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Experimental Investigation of the Effect of the Material Damage Induced in Sheet Metal Forming Process on the Service Performance of 22MnB5 Steel

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Chinese Journal of Mechanical Engineering 2016年第4期29卷 747-755页

作者： ZHUANG Weimin XIE Dongxuan chen yanhong State Key Laboratory of Automotive Simulation and Control Jilin University Department of Aeronautics Imperial College

The use of ultra-high strength steels through sheet metal forming process offers a practical solution to the lightweight design of ***,sheet metal forming process not only produces desirable changes in material properties but also causes material damage that may adversely influence the service performance of the material ***,an investigation is conducted to experimentally quantify such influence for a commonly used steel（the 22MnB5 steel） based on the hot and cold forming *** each process,a number of samples are used to conduct a uniaxial tensile test to simulate the forming *** that,some of the samples are trimmed into a standard shape and then uniaxially extended until fracture to simulate the service ***,a microstructure test is conducted to analyze the microdefects of the remaining *** on the results of the first two tests,the effect of material damage on the service performance of 22MnB5 steel is *** is found that the material damages of both the hot and cold forming processes cause reductions in the service performance,such as the failure strain,the ultimate stress,the capacity of energy absorption and the ratio of residual *** reductions are generally lower and non-linear in the former process but higher and linear in the latter ***,it is found from the microstructure analysis that the difference in the reductions of the service performance of 22MnB5 by the two forming processes is driven by the difference in the micro damage mechanisms of the two *** findings of this research provide a useful reference in terms of the selection of sheet metal forming processes and the determination of forming parameters for 22MnB5.

关键词： material damage sheet metal forming ultra-high strength steel 22MnB5 steel

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Error Analysis of FLC Experimental Data at Warm/Hot Stamping Conditions

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Chinese Journal of Mechanical Engineering 2014年第4期27卷 730-737页

作者： ZHUANG Weimin ZHANG Mengxi chen yanhong State Key Laboratory of Automotive Dynamic Simulation Jilin University Department of Aeronautics Imperial College

Forming limit curves（FLCs） are commonly used for evaluating the formability of sheet metals. However, it is difficult to obtain the FLCs with desirable accuracy by experiments due to that the friction effects are non-negligible under warm/hot stamping conditions. To investigate the experimental errors, experiments for obtaining the FLCs of the AA5754 are conducted at 250℃. Then, FE models are created and validated on the basis of experimental results. A number of FE simulations are carried out for FLC test-pieces and punches with different geometry configurations and varying friction coefficients between the test-piece and the punch. The errors for all the test conditions are predicted and analyzed. Particular attention of error analysis is paid to two special cases, namely, the biaxial FLC test and the uniaxial FLC test. The failure location and the variation of the error with respect to the friction coefficient are studied as well. The results obtained from the FLC tests and the above analyses show that, for the biaxial tension state, the friction coefficient should be controlled within 0.15 to avoid significant shifting of the necking location away from the center of the punch; for the uniaxial tension state, the friction coefficient should be controlled within 0.1 to guarantee the validity of the data collected from FLC tests. The conclusions summarized are beneficial for obtaining accurate FLCs under warm/hot stamping conditions.

关键词： forming limit curve(FLC) error analysis warm/hot stamping finite element analysis

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Comparison of Extractive Distillation and Pressure-Swing Distillation for Methanol and Acetonitrile Separation

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China Petroleum Processing & Petrochemical Technology 2020年第4期22卷 137-146页

作者： Han Dongmin chen yanhong Department of Chemical Engineering Shengli CollegeChina University of PetroleumDongying257061

In the present work,a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile separation is performed for the first *** separation alternatives,including the conventional extractive distillation,the extractive distillation with vapor or liquid side-stream,the pressure-swing distillation with or without full heat integration,and the heat-pump assisted pressure-swing distillation are rigorously simulated and optimized based on the minimum total annual cost(TAC)via the sequential iterative *** results show that TAC and CO2 emission of the new extractive distillation with vapor side-stream(Vapor-SED)are similar to those of the extractive distillation with liquid side-stream(Liquid-SED).Furthermore,the Vapor-SED and Liquid-SED can achieve 30.01%and 30.56%reduction in TAC and 23.32%and 23.49%reduction in CO2 emission,respectively,over the most competitive fully heat-integrated PSD ***,the extractive distillation with vapor or liquid side-stream appears to be a better option economically and environmentally for the separation of methanol and acetonitrile.

