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Computer vision-aided DEM study on the compaction characteristics of graded subgrade filler considering realistic coarse particle shapes

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Railway Engineering Science 2024年第2期32卷 194-210页

作者： Taifeng Li Kang Xie Xiaobin Chen Zhixing Deng qian su Railway Engineering Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China Department of Civil Engineering Central South UniversityChangsha 410075China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

The compaction quality of subgrade filler strongly affects subgrade *** main objective of this research is to analyze the macro-and micro-mechanical compaction characteristics of subgrade filler based on the real shape of coarse ***,an improved Viola-Jones algorithm is employed to establish a digitalized 2D particle database for coarse particle shape evaluation and discrete modeling purposes of subgrade *** indexes of 2D subgrade filler are then computed and statistically ***,numerical simulations are performed to quantitatively investigate the effects of the aspect ratio(AR)and interparticle friction coefficient(μ)on the macro-and micro-mechanical compaction characteristics of subgrade filler based on the discrete element method(DEM).The results show that with the increasing AR,the coarse particles are narrower,leading to the increasing movement of fine particles during compaction,which indicates that it is difficult for slender coarse particles to inhibit the migration of fine ***,the average displacement of particles is strongly influenced by the AR,indicating that their occlusion under power relies on particle *** dis-placement and velocity of fine particles are much greater than those of the coarse particles,which shows that compaction is primarily a migration of fine *** the cyclic load,the interparticle friction coefficientμhas little effect on the internal structure of the sample;under the quasi-static loads,however,the increase inμwill lead to a significant increase in the porosity of the *** study could not only provide a novel approach to investigate the compaction mechanism but also establish a new theoretical basis for the evaluation of intelligent subgrade compaction.

关键词： subgrade filler particles Deep learning particle Shape analysis Particle library Compaction characteristics Discrete element method(DEM)

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Optimization of inter-helix spacing for helical piles in sand

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第3期14卷 936-952页

作者： Kang Shao qian su Junwei Liu Kaiwen Liu Zhipeng Xiong Tengfei Wang Key Laboratory of High-Speed Railway Engineering Ministry of Education School of Civil EngineeringSouthwest Jiaotong UniversityChengdu610031China School of Civil Engineering Qingdao University of TechnologyQingdao266033China Guangxi Communications Investment Group Co.Ltd Nanning530022China

The optimization of the inter-helix spacing is a key issue of the axial bearing capacity of helical *** this paper,based on the cavity expansion,an analytical approach considering the small-strain stiffness,strength,compressibility and stress level of sand around the helical pile was proposed to analyze the influence zone of the helices to determine the optimal inter-helix spacing in *** calculation results of the proposed method were verified using the centrifuge test data and finite element analysis for helical pile in Congleton HST95 *** were also compared with those using the Meyerhof pile foundation *** results show that the optimal inter-helix spacing based on Meyerhof pile foundation theory differs significantly from the *** range of the influence zone for the helices in sand calculated by the cavity expansion theory matches with the data from *** calculation results with the proposed method are consistent with the range of the optimal spacing ratio inferred in the centrifuge *** results based on the two-dimensional(2D)finite element model(FEM)are also basically consistent with the calculated analytical solution.

关键词： Helical pile Sand Analytical solution Cavity expansion theory Optimal inter-helix spacing

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Deformation and failure modes of composite foundation with sub-embankment plain concrete piles

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Research in Cold and Arid Regions 2013年第5期5卷 614-625页

作者： qian su JunJie Huang School of Civil Engineering Southwest Jiaotong University Key Laboratory of High-Speed Railway Engineering of Ministry of Education Southwest Jiaotong University

With the development of high-speed railway in China, composite foundation with rigid piles has become a stamdard solution of meeting the high requirements of stability and post-construction settlement of embankment on soft subgrade. Among several im- provement pattems, plain concrete piles have been extensively used to treat soft ground supported embankment. To investigate the deformation and failure modes of unimproved soft ground and soft ground reinforced by sub-embankment plain concrete piles, and to learn the influences of track and vehicle load, the effect of pile spacing, as well as the compression moduli of soil layers and upper load condition on the failure modes, a series of centrifuge model tests were performed. Test results indicate that the dis- placement of unimproved soft ground under the embankment increases continuously as embankment, track and train loading, and slip circle failure takes place. The deformation law of soft ground reinforced by sub-embankment plain concrete piles depends on pile spacing, compression modulus of the soft ground, and loading conditions. It was also found that plain concrete piles show displacement and failure patterns depending on its location, compression modulus of soft soil around the pile, and loading condi- tions. Furthermore, the evaluation of improved ground stability as well as the model test procedure is also presented.

