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气候变化背景下沿海城市轨道交通网络韧性评估——以深圳市为例

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灾害学 2025年第1期40卷 167-173,186页

作者：胡文昊尚凯葛懿夫翟国方张钰佳南京大学建筑与城市规划学院江苏南京210093 清华大学建筑学院北京100084

轨道交通网络是大型城市人口高效通勤的有力保障,在全球气候变化背景下,沿海城市轨道交通网络受到海平面上升及一系列连锁效应的威胁。该文以深圳市为例对未来不同情景下的轨道交通网络进行复杂网络建模及韧性评估。结果表明:①海平面... 详细信息

轨道交通网络是大型城市人口高效通勤的有力保障,在全球气候变化背景下,沿海城市轨道交通网络受到海平面上升及一系列连锁效应的威胁。该文以深圳市为例对未来不同情景下的轨道交通网络进行复杂网络建模及韧性评估。结果表明:①海平面的不断上升,对轨道交通网络的整体韧性带来显著影响;②当考虑到气候变化的累积效应时,网络韧性下降更加显著;③关键站点的失效对轨道交通网络的影响更大,包括自身失效的影响和造成其他站点间接失效的影响;④沿海存在多处较严重的地表沉降区域,区域内站点受到地表沉降和海平面上升的共同作用。研究以海平面上升作为灾害背景进行轨道交通网络的韧性评估并将地表沉降因素考虑在内,可为沿海城市轨道交通的长期安全发展提供理论参考。

关键词：气候变化海平面上升轨道交通网络韧性

Applying resolved-scale linearly forced isotropic turbulence in rational subgrid-scale modeling

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Acta Mechanica Sinica 2019年第3期35卷 486-494页

作者： Chuhan Wang Mingwei ge School of Renewable Energy North China Electric Power UniversityBeijing 102206China LMP Ecole Centrale de PékinBeihang UniversityBeijing 100191China

In previous attempts of rational subgrid-scale (SGS) modeling by employing the Kolmogorov equation of filtered (KEF) quantities, it was necessary to assume that the resolved-scale second-order structure function is stationary. Forced isotropic turbulence is often used as a framework for establishing and validating such SGS models based on stationary restrictions, for it generates statistical stationary samples. However, traditional forcing method at low wavenumbers cannot provide an analytic form of forcing term for a complete KEF in physical space, which has been illustrated to be essential in the modeling of such SGS models. Thus, an alternative forcing method giving an analytic forcing term in physical space is needed for rational SGS modeling. Giving an analytic linear driving term in physical space, linearly forced isotropic turbulence should be considered an ideal theoretical framework for rational SGS modeling. In this paper, we demonstrate the feasibility of establishing a rational SGS model with stationary restriction based on linearly forced isotropic turbulence. The performance of this rational SGS model is validated. We, therefore, propose the use of linearly forced isotropic turbulence as a complement to free-decaying isotropic turbulence and low-wavenumber forced isotropic turbulence for SGS model validations.

关键词： Homogeneous isotropic turbulence Large-eddy simulation Subgrid-scale model Forced turbulence

Effect of particle size on the thermal performance of NaNO3/SiC)2/C composite phase-change materials

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Particuology 2019年第3期17卷 169-175页

作者： Liang Liu Liqiong Wang Weichun ge Yanfeng ge Yun Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China State Grid Liaoning Electric Power Supply Co. Ltd. Shenyang 110004 China

Storage of thermal energy is a key technology for energy conservation and application of renewable energy sources. In this paper, the thermal performance of inorganic composite phase-change materials (PCMs;NaNO3/SiO2/C) is studied under extreme thermal conditions and the effect of raw particle size is examined. We designed a thermal shock test platform with a diffusive combustion system and in-situ infrared thermal imaging. The influences of the heat flux magnitude and exposure time on the performance of the PCMs were examined under vertical thermal shock conditions. Leakage of molten salt in the composite PCMs was observed as the heat flux reached a threshold point. The morphology and thermal properties were characterized by ex-situ SEM, XRD, DSC, and BET. Raw particles with sizes in the range of 105-500 μm were used to synthesize the composite material and examine its role in thermal shock behavior. Our experiments showed that deterioration of the thermal storage density was slowed as the particle size was increased. This work provides useful guidance for improving the anti-thermal shock ability of future material designs.

