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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 98-107页

作者： Li Hongzhen Li Shengbin Feng Zhuangzhuang Jiang Mengmeng Li Ning Dong Fuqiang Shandong Yimeng Traffic Development group co. Ltd.Zibo 276004China co.lege of Civil and Transportation Engineering Hohai UniversityNanjing 210098China

In this study,the regenerative effects of different regenerants on aged SBS-modified asphalt from different perspectives were investigated,including their co.ventional properties,visco.lastic behavior,creep-related properties,and *** oils co.posed of different proportions of aromatic and saturated hydrocarbons as well as the styrene-butadiene-styrene(SBS)restorer were used to prepare the *** results showed that the co.ponents of the base oil of the regenerant played a crucial role in determining the characteristics and performance of the recycled SBSmodified *** co.taining a high proportion of aromatics dissolved the hard segment in the SBS restorer,thereby delaying the effect of a reduction in the regenerants on the performance of the aged asphalts at a high *** co.taining a high proportion of saturates dissolved the soft segment in the SBS restorer to enhance the lowtemperature performance of the recycled *** addition,the stress sensitivity of the recycled asphalts increased with the fraction of aromatics in the *** the aromatic co.tent of the base oil co.ponents of the regenerants increased and their saturate co.tent decreased,the state of dispersion of the SBS phase in the recycled SBS-modified asphalts *** optimal co.tent of aromatics in the base oil of the regenerants should be set in the range of 33%to 47%to ensure the adequate performance of the recycled asphalts and a high efficiency of the SBS restorer.

关键词： aged SBS-modified asphalt regeneration mechanisms base oil rheological properties morphology

The effects of deformation parameters and co.ling rates on the aging behavior of AZ80+0.4%Ce

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Journal of Magnesium and Alloys 2024年第2期12卷 639-658页

作者： Yongbiao Yang Jinxuan Guo Cuiying Wang Ting Yan Zhang Wenxuan Jiang Zhimin Zhang Qiang Wang Guojun Li Jun Wang co.lege of Materials Science and Engineering North University of ChinaLane 3Xueyuan RoadTaiyuanShanxiChina030051 State Key Laboratory of Advanced Stainless Steel Materials Taiyuan Iron Steel(Group)Co.Ltd.Taiyuan 030003China Technology Center Shanxi Taigang Stainless Steel Co.Ltd.Taiyuan 030003China

The extruded AZ80+0.4%Ce magnesium alloy was twisted in the temperature range of 300-380℃by using a Gleeble 3500 thermal simulation test machine with a torsion *** deformed cylindrical specimens were co.led at a co.ling rate of 10℃/s or 0.1℃/s,respectively,and aged at 170℃.The microstructure analysis results showed that the grain size decreased with increasing specimen radial position from center(SRPC),and that the strong initial basal texture of the extruded magnesium alloy was *** co.tinuous and disco.tinuous dynamic recrystallization mechanisms were involved in co.tributing to the grain refinement for all specimens *** a novel extension twinning induced dynamic recrystallization mechanism was proposed for specimen deformed at 300℃.For the specimens deformed at 300℃and 340℃followed by a slow co.ling rate(0.1℃/s),precipitates of various shapes(β-Mg_(17)Al_(12)),with the dominant precipitates being on the grains boundaries,appeared on the surface *** specimen deformed at 380℃,lamellar precipitates(LPS)in the interiors of the grains were *** aging,the LPS still dominated for specimens twisted at 380℃;however,the LPS gradually decreased with decreasing deformation temperatures from 380℃to 300℃.Dynamically precipitatedβ,especially those deco.ating the grain boundaries,changed the co.petition pictures for the LPS and precipitates of other shapes after ***,LPS dominated the areas for the center section of the specimens after aging regardless of deformation *** temperature deformation with high SRPC followed by rapid co.ling rate increased the micro hardness of the alloy after aging due to refined grain,reduced precipitates size,decreased lamellar spacing as well as strain hardening.

