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From risk control to resilience: developments and trends of urban roads designed as surface flood passages to cope with extreme storms

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 103-120页

作者： Zhiyu Shao Yuexin Li Huafeng gong Hongxiang Chai College of Environment and Ecology Chongqing UniversityChongqing 400030China Key Laboratory of Ecological Environment of Ministry of Education of Three Gorges Reservoir Area Chongqing UniversityChongqing 400030China T.Y.Lin International Engineering Consulting(China)Co.Ltd. Chongqing 400045China

Urban roads can be designated as surface flood passages to transport excess runoff during extreme storms, thereby preventing local flooding, which is known as the major drainage system. However, this practice poses significant risks, including human loss and property damage, due to the high flow rate and velocity carried by roads. Moreover, urban roads with low flood-resilience may significantly hamper the transportation function during severe storms, leading to dysfunction of the city. Therefore, there is an urgent need to transform risk-oriented flood passages into resilient urban road-based flood passages. This paper presents a systematic review of existing methodologies in designing a road network-based flood passage system, along with the discussion of new technologies to enhance system resilience. The study also addresses current knowledge gaps and future directions. The results indicate that flood management measures based on the urban road network should integrate accessibility assessment, lifeline and emergency planning to ensure human well-being outcomes. Furthermore, the special needs and features of vulnerable groups must be taken into serious consideration during the planning stage. In addition, a data-driven approach is recommended to facilitate real-time management and evaluate future works.

关键词： Major drainage Flood mitigation Resilient city Stormwater model Urban flooding

Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China Earth Sciences 2024年第5期67卷 1436-1458页

作者： Qing gong Ming-Xing LING Wang ZHENG State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)***,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic *** stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic *** date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the ***,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of *** a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

A vibration isolator with a controllable quasi-zero stiffness region based on nonlinear force design

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1279-1294页

作者： Xinyu LIAN Bing LIU Huaxia DENG Xinglong gong CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences State Key Laboratory of Fire Science University of Science and Technology of China

To achieve stability optimization in low-frequency vibration control for precision instruments, this paper presents a quasi-zero stiffness(QZS) vibration isolator with adjustable nonlinear stiffness. Additionally, the stress-magnetism coupling model is established through meticulous theoretical derivation. The controllable QZS interval is constructed via parameter design and magnetic control, effectively segregating the high static stiffness bearing section from the QZS vibration isolation section. Furthermore, a displacement control scheme utilizing a magnetic force is proposed to regulate entry into the QZS working range for the vibration isolation platform. Experimental results demonstrate that the operation within this QZS region reduces the peak-to-peak acceleration signal by approximately 66.7% compared with the operation outside this region, thereby significantly improving the low frequency performance of the QZS vibration isolator.

关键词： 70K20 low frequency nonlinear O328 quasi-zero stiffness (QZS) vibration isolator

Effect of boundary conditions on shakedown analysis of heterogeneous materials

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 39-68页

作者： Xiuchen gong Yinghao NIE Gengdong CHENG Kai LI State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentInternational Research Center for Computational MechanicsDepartment of Engineering MechanicsDalian University of TechnologyDalian 116023Liaoning ProvinceChina

The determination of the ultimate load-bearing capacity of structures made of elastoplastic heterogeneous materials under varying loads is of great importance for engineering analysis and design. Therefore, it is necessary to accurately predict the shakedown domains of these materials. The static shakedown theorem, also known as Melan's theorem, is a fundamental method used to predict the shakedown domains of structures and materials. Within this method, a key aspect lies in the construction and application of an appropriate self-equilibrium stress field(SSF). In the structural shakedown analysis, the SSF is typically constructed by governing equations that satisfy no external force(NEF) boundary conditions. However, we discover that directly applying these governing equations is not suitable for the shakedown analysis of heterogeneous materials. Researchers must consider the requirements imposed by the Hill-Mandel condition for boundary conditions and the physical significance of representative volume elements(RVEs). This paper addresses this issue and demonstrates that the sizes of SSFs vary under different boundary conditions, such as uniform displacement boundary conditions(DBCs), uniform traction boundary conditions(TBCs), and periodic boundary conditions(PBCs). As a result, significant discrepancies arise in the predicted shakedown domain sizes of heterogeneous materials. Built on the demonstrated relationship between SSFs under different boundary conditions, this study explores the conservative relationships among different shakedown domains, and provides proof of the relationship between the elastic limit(EL) factors and the shakedown loading factors under the loading domain of two load vertices. By utilizing numerical examples, we highlight the conservatism present in certain results reported in the existing literature. Among the investigated boundary conditions, the obtained shakedown domain is the most conservative under ***, utilizing PBCs to

