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Multimorphism and gap opening of charge-density-wave phases in monolayer VTe2

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Nano Research 2020年第6期13卷 1733-1738页

作者： Meizhuang Liu Changwei Wu Zizhao Liu zhiqiang wang Dao-Xin Yao Dingyong Zhong School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou510275China

Vanadium dichalcogenides have attracted increasing interests for the charge density wave phenomena and possible ***,we report on the multiphase behavior and gap opening in monolayer VTe2 grown by molecular beam *** tunneling microscopy(STM)and spectroscopy study revealed the(4×4)metallic and gapped(2√3×2√3)charge-density wave(CDW)phases with an energy gap of≈40 *** the in-plane condensation of vanadium atoms,the typical star-of-David clusters and truncated triangle-shaped clusters are formed in the(4×4)and(2√3×2√3)phases respectively,resulting in different surface morphologies and electronic structures as confirmed by density functional theory(DFT)calculations with on-site Coulomb *** CDW-driven reorganization of the atomic structure weakens the ferromagnetic superexchange coupling and strengthens the antiferromagnetic exchange coupling on the contrary,suppressing the long-range magnetic order in monolayer *** electron correlation is found to be important to explain the gap opening in the(2√3×2√3)phase.

关键词： transition-metal dichalcogenides charge density wave 1T-VTe2 scanning tunneling microscopy

Co@CoO:An efficient catalyst for the depolymerization and upgrading of lignocellulose to alkylcyclohexanols with cellulose intact

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Journal of Energy Chemistry 2023年第2期77卷 191-199,I0006页

作者： Shuang Xiang Lin Dong zhiqiang wang Xue Han Yong Guo Xiaohui Liu Xue-Qing Gong Yanqin wang Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterResearch Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsJiangsu Province Key Laboratory of Green Biomass-based Fuels and ChemicalsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037JiangsuChina Department of Chemistry University of ManchesterManchester M139PLUK

The depolymerization and upgrading of lignin from raw biomass,while keeping cellulose intact is important in biorefinery and various metal-based catalysts have been used in reductive catalytic fractionation,a key method in"lignin-first"strategy,Recently,we found that a core-shell structured Co@CoO catalyst with CoO shell as the real active site had excellent performance in the hydrogenolysis of 5-hydromethylfurfural to 2,5-dimethylfuran due to its unique ability to dissociate H_(2)and yield active H^(δ-)species(Xiang et al.,2022).In this work,we report a one-pot depolymerization and upgrading of lignocellulose to alkylcyclohexanols,a flavour precursor,with intact cellulose over this unique core-shell structured catalyst,Co@*** model compounds(β-O-4,4-O-5,α-O-4)were first used to clarify the activity of Co@CoO ***,the one-pot conversion of various organosolv lignin(birch,pine and poplar)to alkylcyclohexanols was realized with the mass yield of alkylcyclohexanols up to25.8 wt%from birch lignin under the reaction condition of 210℃,1 MPa H_(2),16 ***,the corresponding woody sawdusts were used as feedstocks and found that the Co@CoO catalyst indeed preferentially depolymerized and upgraded the lignin part and obtained the same alkylcyclohexanols products with the retention of cellulose-rich *** collected alkylcyclohexanols were further esterified to obtain valueadded esters,which can be used as *** work will inspire the design of new efficient metal oxide catalysts in lignin fractionation and depolymerization to high-value-added chemicals with intact cellulose.

关键词： Lignocellulose Lignin Depolymerization Co@CoO Alkylcyclohexanols

Alternating deposition films of a polymer and dendrimers bearing diphenylanthracene

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Chinese Science Bulletin 2005年第3期50卷 208-212页

作者： SUN Jing wang Liyan GAO Jian YU Xi wang zhiqiang Key Laboratory of Supramolecular Structure and Materials Jilin University Changchun 130012 China Key Laboratory of Organic Optoelectronics and Molecular Engineering Tsinghua University Bejjng 100084. China

Two generations of carboxyl-terminated poly (aryl ether) dendrimers bearing 9,10-diphenylanthracene cores are designed and synthesized. Alternating deposition of two dendrimers and poly(4-vinylpyridine) is studied with UV-Vis spectroscopy, FT-IR spectroscopy and atomic force microscopy. Experimental results indicate that this method to introduce chromophore into multilayer film can effectively prevent desorption of dye molecule. Moreover, it is found that dendrimer can inhibit the aggregation of fluorophore in film using fluorescence spectroscopy. Increase of dendrimer’s generation can enhance fluorescence intensity of each fluorophore. This provides a new approach to design lumi- nescent thin film.