关键词： azeotrope extractive distillation pressure swing distillation TAC methanol/acetonitrile

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Vultures as a model for testing molecular adaptations of dietary specialization in birds

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Avian Research 2023年第3期14卷 425-434页

作者： yanhong chen Ling Xiang Pan chen Huabin Zhao Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources College of Life SciencesAnhui Normal UniversityWuhu241000China Key Laboratory of Biodiversity and Environment on the Qinghai-Tibetan Plateau Ministry of EducationCollege of Life SciencesWuhan UniversityWuhan430072China Key Laboratory of Biodiversity and Environment on the Qinghai-Tibetan Plateau Ministry of EducationSchool of Ecology and EnvironmentTibet UniversityLhasa850000China

Vultures are the only obligate scavengers among extant *** provide valuable ecological services in ecosystems through removing carcasses,thus preventing the growth of other scavenger populations and the spread of ***,their specific diets expose them to various deadly pathogens,which makes them potential candidates for studying molecular adaptations required to survive this extremely specialized scavenging *** this review,we summarize the morphological characteristics and behavioral habits,origin and phylogeny,and molecular adaptations to scavenging in both Old and New World *** two groups of vultures share a similar appearance,indicative of convergent *** have experienced different degrees of specialization in their sensory organs;Old World vultures depend on sight,while New World ones depend on both smell and *** fossil records and molecular data suggest that vultures evolved independently,with distinct phylogenetic *** also explored their adaptation to scavenging in facial and intestinal microbiomes,gastric acid secretion and *** with the facial microbiome,the intestinal microbiome had a lower diversity,dominated by Fusobacteria and *** phages and single invertebrate species Adineta vaga,which feeds on dead bacteria and protozoa,present in the gut suggest a possible alternative defense *** genes involved in gastric acidic secretion(including ATP4B,SLC26A7 and SST)and immunity(including BCL6,STING,and TLRs) undergoing positive selection likely have essential roles in eliminating invasive pathogens and initiating an innate immune *** together,this review presents the current research status of vultures and highlights the use of vultures as a model for exploring molecular adaptations of dietary specialization in *** also provides a theoretical basis for the study of the genetic mechanisms of vultures to scavenging,and contributes to the

关键词： Vultures Scavenging Molecular adaptation Microbiomes Gastric acidic secretion Immunity

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Establishment of the thermo-mechanical coupling model of axle box bearings with track irregularity excitation and analysis of its temperature characteristics

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1965-1986页

作者： Min WANG Shaopu YANG Yongqiang LIU yanhong chen Kai ZHANG State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China CRRC Tangshan Co. Ltd.Tangshan063000Hebei ProvinceChina China Water Resources Beifang Investigation Designand Research Co.Ltd.Tianjin300222China

As an important component of the running gear of high-speed trains,axle box bearings can cause lubricating grease failure and damage to bearing components under continuous high-temperature operation,which will affect the normal operation of highspeed ***,bearing temperature is one of the key parameters to be monitored in the online monitoring system for *** on the thermal network method,this paper establishes a thermal network model for the axle box bearing,considering the radial thermal deformation of the double-row tapered roller bearing components caused by the oil film characteristics and the temperature variations of the lubricating grease.A thermo-mechanical coupling model for the grease-lubricated double-row tapered roller axle box bearing of high-speed trains with track irregularity excitation is *** correctness of the model is verified using the test bench data,and the temperature of the bearing at different rotational speeds,loads,fault sizes,and ambient temperatures are investigated.

关键词： axle box bearing thermal network method temperature rotational speed

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Debranching enzymes decomposed corn arabinoxylan into xylooligosaccharides and achieved prebiotic regulation of gut microbiota in broiler chickens

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Journal of Animal Science and Biotechnology 2023年第4期14卷 1485-1500页

作者： Wei Wu Huajin Zhou yanhong chen Yuming Guo Jianmin Yuan State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural University2 Yuanmingyuan West RoadHaidian DistrictBeijing 100193PR China

