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基于车轨耦合动力学分析的地铁e型弹条扣件疲劳寿命预测

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科学技术与工程 2024年第2期24卷 766-772页

作者：陈金明钟盛华刘逸平彭睿李滨杨德坚广州计量检测技术研究院广州510663 华南理工大学土木与交通学院广州510641

地铁是城市交通的重要组成部分,而扣件系统是地铁轨道结构的关键部件,起到固定钢轨、减振降噪的作用。为分析地铁e型弹条扣件的疲劳性能,基于车辆轨道动力学理论,通过多体动力学软件UM建立了车轨耦合模型,研究了车辆速度、轨道不平顺类... 详细信息

地铁是城市交通的重要组成部分,而扣件系统是地铁轨道结构的关键部件,起到固定钢轨、减振降噪的作用。为分析地铁e型弹条扣件的疲劳性能,基于车辆轨道动力学理论,通过多体动力学软件UM建立了车轨耦合模型,研究了车辆速度、轨道不平顺类型以及曲线半径与钢轨动力学响应的关系;并通过有限元软件ABAQUS对扣件系统进行了仿真计算,将车轨耦合动力分析得到的钢轨位移作为疲劳荷载,采用应力疲劳计算的方法对弹条的疲劳寿命进行了预测和分析。结果表明:钢轨位移响应受不平顺类型和车辆速度的影响较小,而加速度响应对两者则比较敏感;轨道曲线半径的改变,对内轨位移的影响相对明显,随着半径的减小,内轨的位移时程曲线出现明显的上移,同时对加速度的影响也增大,内轨加速度峰值呈增大趋势;基于此模型计算的弹条疲劳寿命为2.14×10^(7)次,寿命最低处位于弹条后拱小圆弧段,与实际断裂位置相吻合;弹条初始安装扣压力对弹条疲劳寿命的影响很大,随着初始安装扣压力的增大,弹条的疲劳寿命不断减小,且减小的速度趋于增大,为确保弹条扣件处于良好的工作状态,初始扣压力应当控制在11~15 kN范围内。

关键词：扣件系统 e型弹条车轨耦合动力学疲劳寿命

Effects of Logging on the Genetic Diversity of Quercus tiaoloshanica Chun et Ko in a Tropical Montane Forest of Hainan Island, Southern China

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Journal of Integrative Plant Biology 2005年第10期47卷 1184-1192页

作者： Jian-Wei ZHENG Shu-Qing AN Lin CHEN Xin LENG zhong-sheng WANG hua-Jun XIANG Laboratory of Forest Ecology and Global Changes School of Life Science Nanjing University Nanjing 210093 China

Quercus tiaoloshanica Chun et Ko, which has a narrow range of distribution, is one of the important endemic species of the tropical montane rain forest on Hainan Island, southern China. Long-term logging and habitat destruction have resulted in population decline and distribution retreat of Q. tiaoloshanica. To determine the impact of logging on the genetic diversity of Q. tiaoloshanica, the authors investigated the genetic structures using amplified fragment length polymorphism markers in four regenerated stands after logging and in one unlogged stand. Compared with the unlogged stand, the effective number of alleles per locus dropped by 1.0% in selective logging stands and by 2.0% in clear logging stands, corresponding to reductions of 3.8% and 5.2%, respectively, in mean Nei＇s gene diversity and 2.9% and 3.5%, respectively, in mean Shannon diversity index. No substantial genetic erosion was detected in any of the regenerated stands owing to the high tree density and high heterogeneity of the Q. tiaoloshanica stands investigated. Meanwhile, there was no natural regeneration of the species observed in a Dacrydium pierrei Hickel plantation 700 m away from the regenerated stands, suggesting the limited ability of seed dispersal of Q. tiaoloshanica. Clear logging should be undertaken cautiously because the total number of plant species dropped by 15.2% in the clear-logged stands compared with the unlogged stand. To conserve the genetic diversity of this species, as well as the plant biodiversity of tropical forests, the habitats of Q. tiaoloshanica should be protected against exploitation in terms of agricultural or other forms of land use, and some mature trees should be preserved as seed sources to maintain an adequate regeneration base for this species in the management of logging.

关键词： amplified fragment length polymorphism genetic erosion logging Quercus tiaoloshanica tropical forest.

