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Short-Time Dynamics of the Random n-Vector Model

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Communications in Theoretical Physics 2001年第11期36卷 611-616页

作者： CHEN Yuan LI Zhi-Bing FANG Hai HE shun-Shan situ shu-ping Department of Physics Guangzhou UniversityGuangzhou 510405China Department of PhysicsZhongshan UniversityGuangzhou 510275China Department of PhysicsZhongshan UniversityGuangzhou 510275China Department of PhysicsZhongshan UniversityGuangzhou 510275China Department of PhysicsZhongshan UniversityGuangzhou 510275China

Short-time critical behavior of the random n-vector model is studied by the theoretic renormalization-group *** scaling laws are studied in a frame of the expansion in e = 4 - d for n ≠ 1 and for n = *** d ＜ 4,the initial slip exponents θ′ for the order parameter and θ for the response function are calculated up to the second order in e ＝ 4 - d for n ≠ 1 and for n ＝ 1 at the random fixed point *** results show that the random impurities exert a strong influence on the short-time dynamics for d ＜ 4 and n ＜ nc.

关键词： n-vector model,short-time critical dynamics,quenched impurities,initial slip exponent

Dynamics of the Random Ising Model with Long-Range Interaction

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Communications in Theoretical Physics 2001年第10期36卷 469-472页

作者： CHEN Yuan LI Zhi-Bing FANG Hai HE shun-Shan situ shu-ping Department of Physics Guangzhou University Guangzhou 510405 China Department of Physics Zhongshan University Guangzhou 510275 China Associate Member of ICTP Trieste Italy Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China Department of Physics Zhongshan University Guangzhou 510275 China

Critical dynamics of the random Ising model with long-range interaction decaying as r-(d+σ) where d is the dimensionality) is studied by the theoretic renormalization-group approach. The system is released to an evolution within a model A dynamics. Asymptotic scaling laws are studied in a frame of the expansion in = 2σ - d. In dimensions d ＜ 2σ. the dynamic exponent z is calculated to the second order in at the random fixed point.

关键词： Ising model, critical dynamics, long-range interaction, quenched impurities

A cumulative damage model for predicting and assessing raveling in asphalt pavement using an energy dissipation approach

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 949-962页

作者： Kailing DENG Duanyi WANG Cheng TANG Jianwen situ Luobin CHEN School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510640China

Raveling is a common distress of asphalt pavements,defined as the removal of stones from the pavement *** predict and assess raveling quantitatively,a cumulative damage model based on an energy dissipation approach has been developed at the meso *** construct the model,a new test method,the pendulum impact test,was employed to determine the fracture energy of the stone-mastic-stone meso-unit,while digital image analysis and dynamic shear rheometer test were used to acquire the strain rate of specimens and the rheology property of mastic,*** of the model reveals that when the material properties remain constant,the cumulative damage is directly correlated with loading time,loading amplitude,and loading ***,damage increases with superimposed linear and cosine variations over time.A higher stress amplitude results in a more rapidly increasing rate of damage,while a lower load frequency leads to more severe damage within the same loading ***,an example of the application of the model has been presented,showing that the model can be utilized to estimate failure life due to *** model is able to offer a theoretical foundation for the design and maintenance of anti-raveling asphalt pavements.

关键词： asphalt pavement raveling cumulative damage dissipation energy theory

Influence of syngas components and ash particles on the radiative heat transfer in a radiant syngas cooler

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Chinese Journal of Chemical Engineering 2024年第4期68卷 203-215页

作者： Chen Han Youmin situ Huaxing Zhu Jianliang Xu Zhenghua Dai Guangsuo Yu Haifeng Liu National Energy Coal Gasification Technology Research and Development Center East China University of Science and TechnologyShanghai 200237China Shanghai Engineering Research Center of Coal Gasification East China University of Science and TechnologyShanghai 200237China

Radiant syngas cooler(RSC)is widely used as a waste heat recovery equipment in industrial *** this work,an RSC with radiation screens is established and the impact of gaseous radiative property models,gas components,and ash particles on heat transfer is investigated by the numerical simulation *** the syngas components and the pressure environment of the RSC,a modified weighted-sum-of-gray-gases model was *** modified model shows high accuracy in *** computational fluid dynamics simulation,the calculated steam production is only 0.63%in error with the industrial *** with Smith's model,the temperature decay along the axial direction calculated by the modified model is *** components are of great significance to heat recovery capacity,especially when the absorbing gas fraction is less than 10%.After considering the influence of particles,the outlet temperature and the proportion of radiative heat transfer are less affected,but the difference in steam output reaches 2.7 t·h^(-1).The particle deposition on the wall greatly reduces the heat recovery performance of an RSC.

