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Strategic interaction between institutional investors and supervision department:a theoretical analysis of low‑price collusion in SBIC

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Financial Innovation 2023年第1期9卷 1313-1348页

作者： xin li Zhuming chen School of Economics Sichuan UniversityChengdu 610065China School of Business Sun Yat-sen UniversityGuangzhou 510275China

We introduce evolutionary game method to analyze low-price collusion in inquiry market of Sci-Tech Innovation Board of China(SIBC)from the perspective of strategic interaction between large institutional investors(liIs),small and medium-sized institutional investors(SMIIs),and supervision department(SD).The results show that supervision behaviors of SD,and quotation behaviors of institutional investors,are subject to supervision conditions.Under the condition that benefits of tough supervision are lower a lot than minimum benefits of light supervision(light supervision condition),SD will choose light supervision and institutional investors will turn to illegal quotation in response.Finally,a steady-state equilibrium with low-price collusion will form in SIBC’s inquiry market even with a large supervision penalty for illegal quotation.On the contrary,under the condition that benefits of tough supervision are higher a lot than maximum benefits of light supervision(tough supervision condition)and with a large penalty for illegal quotation,SD and institutional investors will choose tough supervision and legal quotation.Further numerical simulations under light supervision condition show that:(1)High-price culling rule will become a booster for low-price collusion and accelerate SMIIs’evolutionary process to imitative quotation.(2)Blindly increasing penalties for illegal quotation or reducing the culling rate is not an appropriate approach to solve the problem of low-price collusion since it cannot shift supervision condition from light into tough and make SD supervise toughly.(3)Institutional investors’choices of quotation strategies are more volatile and highly susceptible to supervision behaviors of SD when facing exogenous uncertainty.Therefore,the keys to solving the problem of low-price collusion are shifting supervision condition from light into tough through increasing incremental benefits of tough supervision,and providing institutional investors with a stable and predictable supervision policy.In conclusion,

关键词： Sci-Tech Innovation Board of China Low-price collusion Supervision condition Tripartite evolutionary game

Efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates:A concise synthesis of difluoromethylene-containing 1,4-thiazine derivatives

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Chinese Chemical Letters 2024年第4期35卷 367-370页

作者： Zhiwei chen Heyun Sheng Xue li Menghan chen xin li Qiuling Song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Fujian University Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhou 350108China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A practical method for the construction of difluoromethylene-containing 1,4-thiazine moieties using readily available diethyl bromodifluoromethanephosphonate(BrCF_(2)PO(OEt)_(2))as difluorocarbene precusor has been developed.This transformation features the efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates.A series of structurally novel and functionalized difluoromethylene-containing 1,4-thiazine derivatives were thus synthesized in good yields.

关键词： Difluoromethylene Pyridinium 1 4-zwitterionic thiolates 1 4-Thiazine derivatives

Variable Metric Method for Unconstrained Multiobjective Optimization Problems

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Journal of the Operations Research Society of China 2023年第3期11卷 409-438页

作者： Jian chen Gao-Xi li xin-Min Yang Department of Mathematics Shanghai UniversityShanghai200444China School of Mathematics and Statistics Chongqing Technology and Business UniversityChongqing400067China National Center for Applied Mathematics of Chongqing and School of Mathematical SciencesChongqing Normal UniversityChongqing401331China

In this paper,we propose a variable metric method for unconstrained multiobjective optimization problems(MOPs).First,a sequence of points is generated using different positive definite matrices in the generic framework.It is proved that accumulation points of the sequence are Pareto critical points.Then,without convexity assumption,strong convergence is established for the proposed method.Moreover,we use a common matrix to approximate the Hessian matrices of all objective functions,along which a new nonmonotone line search technique is proposed to achieve a local superlinear convergence rate.Finally,several numerical results demonstrate the effectiveness of the proposed method.

关键词： Multiobjective optimization Variable metric method Pareto point Superlinear convergence

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： xin chen Yu Zhang Chang chen Huinan li Yuran lin Ke Yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at present.Here,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for lithium–oxygen battery.On one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox kinetics.On the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic molecules.Therefore,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product lithium Oxygen battery

The linkage between Midwinter Suppression of the North Pacific Storm Track and Atmospheric Circulation Features in the Northern Hemisphere

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Advances in Atmospheric Sciences 2022年第3期39卷 502-518页

作者： Minghao YANG Chongyin li xin li Xiong chen lifeng li College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

The midwinter suppression(MWS) of the North Pacific storm track(NPST) has been an active research topic for decades. Based on the daily-mean NCEP/NCAR reanalysis from 1948 to 2018, this study investigates the MWS-related atmospheric circulation characteristics in the Northern Hemisphere by regression analysis with respect to a new MWS index, which may shed more light on this difficult issue. The occurrence frequency of the MWS of the upper-tropospheric NPST is more than 0.8 after the mid-1980 s. The MWS is accompanied by significantly positive sea-level pressure anomalies in Eurasia and negative anomalies over the North Pacific, which correspond to a strengthened East Asian winter monsoon. The intensified East Asian trough and atmospheric blocking in the North Pacific as well as the significantly negative low-level air temperature anomalies, lying upstream of the MNPST, are expected to be distinctly associated with the MWS. However, the relationship between the MWS and low-level atmospheric baroclinicity is somewhat puzzling.From the diagnostics of the eddy energy budget, it is identified that the inefficiency of the barotropic energy conversion related to the barotropic governor mechanism does not favor the occurrence of the MWS. In contrast, weakened baroclinic energy conversion, buoyancy conversion, and generation of eddy available potential energy by diabatic heating are conducive to the occurrence of the MWS. In addition, Ural blocking in the upstream region of the MNPST may be another candidate mechanism associated with the MWS.