关键词：交互沉积薄膜聚合物联苯蒽模树石化学结构

First-Principles Study of Lithium and Sodium Atoms Intercalation in Fluorinated Graphite

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Engineering 2015年第2期1卷 243-246页

作者： Fengya Rao zhiqiang wang Bo Xu Liquan Chen Chuying Ouyang Department of Physics Jiangxi Normal University Laboratory for Solid State Ionics Institute of Physics Chinese Academy of Sciences

The structure evolution of fluorinated graphite （CFx） upon the Li/Na intercalation has been studied by first- principles calculations. The Li/Na adsorption on single CF layer and intercalated into bulk CF have been calculated. The better cycling performance of Na intercalation into the CF cathode, comparing to that of Li intercalation, is attributed to the different strength and characteristics of the Li-F and Na-F interactions. The interactions between Li and F are stronger and more localized than those between Na and E The strong and localized Coulomb attraction between Li and F atoms breaks the C-F bonds and pulls the F atoms away, and graphene sheets are formed upon Li intercalation.

关键词： first-principles Li/Na rechargeable batteries fluorinated graphite.

Efficient and stable non-doped deep-blue organic light emitting diode based on an anthracene derivative

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Science China Chemistry 2011年第4期54卷 666-670页

作者： wang zhiqiang ZHENG CaiJun LIU Heng OU XueMei ZHANG XiaoHong Nano-organic Photoelectronic Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100190China College of Chemistry and Chemical Engineering Luoyang Normal UniversityLuoyang 471022China Binzhou Polytechnic Binzhou 256603China

A new anthracene derivative 9,10-bis[3,5-di(4-tert-butylphenyl)phenyl]anthracene (BPPA) was synthesized via Suzuki coupling reaction and characterized by 1H NMR spectrum,mass spectrum,and elemental *** exhibits deep-blue emission both in solution and in solid thin *** compound has a non-planar structure that results in high thermal stability and the phenomenon of *** non-doped device based on this material shows stable deep-blue emission with the 1931 Commission international de I'Eclairage (CIE) coordinate of (0.15,0.05) under different applied *** device exhibits the maximum external quantum efficiency of 2.2% at 14.9 mA/cm2 with luminance of 105 cd/m2.

关键词： organic light emitting diodes anthracene derivative deep-blue emission theoretical calculations thermal properties

High-efficiency CO_(2) sequestration through direct aqueous carbonation of carbide slag: determination of carbonation reaction and optimization of operation parameters

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Frontiers of Environmental Science & Engineering 2024年第1期18卷 157-167页

作者： zhiqiang wang Longpeng Cui Yanfang Liu Jili Hou Hongwei Li Liang Zou Fuxia Zhu Department of Coal and Syngas Conversion Sinopec Research Institute of Petroleum Processing Co.Ltd.Beijing 100083China

Under the dual-carbon target, CO_(2) mineralization through solid wastes presents a mutually beneficial approach for permanent carbon emission reduction at a low material cost, while also enabling the resource utilization of these wastes. However, despite its potential, a comprehensive understanding about the effect of industrial solid waste properties and operating parameters on the carbonation process, and the mechanism of direct aqueous carbonation is still lacking. A series of experiments were conducted to compare the carbonation performance of fly ash, steel slag, and carbide slag. Subsequently, CO_(2) mineralization by carbide slag was systematically studied under various operating parameters due to its high CO_(2) sequestration capacity. Results showed the reactivity of CaO and Ca(OH)2 was higher than that of CaO·SiO_(2) and 2CaO·SiO_(2). Carbide slag demonstrated a sequestration capacity of 610.8 g CO_(2)/kg and carbonation efficiency ζCa of 62.04% under the conditions of 65 ℃, 1.5 MPa initial CO_(2) pressure, 15 mL/g liquid-to-solid ratio, and 200 r/min stirring speed. Moreover, the formation of carbonates was confirmed through XRD, SEM-EDS, TG, and FTIR. A mechanism analysis revealed that initially, the rate of the carbonation process was primarily controlled by the mass transfer of CO_(2) in the gas–liquid interface. However, the rate-determining step gradually shifted to the mass transfer of Ca2+ in the solid–liquid interface as the reaction time increased. This study lays the foundation for the large-scale implementation of CO_(2) sequestration through carbide slag carbonation.

