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Preliminary prediction of the control reproduction number of COVID-19 in Shaanxi Province,China

Applied Mathematics(A Journal of Chinese Universities) 2021年第2期36卷 287-303页

作者： LI Zhi-min ZHANG Tai-lei GAO Jian-zhong LI Xiu-qing MA Ling juan bao xiong-xiong School of Science Chang'an UniversityXi'an 710064China School of Ecological Environment Northwestern Polytechnical UniversityXi'an 710072China College of Economics and Management Shanxi Normal UniversityLinfen 041004China

Objectives Firstly,according to the characteristics of COVID-19 epidemic and the control measures of the government of Shaanxi Province,a general population epidemic model is ***,the control reproduction number of general population epidemic model is *** on the epidemic model of general population,the epidemic model of general population and college population is further established,and the control reproduction number is also *** For the established epidemic model,firstly,the expression of the control reproduc-tion number is obtained by using the next generation ***,the real-time reported data of COVID-19 in Shaanxi Province is used to fit the epidemic model,and the parameters in the model are estimated by least square method and ***,the Latin hypercube sampling method and partial rank correlation coefficient(PRCC)are adopted to analyze the sensitivity of the *** The control reproduction number remained at 3 from January 23 to January 31,then gradually decreased from 3 to slightly greater than 0.2 by using the real-time reports on the number of COVID-19 infected cases from Health Committee of Shaanxi Province in *** order to further control the spread of the epidemic,the following measures can be taken:(i)reducing infection by wearing masks,paying attention to personal hygiene and limiting travel;(i)improving isolation of suspected patients and treatment of symptomatic *** particular,the epidemic model of the collge population and the general population is estab-lished,and the control reproduction number is given,which will provide theoretical basis for the prevention and control of the epidemic in the colleges.

关键词： COVID-19 control reproduction number general population college population Shaanxi Province

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Profit Guided or Statistical Error Guided? A Study of Stock Index Forecasting Using Support Vector Regression

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Journal of Systems Science & Complexity 2017年第6期30卷 1425-1442页

作者： HU Zhongyi bao Yukun CHIONG Raymond xiong Tao School of Information Management Wuhan University School of Management Huazhong University of Science and Technology School of Electrical Engineering and Computing The University of Newcastle College of Economics and Management Huazhong Agricultural University

Stock index forecasting has been one of the most widely investigated topics in the field of financial forecasting. Related studies typically advocate for tuning the parameters of forecasting models by minimizing learning errors measured using statistical metrics such as the mean squared error or mean absolute percentage error. The authors argue that statistical metrics used to guide parameter tuning of forecasting models may not be meaningful, given the fact that the ultimate goal of forecasting is to facilitate investment decisions with expected profits in the future. The authors therefore introduce the Sharpe ratio into the process of model building and take it as the profit metric to guide parameter tuning rather than using the commonly adopted statistical metrics. The authors consider three widely used trading strategies, which include a na¨?ve strategy, a filter strategy and a dual moving average strategy, as investment scenarios. To verify the effectiveness of the proposed profit guided approach, the authors carry out simulation experiments using three global mainstream stock market indices. The results show that profit guided forecasting models are competitive, and in many cases produce significantly better performances than statistical error guided models. This implies thatprofit guided stock index forecasting is a worthwhile alternative over traditional stock index forecasting practices.

关键词： Financial market investment trading strategy parameter optimization stock index forecasting support vector regression

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Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng Chen Junfang bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

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CaH2-promoted activity of Ni-carbonate interface for CO2 methanation

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Journal of Energy Chemistry 2025年第1期100卷 522-532页

作者： Jin-Peng Wang Guo-Cui Mao Hui-Lin Jiang bao-Xia Dong Yun-Lei Teng School of Chemistry and Chemical Engineering Yangzhou University

Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic *** interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO2hydrogenation reaction,involving surface carbonate hydrogenation and ***,there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic *** work demonstrated that the incorporation of CaH2in Ni/CaCO3enhances the CO2methanation activity of the *** CO2conversion for Ni/CaH2-CaCO3reached 68.5%at 400°C,which was much higher than that of the Ni/CaCO3（31.6%） and Ni/CaH2-CaO （42.4%） ***,the Ni/CaH2-CaCO3catalysts remained stable during the stability test for 24 h at 400°C and 8 *** research revealed that CaH2played a crucial role in promoting the activity of the Ni-carbonate interface for ***2could modify the electronic structure of Ni and tune the structural properties of CaCO3to generate medium basic sites （OH groups）,which are favorable for the activation of H2and ***-situ Fourier transform infrared spectroscopy （FTIR） analysis combined with density functional theory calculations demonstrated that CO2activation occurs at the hydroxyl group （OH） on the CaH2-modified Ni-carbonate surface,leading to the formation of CO3H****,our study has confirmed that CO2methanation over the Ni/CaH2-CaCO3catalysts proceeds via the formate pathway.

