^(-2) and high Faradaic efficiency(FE)>90%over the potential range from^(-1).2 to-1.5 V *** hydrogen electrode(RHE),as well as the long-term operational stability over 240 h without degradation in H-type *** results and density function theory calculations show that the synergistic effect of surface iodine and PGDY is responsible for this active and extremely stable process of CO_(2) electroreduction via lowering the energy barriers for formation of*OCHO intermediate,suppressing the competitive HER by enhancing the concentration of both K+and CO_(2) at reaction interface,as well as preventing the dissolution and re-deposition of active Bi atoms on surface during catalytic *** work provides new insight into designing highly active and stable electrocatalysts for CO_(2) reduction.

关键词： CO_(2) reduction electrocatalysis Bi-based catalysts acidic electrolyte

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In situ meso-tetra(4-carboxyphenyl)porphyrin ligand substitution in Hf-MOF for enhanced catalytic activity and stability in photoredox reactions

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Rare Metals 2024年第6期43卷 2682-2694页

作者： Jie Hu Hong-Xin Lao xiu-Wu Xu Wei-Kang wang Le-Le wang Qin-Qin Liu School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China College of Chemistry and Materials Engineering Research Center of Carbon NeutralityAnhui Normal UniversityWuhu 241002China Fujian Provincial Key Laboratory of Ecology-Toxicological Effects and Control for Emerging Contaminants Putian UniversityPutian 351100China

Though there are numerous intrinsic merits of metal-organic frameworks(MOFs),low charge separation efficiency has imposed heavy restrictions on their photocatalytic ***,in situ porphyrin ligand substitution,as a strategy for improving the charge separation efficiency and increasing the amounts of active sites,has been designed and realized in a Hf-biphenyl dicarboxylic acid(BPDC)***,a size and geometry matched meso-tetra(4-carboxyphenyl)porphyrin(TCPP)ligand was selected and doped into Hf-BPDC MOF by forming coordinating bonds with Hf centers,forming dualligand Hf-BPDC-TCPP *** resultant Hf-BPDC-TCPP MOF showed significantly improved activity and chemical stability in the photocatalytic H_(2)generation(261μmol·g^(-1)·h^(-1))and tetracycline(TC)degradation reactions(95.8%),which was 48 and 1.47 folds higher than that of the Hf-BPDC *** and electrochemical studies revealed that the introduction of porphyrin ligand could generate a stronger internal electric field for boosting the charge separation and transfer,increase the specific surface area for providing more active sites,and narrow the band gap to enhance the visible light *** in situ ligand substitution method provides a promising approach to build a tunable platform for constructing high-performance MOF photocatalysts.

关键词： Ligand substitution Metal organic frameworks Meso-tetra(4-carboxyphenyl)porphyrin Hydrogen evolution reaction Tetracycline degradation

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Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

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China Ocean Engineering 2024年第3期38卷 363-378页

作者： ZHAO Mi YU Wan-li wang Pi-guang QU Yang DU xiu-li Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic *** this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field

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Analytical Solution and Simplified Formula for Added Mass of Horizontal and Vertical Motions of Truncated Cylinders Under Earthquake Action

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China Ocean Engineering 2024年第1期38卷 54-67页

作者： wang Pi-guang LYU Si-yu QU Yang ZHAO Mi DU xiu-li State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Tech-nologyBeijing 100124China

This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water *** governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible *** governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary *** analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite *** main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion *** added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering *** calculation results show that the simplified formulas are in good agreement with the analytical solutions.

关键词： earthquake hydrodynamic pressure truncated cylinder added mass simplified formula

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Rhodium-Catalyzed Regioselective C-O and C-C Bonds Formation of 3.Oxopent-4-enenitriles with Alkynes for the Synthesis of Polysubstituted 2H-Pyrans

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Chinese Journal of Chemistry 2024年第17期42卷 1986-1992页

作者： Kelu Yan Xiao Liu Jiangwei Wen Qiuyun Li Junjie wang Yang Zheng xiu wang Key Laboratory of Life-Organic Analysis of Shandong Province School of Chemistry and Chemical EngineeringQufu Normal UniversityQufuShandong273165China Faculty of Chemistry and Chemical Engineering Yancheng Institute of TechnologyYanchengJiangsu 224051China

The rhodium-catalyzed C-H bond activation and cyclization of 3.oxopent-4-enenitriles with alkynes proceed *** 2H-pyrans with multiple substituents are achieved in good yields through regioselective formation of C-O and C-C *** involving hydroxy-alkynoates resulted in products with a furo[3.4-b]pyran skeleton via further intramolecular ester exchange *** from the traditional"1-oxatrienes pathway",this method for the synthesis of useful 2H-pyrans possesses certain highlights in terms of readily available substrates,stable and easily derivatized products,gentle and convenient operation process,and step and atomeconomy.

关键词： Rhodium/C-H activation 3.Oxopent-4-enenitriles Alkynes 2H-Pyrans Transition metals Regioselectivity Cyclization Comprehensive Summary

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Multiple Normalized Solutions for Nonlinear Biharmonic Schr?dinger Equations in ■with L-Subcritical Growth

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Acta Mathematicae Applicatae Sinica 2024年

作者： Jun wang Li wang Ji-xiu wang Department of Mathematics Sun Yat-sen University College of Science East China Jiaotong University School of Mathematics and Statistics Hubei University of Arts and Science

In this article, we consider the existence of normalized solutions for the following nonlinear biharmonic Schr?dinger equations:■where c, ε > 0, N ≥ 5, λ ∈ R is a Lagrange multiplier and is unknown, h ∈ C（■N, [0, ∞）), f : R → R is continuous function satisfying L2-subcritical growth. When ε is small enough, we get multiple normalized solutions. Moreover, we also obtain orbital stability of the solutions.

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