Background Corn arabinoxylan(AX)is a complicated and multibranched antinutritional factor,thereby proving the use of endo-xylanase(EX)to be marginally *** study focused on specific types of AX-degrading enzymes(ADEs)to exert the synergy of debranching enzymes and track the prebiotic potential of enzymatic *** study investigated the effects of ADEs on the growth performance,intestinal histomorphology,absorption functions,changes in polysaccharide components,fermentation,and gut microbiota of broiler *** hundred seventysix five-day-old Arbor Acres male broiler chickens were randomly allocated into eight treatments with six replicates *** basal diets supplemented with or without enzymes were fed for a 21-day period,specifically including EX,its compatible use with arabinofuranosidase(EXA)or ferulic acid esterase(EXF),and compound groups with the above three enzymes(XAF).Results Specific ADEs stimulated the jejunal villus height and goblet cell number and evidently decreased the crypt depth(P<0.05),while the ratio of ileal villus height to crypt depth was significantly increased in EXF(P<0.05).Maltase activities of ileal mucosa in XAF groups were extremely enhanced(P<0.01),and EX boosted the activity of Na+-K+ATPase in the small intestine(P<0.01).The insoluble AX concentrations comparatively lessened,thereby notably raising the sundry xylooligosaccharide(XOS)yield in the ileal chyme(P<0.05),which was dominant in xylobiose and *** in the abundance and diversity of ileal microbial communities within the EXA,EXF,and XAF treatments were observed(P<0.05).Positive correlations between microbiota and XOS were revealed,with xylobiose and xylotriose being critical for ten beneficial bacteria(P<0.05).EXF increased the BWG and FCR of broiler chickens in this phase(P<0.05),which was attributed to the thriving networks modified by *** intracecal contents of acetic acid,butyric acid,and propionic acid were greatly

关键词： Arabinoxylan Corn Prebiotic Specific xylanase Xylooligosaccharide

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Geochronology and Geochemistry of the Subduction-related Rocks with High Sr/Y Ratios in the Zedong Area: Implications for the Magmatism in Southern Lhasa Terrane during Late Cretaceous

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Acta Geologica Sinica(English Edition) 2015年第2期89卷 351-368页

作者： chen yanhong YANG Jingsui XIONG Fahui ZHANG Lan LAI Shengmin chen Mei CARMA State Key Laboratory for Continental Tectonics and DynamicsInstitute of GeologyChinese Academy of Geological Sciences School of Earth Sciences and Mineral Resources China University of Geosciences

The southern Lhasa Terrane is famous for its huge magmatic belt which records the magmatism during Mesozoic and Cenozoic. Although the Mesozoic continental-margin setting in the southern Lhasa Terrane has been identified, details of this tectonic setting and the evolution history during the Late Cretaceous remain unclear. To further constrain these issues, we present zircon LA-ICP-MS U-Pb, Hf isotopic and geochemical data of the Gongbari dacites （of the Sangri Group） which intruded by Paleocene granodiorites from the eastern part of the southern Lhasa Terrane, Tibet. New age data indicate that the dacites were generated at -95.4 Ma, which suggests the Sangri Group volcanism may last to Late Cretaceous. The Gongbari dacites are characterized by high Sr （428-758 ppm） contents, low concentration of heavy rare earth elements and Y （e.g. Yb=0.78-1.14 ppm; Y=8.85-11.4 ppm） with high Sr/Y （41.91-67.59） and La/Yb （22.64-30.64） ratios, similar to those of adakite. The rocks are calc-alkaline, metaluminous, enriched in LILEs, depleted in HFSEs, and have positive tar（t） values （＋7.7 to ＋11.6）. The Gongbari dacites were probably produced by partial melting of young and hot subducted Neo- Tethyan oceanic crust under amphibolite to garnet amphibolite-facies conditions. Though the Gangdese Mountains may have formed before Indo-Asian collision, the southern margin of Lhasa Terrane might not go through obviously crustal thickening during the northward subduction of Neo-Tethyan oceanic lithosphere.

关键词： Adakitic dacite Sangri Group Neo-Tethyan Ocean Southern Lhasa Terrane Tibet

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Urban Expansion and Its Influencing Factors in Natural Wetland Distribution Area in Fuzhou City,China

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Chinese Geographical Science 2012年第5期22卷 568-577页

作者： CAI Yuanbin ZHANG Hao PAN Wenbin chen yanhong WANG Xiangrong Department of Environmental Science and Engineering Fudan University Shanghai 200433 China Fuzhou Research Academy of Environmental Sciences Fuzhou 350011 China College of Environment and Resourees Fuzhou University Fuzhou 350002 China Zhichen College Fuzhou University Fuzhou 350002 China