关键词： centrifuge model test composite foundation plain concrete pile deformation and failure modes embankment soft ground

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Research progress of MOF-based materials in the photocatalytic CO_(2)reduction

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Carbon Resources Conversion 2024年第1期7卷 103-121页

作者： qian su Qingjie Guo Haiquan Wang Meifang Liu Cheng Zuo College of Chemistry&Chemical and Environmental Engineering Weifang UniversityWeifangPeople’s Republic of China State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia UniversityYinchuanPeople’s Republic of China

Photocatalytic technology could utilize solar energy to reduce CO_(2)into high-value-added fossil fuels,providing promising solutions for global energy and environmental ***-organic frameworks(MOFs)are a class of crystalline porous solids with high porosity and flexible ***-based photocatalysts have excellent CO_(2)capture ability,photochemical and structural characteristics and have shown infinite development potential in CO_(2)***,in practical large-scale applications,MOF-based photocatalysts still have some urgent problems to be solved,such as high composite rate of photogenerated carriers,limited response range to visible spectrum,poor photocatalytic activity and weak reduction *** paper introduces series of MOF-based photocatalysts,including pure MOF materials,compounds,and derivatives,were reviewed based on recent *** was placed on the modification strategy of photocatalysts,the photocatalytic reaction’s key physical and chemical parameters,and the mechanism of synergistic improvement of chemical fuel *** and most importantly,the future development trends and prospects of MOF-based catalysts for photocatalytic CO_(2)reduction were discussed.

关键词： Photocatalysis Metal-organic frameworks Rational design CO_(2)reduction

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New dual functional CYP450 gene involves in isoflavone biosynthesis in Glycine max L.

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Synthetic and Systems Biotechnology 2023年第1期8卷 157-167页

作者： Yaying Xia Chunfeng He su Yan Jinyue Liu Haijun Huang Xue Li qian su Wenbo Jiang Yongzhen Pang Key Laboratory of Plant Resources and Beijing Botanical Garden Institute of BotanyChinese Academy of SciencesBeijing100093China Institute of Animal Science Chinese Academy of Agricultural SciencesBeijing100193China University of Chinese Academy of Sciences Beijing100049China

Glycine max *** a large amount of isoflavonoid compounds,which is beneficial for plant defense,plant-microbe symbiotic interactions,and human *** CYP450 subfamily genes are involved in the flavonoid biosynthetic pathway in *** the present study,we found 24 CYP82 subfamily genes were differentially expressed in various tissues of soybean,in Phytophthora sojae-infected soybean varieties and in soybean hairy roots treated with cell wall glucan *** of them(GmCYP82A2,GmCYP82A3,GmCYP82A4,GmCYP82A23,GmCYP82C20 and GmCYP82D26)were co-expressed with other known isoflavonoid pathway genes in *** enzymatic activity in yeast feeding assays showed that only GmCYP82D26 was able to convert naringenin to daidzein with both aryl migration and dehydration *** GmCYP82D26 was over-expressed in soybean hairy roots,the contents of the two major isoflavonoid aglycones in soybean(daidzein and genistein)were reduced,but total flavonoids were not *** GmCYP82D26 was suppressed by RNAi in the hairy roots,daidzein content was decreased but genistein content was increased,with unchanged total flavonoid ***82D26 was found to be localized in the endoplasmic reticulum at subcellular level when transiently expressed in tobacco leaf ***82D26 gene was preferentially expressed in roots,with low expression level in other tissues in *** modeling and molecular docking showed that GmCYP82D26 could form hydrogen bond with both HEM and naringenin at C5-OH and C4 *** these results indicated that GmCYP82D26 possesses new and dual enzymatic activity,which bridges the two branches(daidzein and genistein branch)of isoflavonoid pathway in soybean.