关键词： Thermal storage Phase change material Particle size Thermal shock Decomposition temperature

From solar terms to medical terms(Part Ⅰ): A first step with big data

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Science China Earth Sciences 2017年第9期60卷 1707-1718页

作者： CHEN ge SHI Jie College of Information Science and Engineering Ocean University of China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Department of Pharmacy Municipal Hospital of Qingdao

The story of the Twenty-four Solar Terms(24-ST_s) is one of the most popular elements in Chinese culture, which has a profound influence on agriculture production, health care, and even daily life in both ancient and modern China. This traditional calendric system was invented by the Chinese ancestors through combining fundamental astronomical knowledge with climatic and phenological conditions in the Yellow River Basin some 2000 years ago. Although the basic philosophy of the 24-ST_s remains valid for the country as a whole to date, their regional robustness has been increasingly challenged by accumulating observational data in terms of temporal shift and spatial inhomogeneity. To tackle these issues, we propose to recalibrate the medically related critical timings of Great Heat and Great Cold in the classic ST system by using big meteorological data, and adjust them by introducing geographically correlated analytical models. As a result, a novel calendric system, called the Twenty-four Medical Terms(24-MT_s), has been developed as an upgraded version of the traditional 24-ST_s. The proposed 24-MT_s are characterized by two striking features with respect to the 24-ST_s: A varying duration of each MT instead of a fixed one for the ST, and a geographically dependent timing for each MT instead of a unified one for the entire nation. As such, the updated 24-MT_s are expected to provide a more realistic estimate of these critical timings around the year, and hence, a more precise guidance to agronomic planning and health care activity in China.

关键词： Solar Terms Medical Terms Big Data

Convergence Rate of the Asymmetric Deffuant-Weisbuch Dynamics

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Journal of Systems Science & Complexity 2015年第4期28卷 773-787页

作者： ZHANG Jiangbo CHEN ge The Faculty of Science Southwest Petroleum University Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences

This paper considers the convergence rate of an asymmetric Deffuant-Weisbuch *** model is composed by finite n interacting *** this model,agent i’s opinion is updated at each time,by first selecting one randomly from n agents,and then combining the selected agent j’s opinion if the distance between j’s opinion and i’s opinion is not larger than the confidence radiusε*** yields the endogenously changing inter-agent *** on the previous result that all agents opinions will converge almost surely for any initial states,the authors prove that the expected potential function of the convergence rate is upper bounded by a negative exponential function of time t when opinions reach consensus finally and is upper bounded by a negative power function of time t when opinions converge to several different limits.

关键词： Convergence rute Deffuant-Weisbuch model multi-agent systems opinion dynamics.

Polymeric piezoelectric accelerometers with high sensitivity,broad bandwidth,and low noise density for organic electronics and wearable microsystems

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Microsystems & Nanoengineering 2024年第3期10卷 63-74页

作者： Chang ge Edmond Cretu The Department of Electrical and Computer Engineering The University of British ColumbiaVancouverBCCanada

Piezoelectric accelerometers excel in vibration *** the emerging trend of fully organic electronic microsystems,polymeric piezoelectric accelerometers can be used as vital front-end components to capture dynamic signals,such as vocal vibrations in wearable speaking assistants for those with speaking ***,high-performance polymeric piezoelectric accelerometers suitable for such applications are *** organic compounds such as PVDF have inferior properties to their inorganic counterparts such as ***,most existing polymeric piezoelectric accelerometers have very unbalanced performance *** often sacrifice resonance frequency and bandwidth for a flat-band sensitivity comparable to those of PZT-based accelerometers,leading to increased noise density and limited application *** this study,a new polymeric piezoelectric accelerometer design to overcome the material limitations of PVDF is *** new design aims to simultaneously achieve high sensitivity,broad bandwidth,and low *** samples were manufactured and characterized,demonstrating an average sensitivity of 29.45 pC/g within a±10 g input range,a 5%flat band of 160 Hz,and an in-band noise density of 1.4μg/√*** results surpass those of many PZT-based piezoelectric accelerometers,showing the feasibility of achieving comprehensively high performance in polymeric piezoelectric accelerometers to increase their potential in novel applications such as organic microsystems.