关键词： Metal hydride Ni catalysts Carbonate Metal-carbonate interface

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Electrodeposited Sn-based Catalysts for CO2 Electroreduction

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Chinese Journal of Structural Chemistry 2020年第2期39卷 206-213,183页

作者： YE Ke WANG Guo-xiong bao Xin-He State Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education College of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China

Electrochemical CO2 reduction reaction(CO2RR) has been considered as a feasible avenue for simultaneous conversion of renewable energy and CO2. Economic and technical analysis suggests that the production of valuable C1 chemicals such as formic acid and CO is the most economically practicable route for CO2RR. This perspective summarizes the performance of electrodeposited Sn-based catalysts for C1 chemicals production and the relative mechanism of CO2RR. Further fundamental understanding and industrial applications of electrodeposited Sn-based catalysts in CO2 electrolyzer device are also discussed.

关键词： tin-based catalysts electrodeposition technology alloy interface electrochemical carbon dioxide reduction reaction

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Analysis of a Composite Admixture Based on Ready-Mixed Concrete Waste Residuals

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Fluid Dynamics & Materials Processing 2023年第8期19卷 1983-1995页

作者： Jinfa Jiang Long xiong Ming bao Zihan Zhou Wuhan Energy Conservation Office Wuhan430000China China Construction Ready Mixed Concrete Co. Ltd.Wuhan430000China

Reasonable treatment and utilization of waste residuals discharged during the production of ready-mixed concrete is an important problem in the cement *** this study,a composite admixture was prepared by using ready-mixed concrete waste residuals,furnace slag,and water granulated *** grinding characteristics of such material were ***,the effect of such admixture on cement hydration and pore structure was analyzed by X-ray diffraction,thermogravimetric-differential scanning calorimetry,scanning electron microcopy and mercury intrusion *** shown by the results:The grinding characteristics of the waste residuals can be improved significantly by mixing them with furnace slag and water granulated ***,the composite admixture does not change the composition of hydration products;rather it contributes to refine the pore structure of the matrix,thus improving the mechanical properties of these cement-based materials.

关键词： Waste residue of ready-mixed concrete station ready mixed concrete composite admixture activity microstructure

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MIMO Scheduling Effectiveness Analysis for Bursty Data Service from View of QoE

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Chinese Journal of Electronics 2017年第5期26卷 1079-1085页

作者： CHEN Lei JIANG Dingde bao Rong xiong Jiping LIU Fuqiang BEI Lulu Jiangsu Province Key Laboratory of Intelligent Industry Control Technology Xuzhou University of Technology School of Computer Science and Engineering Northeastern University College of Mathematics Physics and Information EngineeringZhejiang Normal University College of Electronics and Information Engineering Tongji University

In the user selection phrase of the conventional Multiple-input-multiple-output(MIMO) scheduling schemes,the frequent user exchange deteriorates the Quality of user experience(Qo E) of the bursty data *** the channel vector orthogonalization computation results in a high time *** address these problems,we propose an inertial scheduling policy to reduce the number of noneffective user exchange,and substitute self-organization policy for channel vector orthogonalization computation to reduce computational *** relationship between the scheduling effectiveness and the inertia of objective function is observed in the *** simulation results show that the inertial scheduling policy effectively reduce the number of potential noneffective scheduling which is inversely proportional to the Mean opinion score(MOS)that quantifies the Qo *** proposed scheduling scheme provides significant improvement in Qo E performance in the *** the proposed scheduling scheme does not consider the channel vector orthogonalization in the user selection phrase,its throughput approaches the level of the throughput-oriented scheme because of its selforganization scheduling policy.

关键词： Bursty data service Multiple-inputmultiple-output(MIMO) Quality of user experience(QoE) Time perception

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Wind erodibility indices of aeolian sandy soils impacted by different vegetation restoration:a case study from the Shannan valley of the Yarlung Zangbo River

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Journal of Mountain Science 2022年第10期19卷 2830-2845页

作者： ZHANG bao-jun xiong Dong-hong LIU Lin TANG Yong-fa Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China College of Water Conservancy and Hydropower Engineering Sichuan Agricultural UniversityYa'an 625014China

