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桥上无缝线路断轨力深化研究

铁道标准设计 2022年第12期66卷 27-31页

作者：张泽黄晨睿中铁第四勘察设计院集团有限公司武汉430063 长安大学长安都柏林国际交通学院西安710021

现行TB10015—2012《铁路无缝线路设计规范》中断轨力取值偏于保守,往往限制桥梁设计。以铁路常用的16,20,24,32,40 m简支梁为研究对象,建立钢轨-桥梁-桥梁墩台三维有限元空间力学计算模型。考虑无砟及有砟轨道类型、不同简支梁墩台刚度... 详细信息

现行TB10015—2012《铁路无缝线路设计规范》中断轨力取值偏于保守,往往限制桥梁设计。以铁路常用的16,20,24,32,40 m简支梁为研究对象,建立钢轨-桥梁-桥梁墩台三维有限元空间力学计算模型。考虑无砟及有砟轨道类型、不同简支梁墩台刚度,分别模拟计算双线4根钢轨折断、单根钢轨折断工况下的墩台断轨力,在此基础上,提出简支梁断轨力计算公式修正系数。研究结果表明,墩台刚度接近刚性时,16m,40m跨长简支梁修正系数分别为规范值的0.98,0.8倍,即简支梁跨长越长,修正系数越小;40m跨长简支梁在铺设无砟轨道、有砟轨道的修正系数分别为规范值的0.8,0.9倍,即相同跨长简支梁下,无砟轨道修正系数小于有砟轨道。

关键词：无缝线路简支梁桥三维模型断轨力修正系数

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Designing a location update strategy for free-moving and network-constrained objects with varying velocity

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第8期15卷 675-686页

作者： Yuan-Ko huang Lien-Fa LIN Department of Information Communication Kao-Yuan University

Spatio-temporal databases aim at appropriately managing moving objects so as to support various types of queries. While much research has been conducted on developing query processing techniques, less effort has been made to address the issue of when and how to update location information of moving objects. Previous work shifts the workload of processing updates to each object which usually has limited CPU and battery capacities. This results in a tremendous processing overhead for each moving object. In this paper, we focus on designing efficient update strategies for two important types of moving objects, free-moving objects(FMOs) and network-constrained objects(NCOs), which are classified based on object movement models. For FMOs, we develop a novel update strategy, namely the FMO update strategy(FMOUS), to explicitly indicate a time point at which the object needs to update location information. As each object knows in advance when to update(meaning that it does not have to continuously check), the processing overhead can be greatly reduced. In addition, the FMO update procedure(FMOUP) is designed to efficiently process the updates issued from moving objects. Similarly, for NCOs, we propose the NCO update strategy(NCOUS) and the NCO update procedure(NCOUP) to inform each object when and how to update location information. Extensive experiments are conducted to demonstrate the effectiveness and efficiency of the proposed update strategies.

关键词： Spatio-temporal databases Moving objects Free-moving objects Network-constrained objects

Recent advances in membrane bioreactor technology for wastewater treatment in China

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Frontiers of Environmental Science & Engineering 2010年第3期4卷 245-271页

作者： Xia huang Kang XIAO Yuexiao SHEN State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environmental Science and EngineeringTsinghua UniversityBeijing 100084China

Since the introduction of the membrane bioreactor(MBR)in China in the early 1990s,remarkable progress has been achieved on the research and application of this *** has now become one of the most active fields in the world in this *** review outlines the development of MBR-based processes in China and their performance of treating municipal and industrial *** membrane fouling is a critical operational problem with MBR processes,this paper also proposes updated understanding of fouling mechanisms and strategies of fouling control,which are mainly compiled from publications of Chinese *** for the commercial application of MBR in the country,the latest statistics of large-scale MBR plants(>10000 m^(3)·d^(–1))are provided,and the growth trend of total treatment capacity as well as its driving force is analyzed.