关键词： piezoelectric polymeric overcome

BIOLUMINESCENCE TOMOGRAPHY:BIOMEDICAL BACKGROUND,MATHEMATICAL THEORY,AND NUMERICAL APPROXIMATION

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Journal of Computational Mathematics 2008年第3期26卷 324-335页

作者： Weimin Han ge Wang Department of Mathematics University of Iowa Iowa City IA 52242 USA Division of Biomedical Imaging Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences Virginia Polytechnic Institute and State University Blacksburg Virginia 24061 USA

Over the last couple of years molecular imaging has been rapidly developed to study physiological and pathological processes in vivo at the cellular and molecular levels. Among molecular imaging modalities, optical imaging stands out for its unique advantages, especially performance and cost-effectiveness. Bioluminescence tomography （BLT） is an emerging optical imaging mode with promising biomedical advantages. In this survey paper, we explain the biomedical significance of BLT, summarize theoretical results on the analysis and numerical solution of a diffusion based BLT model, and comment on a few extensions for the study of BLT.

关键词： Biomedical imaging Bioluminescence tomography (BLT) Inverse problem,Regularization Numerical approximation Error analysis

Statistical properties of pseudo-particle systems

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Particuology 2010年第4期8卷 332-342页

作者： Feiguo Chen Wei ge State Key Laboratory of Multi-Phase Complex System Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Pseudo-particle modeling （PPM）, a molecular modeling method which combines time-driven algorithms and hard molecule modeling, was originally developed for simulating gas in complex multiphase systems （ge ＆ Li, 2003; ge et al., 2005; ge, 1998）. In this work, the properties of two- and three-dimensional pseudo-particle systems, namely, mean free path, compressibility factor, self-diffusion coefficient and shear viscosity, are systematically measured by using PPM. it is found that in terms of an effective diameter, the results well conform to the Chapman-Enskog theory, thus suggesting that PPM can be employed to simulate the micro- and meso-scale behavior of ordinary gas and fluid flows.

关键词： Pseudo-particle modeling Molecular dynamics Transport coefficient Chapman-Enskog theory

Investigating the Head Impact Force-Induced Evolution of Hyperphosphorylated Tau Proteins in Brain Tissue Through Mechanical Mesoscale Finite Element Simulation

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Acta Mechanica Solida Sinica 2022年第4期35卷 705-715页

作者： ge He Lei Fan Shanghai Key Laboratory of Mechanics in Energy Enginering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China Department of Mechanical Engineering Michigan State UniversityEast LansingMI 48824USA

For human heads that experienced repetitive subconcussive impacts,abnormal accumulation of hyperphosphorylated tau(p-tau)proteins was found in the postmortem brain *** numerically understand the cause–effect relationship between the external force and the microscopic volume change of the p-tau protein,we created a mesoscale finite element model of the multilayer brain tissue containing microscopic voids representing the p-tau *** model was applied under the loading boundary conditions obtained from a larger length scale simulation.A formerly developed internal state variable elastoplasticity model was implemented to describe the constitutive behaviors of gray and white matters,while the cerebrospinal fluid was assumed to be purely *** effects of the initial sizes and distances of p-tau proteins located at four different brain regions(frontal,parietal,temporal and occipital lobes)on their volumetric evolutions were *** is concluded that both the initial sizes and distances of the proteins have more or less(depending on the specific brain region)influential effects on the growth or contraction rate of the p-tau *** p-tau proteins located within the brain tissue at the frontal and occipital lobes are more heavily affected by the frontal impact load compared with those at the parietal and temporal *** summary,the modeling approach presented in this paper provides a strategy for mechanically studying the evolution of p-tau proteins in the brain tissue and gives insight into understanding the correlation between macroscopic force and microstructure change of the brain tissue.

关键词： Traumatic head injury Hyperphosphorylated tau(p-tau)protein Internal state variable Brain tissue