Controlling aeolian desertification is a key ecological target on the Tibetan Plateau,especially within the widespread river *** recovery can change the near-soil surface characteristics,which thus may influence wind erodibility of ***,these potential effects are not sufficiently evaluated for aeolian sandy *** study selected the Shannan valley of the Yarlung Zangbo River on the southern Tibetan Plateau as a case to investigate the variations in wind erodibility of aeolian sandy soils impacted by different vegetation restoration,since many ecological measures have been implemented in recent decades in the river *** vegetated sandy lands with different restoration types and ages and two bare sandy lands(as controls)were chosen as test *** vegetated sandy lands were covered by Artemisia wellbyi,Hedysarum scoparium,Sophora moorcroftiana,and Populus *** the similar restoration age of 10 *** Sophora moorcroftiana and Populus ***,two restoration ages of 6 and over 30 years were also selected *** erodibility was reflected by wind erodible fraction(EF),mean weight diameter of dry aggregates(MWD),capillary water capacity(CWC),soil cohesion(CS),and soil penetration resistance(PR)from different aspects.A comprehensive wind erodibility index(CWEI)was further produced by a weighted summation method to combine those five indices together and comprehensively quantify the effects of vegetation restoration on wind erodibility of aeolian sandy *** results showed that revegetation was efficient to reduce wind erodibility of aeolian sandy *** generally decreased,while MWD,CWC,CS,and PR increased after vegetation restoration on the aeolian sandy *** CWEI of vegetated sandy lands varied greatly from 0.850 to 0 under different restoration types and ages and decreased by 14.4%to 100%compared to the *** the four different restoration types,Populus *** the relatively minimum CWEI,fol

关键词： Wind erosion Soil erodibility Erodible fraction Vegetation type Ecological restoration Yarlung Zangbo River valley

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Introducing Ce ions and oxygen defects into V_(2)O_(5)nanoribbons for efficient aqueous zinc ion storage

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Nano Research 2023年第2期16卷 2445-2453页

作者： Mingying bao Zhengchunyu Zhang Xuguang An Jie Liu Jinkui Feng baojuan Xi Shenglin xiong Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringState Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Key Laboratory of Mechanical Engineering of Education School of Mechanical EngineeringChengdu UniversityChengdu 610106China Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China School of Materials Science and Engineering Shandong UniversityJinan 250061China

Cost-effectively,eco-friendly rechargeable aqueous zinc-ion batteries(AZIBs)have reserved widespread concerns and become outstanding candidate in energy storage ***,the progress pace of AZIBs suffers from limitation of suitable and affordable cathode ***,a double-effect strategy is realized in a one-step hydrothermal treatment to prepare V_(2)O_(5)nanoribbons with intercalation of Ce and introduction of abundant oxygen defects(Od-Ce@V_(2)O_(5))to enhance electrochemical performance *** with the theoretical calculation results,the introduction of Ce ions intercalation and oxygen vacancies in V2O5 structure enhances the electrical conductivity,reduces the adsorption energy of zinc ions,enlarges the interlayer distance,renders the structure more stable,and facilitates rapid diffusion *** expected,the desirable cathode delivers the reversible capacity of 444 mAh·g^(−1)at 0.5 A·g^(−1)and shows excellent Coulombic efficiency,as well as an extraordinary energy density of 304.9 Wh·kg^(−1).The strategy proposed here may aid in the further development of cathode materials with stable performance for AZIBs.

关键词： double-effect Ce element doping oxygen defects Od-Ce@V_(2)O_(5) aqueous zinc-ion batteries

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Compositionally complex coherent precipitation-strengthened high-entropy alloys:a critical review

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Rare Metals 2022年第6期41卷 2002-2015页

作者： Jin-xiong Hou Bo-Xuan Cao Bo Xiao Zeng-bao Jiao Tao Yang Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China Hong Kong Institute for Advanced Study City University of Hong KongHong Kong 999077China Department of Mechanical Engineering.The Hong Kong Polytechnic University Hong Kong 999077China

The coherent precipitation-strengthened high-entropy alloys(CPS-HEAs)as a new type of structural materials are expected to possess many unique mechanical properties,such as the outstanding strength-ductility com-bination at cryogenic and room *** from this,most of their strengths can even be well retained at elevated *** compositionally complex matrix and nanoprecipitation phases,as well as the coherent interfaces between them,can potentially bring novel merits of these CPS-HEAs,including sluggish dif-fusion,excellent thermal stability,and controlled magnetic *** that the ductile coherent L1_(2)-nanoparticles can improve the strength of alloys without too much reduction of plasticity,while the coherent B2-nanoparticles strengthened HEAs display completely brittle failure upon tensile test at room *** overview of the alloy design,microstructure evolution,oxidation resistance,mechanical and magnetic properties of CPS-HEAs are briefly discussed *** advantages of multicomponent coherent precipitation-strengthened HEAs as well as the limitations in this field are also *** addition,this review also points out the future research directions and prospects.

关键词： High-entropy alloys Coherent precipitation strengthening Multicomponent intermetallic Mechanical properties Magnetic properties

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