关键词： Soybean CYP82 CYP82D26 Isoflavonoids Enzymatic activity

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Topical halometasone cream combined with fire needle pretreatment for treatment of primary cutaneous amyloidosis:Two case reports

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World Journal of Clinical Cases 2022年第20期10卷 7147-7152页

作者： Yan-qian su Zhao-Yang Liu Guo Wei Chun-Min Zhang Department of Dermato-venereology The Second Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina

BACKGROUND Primary cutaneous amyloidosis(PCA)is a chronic metabolic skin disease that has a detrimental impact on physical and mental *** appears as mossy papules and severe itching,which is long-term and *** treatments are unsatisfactory,especially for refractory *** needle therapy,which is widely used in China,has shown good clinical efficacy,as well as advantages concerning safety and *** reports about fire needle treatment of this disease are few at *** suMMARY We report two older men who had developed maculopapules with itchiness on the trunk and arms for more than 10-15 *** to the dermatopathological findings,PCA was our primary *** received topical halometasone cream and pretreatment with fire needle for 8-16 *** patients showed significant improvement of *** patient had recurrence with a minimum of 2 years of *** Topical halometasone cream and pretreatment with fire needle could be a fast,safe,and economic treatment for PCA.

关键词： Primary cutaneous amyloidosis Fire needle Halometasone cream Case report

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Experimental investigation of the thermal insulation performance of Ce/Si/Ti oxide heat-reflective coating

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第10期24卷 912-924页

作者： Rui su Yue LV qian su Yanfei PEI School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

To solve the problem of deformation and cracking of ballastless track slab under temperature load,a composite oxide and a series of heat-reflective coating samples were *** the microscopic level,the elemental composition and optical properties of the materials prepared were analyzed by Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy,and the feasibility of Ce/Si/Ti oxide as functional fillers for heat-reflective coatings of track slabs was *** the macro level,by designing and assembling an indoor sunlight simulation test device,the surface and internal temperatures of the coated and uncoated concrete specimens were analyzed and studied,and the macroscopic cooling effect of the coatings was ***,to study the engineering application effect of the track slab thermal insulation reflective coating,COMSOL was used to build a 3D calculation model of the heat transfer deformation of the ballastless track slab *** research results showed that:Ce/Si/Ti oxide has strong reflectivity and can reflect 95%of infrared light;it has good ultraviolet(UV)shielding ability and can absorb more than 65%of the UV *** TiO2 coating can reduce the temperature of the concrete surface by 6–11℃and that of the inside of the concrete by 10–14℃;the cooling effect decreases evenly with the increase of air *** Ce/Si/Ti oxide coating can reduce the surface temperature of the concrete by 16℃and that of the inside of the concrete by 15℃.In addition,the cooling effect is basically not affected by the air temperature,and it changes non-linearly with the increase of the Ce/Si/Ti oxide *** calculation shows that the heat reflective coating can reduce the surface temperature and internal temperature difference of the track slab by 11.54–21.31℃,and the vertical displacement of the track slab can be reduced by about 35%–70%.Considering the cooling effect,the adhesion strength,and the engineering application effe

关键词： Track slab Solar radiation Thermochromic coating Cooling performance

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Polyurethane grouting materials with different compositions for the treatment of mud pumping in ballastless track subgrade beds:properties and application effect

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Railway Engineering Science 2022年第2期30卷 204-220页

作者： Zhichao Huang qian su Junjie Huang Minqi Dong Dong Li Ting Liu School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of High-Speed Railway Engineering of Ministry of Education Southwest Jiaotong UniversityChengdu 610031China China Railway Fourth survey and Design Institute Group Co. Ltd.Wuhan 430000China China Railway Construction Kunlun Investment Group Co. Ltd.Chengdu 610040China