关键词： midwinter suppression North Pacific storm track anomalous atmospheric circulation eddy energy budget

Detection and characteristics analysis of the western subarctic front using the high-resolution SST product

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Acta Oceanologica Sinica 2023年第6期42卷 24-32页

作者： Changyuan chen chen Wang Huimin li Denghui Hu Gang li xin chen Yijun He School of Marine Sciences Nanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Space Ocean Remote Sensing and Application Ministry of Natural ResourcesBeijing 100081China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201203China

Oceanic front plays a significant role in the ocean vertical mixing and the regulation of air-sea interaction,among others.The western branch of the subarctic front(WSAF)located in the Northwest Pacific has attained lots of attention given its strong intensity and widespread influence on this region.In this study,we take advantage of the merged sea surface temperature(SST)at a high spatial resolution of 0.05°to investigate the characteristics of WSAF.The front detection algorithm that combines the Sobel operator and histogram analysis is adopted.It is advantageous in both preserving the front intensity represented by the SST gradient as well as reducing the detection noise level.We systematically applied this algorithm to the daily SST products for front detection,based on which the WSAF characteristics including its intensity,occurrence of frequency,latitudinal position and coverage area are then extracted.WSAF is mostly located within a small latitude range between 40°N and 41°N with a clear seasonal trend in its intensity that peaks in the winter and troughs in the summer.The seasonal variation of WSAF intensity is almost consistent throughout the temporal period of interest from 2010 to 2018.Similar seasonality is observed for its occurrence of frequency with the winter-summer contrast reaching up to5%.The findings presented here shall help better interpret the WSAF characteristics in the long-term run as well as their impact on the regional weather and climate patterns at high spatial resolution.

关键词： sea surface temperature western subarctic front front detection characteristics analysis

Thermodynamics of Cascaded Waste Heat Utilization from Flue Gas and Circulating Cooling Water

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Journal of Thermal Science 2023年第6期32卷 2166-2178页

作者： li Yuanyuan chen xin JIANG Shan LU Gui State Key Laboratory of New Energy Power Systems North China Electric Power UniversityBeijing102206China Department of Water Resources China Institute of Water Resources and Hydropower ResearchBeijing100038China School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing102206China

A detailed thermal power plant model was developed to evaluate power plant waste heat usage in terms of the operating parameters,energy consumption,water consumption,and pollutant emissions.This model was used to analyze the bypass flue gas energy cascade utilization design which provides excellent energy savings and emission reductions.This paper then presents a design to use the low-temperature waste heat and to extract water from the flue gas.The low-grade heat can be recovered from a coal-fired unit using absorption heat pumps to increase the air preheating.This method significantly reduces the turbine steam extraction in the low pressure stages which increases the turbine power and reduces the coal consumption.This design has a small heat transfer temperature difference between the air preheater and the air warmer,resulting in a smaller exergy loss.The power output of the present design was 1024.28 MW with a coal consumption savings of 3.69 g·(kWh)^(−1).In addition,the present design extracts moisture out of the flue gas to produce 46.48 t·h^(−1)of water.The main goal of this work is to provide a theoretical analysis for studying complex thermal power plant systems and various energy conservation and CO_(2)reduction options for conventional power plants.

关键词： integrated thermal power plant model low-grade waste heat energy cascade utilization exergy losses absorption heat pumps

Information geography: The information revolution reshapes geography

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Science China Earth Sciences 2022年第2期65卷 379-382页

作者： xin li Donghai ZHENG Min FENG Fahu chen State Key Laboratory of Tibetan Plateau Earth System Resource and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The information revolution has been one of the driving forces to the innovation in geography. However, environmental remote sensing, geographic information science and technology, and geocomputing, which once resided within the family of geography, are gradually moving close to information science but are alienated from geography. Therefore, it is necessary to reexamine the interactive convergence of geography and information science, and advance the disciplinary system of geographic science to accommodate the researches with information as subjects and methods. In this paper, we propose to reformulate the relationship between geographic science and information science with a new discipline, i.e., information geography, which not only refers to the geography of information but also a methodological system for studying geography using information science.This paper summarizes the background of information geography’s emergence, its definition, and the difference and similarities with other disciplinary concepts. The impact of information geography on geographic paradigm shift is also investigated from the ontological, epistemological, and methodological perspectives.

关键词： Information geography Geography Information revolution Methodology Geographic paradigm

Multiplicity of solutions for the semilinear subelliptic Dirichlet problem

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Science China Mathematics 2024年第3期67卷 475-504页

作者： Hua chen Hong-Ge chen Jin-Ning li xin liao School of Mathematics and Statistics Wuhan UniversityWuhan 430072China Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

In this paper,we study the semilinear subelliptic equation{−△Xu=f(x,u)+g(x,u)inΩ,u=0 on∂Ω,where△X=−∑m i=1 Xi∗Xi is the self-adjoint Hormander operator associated with the vector fields X=(X_(1),X_(2),...,X_(m))satisfying the Hormander's condition,f(x,u)∈C(Ω×R),g(x,u)is a Carathéodory function onΩ×R,andΩis an open bounded domain in R~n with smooth boundary.Combining the perturbation from the symmetry method with the approaches involving the eigenvalue estimate and the Morse index in estimating the minimax values,we obtain two kinds of existence results for multiple weak solutions to the problem above.Furthermore,we discuss the difference between the eigenvalue estimate approach and the Morse index approach in degenerate situations.Compared with the classical elliptic cases,both approaches here have their own strengths in the degenerate cases.This new phenomenon implies that the results in general degenerate cases would be quite different from the situations in classical elliptic cases.

关键词： degenerate elliptic equations Hormander operators perturbation method Morse index