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Learning in games:a systematic review

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Science China(Information Sciences) 2024年第7期67卷 133-159页

作者： Rong-jun QIN Yang yu National Key Laboratory for Novel Software Technology Nanjing University Polixir Technologies

game theory studies the mathematical models for self-interested individuals. Nash equilibrium is arguably the most central solution in game theory. While finding the Nash equilibrium in general is known as polynomial parity arguments on directed graphs(PPAD)-complete, learning in games provides an alternative to approximate Nash equilibrium, which iteratively updates the player's strategy through interactions with other players. Rules and models have been developed for learning in games, such as fictitious play and no-regret learning. Particularly, with recent advances in online learning and deep reinforcement learning,techniques from these fields greatly boost the breakthroughs in learning in games from theory to *** a result, we have witnessed many superhuman game AI systems. The techniques used in these systems evolve from conventional search and learning to purely reinforcement learning(RL)-style learning methods,gradually getting rid of the domain knowledge. In this article, we systematically review the above techniques,discuss the trend of basic learning rules towards a unified framework, and recap applications in large ***, we discuss some future directions and make the prospect of future game AI systems. We hope this article will give some insights into designing novel approaches.

关键词： non-cooperative games learning in games no-regret learning reinforcement learning superhuman AI

Equivalence between the internal observability and equation

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 89-97页

作者： LIU Wen-jun TU Zhi-yu School of Mathematics and Statistics Nanjing University of Information Science and TechnologyNanjing 210044China

This paper is concerned with a third order in time linear Moore-gibson-Thompson equation which describes the acoustic velocity potential in ultrasound wave *** by the work of Kaltenbacher,Lasiecka and Marchand(Control Cybernet.2011,40:971-988),we establish an observability inequality of the conservative problem,and then discuss the equivalence between the exponential stabilization of a dissipative system and the internal observational inequality of the corresponding conservative system.

关键词： Moore-gibson-Thompson equation internal observability exponential stability

First Digit Distributions of gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第5期24卷 70-75页

作者： Hou-yu Lai jun-Jie Wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s *** this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (gRBs) for the first *** a complete gRB sample detected by the fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s ***,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral *** on the conventional duration classification scheme,we also check if the durations and fluences of long and short gRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s *** find that the fluences of both long and short gRBs still agree with the Benford distribution,but their durations do not follow Benford’s *** results hint that the long–short gRB classification scheme does not directly represent the intrinsic physical classification scheme.

关键词： (stars:)gamma-ray burst general-methods statistical-astronomical databases miscellaneous

A Simple Proof of ACC for Minimal Log Discrepancies for Surfaces

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Acta Mathematica Sinica,English Series 2024年第2期40卷 425-434页

作者： Jing jun HAN yu Jie LUO Shanghai Center for Mathematical Sciences Fudan UniversityJiangwan CampusShanghai 200438P.R.China Department of Mathematics Johns Hopkins UniversityBaltimoreMD 21218USA

Following Shokurov's idea,we give a simple proof of the ACC conjecture for minimal log discrepancies for surfaces.

关键词： Ascending chain condition minimal log discrepancies minimal model program surface

Evolution of copper species during heat treatment and its effect on CO oxidation reaction on CuCeZrO_(y) catalyst synthesized by a facile solvent-free route

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Journal of Rare Earths 2024年第4期42卷 660-667页

作者： guangying Fu Dongsen Mao jun yu Qiangsheng guo School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai21418 China The ZeoMat group Qingdao Institute of Bioenergy and Bioprocess TechnologyCASQingdao26611China

Several ternary oxides CuCeZrO_(y)(CCZ)were synthesized by a facile grinding method followed by calcination at high temperatures,and used as catalysts for CO oxidation at low *** influences of calcination temperature(400-600℃)on the physicochemical properties of the assynthesized ternary oxides were investigated by thermogravimetric analysis/differential scanning calorimetry(TgA/DSC),X-ray diffraction(XRD),transmission electron microscopy(TEM),Raman,inductively coupled plasma-optical emission spectrometry(ICP-OES),N_(2) adsorption,H_(2)-temperature programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)*** results show that the increase in calcination temperature from 400 to 500℃is conducive to the high dispersion of CuOx on catalyst surface and the incorporation of Cu species into the support to form the Cu-Ce-Zr-O solid *** raising of calcination temperature from 500 to 600℃,however,leads to the segregation of Cu species from the solid solution to aggregate on support surface and growth of highly dispersed CuOx *** highest catalytic activity is acquired over the CCZ calcined at 500℃,which can be ascribed to the largest contents of Cu+species and oxygen vacancies owing to the formation of the maximum amount of Cu-Ce-Zr-O solid solution.