关键词： membrane bioreactor(MBR) municipal wastewater treatment industrial wastewater treatment membrane fouling commercial application China

Interannual evolution of the chemical composition,sources and processes of PM_(2.5)in Chengdu,China:Insights from observations in four winters

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Journal of Environmental Sciences 2024年第4期138卷 32-45页

作者： Junke Zhang Jiaqi Li Yunfei Su Chunying Chen Luyao Chen Xiaojuan huang Fangzheng Wang Yawen huang Gehui Wang Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Department of Environmental Science&Engineering Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3)Fudan UniversityShanghai 200438China Key Lab of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China

The air quality in China has improved significantly in the last decade and,correspondingly,the characteristics of PM_(2.5)have also *** studied the interannual variation of PM_(2.5)in Chengdu,one of the most heavily polluted megacities in southwest China,during the most polluted season(winter).Our results show that the mass concentrations of PM_(2.5)decreased significantly year-by-year,from 195.8±91.0μg/m~3in winter 2016 to 96.1±39.3μg/m^(3)in winter *** mass concentrations of organic matter(OM),SO_()4^(2-),NH_(4)^(+)and NO_(3)^(-)decreased by 49.6%,57.1%,49.7% and 28.7%,*** differential reduction in the concentrations of chemical components increased the contributions from secondary organic carbon and NO_(3)^(-)and there was a larger contribution from mobile *** contribution of OM and NO_(3)^(-)not only increased with increasing levels of pollution,but also increased year-by-year at the same level of *** sources of PM_(2.5)were identified:combustion sources,vehicular emissions,dust and secondary *** aerosols made the highest contribution and increased year-by-year,from 40.6%in winter 2016 to 46.3% in winter *** contrast,the contribution from combustion sources decreased from 14.4% to 8.7%.Our results show the effectiveness of earlier pollution reduction policies and emphasizes that priority should be given to key pollutants(e.g.,OM and NO_(3)^(-))and sources(secondary aerosols and vehicular emissions)in future policies for the reduction of pollution in Chengdu during the winter months.

关键词： PM_(2.5) Chemical composition Sources Interannual evolution Winter Chengdu

Synthesis of Load Impedances That Reduce TE-Scattering from Conducting Cylinder with Arbitrary Cross Section

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Journal of Systems Engineering and Electronics 1997年第4期8卷 40-49页

作者： Yin, Hongcheng huang, Chen Xiao, Zhihe Air Force Radar Research Inst Beijing China

The reduction of TE-scattering by a conducting cylinder with multiple surface impedance loads is investigated. Synthesis procedures are developed to find the optimal loading which result in zero scattering in the desired directions or at several frequencies. Numerical results of these procedures are presented. The theoretical predictions are confirmed with an experiment. The proposed synthesis procedure is completely general and can be applied to arbitrarily shaped conducting bodies.

关键词： Electromagnetic scattering Impedance loading Impedance synthesis Radar cross section.

Osteoimmunology: memorandum for rheumatologists

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Science China(Life Sciences) 2016年第12期59卷 1241-1258页

作者： Lidan Zhao Linfang huang Xuan Zhang Department of Rheumatology & Clinical Immunology Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College the Ministry of Education Key Laboratory Department of Rheumatology the First People's Hospital of Yueyang

Rapid progress has been made in exploring the connections between the skeletal system and the immune system over the past decade. Bone tissue forms developmental niches for hematopoietic stem cells, and activated immune cells are involved in bone metabolism regulation and are potent mediators of osteoporosis and bone erosion under pathological conditions. The interdisciplinary field of osteoimmunology has emerged to pool the knowledge of the interdependence of these two systems, including the shared ligands and receptors, their crosstalk and interaction, and common intracellular signaling pathways with bidirectional influence. The receptor activator of nuclear factor-kappa B(RANK)/RANK ligand(RANKL)/osteoprotegerin(OPG) triad is the key vinculum, with multifaceted potency, being not only essential for osteoclastogenesis but also critical for lymph node organogenesis and lymphopoiesis as well as for immune regulation. In this review, we summarize the progress in this area, focusing on those aspects of interest concerning rheumatic diseases.

