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Mo2C@3D ultrathin macroporous carbon realizing efficient and stable nitrogen fixation

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Science China Chemistry 2020年第11期63卷 1570-1577页

作者： Zhiwei Fang Desiree Fernandez nana wang Zhongchao Bai Guihua Yu Materials Science and Engineering Program Texas Materials InstituteThe University of Texas at AustinAustinTexas 78712United States Institute for Superconducting and Electronic Materials University of WollongongInnovation CampusWollongongNew South Wales 2500Australia

Ammonia is a key feedstock of fertilizers for farming and convenient hydrogen carrier as an emerging clean fuel,but industrial ammonium production process,Haber-Bosch reaction,is an energy-intensive process,consuming 1%–2%of global energy and producing 3%global *** nitrogen reduction reaction(NRR)is one of the most promising routes to realize highly efficient NH3 production under ambient ***,up to now,few precious-metal-free electrocatalysts with desirable catalytic performance have been *** this work,Mo2C nanodots anchored on three-dimensional ultrathin macroporous carbon(Mo2C@3DUM-C)framework is developed toward significantly enhanced nitrogen reduction *** to the special structural design of 3D ultrathin macroporous carbon and highly active and stable Mo2C toward N2 electrochemical reduction,the Mo2C@3DUM-C framework exhibits a high Faradaic efficiency of 9.5%for NH3 production at−0.20 V and the yield rate reaches 30.4µg h−1 mgMo2C−*** electrochemical characterizations reveal the enhanced electron transfer and increased electrochemical surface area in the 3D macroporous carbon ***,the Mo2C@3DUM-C electrocatalysts hold high catalytic stability after long-term NRR *** temperature-dependent yield rate of NH3 demonstrates that the activation energy of nitrogen reduction on the employed catalyst was calculated to be 28.1 kJ mol−*** proposed earth-abundant Mo2C@3DUM-C demonstrates an alternative insight into developing efficient and stable nitrogen fixation catalysts in acids as alternatives to noble metal catalysts.

关键词： electrocatalyst nitrogen fixation nanoparticles molybdenum macroporous carbon

I-Total Coloring and VI-Total Coloring of mC_(4) Vertex-Distinguished by Multiple Sets

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Wuhan University Journal of Natural Sciences 2023年第3期28卷 201-206页

作者： wang nana CHEN Xiang'en College of Mathematics and Statistics Northwest Normal UniversityLanzhou 730070GansuChina

We give the optimal I-(VI-)total colorings of mC_(4)which are vertex-distinguished by multiple sets by the use of the method of constructing a matrix whose entries are the suitable multiple sets or empty sets and the method of distributing color set in *** we obtain I-(VI-)total chromatic numbers of mC_(4)which are vertex-distinguished by multiple sets.

关键词： mC_(4) I-total coloring VI-total coloring multiple sets vertex-distinguished

Dynamic of a stochastic delayed one-predator two-prey model with Lévy jumps in polluted environments

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International Journal of Biomathematics 2021年第1期14卷 125-150页

作者： Yongxin Gao nana wang Shiquan Tian College of Science Civil Aviation University of ChinaTianjin 300300P.R.China

This paper is concerned with a stochastic delayed one-predator two-prey model with Lévy jumps in polluted ***,under some simple assumptions,we prove that there exists a unique global nonnegative solution which is permanent in time ***,sufficient criteria for the extinction of each species are ***,we carry out some numerical simulations to verify the theoretical results.

关键词： One-predator two-prey model delay white noise Levy noise toxicant

Tunneling, Information Asymmetry, and Private Placement Discounts

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Frontiers of Business Research in China 2012年第3期6卷 325-346页

作者： Dan He nana wang School of Business Southwestern University of Finance and EconomicsChengdu 611130China

Private placement has become an increasingly important method of equity refinancing for regulators, listed companies, and investors. This paper analyzes factors influencing private placement discounts based on the controlling shareholder＇s opportunistic behavior and information asymmetry. Our findings indicate that the type of subscriber is a key determinant of the private placement discount, particularly when the subscriber is the controlling shareholder. Asymmetric information between listed companies and investors is another important determinant： The higher the degree of information asymmetry, the greater the private placement discounts.

关键词： tunneling information asymmetry private placement discount

Fabrication and Properties of DC Magnetron Sputtered Indium Tin Oxide on Flexible Plastic Substrate

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Journal of Materials Science & Technology 2009年第1期25卷 119-122页

作者： Hui Lin Junsheng Yu nana wang Shuangling Lou Yadong Jiang State Key Laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic Information University of Electronic Science and Technology of China （UESTC） Chengdu 610054 China

Indium tin oxide （ITO） thin films deposited on flexible polyethylene terephthalate （PET） substrates at low temperature by DC magnetron sputtering from an In-Sn （90-10 wt pct） alloy target were studied. The correla- tion between deposition conditions and ITO property was systematically investigated and characterized. These as-deposited ITO films were used as the anode contact for flexible organic light-emitting diodes （FOLEDs）. The fabricated FOLEDs with a structure of PET/ITO/NPB （50 nm）/Alq （20 nm）/Mg：Ag （100 nm） showed a maximum luminance of 2125 cd/m^2 at 13 V.