关键词： CuCeZrO_(y)catalyst co oxidation Calcination temperature grinding method Oxalate precursor Rare earths

Investigation on the influence of vortex generator on particle resuspension

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Particuology 2024年第3期86卷 126-136页

作者： Dongchi yu.jun-Li Lin Jin-Han Xie ASML 80W Tasman DrSan Jose95134CaliforniaUSA Department of Mechanics and Engineering Science at College of Engineering and State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing100081China

The vortex generator(Vg)and its well-known effect in flow optimization are widely studied and employed across different engineering ***,while the same working principles of Vg may be well suited for the applications on surface-cleaning technologies,such promising potential is hardly,if any,explored in the published ***,in the present study,the influence on flow-induced particle resuspension brought by a rectangular vg in a channel flow is investigated with the help of highfidelity computational fluid dynamics *** increases of particle removal forces and resuspension rates are discovered in long,strip-like regions with reduced boundary-layer thickness resulted from the vg-induced vortices,and the enhancement effect is especially significant for configurations with the Vg installed at a greater angle of *** is also shown that while the resuspension enhancements on the lower and the upper surfaces of the channel exhibit distinct statistical characteristics,having a Vg in the channel improves the overall particle-removing capability of the channel flow by introducing higher surface-averaged removal forces and particle resuspension *** but not least,the increase of resuspension rate is especially significant for the smaller,micron-scale particles which are otherwise hardly disturbed by a Vg-less channel flow,and such resuspension-enhancement effectgenerally subsides with increasing particle size.

关键词： Particle resuspension Vortexgenerator CFD Surface cleaning

Progress on the glassy-crystal laminates:From design,microstructure to deformation and future solutions

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Journal of Materials Science & Technology 2024年第5期172卷 113-144页

作者： yu Chen Ronggao Cui jun Shen gang Wang College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Department of Motor Design Business Weichai New Energy Technology Co.Ltd.Weifang 261061China guangdong Key Laboratory of Electromagnetic Control and Intelligent Robots Shenzhen UniversityShenzhen 518060China Laboratory for Microstructures Institute of MaterialsShanghai UniversityShanghai 200444China

The development of new design strategies to create innovative structural materials,refine existing ones,and achieves compatible combinations of strength and plasticity remains a worldwide *** alloys,such as shape memory alloys(SMAs),bulk metallic glasses(BMgs),high entropy alloys(HEAs),and heterogeneous pure metals such as Cu,have excellent mechanical responses,but they still fall short of meeting all the requirements of structural materials due to specific flaws,such as lack of tensile de-formation for BMgs and low yielding strength for *** address these shortcomings,proposals such as integrating glassy matrices and crystallized alloys,such as HEAs/SMAs,have been ***,these solutions have unresolved issues,such as the challenging control of B2 phase formation in BMg ***,glass-crystal(A/C)laminated alloys with alternating layers have been reported to exhibit improved mechanical properties and activated work-hardening behaviors,but they still face press-ing issues such as bonding interfaces and unknown deformation *** review focuses on design routes such as the selection of alloy components and processing techniques,exploration of micro-structural evolution and deformation modes with an increase in strain,and future solutions to address pressing and unsolved *** prominent advantages include diversified deformation mechanisms,such as deformation twinning,martensitic phase transformation,and precipitation hardening,as well as tuned interactive reactions of shear bands(SBs)near the A/C ***,this review provides a promising pathway to design and develop structural materials in the materials field community.

关键词： glassy-crystal laminates Bulk metallic glasses High entropy alloys Shape memory alloys Microstructure Deformation mechanisms Future solutions

Probiotics intervention in colorectal cancer:From traditional approaches to novel strategies

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Chinese Medical Journal 2024年第1期137卷 8-20页

作者： Suki Ha Xiang Zhang jun yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong SARChina

The intestine harbors a large population of microorganisms that interact with epithelial cells to maintain host healthy physiological *** intestinal microbiota engage in the fermentation of non-digestible nutrients and produce beneficial metabolites to regulate host homeostasis,metabolism,and immune *** disruption of microbiota,known as dysbiosis,has been implicated in many intestinal diseases,including colorectal cancer(CRC).As the third most common cancer and the second leading cause of cancer-related death worldwide,CRC poses a significant health *** is an urgent need for novel interventions to reduce CRC incidence and improve clinical *** the intestinal microbiota has emerged as a promising approach for CRC prevention and *** research efforts in CRC probiotics primarily focus on reducing the incidence of CRC,alleviating treatment-related side effects,and potentiating the efficacy of anticancer therapy,which is the key to successful translation to clinical *** paper aims to review the traditional probiotics and new interventions,such as next-generation probiotics and postbiotics,in the context of *** underlying mechanisms of probiotic anti-cancer effects are also discussed,including the restoration of microbial composition,reinforcement of gut barrier integrity,induction of cancer cell apoptosis,inactivation of carcinogens,and modulation of host immune *** paper further evaluates the novel strategy of probiotics as an adjuvant therapy in boosting the efficacy of chemotherapy and *** all the promising findings presented in studies,the evaluation of potential risks,optimization of delivery methods,and consideration of intra-patient variability of gut microbial baseline must be thoroughly interpreted before bench-to-bedside translation.

关键词： colorectal cancer probiotics gut microbiota dysbiosis adjuvant therapy immune modulation gut barrrier

Risk assessment of oil and gas investment environment in countries along the Belt and Road Initiative

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Petroleum Science 2024年第2期21卷 1429-1443页

作者： Bao-jun Tang Chang-Jing Ji yu-Xian Zheng Kang-Ning Liu Yi-fei Ma jun-yu Chen Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing100081China School of Management and Economics Beijing Institute of TechnologyBeijing100081China Collaborative Innovation Center of Electric Vehicles in Beijing BeijingChina Sustainable Development Research Institute for Economy and Society of Beijing BeijingChina Institute of Carbon Neutrality ShanghaiTech UniversityShanghai201210China

With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-gRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the gM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.

关键词： Belt and Road Initiative Oil and gas Investment Risk assessment