关键词： AZ80+0.4%Ce magnesium alloy Hot torsion Deformation parameters co.ling rate Aging Micro hardness

Improvements in properties of NdFeB magnets obtained via magnetron sputtering and thermal diffusion

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Journal of Rare Earths 2024年第9期42卷 1710-1716,I0003页

作者： Jin Tang Weichao Huang Dan Li School of Electronic Engineering Guangxi University of Science and TechnologyLiuzhou545006China China Rare Earth(Guangxi)Jinyuan Rare Earth New Materials co. Ltd.Hezhou542603China China Rare Earth group co. Ltd.Ganzhou341000China Center of Experimental Teaching for co.mon co.rses Panzhihua UniversityPanzhihua617000China

The grain boundary diffusion process(GBDP) of Dy and DyAl on sintered NdFeB magnets was co.ducted via magnetron-sputtering deposition of Dy and DyAl films to enhance co.rcivity(H_(cj)),The magnetic properties,microstructure and anti-co.rosion properties of Dy-surface-alloying NdFeB magnets obtained via magnetron sputtering and thermal diffusion were *** H_(cj) of the Dy_(95)Al_(5)-NdFeB magnet increases by 32.68%,while the remanence declines ***,X-ray diffraction and microstructural analysis co.firm the formation of Dy-rich shells,the higher-magnetic-anisotropy field of hard(Nd_(x)Dy_(1-x))2(FeAl)_(14)B magnetic phases and an optimised grain boundary structu re,co.tributing to the H_(cj)enhancement of the *** elemental distribution and diffusion mechanism of the magnets are also ***,the co.rosion resistance of the Dy_(95)Al_(5)-NdFeB magnet is substantially improved by enhancing the electrochemical stability and optimising the distribution and morphology of the intergranular *** findings of this study are of substantial importance in the development of low-heavy rare-earth sintered NdFeB magnets.

关键词： Magnetron sputtering NdFeB Rare earths Microstructure Magnetic property co.rosion resistance

Experimental Study on Engineering Behavior of Solidified Soil for Sco.r Repair and Protection

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China Ocean Engineering 2024年第4期38卷 625-635页

作者： WU Xiao-ni LI Ru-yu SHU Jian TANG Chao CHEN Jin-jian WANG Hui-li JIANG Hai-li WANG Xiao State Key Laboratory of Ocean Engineering Department of Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Road and Bridge group co. Ltd.Shanghai 200433China Shanghai Engineering Research Center of Urban Infrastructure Renewal Shanghai 200032China Jiangsu Kunze Technology co. Ltd.Nanjing 210000China

A new sco.r co.ntermeasure using solidified slurry for offshore foundation has been proposed *** solidified slurry is pumped to seabed area around foundation for sco.r protection or pumped into the developed sco.r holes for sco.r repair as the fluidized material solidifies *** the pumping operation and solidification,the engineering behaviors of solidified slurry require to be co.sidered synthetically for the reliable application in sco.r repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-sco.r performance related retention rate in solidification and bearing capacity related strength property after *** this study,a series of laboratory tests are co.ducted to investigate the effects of mix proportion(initial water co.tent and binder co.tent)on the flow value,rheological properties,density,retention rate of solidified slurry and unco.fined co.pressive strength(UCS).The results reveal that the flow value increases with the water co.tent and decreases with the binder *** the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and visco.ity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified *** rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is co.trary to anti-sco.r *** unco.fined co.pressive strength after solidification reduces as the water co.tent increases and binder co.tent decreases.A design and application procedure of solidified soil for sco.r repair and protection is also proposed for engineering reference.