Mud pumping in subgrade beds under ballastless tracks will deteriorate the dynamic performance of infrastructure under railway lines,reduce the smoothness of the railway lines,and seriously affect the comfort and safety of the *** to their good mechanical properties,twocomponent polyurethane materials can be used for grouting to treat the fouling problems caused by ballastless track mud *** develop a polyurethane formula suitable for the treatment of ballastless track mud pumping,we first performed indoor experiments to investigate the mechanical properties and gelation time of polyurethane elastomers synthesized with different raw material composition ratios,to determine an optimal composition ratio of the raw ***,we conducted a dynamic field test to verify the remediation effect of the polyurethane material fabricated according to the design *** results showed that polyurethane grouting material with the selected design ratios improved the contact characteristics between the surface layer of the subgrade bed and the base plate in the area,coordinating the dynamic response between the track structure and the subgrade ***,the obtained polyurethane grouting material could be used to renovate mud pumping areas of ballastless tracks with a good treatment effect.

关键词： Ballastless track Mud pumping Twocomponent polyurethane Proportioning design Field dynamic test

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Physical modeling of long-term dynamic characteristics of the subgrade for medium-low-speed maglevs

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Railway Engineering Science 2023年第3期31卷 293-308页

作者： Minqi Dong Wubin Wang Chengjin Wang Zhichao Huang Zhaofeng Ding Zhixing Deng qian su School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China National Engineering Research Center of Geological Disaster Prevention Technology in Land Transportation Southwest Jiaotong UniversityChengdu 611756China China Railway Maglev Transportation Investment Construction China Railway Construction Corporation LimitedWuhan 430000China

To investigate the dynamic characteristics and long-term dynamic stability of the new subgrade structure of medium-low-speed(MLS)maglevs,cyclic vibration tests were performed under natural and rainfall conditions,and the dynamic response of the subgrade structure was *** dynamic response attenuation characteristics along the depth direction of the subgrade were compared,and the distribution characteristics of the dynamic stress on the surface of the subgrade along the longitudinal direction of the line were *** critical dynamic stress and cumulative deformation were used as indicators to evaluate the long-term dynamic stability of the *** show that water has a certain effect on the dynamic characteristics of the subgrade,and the dynamic stress and acceleration increase with the water *** the dowel steel structure set between the rail-bearing beams,stress concentration at the end of the loaded beam can be prevented,and the diffusion distance of the dynamic stress along the longitudinal direction *** dynamic stress measured in the subgrade bed range is less than 1/5 of the critical dynamic *** postconstruction settlement of the subgrade after similarity ratio conversion is 3.94 mm and 7.72 mm under natural and rainfall conditions,respectively,and both values are less than the 30 mm limit,indicating that the MLS maglev subgrade structure has good long-term dynamic stability.

关键词： Medium-low-speed maglev subgrade Dynamic characteristics Long-term dynamic stability Model test

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Metabolic disorders in prediabetes:From mechanisms to therapeutic management

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World Journal of Diabetes 2024年第3期15卷 361-377页

作者： Wen-Xin Ping Shan Hu Jing-qian su Song-Ying Ouyang Biomedical Research Center of South China College of Life SciencesFujian Normal UniversityFuzhou 350117Fujian ProvinceChina

Diabetes,one of the world's top ten diseases,is known for its high mortality and complication rates and low cure *** precedes the onset of diabetes,during which effective treatment can reduce diabetes *** risk factors include high-calorie and high-fat diets,sedentary lifestyles,and *** may include considerable damage to vital organs,including the retina,liver,and *** for treating prediabetes include a healthy lifestyle diet and pharmacological ***,while these options are effective in the short term,they may fail due to the difficulty of long-term *** may also be used to treat *** review examines prediabetic treatments,particularly metformin,glucagon-like peptide-1 receptor agonists,sodium glucose cotransporter 2 inhibitors,vitamin D,and herbal *** the remarkable impact of prediabetes on the progression of diabetes mellitus,it is crucial to intervene promptly and effectively to regulate ***,the current body of research on prediabetes is limited,and there is considerable confusion surrounding clinically relevant *** paper aims to provide a comprehensive summary of the pathogenesis of prediabetes mellitus and its associated therapeutic *** ultimate goal is to facilitate the clinical utilization of medications and achieve efficient and timely control of diabetes mellitus.

关键词： Prediabetes Glucagon-like peptide agonists Sodium–glucose cotransporter 2 inhibitors Vitamin D Chinese herbal medicines

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