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Complex adaptive system theory,agent-based modeling,and simulation in dominant technology formation

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Journal of Systems Engineering and Electronics 2024年第1期35卷 130-153页

作者： zhang Ruihan sun Bing Glorious sun School of Business and Management Donghua UniversityShanghai 200051China School of Economics and Management Harbin Engineering UniversityHarbin 150001China

Dominant technology formation is the key for the hightech industry to“cross the chasm”and gain an established foothold in the market(and hence disrupt the regime).Therefore,a stimulus-response model is proposed to investigate the dominant technology by exploring its formation process and ***,based on complex adaptive system theory and the basic stimulus-response model,we use a combination of agent-based modeling and system dynamics modeling to capture the interactions between dominant technology and the socio-technical *** results indicate the following:(i)The dynamic interaction is“stimulus-reaction-selection”,which promotes the dominant technology’s formation.(ii)The dominant technology’s formation can be described as a dynamic process in which the adaptation intensity of technology standards increases continuously until it becomes the leading technology under the dual action of internal and external mechanisms.(iii)The dominant technology’s formation in the high-tech industry is influenced by learning ability,the number of adopting users and ***,a“critical scale”of learning ability exists to promote the formation of leading technology:a large number of adopting users can promote the dominant technology’s formation by influencing the adaptive response of technology standards to the socio-technical landscape and the choice of technology standards by the socio-technical *** is a minimum threshold and a maximum threshold for the role of adaptability in the dominant technology’s formation.(iv)The socio-technical landscape can promote the leading technology’s shaping in the high-tech industry,and different elements have different *** study promotes research on the formation mechanism of dominant technology in the high-tech industry,presents new perspectives and methods for researchers,and provides essential enlightenment for managers to formulate technology strategies.

关键词： complex adaptive system theory agent-based modeling and simulation dominant technology socio-technical landscape adaptation-choice

Study on Coded Permutation Entropy of Finite Length Gaussian White Noise Time Series

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Chinese Journal of Electronics 2024年第1期33卷 185-194页

作者： Huihui sun Xiaofeng zhang School of Physics and Information Technology Shaanxi Normal University

As an extension of permutation entropy(PE), coded permutation entropy(CPE) improves the performance of PE by making a secondary division for ordinal patterns defined in PE. In this study, we provide an exploration of the statistical properties of CPE using a finite length Gaussian white noise time series theoretically. By means of the Taylor series expansion, the approximate expressions of the expected value and variance of CPE are deduced and the Cramér-Rao low bound(CRLB) is obtained to evaluate the performance of the CPE estimator. The results indicate that CPE is a biased estimator, but the bias only depends on relevant parameters of CPE and it can be easily corrected for an arbitrary time series. The variance of CPE is related to the encoding patterns distribution,and the value converges to the CRLB of the CPE estimator when the time series length is large enough. For a finitelength Gaussian white noise time series model, the predicted values can match well with the actual values, which further validates the statistic theory of CPE. Using the theoretical expressions of CPE, it is possible to better understand the behavior of CPE for most of the time series.

关键词： Time series analysis White noise Predictive models Taylor series Entropy Encoding Time measurement

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ONE-PARAMETER FINITE DIFFERENCE METHODS AND THEIR ACCELERATED SCHEMES FOR SPACE-FRACTIONAL SINE-GORDON EQUATIONS WITH DISTRIBUTED DELAY

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Journal of Computational Mathematics 2024年第3期42卷 705-734页

作者： Tao sun Chengjian zhang Haiwei sun School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan 430074China Department of Mathematics University of MacaoMacaoChina

This paper deals with numerical methods for solving one-dimensional(1D)and twodimensional(2D)initial-boundary value problems(IBVPs)of space-fractional sine-Gordon equations(SGEs)with distributed *** 1D problems,we construct a kind of oneparameter finite difference(OPFD)*** is shown that,under a suitable condition,the proposed method is convergent with second order accuracy both in time and *** implementation,the preconditioned conjugate gradient(PCG)method with the Strang circulant preconditioner is carried out to improve the computational efficiency of the OPFD *** 2D problems,we develop another kind of OPFD *** such a method,two classes of accelerated schemes are suggested,one is alternative direction implicit(ADI)scheme and the other is ADI-PCG *** particular,we prove that ADI scheme can arrive at second-order accuracy in time and *** some numerical experiments,the computational effectiveness and accuracy of the methods are further ***,for the suggested methods,a numerical comparison in computational efficiency is presented.