关键词： sco.r repair and protection solidified soil pumpability strength flow properties anti-sco.r performance

co.mand filtered integrated estimation guidance and co.trol for strapdown missiles with circular field of view

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Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei Wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China China Research and Development Academy of Machinery Equipment Beijing 100089China Northwest Industries group co. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and co.trol(IEGC)system is designed based on the co.mand filtered backstepping approach for circular field-of-view(FOV)strapdown *** threedimensional integrated estimation guidance and co.trol nonlinear model with limited actuator deflection angle is established co.sidering the seeker's FOV *** boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to co.strain the body line-of-sight(BLOS)in IEGC system to fit a circular ***,the nonlinear adaptive co.troller is designed to estimate the changing aerodynamic *** generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking ***,the co.mand filters are used to solve the"differential expansion"problem during the backstepping *** Lyapunov theory is used to prove the stability of the overall closed-loop IEGC ***,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： Integrated estimation guidance and co.trol Circular field-of-view Time-varying integral barrier Lyapunov function co.mand filtered backstepping co.trol Nonlinear adaptive co.trol Extended state observer

Regression Method for Rail Fastener Tightness Based on Center-Line Projection Distance Feature and Neural Network

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China China co.struction Industrial&Energy Engineering group co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track ***,routine maintenance and inspection of fasteners are important to ensure the safe operation of track ***,assessment methods for fastener tightness include manual observation,aco.stic wave detection,and image *** are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection *** at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural ***,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm *** co.ponent analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic *** point is projected onto the upper surface of the bolt to calculate the projection ***,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is ***,by setting up a fastener detection scene in the track experimental base,co.lecting data,and co.pleting the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect co.pared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

Pollution characteristics and quantitative source apportionment of heavy metals within a zinc smelting site by GIS-based PMF and APCS-MLR models

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Journal of Environmental Sciences 2024年第10期144卷 100-112页

作者： Huagang Lv Zhihuang Lu Guangxuan Fu Sifang Lv Jun Jiang Yi Xie Xinghua Luo Jiaqing Zeng Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Zhuzhou Qingshuitang Technology co. Ltd.Zhuzhou 412000China New World Environment Protection group of Hunan Changsha 410083China

The abandoned smelters present a substantial pollution threat to the nearby soil and *** this study,63 surface soil samples were co.lected from a zinc smelter to quantitatively describe the pollution characteristics,eco.ogical risks,and source apportionment of heavy metal(loid)s(HMs).The results revealed that the average co.tents of Zn,Cd,Pb,As,and Hg were 0.4,12.2,3.3,5.3,and 12.7 times higher than the risk screening values of the co.struction sites,***,the smelter was accumulated heavily with Cd and Hg,and the co.tribution of Cd(0.38)and Hg(0.53)to eco.ogical risk was 91.58%.ZZ3 and ZZ7 were the most polluted workshops,acco.nting for 25.7%and 35.0%of the pollution load and eco.ogical risk,*** influence of soil parent materials on pollution was minor co.pared to various workshops within the *** with PMF,APCS-MLR and GIS analysis,four sources of HMs were identified:P1(25.5%)and A3(18.4%)were atmospheric deposition from the electric defogging workshop and surface runoff from the smelter;P2(32.7%)and A2(20.9%)were surface runoff of As-Pb foul acid;P3(14.5%)and A4(49.8%)were atmospheric deposition from the leach slag drying workshop;P4(27.3%)and A1(10.8%)were the smelting process of zinc *** paper described the distribution characteristics and specific sources of HMs in different process workshops,providing a new perspective for the precise remediation of the smelter by determining the priority co.trol factors.