关键词： Flexible Organic light-emitting diodes Indium tin oxide DC sputtering

Green light-emitting diodes based on hybrid perovskite films with mixed cesium and methylammonium cations

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Nano Research 2017年第4期10卷 1329-1335页

作者： Junjie Si Yang Liu nana wang Meng Xu Jing Li Haiping He Jianpu wang Yizheng Jin State Key Laboratory of Silicon Materials Center for Chemistry of High-Performance & Novel Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University (NanjingTech) 30 South Puzhu Road Nanjing 211816 China State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Center for Chemistry of High-Performance & Novel Materials State Key Laboratory of Silicon Materials Department of ChemistryZhejiang University Hangzhou 310027 China

We report the formation of high-quality Cs0.4MA0.6PbBr3 thin films with nearly full surface coverage and good emission properties upon the introduction of Cs^＋ into perovskite crystals. The Cs0.4MA0.6PbBr3 thin films were applied as emissive layers in light-emitting diodes. A maximum external quantum efficiency of -2.0% was achieved for these green-emitting devices.

关键词： perovskite light-emitting diodes cesium emission properties external quantum efficiency

Mechanical performance study of the retractable pier column after stiffening

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International Journal of Coal Science & Technology 2020年第4期7卷 725-739页

作者： Yi Zhang Xiaoye wang Liming Zhao Jie Liu nana wang Yingying Ding School of Mechanics and Architecture Engineering China University of Mining and Technology.Beijing 10(X)83.China

To solve the problem that the overlapping parts of a retractable pier column are prone to damage,this paper proposed the reinforcing measure of setting a stiffener ring at the bottom of the steel *** study how the stiffener-ring parameters influence the mechanical properties of the pier column.12 scale model specimens(including nine specimens with stiffener-ring widths of 40,50,and 60 mm and three unstiffened comparison specimens)were tested under axial *** on the test results,the specimen load-displacement,load-deflection,and load-strain curves were analyzed,and a finite-element model of a pier column under axial compression was established to determine the optimal stiffener *** results show that setting a stiffener ring enhances the cooperative working ability between the steel pipe and the internal filling material and restrains the lateral deformation of the pier column,thereby improving the ultimate bearing capacity and overall stability of the pier *** ultimate bearing capacity of the pier column is related to the width and thickness of the stiffener *** optimal size of the stiffener ring of the model pier column is 70 mm in width and 4 mm in *** present research results provide a reference for designing compressible pier columns and column stiffening in mines and have important practical significance.

关键词： Retractable pier column Stiffening reinforcing Axial compression test Ultimate bearing capacity Finiteelement analysis

Beyond electrode materials structure design:Binders play a vital role for battery application of micro-size electroactive materials

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Nano Research Energy 2023年第3期2卷 1-4页

作者： Mingyue wang Zhongchao Bai nana wang Institute for Superconducting and Electronic Materials(ISEM) Australian Institute for Innovative Materials(AIIM)Innovation CampusUniversity of WollongongSquires WayNorth WollongongNSW 2500Australia

Micrometre-sized electroactive particles with high tapping density show significant potential for commercial application since they effectively alleviate low Coulombic efficiency and excessive solid electrolyte interphase(SEI)issues brought by ***,optimizing the electrode architecture using novel design concepts can improve the energy *** the electrode material structure design strategy,binder plays a vital role in providing the mechanical stability and regulating the charge *** highlight presents the latest development to design high-capacity batteries by optimizing the binder structures in electrodes and emphasizes the significance of binder design for further commercial application.

关键词： micro-size electroactive materials binders mass transport high energy density

Laboratory and pilot scale studies on fast pyrolysis of corn stover

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International Journal of Agricultural and Biological Engineering 2008年第1期1卷 57-63页

作者： Yi Weiming Bai Xueyuan Li Zhihe wang Lihong wang nana Yang Yanqiang School of Light Industry and Agricultural Engineering Shandong University of TechnologyShandong Research Center of Engineering and Technology for Clean EnergyZibo CityShandong Province255049China

In order to design a hot ceramic ball heated down-flow tuber reactor for the pyrolysis liquefaction of agricultural residues,the devolatilization characteristics of pulverized corn stover were studied in a Laminar Entrained Flow Furnace(LEFF)with the temperature range of 800-950 *** flow characteristics of corn stover particles and ceramic balls in a vertical square tube were measured and analyzed by the techniques of particle image velocimetry(PIV).The devolatilization experiments were carried out in an isothermal manner and the maximum of volatile matter of pulverized corn stover particles was 72.68%with the residence time of 189 ms at 950 *** of the first order Arrhenius equation for describing the pulverized corn stover flash pyrolysis were *** the PIV experiments,the corn stover particle axial velocity were measured at different cross-sections of the tube for different *** the tuber connected with a suction pump,the maximum velocity was about 0.79 m/s,determined by the flow rate of the suction ***,a hot ceramic ball heated down-flow tuber reactor was constructed for pilot *** capacity of the reactor was 110.5 kg/h of corn stover powder and the yield of bio-oil was 41.6%of the feed stock.

关键词： Corn stover pyrolysis bio-oil particle image velocimetry