关键词： Fractional sine-Gordon equation with distributed delay One-parameter finite difference methods Convergence analysis ADI scheme PCG method

Effect of wire mesh casing treatment on axial compressor performance and stability

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Chinese Journal of Aeronautics 2024年第3期37卷 60-76页

作者： Ming zhang Jiaming zhang Jiahao HU Xu DONG Dakun sun Xiaofeng sun School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China

In this paper,a kind of Wire Mesh Casing Treatment(WMCT)is proposed to improve the stable operating range of the *** contrast to the traditional circumferential groove,as for WMCT,a layer of wire mesh is laid on the surface of the circumferential *** studies were conducted on the low-speed axial flow compressor,including the groove width,axial location,and mesh *** optimum axial location for WMCT is related to its groove width.A higher wire mesh count results in a smaller compressor stall margin *** simulations were carried out to study the effect of WMCT on the flow structure of the *** wire mesh in the WMCT has a certain flow resistance,which restricts the flow into and out of the *** to the WMCT,the flow parameter in the tip region of the rotor is less sensitive to changes in the operating conditions of the *** WMCT causes the rotor tip blade loading to shift backward,inhibiting the formation of spill forward of the leakage flow,and thus improving the stability of the *** flow resistance on the groove surface is a new degree-of-freedom for the casing treatment designer.

关键词： Axial compressor Wire mesh casing treatment Tip clearance flow Stall margin Blade loading

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天然气调质煤粉再燃中关键参数的实验研究

煤炭学报 2024年第7期49卷 3245-3252页

作者：李玉凯孙绍增赵义军张文达冯冬冬哈尔滨工业大学能源科学与工程学院黑龙江哈尔滨150001

针对煤粉再燃技术,提出了一种结合再循环烟气输送煤粉和天然气调质的方案。其目的在于提高再燃煤粉的还原能力,从而降低燃煤锅炉产生的氮氧化物排放。为了探索如何利用天然气中高活性成分,创造一个更有利于煤粉还原NO_(x)的环境,利用模... 详细信息

针对煤粉再燃技术,提出了一种结合再循环烟气输送煤粉和天然气调质的方案。其目的在于提高再燃煤粉的还原能力,从而降低燃煤锅炉产生的氮氧化物排放。为了探索如何利用天然气中高活性成分,创造一个更有利于煤粉还原NO_(x)的环境,利用模拟实际燃煤锅炉条件下的多反应控制段携带流反应器实验系统,研究了天然气调质的整个过程。结果表明,天然气调质产生的大量还原性物质,如CO*、OH*、H和CHi等优化了煤焦的物理化学结构,增强了煤焦还原氮氧化物的能力。与传统的再循环烟气输送煤粉相比,添加天然气调质后,NO_(x)的还原效率提高了约12.23%。通过实验和数据分析,解析了天然气调质技术对于煤粉再燃的显著影响,并提出了在工程应用中的具体参数要求。从工程应用角度来看,为了实现高效率的氮氧化物还原,并兼顾煤粉的燃烬和经济性,需要对再燃区的过量空气系数、停留时间和燃料比进行精确控制,分别为0.8、0.6 s和20%。总的来说,采用天然气调质技术可在保证氮氧化物超低排放的同时,尽量减少活性气体的使用,从而提高系统运行的经济性。该灵活的天然气使用技术不仅在实验室条件下取得了良好的效果,也为工程实践提供了可行的方案,保证系统运行的经济性。

关键词：天然气调质再燃 NOx 燃烧参数

Revealing structure correlation between ionic liquid and metal-organic framework matrix

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Magnetic Resonance Letters 2024年第2期4卷 65-72页

作者： Ligang Xu wenda zhang Chenjie Lou Chenxu Geng Yuxiu sun Jie Liu Yongchao Shi Huajie Luo Jipeng Fu Haiyan Zheng Mingxue Tang Center for High Pressure Science and Technology Advanced Research Beijing100193China College of Materials Science and Engineering Guilin University of TechnologyGuilin541004China State Key Laboratory of Separation Membranes and Membrane Processes School of Material Science and EngineeringTiangong UniversityTianjin300387China University of Science and Technology Beijing Beijing100083China Key Laboratory of Rare Earth Optoelectronic Materials and Devices of Zhejiang Province Institute of Optoelectronic Materials and DevicesChina Jiliang UniversityHangzhou310018China

Solid-state batteries are rising rapidly in response to the fast-increasing energy ***-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray *** study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.