关键词： Industrial by-products Direct aqueous carbonation CO_(2)sequestration Mass transfer

Effect of Fe_(2)O_(3) on the Formation of Micro Glass Beads under Air Staged Combustion

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Journal of Harbin Institute of Technology(New Series) 2022年第3期29卷 46-56页

作者： Yuanjun Zhang Dakai wang Xingxing Cheng zhiqiang wang School of Energy and Power Engineering Shandong UniversityJinan 250061China

The effect of Fe_(2)O_(3) on the formation of micro glass beads(MGBs)under air staged combustion was *** experimental temperature was 1450℃,and Hegang bituminous coal was used as the experimental object.X⁃ray diffractometer(XRD),ash fusion tester,viscosity formula and scanning electron microscopy(SEM)were used to analyze the fly *** Measurer 1.2 software was used to measure the diameter of *** results showed that with the increase of Fe_(2)O_(3) in Hegang coal,the glass phase in fly ash first increased and then *** the amount of Fe_(2)O_(3) was 15%,the content of the glass phase was the highest,which was 51.26%.The ash melting point first decreased and then increased,while the viscosity gradually decreased and the particles gradually became *** the increase of Fe_(2)O_(3),the proportion of MGBs with particle size less than 10μm increased *** the above results,it can be concluded that the addition of Fe_(2)O_(3) is conducive to the formation of MGBs and the reduction of particle size.

关键词： micro glass beads fly ash Fe_(2)O_(3) air staged combustion

Dendritic tellurides acting as antioxidants

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Chinese Science Bulletin 2006年第19期51卷 2315-2321页

作者： XU Huaping wang Yapei wang zhiqiang LIU Junqiu Mario Smet Wim Dehaen Key Lab of Organic Optoelectronics and Molecular Engineering Department of Chemistry Tsinghua University Beijing 100084 China Key Lab for Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130023 China Laboratory for Organic Synthesis University of Leuven Celestijnenlaan 200E B-3001 Leuven Belgium

We have described the synthesis of a series of poly(aryl ether) dendrimers with telluride in the core and oligo(ethylene oxide) chains at the pe- riphery which act as glutathione peroxidase (GPx) mimics. These series of compounds were well characterized by H-NMR, 1 13C-NMR and ESI-MS. Using different ROOH (H2O2, cumene hydroperoxide) for testing the antioxidizing properties of these com- pounds, we have found that from generation 0 to 2, the activity of the dendritic GPx mimics first de- creased and then increased. This can be explained on the basis of a greater steric hindrance, going from generation 0 to 1, and stronger binding interactions going from generation 1 to 2. In other words, there exists a balance between binding interactions and steric hindrance that may optimize the GPx activity.

关键词：抗氧化剂碲化物谷胱甘肽过氧化物酶氧化乙烯合成

Effect of Niobium on Microstructure and Properties of the CoCrFeNb_xNi High Entropy Alloys

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Journal of Materials Science & Technology 2017年第7期33卷 712-717页

作者： Hui Jiang Li Jiang Dongxu Qiao Yiping Lu Tongmin wang zhiqiang Cao Tingju Li Key Laboratory of Solidification Control and Digital Preparation Technology （Liaoning Province） School of Materials Science and Engineering Dalian University of Technology Dalian 116024. China

A series of CoCrFeNb_xNi（x values in molar ratio, x = 0, 0.25, 0.45, 0.5, 0.75, 1.0 and 1.2） high entropy alloys（HEAs） was prepared to investigate the alloying effect of Nb on the microstructures and mechanical properties. The results indicate that the prepared CoCrFeNb_xNi（x 〉 0） HEAs consist of a simple FCC solid solution phase and a Laves phase. The microstructures of the alloys change from an initial single-phase FCC solid solution structure（x = 0） to a hypoeutectic microstructure（x = 0.25）, then to a full eutectic microstructure（x = 0.45） and finally to a hypereutectic microstructure（0.5 〈 x 〈 1.2）. The compressive test results show that the Nb0.45（x = 0.45） alloy with a full eutectic microstructure possesses the highest compressive fracture strength of 2558 MPa and a fracture strain of 27.9%. The CoCrFeNi alloy exhibits an excellent compressive ductility, which can reach 50% height reduction without fracture. The Nb0.25 alloy with a hypoeutectic structure exhibits a larger plastic strain of 34.8%. With the increase of Nb content, increased hard/brittle Laves phase leads to a decrease of the plasticity and increases of the Vickers hardness and the wear resistance. The wear mass loss, width and depth of wear scar of the Nb1.2（x = 1.2） alloy with a hypereutectic structure are the lowest among all alloy systems, indicating that the wear resistance of the Nb1.2 alloy is the best one.

关键词： Alloy design Microstructure Mechanical properties Wear resistance