Template-free preparation of porous Co microfibers from spent lithium-ion batteries as a promising microwave absorber

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Rare Metals 2022年第10期41卷 3475-3485页

作者： Xiao-Min Wu Fei Xie Yong-Lin Yao Yue Sun zhong-sheng hua Zhuo Zhao Yong-Xiang Yang Anhui Province Key Laboratory of Metallurgical Engineering&Resources Recycling School of Metallurgical EngineeringAnhui University of TechnologyMaanshan243002China Department of Materials Science and Engineering Delft University of TechnologyDelft2628CDNetherlands

In order to take full advantage of the secondary resources,in this paper,we reported a template-free process to prepare porous Co microfibers from spent lithiumion batteries(LIBs).First,the waste LiCoO_(2) powders were leached by oxalic acid at a suitable temperature,and rodlike cobalt oxalate powders were ***,the porous Co microfibers were prepared by using the cobalt oxalate as precursors through a thermal decomposition at420 ℃ under nitrogen *** prepared Co microfibers possess diameters of 1-2 μm,and each microfiber consists of small particles with size of100-200 *** Co microfibers(25 wt%)/paraffin composite exhibited excellent microwave absorption *** the sample thickness is 4.5 mm,the reflection losses reach-36.14 and-38.20 dB at 4.16 and 17.60 GHz,respectively,and the effective bandwidth reaches up to 5.52 *** indicates that the Co microfibers can be used as a promising microwave ***,this paper demonstrates a novel process to make a high value-added product through recycling from the spent lithium-ion *** addition,it is advantageous to eliminate the hazard of spent lithium-ion batteries and electromagnetic radiation to environment and human health.

关键词： Spent lithium-ion batteries(LIBs) Co microfibers Recycling Oxalic acid leaching Microwave absorption

Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research International 2024年第7期31卷 1811-1823页

作者： zhong-lin Wang Zhi-hua Gong Quan Li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

Electrochemical behavior and electrolytic preparation of lead in eutectic NaCl−KCl melts

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Transactions of Nonferrous Metals Society of China 2020年第9期30卷 2568-2576页

作者： Zeng-li ZHU huan LIU Jie-shuang-yang CHEN Hui KONG Liang XU zhong-sheng hua Zhuo ZHAO School of Metallurgical Engineering Anhui University of TechnologyMa’anshan 243032China Jinguan Copper Branch Tongling Nonferrous Metals Group Holding Co.Ltd.Tongling 244000China Anhui Provincial Key Laboratory of Metallurgical Engineering&Resources Recycling Anhui University of TechnologyMa’anshan 243002China

A novel molten salt extraction process consisting of chlorination roasting and molten salt electrolysis was proposed to develop a more efficient and environmental friendly technology for recovering lead from spent lead acid batteries(LABs).The feasibility of this process was firstly assessed based on thermodynamics *** electrochemical behavior of Pb(II)on a tungsten electrode in the eutectic NaCl−KCl melts at 700℃ was then investigated in detail by transient electrochemical *** results indicated that the reduction reaction of Pb(II)in NaCl−KCl melts was a one-step process exchanging two electrons,and it was determined to be a quasi-reversible diffusion-controlled ***,potentiostatic electrolysis was carried out at−0.6 V(vs Ag/AgCl)in the NaCl−KCl−PbCl2 melts,and the obtained cathodic product was identified as pure Pb by X-ray diffraction *** investigation demonstrated that it is practically feasible to produce pure Pb metal by electrochemical reduction of PbCl2 in eutectic NaCl−KCl melts,and has provided important fundamental for the further study on lead recovery from spent LABs via molten salt extraction process.

关键词： electrochemical behavior Pb(II) reduction spent lead acid batteries eutectic NaCl−KCl melt

Electrochemical reduction mechanism of Zn^(2+)in molten NaCl-KCl eutectic

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Transactions of Nonferrous Metals Society of China 2022年第9期32卷 3088-3098页

作者： Xiao-bin WU Zeng-li ZHU Hui KONG You-qi FAN Si-wei CHENG zhong-sheng hua School of Metallurgical Engineering Anhui University of TechnologyMa’anshan 243032China Anhui Provincial Key Laboratory of Metallurgical Engineering&Resources Recycling Anhui University of TechnologyMa’anshan 243002China

A process comprising selective chlorination and molten salt electrolysis was proposed to develop an efficient and environmental-friendly technology for zinc recovery from metallurgical *** theoretical feasibility of this technology was firstly estimated based on thermodynamic ***,the electrochemical behavior of Zn^(2+)on tungsten electrode was investigated in molten NaCl-KCl eutectic at 973 K by many electrochemical transient *** results showed that the reduction of Zn^(2+)on tungsten electrode was found to be a one-step process exchanging two electrons with the initial reduction potential of-0.74 V(vs Ag/AgCl),and the electrode process was considered as quasi-reversible and controlled by *** diffusion coefficient of Zn^(2+)ions in the melts was determined in the order of 10^(-5)cm^(2)/***,the electrolytic preparation of zinc was carried out by potentiostatic electrolysis in molten NaCl-KCl-ZnCl_(2)eutectic at-1.6 V(vs Ag/AgCl).Spheroidic granular metal with silver-white luster was attained after electrolysis for 9.5 h,and identified as pure *** present study confirms that it is practically feasible to extract pure zinc metal by direct electrolysis of ZnCl_(2)in molten NaCl-KCl eutectic,and provides a valuable theoretical reference for the efficient recovery of zinc from metallurgical dusts.