关键词： heterogeneous material self-equilibrium stress field(SSF) shakedown analysis effect of boundary conditions

Constrained Multi-Objective Optimization With Deep Reinforcement Learning Assisted Operator Selection

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 919-931页

作者： Fei Ming Wenyin gong Ling Wang Yaochu Jin the School of Computer Science China University of GeosciencesWuhan 430074China the Department of Automation Tsinghua UniversityBeijing 100084China the Faculty of Technology Bielefeld UniversityNorth Rhine-Westphalia33619 BielefeldGermany

Solving constrained multi-objective optimization problems with evolutionary algorithms has attracted considerable *** constrained multi-objective optimization evolutionary algorithms(CMOEAs)have been developed with the use of different algorithmic strategies,evolutionary operators,and constraint-handling *** performance of CMOEAs may be heavily dependent on the operators used,however,it is usually difficult to select suitable operators for the problem at ***,improving operator selection is promising and necessary for *** work proposes an online operator selection framework assisted by Deep Reinforcement *** dynamics of the population,including convergence,diversity,and feasibility,are regarded as the state;the candidate operators are considered as actions;and the improvement of the population state is treated as the *** using a Q-network to learn a policy to estimate the Q-values of all actions,the proposed approach can adaptively select an operator that maximizes the improvement of the population according to the current state and thereby improve the algorithmic *** framework is embedded into four popular CMOEAs and assessed on 42 benchmark *** experimental results reveal that the proposed Deep Reinforcement Learning-assisted operator selection significantly improves the performance of these CMOEAs and the resulting algorithm obtains better versatility compared to nine state-of-the-art CMOEAs.

关键词： Constrained multi-objective optimization deep Qlearning deep reinforcement learning(DRL) evolutionary algorithms evolutionary operator selection

Influence of ground effect on flow field structure and aerodynamic noise of high-speed trains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 147-160页

作者： Xiaoming TAN Linli gong Xiaohong ZHANG Zhigang YANG Key Laboratory of Intelligent Manufacturing and Service Performance Optimization of Laser and Grinding in Mechanical Industry Hunan Institute of Science and TechnologyYueyang414000China Key Laboratory of Traffic Safety on Track(Central South University) Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China

The simulation of the ground effect has always been a technical difficulty in wind tunnel tests of high-speed *** this paper,large eddy simulation and the curl acoustic integral equation were used to simulate the flow-acoustic field results of high-speed trains under four ground simulation systems(GSSs):“moving ground+rotating wheel”,“stationary ground+rotating wheel”,“moving ground+stationary wheel”,and“stationary ground+stationary wheel”.By comparing the fluid-acoustic field results of the four GSSs,the influence laws of different GSSs on the flow field structure,aero-acoustic source,and far-field radiation noise characteristics were investigated,providing guidance for the acoustic wind tunnel testing of high-speed *** calculation results of the aerodynamic noise of a 350 km/h high-speed train show that the moving ground and rotating wheel affect mainly the aero-acoustic performance under the train *** influence of the rotating wheel on the equivalent sound source power of the whole vehicle was not more than 5%,but that of the moving ground slip was more than 15%.The average influence of the rotating wheel on the sound pressure level radiated by the whole vehicle was 0.3 dBA,while that of the moving ground was 1.8 dBA.