关键词： Radiant syngas cooler Weighted-sum-of-gray-gases model Numerical simulation Particle radiation

Reactive oxygen species:Multidimensional regulators of plant adaptation to abiotic stress and development

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Journal of Integrative Plant Biology 2024年第3期66卷 330-367页

作者： Pengtao Wang Wen-Cheng Liu Chao Han situ Wang Ming-Yi Bai Chun-Peng Song State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityKaifeng 475004China The Key Laboratory of Plant Development and Environmental Adaptation Biology Ministry of EducationSchool of Life SciencesShandong UniversityQingdao 266237China Faculty of Science McGill UniversityMontreal H3B1X8Canada

Reactive oxygen species(ROS)are produced as undesirable by-products of metabolism in various cellular compartments,especially in response to unfavorable environmental conditions,throughout the life cycle of *** ROS production disrupts normal cellular function and leads to oxidative *** cope with excessive ROS,plants are equipped with a sophisticated antioxidative defense system consisting of enzymatic and non-enzymatic components that scavenge ROS or inhibit their harmful effects on ***,when maintained at relatively low levels,ROS act as signaling molecules that regulate plant growth,development,and adaptation to adverse ***,we provide an overview of current approaches for detecting *** also discuss recent advances in understanding ROS signaling,ROS metabolism,and the roles of ROS in plant growth and responses to various abiotic stresses.

关键词： abiotic stress growth and development plant reactive oxygen species

Vibration transfer from underground train to multi-story building:Modelling and validation with in-situ test data

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Underground Space 2024年第6期19卷 301-316页

作者： Li Wang Xin Gao Caiyou Zhao ping Wang Zili Li Section of Railway Engineering Delft University of TechnologyStevinweg 12628CN DelftThe Netherlands Key Laboratory of High-speed Railway Engineering(Southwest Jiaotong University) Ministry of EducationChengdu 610031China

Excessive underground train-induced vibration becomes a serious environmental problem in *** investigate the vibration transfer from an underground train to a building nearby,an explicit-integration time-domain,three-dimensional finite element model is *** underground train,track,tunnel,soil layers and a typical multi-story building nearby are all fully coupled in this *** complex geometries involving the track components and the building are all modelled in detail,which makes the simulation of vibration transfer more realistic from the underground train to the *** model is validated with in-situ tests data and good agreements have been achieved between the numerical results and the experimental results both in time domain and frequency *** proposed model is applied to investigate the vibration transfer along the floors in the building and the influences of the soil stiffness on the vibration characteristics of the track-tunnel-soil-building *** is found that the building vibration induced by an underground train is dominant at the frequency determined by the P2 resonance and influenced by the vibration modes of the *** vertical vibration in the building decreases in a fluctuant pattern from the foundation to the top floor due to loss of high frequency contents and local *** vibration levels in different rooms at a same floor can be different due to the different local stiffness.A room with larger space thus smaller local stiffness usually has higher vibration *** soil layers make the tunnel lining and the building have more low frequency *** influence of the soil stiffness on the amplification scale along the floors of the building is found to be nonlinear and frequency-dependent,which needs to be further investigated.

关键词： Railway vibration Underground train Multi-story building vibration Finite element model Dynamic interaction

Teleoperation with automatic posture regulation and broad learning control for assembly tasks

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Science China(Information Sciences) 2024年第11期67卷 359-360页

作者： Liwen situ Zhenyu LU Chenguang YANG School of Automation Science and Engineering South China University of Technology Bristol Robotics Laboratory University of the West of England

In recent years, robot teleoperation systems have been widely used in assembly tasks due to their ability to combine human control with robotic execution, addressing limitations in precision, perception, and intelligence faced by fully automated robots. However, robot teleoperation for assembly tasks still encounters several challenges. In complex and unstructured environments, telerobots must regulate the posture of their manipulators to avoid obstacles and singularities, ensuring the safety of human operators [1].