关键词： osteoimmunology bone remodeling osteoclastogenesis immune cells RANKL

First-passage failure of MDOF nonlinear oscillator

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Science China(Technological Sciences) 2011年第8期54卷 1999-2006页

作者： XU Ming JIN XiaoLing huang ZhiLong Department of Mechanics Zhejiang University Hangzhou 310027 China

First-passage failure of multiple-degree-of-freedom nonlinear oscillators with lightly nonlinear dampings and strongly nonlinear stiffness subject to additive and/or parametric Gaussian white noise excitations is studied. First, by using the stochastic averaging method based on the generalized harmonic functions, the averaged It stochastic differential equation for the amplitudes of the nonlinear oscillators can be derived. Then the associated backward Kolmogorov equation of the conditional reliability function is established, and the conditional reliability is approximately expressed as a series expansion in terms of Kummer functions with time-dependent coefficients. By using the Galerkin method, the time dependent coefficients of the associated conditional reliability function can be solved by a set of differential equations. Finally, the proposed procedure is applied to Duffing-Van der Pol systems under external and/or parametric excitations of Gaussian white noises. The results are also verified by those obtained from Monte Carlo simulation of the original system. The effects of system parameters on first-passage failure are discussed briefly.

关键词： first-passage stochastic averaging method generalized harmonic function Kummer function Galerkin method

Estimating Soil Salinity in the Yellow River Delta, Eastern China——An Integrated Approach Using Spectral and Terrain Indices with the Generalized Additive Model

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Pedosphere 2016年第5期26卷 626-635页

作者： SONG Chuangye REN Hongxu huang Chong State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Key Laboratory of Plant Resources Institute of Botany Chinese Academy of Sciences Institute of Geographical Sciences and Natural Resources Chinese Academy of Sciences

Soil salinity is one of the most severe environmental problems worldwide. It is necessary to develop a soil-salinity-estimation model to project the spatial distribution of soil salinity. The aims of this study were to use remote sensed images and digital elevation model(DEM) to develop quantitative models for estimating soil salinity and to investigate the influence of vegetation on soil salinity estimation. Digital bands of Landsat Thematic Mapper(TM) images, vegetation indices, and terrain indices were selected as predictive variables for the estimation. The generalized additive model(GAM) was used to analyze the quantitative relationship between soil salt content, spectral properties, and terrain indices. Akaike's information criterion(AIC) was used to select relevant predictive variables for fitted GAMs. A correlation analysis and root mean square error between predicted and observed soil salt contents were used to validate the fitted GAMs. A high ratio of explained deviance suggests that an integrated approach using spectral and terrain indices with GAM was practical and efficient for estimating soil salinity. The performance of the fitted GAMs varied with changes in vegetation *** in sparsely vegetated areas was estimated better than in densely vegetated areas. Visible red and near-infrared bands, and the second and third components of the tasseled cap transformation were the most important spectral variables for the estimation. Variable combinations in the fitted GAMs and their contribution varied with changes in vegetation cover. The contribution of terrain indices was smaller than that of spectral indices, possibly due to the low spatial resolution of DEM. This research may provide some beneficial references for regional soil salinity estimation.

关键词： Akaike's information criterion digital elevation model Landsat TM image soil salt content terrain in indices vegetation cover

A review of research on urban parking prediction

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 700-720页

作者： Changxi Ma Xiaoting huang Jiangchen Li School of Traffic and Transportation Lanzhou Jiaotong UniversityLanzhou 730070China College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The rapid growth of urban traffic has intensified daily congestion,affecting both traffic flow and *** parking prediction plays a vital role in effectively managing limited parking resources and is essential for the successful implementation of advanced intelligent *** an effort to comprehensively assess the latest developments in parking prediction,we curated a dataset of 639 articles spanning from 2010 to the present,using the Scopus ***,we performed a bibliometric analysis utilizing VOSviewer *** findings not only illuminate emerging trends within the parking prediction field but also provide strategic guidance for its ***,we categorized advancements in three focal areas:behavior prediction,demand prediction,and parking space prediction.A comprehensive overview of the present research status and future directions was then *** findings underscore the substantial progress achieved in current parking prediction models,achieved through diverse avenues like multi-source data integration,multi-variable feature extraction,nonlinear relationship modeling,deep learning techniques application,and ensemble model *** innovative endeavors have not only pushed the theoretical boundaries of parking prediction but also significantly heightened the precision and applicability of predictive models in practical *** research should explore avenues such as processing unstructured parking datasets,developing predictive models for small-scale data,mitigating noise interference in parking data,and harnessing potent platform fusion *** study's significance transcends guiding and catalyzing advancement in academic and practical domains;it holds paramount relevance across academic research,technological innovation,decision-making support,business applications,and policy formulation.

关键词： Parking prediction Machine learning Smart parking Deep learning