关键词： electrochemical reduction zinc ions electrochemical behavior molten NaCl-KCl eutectic metallurgical dusts

Cardiovascular computed tomography in cardiovascular disease:An overview of its applications from diagnosis to prediction

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Journal of Geriatric Cardiology 2024年第5期21卷 550-576页

作者： zhong-hua SUN Discipline of Medical Radiation Science Curtin Medical SchoolCurtin UniversityPerthAustralia Curtin Health Innovation Research Institute(CHIRI) Curtin UniversityPerth 6012Australia

Cardiovascular computed tomography angiography(CTA)is a widely used imaging modality in the diagnosis of cardiovascular *** in CT imaging technology have further advanced its applications from high diagnostic value to minimising radiation exposure to *** addition to the standard application of assessing vascular lumen changes,CTA-derived applications including 3D printed personalised models,3D visualisations such as virtual endoscopy,virtual reality,augmented reality and mixed reality,as well as CT-derived hemodynamic flow analysis and fractional flow reserve(FFRCT)greatly enhance the diagnostic performance of CTA in cardiovascular *** widespread application of artificial intelligence in medicine also significantly contributes to the clinical value of CTA in cardiovascular *** value of CTA has extended from the initial diagnosis to identification of vulnerable lesions,and prediction of disease extent,hence improving patient care and *** this review article,as an active researcher in cardiovascular imaging for more than 20 years,I will provide an overview of cardiovascular CTA in cardiovascular *** is expected that this review will provide readers with an update of CTA applications,from the initial lumen assessment to recent developments utilising latest novel imaging and visualisation *** will serve as a useful resource for researchers and clinicians to judiciously use the cardiovascular CT in clinical practice.

关键词： diagnosis cardiovascular prediction

Phenotype of Rice Floury Endosperm Mutant flo7 and Fine Mapping of Mutated Gene

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Rice science 2015年第4期22卷 162-170页

作者： sheng zhong-hua FANG Peng-fei LI San-feng JIAO Gui-ai XIE Li-hong HU Pei-song TANG Shao-qing WEI Xiang-jin State Key Laboratory of Rice Biology/Key Laboratory of Rice Biology and Genetic Breeding of Ministry of Agriculture China National Rice Research Institute

The major storage substance in rice endosperm is starch, which accounts for 80% of dry matter weight. In this study, rice mutant flo7, selected from the progeny of Nipponbare＇s tissue culture, displayed floury and opaque endosperm. Compared with its corresponding wild type （WT） Nipponbare, the mutant rio7 produced longer, narrower, thinner and lighter grains. The levels of glucose, fructose and sucrose in the mutant flo7 endosperm were higher than those in the WT endosperm, whereas the protein content was not affected. With respect to both amylose content and gel consistency, the mutant flo7 was lower than WT, but its alkali value was higher. Scanning electron microscopic examinations showed that the endosperm of the mutant flo7 contained irregular, loosely packed and compound starch granules. Genetic analysis indicated that the mutant phenotype was determined by a single recessive nuclear gene The flo7 locus was mapped to a region on the long arm of chromosome 12, within a 95.1 kb interval defined by the markers C2-11 and C5-15. There are 13 open reading frames in the mapping interval. Transcription profiling of the developing grains showed that a number of genes involved in starch synthesis were affected differently in the mutant flo7.

关键词： flo7 floury endosperm starch fine mapping rice mutant

Triple reverse order law for the Drazin inverse

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 55-68页

作者： WANG hua zhong Cheng-cheng College of Sciences Inner Mongolia University of TechnologyHohhot 010051China College of Engineering University of Jinan Quancheng CollegeYantai 265600China

In this paper,we investigate the reverse order law for Drazin inverse of three bound-ed linear operators under some commutation ***,the Drazin invertibility of sum is also obtained for two bounded linear operators and... 详细信息

关键词： Drazin inverse reverse order law space decomposition