关键词： Nuclear magnetic resonance Solid-state batteries MOF-808 Ionic liquid Local structure

Jackknife Model Averaging for Quantile Single-Index Coefficient Model

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Journal of Systems Science & Complexity 2024年第4期37卷 1685-1713页

作者： sun Xianwen zhang Lixin School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China School of Statistics and Mathematics Zhejiang Gongshang UniversityHangzhou 310018China

In the past two decades,model averaging,as a way to solve model uncertainty,has attracted more and more *** this paper,the authors propose a jackknife model averaging(JMA) method for the quantile single-index coefficient model,which is widely used in *** model misspecification,the model averaging estimator is proved to be asymptotically optimal in terms of minimizing out-of-sample quantile *** experiments are conducted to compare the JMA method with several model selections and model averaging methods,and the results show that the proposed method has a satisfactory *** method is also applied to a real dataset.

关键词： Final prediction error JMA criterion model averaging quantile loss single-index coefficient model

Changes in extreme high temperature warning indicators over China under different global warming levels

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Science China Earth Sciences 2024年第6期67卷 1895-1909页

作者： Yuxia zhang Ying sun Ting HU Chinese Academy of Meteorological Sciences Beijing 100081China National Climate Center Laboratory for Climate StudiesChina Meteorological AdministrationBeijing 100081China

High temperature warning indicators play a pivotal role in meteorological departments,serving as crucial criteria for issuing warnings that guide both social production and daily *** their importance,limited studies have explored the relationship between different global warming levels and changes in high temperature warning *** this study,we analyze data from 2,419 meteorological stations over China and utilize the Coupled Model Intercomparison Project Phase 6(CMIP6)models to examine historical changes in high temperature warning indicators used by the China Meteorological *** evaluate model performance and estimate future changes in these indicators using an annual cycle bias correction *** results indicate that since 1961,the number of high temperature days(TX35d and TX40d)and length of season(TX40d and TX40l)with daily maximum temperature reaching or exceeding 35℃ and 40℃ have increased over *** intensity of high temperatures(TXx)has strengthened and the geographical extent affected by high temperatures has *** 2022,the occurrence of 40℃ high temperatures surges,with Eastern China experiencing a two-day increase in TX40d and an extended seasonal length in TX40l by over five *** CMIP6 models have underestimated the high temperature indictors associated with 35℃ during historical periods,notable difference is not observed between the models and observations for TX40d and TX40l,given their rare ***,future projections,after bias correction,indicate that the increasing trends for 35℃ and 40℃ high temperature days and length of season become more pronounced than the raw projection,suggesting a more severe increase than that anticipated *** global warming intensifies,the high temperature days and length of season are projected to increase non-linearly,while the intensity of high temperatures is expected to increase *** every 1℃ increase in global temperature,the intensity is

关键词： Extreme high temperatures Meteorological warning CMIP6 Global warming levels Future projection

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Feeding prehistoric coastal community:A study of marine faunal remains at the Jingtoushan site

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Science China Earth Sciences 2024年第5期67卷 1574-1590页

作者： Endong WU Guoping sun Ying zhang School of Culture History and LanguageAustralian National UniversityCanberra 2600Australia Zhejiang Provincial Institute of Cultural Relics and Archaeology Hangzhou 310012China National Centre for Archaeology Beijing 100013China

This article examines the abundant marine mollusc,and fish remains at the Jingtoushan shell midden(8,300 to7,800 cal a BP)in Zhejiang Province,China,to investigate the fishing economy,community development,the palaeoenvironment,and their interactions among the prehistoric populations in the lower Yangtze River Basin and southeastern coastal *** also attempts to explore the prosperity and decline of coastal settlements in China during the Neolithic Age and the potential reasons for their rise and fall,*** on the ecological and biological principles of marine animals,standard zooarchaeological methods and radiocarbon dating analysis are used for sampling,identification,measurement,and *** show that at least 11 mollusc taxa and 14 fish taxa can be identified from the Jingtoushan faunal *** ancient Jingtoushan residents possibly lived in a settlement close to the coast and engaged in inshore and offshore fishing,hunting,and gathering as their primary subsistence strategies,with low-level rice cultivation as a supplementary means of ***,the changes in the coastal environment could be one of the reasons why the Jingtoushan residents abandoned their *** research contributes to Chinese Neolithic archaeology with new evidence of the exploitation of marine resources around 8000 a BP in the eastern coastal areas and the relationship between Neolithic community development and environmental changes.

关键词： Neolithic Age Marine faunal remains Fishing economy Palaeoenvironment Community development