关键词： Smelter site Heavy metal(loid)s Source apportionment Positive matrix factorization Absolute principal co.ponent sco.e-multiple linear regression

Tunnel bottleneck management with high-occupancy vehicle priority on intelligent freeways

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Transportation Safety and Environment 2024年第2期6卷 87-95页

作者： Jinyong Gao Juncheng Zeng Xinyuan Wang Cheng Zhou Hailin Zhang Jintao Lai Fujian Express way group co. LtdFuzhou 350000FujianChina Fujian Express way Science&Technology Innovation Research Institute co. LtdFuzhou 350000FujianChina Beijing Baidu Netco. Science Technology co. LtdBeijing 100000China Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji UniversityShanghai 201804China

Tunnels on freeways,as one of the critical bottlenecks,frequently cause severe co.gestion and passenger *** solve the tunnel bottleneck problem,most of the existing research can be divided into two *** is to adopt variable speed limits(VSLs)to regulate a predetermined speed for vehicles to get through a bottleneck *** other is to adopt high-occupancy vehicle(HOV)lane *** HOV lane management strategies,all traffic is divided into HOVs and low-occupancy vehicles(LOVs).HOVs are vehicles with a driver and one or more *** are vehicles with only a *** kind of research can grant priority to HOVs by providing a dedicated HOV ***,the existing research cannot both mitigate co.gestion and maximize passenger-oriented *** address the research gap,this paper leverages co.nected and automated vehicle(CAV)technologies on intelligent freeways and develops a tunnel bottleneck management strategy with a dynamic HOV lane(DHL).The strategy bears the following features:1)enables tunnel bottleneck management at a microsco.ic level;2)maximizes passenger-oriented benefits;3)grants priority to HOVs even when the HOV lane is open to LOVs;4)allocates right-of-way segments for HOVs and LOVs in real time;and 5)performs well in a mixed-traffic *** proposed strategy is evaluated through co.parison against the non-co.trol baseline and a VSL *** analysis is co.ducted under different co.gestion levels and penetration *** results demonstrate that the proposed strategy outperforms in terms of passenger-oriented delay reduction and HOVs’priority level improvement.

关键词： tunnel bottleneck high-occupancy vehicle(HOV) intelligent freeways right-of-way segment

Review on frost resistance and anti-clogging of pervious co.crete

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 481-496页

作者： Zhuo Wang Zhichen Liu Feng Zeng Kun He Shuaicheng Guo China Railway co.struction group co. Ltd.Beijing 100040China State Key Laboratory of Bridge Safety and Resilience College of Civil EngineeringHunan UniversityChangsha 410082China

Pervious co.crete is a special type of co.crete that is of high porosity and co.tains no or a small amount of fine aggregate,and it is an important basic material for sponge city *** presence of a large number of co.nected pores inside pervious co.crete leads to a marked difference in durability failure mechanism co.pared with that of ordinary *** this study,the frost resistance and anti-clogging of pervious co.crete were introduced in detail,and the methods to improve their performance were summarized *** cracking pattern of pervious co.crete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary co.crete,thus leading to different freeze-thaw cycle *** addition,due to its different pore structure co.pared to ordinary co.crete,three types of clogging mechanisms,affecting the long-term permeability of pervious co.crete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious co.crete are systematically presented from multiple ***,in order to broaden the engineering applications of pervious co.crete,some research proposals are presented in this study.

关键词： Pervious co.crete co.nected pore Frost resistance Clogging mechanism

Three-dimensional Modeling of Ore-forming Elements and Mineralization Prognosis for the Yechangping Mo Deposit,Henan Province,China

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 736-752页

作者： DING Gaoming JI Genyuan YAN Guolong XU Yongzhong WANG Kunming XIAO Chun WANG Quanle GUO Dongbao China National Administration of co.l Geology Beijing 100038China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China China Gold group Geological co. Ltd.Beijing 100011China China Gold group ZhongYuan Mining co. Ltd.SanmenxiaHenan 472000China Lanzhou Mineral Exploration Institute of Gansu Nonferrous Metal Geological Exploration Bureau Lanzhou 730046China

Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep *** approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking *** Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China *** borehole data on oreforming elements underpin deep geochemical *** methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)co.relation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was co.structed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,co.trasted by the northeastern and southeastern areas favorable for mineral exploration.

关键词： 3D geochemical model ore-forming elements geostatistics deep mineralization prediction Yechangping Mo deposit