关键词： High-speed train Aero-acoustics Flow field structure Large eddy simulation Moving ground condition Rotating wheel

DEM investigation of strength and critical state behaviours of granular materials under true triaxial loadings

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Particuology 2024年第2期85卷 198-212页

作者： Minyi Zhu Guobin gong Jun Xia Stephen Wilkinson Department of Civil Engineering Xi'an Jiaotong-Liverpool UniversityChina Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolUK Faculty of Engineering and Information Sciences University of Wollongong in DubaiUnited Arab Emirates

This paper investigates the strength and critical state(CS)behaviours of granular materials via DEM simulations of true triaxial drained tests under three different loading modes including constant b(in-termediate stress ratio)tests with constantσ'1(major principal stress),constant p(mean pressure)and constantσ'3(minor principal stress)*** this end,a series of samples are generated with the same particle size distribution,and with the confining stresses ranging from 100 kPa to 900 *** CS is achieved for all *** the macroscopic behaviours and the microscopic behaviours are examined and compared considering different loading modes,confining stresses and intermediate stress ratios(b).The critical state lines(CSLs)are found to be unique and independent of the loading modes,but dependent on the b *** CSLs with b=0 and b=1 form the two boundaries of CSLs respectively beyond which CSLs under all other b tests cannot go *** different strength criteria are examined and compared in terms of both peak and CS *** Mohr-Coulomb strength criterion is found to be only suitable for axisymmetric loading *** Lade-Duncan criterion is only suitable for describing peak strengths,which is dependent on the loading modes and confining *** Satake criterion and Matsuoka-Nakai criterion are the more appropriate strength criteria for describing CS failures,indicating that the CS values of both the Satake parameter and the Matsuoka-Nakai parameter describe an inherent property that characterizes the CS failure for a given type of *** CS mechanical coordination number is fitted by a curved line for a given b value,which is unique regardless of the loading *** peak and CS values of both major and minor principal fabric tensors decrease with increasing b values,while they increase with increasing b values for the intermediate principal fabric tensor.

关键词： Discrete element method Intermediate stress ratio Dilation Critical state Failure criterion

International law obligations for the disposal of Fukushima nuclear-contaminated water under the principles of nuclear safety

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Chinese Journal of Population,Resources and Environment 2024年第1期22卷 10-19页

作者： Wei gong Law School Southwest UniversityChongqing 400715China

The disposal of contaminated water from Japan’s Fukushima nuclear power plant is a significant international nuclear safety issue with considerable cross-border *** matter requires compliance not only with the law of the sea but also with the principles of nuclear safety under international *** principles serve as the overarching tenet of international and China’s domestic nuclear laws,applicable to nuclear facilities and *** principle of safety in nuclear activities is fully recognized in international and domestic laws,carrying broad legal binding ***’s discharge of nuclear-contaminated water into the sea violates its obligations under the principle of safety in nuclear activities,including commitments to optimum protection,as low as reasonably practicable,and *** Japanese government and the International Atomic Energy Agency(IAEA)have breached the obligation of optimum protection by restricting the scope of assessments,substituting core concepts,and shielding dissenting *** the absence of clear radiation standards,they have acted unilaterally without fulfilling the obligation as low as reasonably practicable *** discharge of Fukushima nuclear-contaminated water poses an imminent and unpredictable risk to all countries worldwide,including Japanese *** and the IAEA should fulfill their obligations under international law regarding disposal,adhering to the principles of nuclear safety,including optimum protection,the obligation as low as reasonably practicable,and prevention through multilateral ***,the obligation to provide optimum protection should be implemented by re-evaluating the most reliable disposal technologies and methods currently available and comprehensively assessing various *** standard of the obligation as low as reasonably practicable requires that the minimization of negative impacts on human health,livelihoods,and the environment should not b

关键词： Principles of nuclear safety Disposal of nuclear-contaminated water Optimum protection Prevention As low as reasonably achievable

Acupuncture Legislation in the United States: Minnesota as a Case Study

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Chinese Medicine and Culture 2024年第2期7卷 104-118页

作者： Changzhen gong American Academy of Traditional Chinese Medicine Roseville 55113USA

2023 marks the 50th anniversary of legal regulation of acupuncture in the United States,as the first acupuncture law was enacted in ***,like any other medical modality,is regulated at the state level,with each state formulating and enforcing its own laws and statutes over *** article narrates the legislative process and major developments of the acupuncture profession in Minnesota,in the context of legislative developments across the *** tells how this midsize,Midwest state’s acupuncture profession became regulated,and examines the challenges faced by the profession before and after state statutes were *** stands as a representative example of the legislative process in other states.

关键词： Acupuncture Acupuncture law Legislature Minnesota Acupuncture Association Minnesota Board of Medical Practice Minnesota Department of Health