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Non-contact and full-field online monitoring of curing temperature during the in-situ heating process based on deep learning

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Advances in Manufacturing 2024年第1期12卷 167-176页

作者： Qiang-Qiang Liu shu-Ting Liu Ying-Guang Li Xu Liu Xiao-Zhong Hao College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing211816People’s Republic of China

Online monitoring of the curing temperature field is essential to improving the quality and efficiency of the manufacturing process of composite *** embedded sensor-based technologies have difficulty monitoring the full temperature field or have to introduce heterogeneous items that could have an undesired impact on the *** this paper,a non-contact,full-field monitoring method based on deep learning that predicts the internal temperature field of composite parts in real time using surface temperature measurements of auxiliary materials is *** the proposed method,an average temperature monitoring accuracy of 97%is achieved in various heating *** addition,this method also demonstrates satisfying feasibility when a stronger thermal barrier covers the *** method was experimentally validated during the self-resistance electric heating process,in which the monitoring accuracy reached 93.1%.This method can potentially be applied to automated manufacturing and process control in the composites industry.

关键词： Online monitoring Curing temperature field Deep learning(DL) In-situ heating

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佛山市冬夏季非甲烷烃污染特征研究

环境科学 2016年第11期37卷 4124-4132页

作者：周雪明项萍段菁春贺克斌马永亮邓思欣司徒淑娉谭吉华中国科学院大学资源与环境学院北京100049 清华大学环境学院国家环境保护大气复合污染来源与控制重点实验室北京100084 中国环境科学研究院环境基准与风险评估国家重点实验室北京100012 佛山市环境保护局佛山528000 中国科学院生态环境研究中心北京100085

2014年冬季和2015年夏季在佛山市采集了30个非甲烷烃(NMHCs)的样品,定量分析了多种化合物.结果表明,采样期间佛山市冬季和夏季NMHCS的浓度分别为122.30μg·m^(-3)和56.22μg·m^(-3).其中冬季和夏季NMHCs中浓度最高的5个物种由大到小... 详细信息

2014年冬季和2015年夏季在佛山市采集了30个非甲烷烃(NMHCs)的样品,定量分析了多种化合物.结果表明,采样期间佛山市冬季和夏季NMHCS的浓度分别为122.30μg·m^(-3)和56.22μg·m^(-3).其中冬季和夏季NMHCs中浓度最高的5个物种由大到小依次为:甲苯(25.12μg·m^(-3))、间/对-二甲苯(13.76μg·m^(-3))、丙烷(9.17μg·m^(-3))、乙苯(7.25μg·m^(-3))、乙烯(6.77μg·m^(-3))和甲苯(6.18μg·m^(-3))、间/对-二甲苯(5.21μg·m^(-3))、邻-二甲苯(4.15μg·m^(-3))、β-蒎烯(3.75μg·m^(-3))、丙烷(3.29μg·m^(-3)).相比2008年,NMHCs有大幅度下降.冬季芳烃、烷烃、烯烃和炔烃所占比例分别为51.20%、34.70%、10.04%和4.05%;夏季芳烃、烷烃、烯烃和炔烃所占比例分别为43.93%、33.99%、19.20%和2.88%.因为NMHCs/NOx的冬、夏季值分别为0.90和1.88,表明采样期间佛山市大气臭氧峰值浓度都是受NMHCs控制,还应继续加强NMHCs的控制.佛山市NMHCs冬季和夏季的丙烯等效浓度和臭氧生成潜势分别为45.09μg·m^(-3)和40.64μg·m^(-3)、392.77μg·m^(-3)和207.77μg·m^(-3).间/对-二甲苯、甲苯和间/对-二甲苯、异戊二烯分别对冬季和夏季的臭氧生成潜势起到很重要的贡献.采样期间佛山市冬季和夏季的苯/甲苯的值为0.15和0.20,表明佛山市冬夏季NMHCs的主要来源是工业过程.相对2008年,本研究中异戊烷不属于佛山市NMHCs中浓度最高的5种污染物,说明佛山市在防止汽油挥发对环境造成影响方面的措施取得了明显成效.

关键词：非甲烷烃冬季夏季污染特征佛山市