This paper principally focuses on land use dynamics,urban expansion and underlying driving forces in the Natural Wetland Distribution Area(NWDA)of Fuzhou City in the southeastern *** on time series Landsat TM/ETM+imageries and historical data,relationships between urban land expansion and its influencing factors from 1989 to 2009 were analyzed by using an integrated approach of remote sensing(RS)and geographic information system(GIS)*** results showed that built-up land increased from 151.16 km2in 1989 to 383.76 km 2in 2009. Approximately 64.25%of the newly emerging built-up land was converted from cropland(29.47%),forest and shrub (25.78%),water(3.73%),wetland(4.61%),and bare land(0.66%)during 1989 and *** a remarkable decrease in cropland,the proportion of non-agricultural population increased by 23.6%.Moreover,rapid development of infrastructures,facilities,industrial parks,and urban and rural settlements along the Minjiang River resulted in the eastward and southward expansion of built-up ***,the growth pattern of built-up land in the NWDA is highly correlated with socio-economic factors,including the gross domestic product(GDP),GDP per capita,and structure of *** a result,the observed environmental degradation such as loss of cropland and wetland due to heavy pressure of rapid urbanization have greatly impaired the carrying capacity of ***,in addition to scientific and rational policies towards minimizing the adverse effects of urbanization,coordination between the administrative agencies should be urgently strengthened to balance the conflicts between urban development and ecological conservation to make sure the sustainable land use.

关键词： land use urban expansion natural wetland socio-economic factors remote sensing (RS) geographic in-formation system (GIS)

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Vinous-throated parrotbills breed in invasive smooth cordgrass habitat:Can native birds avoid the potential ecological trap?

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Avian Research 2023年第3期14卷 369-376页

作者： Pan chen yanhong chen Huimin chen Taiyu chen Bin Liu Manyu Zhang Silu Wang Changhu Lu Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources College of Life SciencesAnhui Normal UniversityWuhu241000China College of Biology and Environment Nanjing Forestry UniversityNanjing210037China

Native animals are facing long-term coexistence with invasive plants worldwide,the impacts of which on animal behavior remain poorly *** ecological traps could threaten native birds breeding in invasive plant habitats,but behavioral strategies for birds to avoid such risks are few *** invasion of Smooth Cordgrass(Spartina alterniflra) has seriously varied the vegetation landscape in the coastal wetlands of eastern China,and affected the habitat selection of native ***,we investigated the nesting and breeding characteristics of a common native passerine,the Vinous-throated Parrotbill(Sinosuthora webbiana),in habitats dominated by native Common Reed(Phragmites australis) and exotic *** found that parrotbills could complete their breeding cycle in cordgrass *** nest failure was attributed to predation in native habitat but tide inundation in cordgrass ***,the nest success rate and daily survival rate(DSR) in cordgrass habitat were ***,nest height was markedly higher in cordgrass habitat and was the most important influencing variable(positively correlated with the DSR).These results suggest that cordgrass habitat is a potential ecological trap due to the tide inundation,but some parrotbills seem to effectively avoid this risk by increasing nest *** study reveals that a native passerine changes its nesting behavior to accommodate invasive plant habitat and highlights that habitat changes caused by invasive plants may drive the adaptive evolution of native animal *** limitation of these results must be acknowledged for the small sample size,and there is a need for a larger sample and long-term data for further verification.

关键词： Adaptive evolution Behavioral plasticity Nesting behavior Sinosuthora webbiana Spartina alterniflora

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Phylogenetic constrains on mycorrhizal specificity in eight Dendrobium(Orchidaceae) species

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Science China(Life Sciences) 2017年第5期60卷 536-544页

作者： Xiaoke Xing Xueting Ma Jinxin Men yanhong chen Shunxing Guo Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education Institute of Medicinal Plant Development Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100193 China

Plant phylogeny constrains orchid mycorrhizal(OrM) fungal community composition in some orchids. Here, we investigated the structures of the OrM fungal communities of eight Dendrobium species in one niche to determine whether similarities in the OrM fungal communities correlated with the phylogeny of the host plants and whether the Dendrobium-OrM fungal interactions are phylogenetically conserved. A phylogeny based on DNA data was constructed for the eight coexisting Dendrobium species,and the OrM fungal communities were characterized by their roots. There were 31 different fungal lineages associated with the eight Dendrobium species. In total, 82.98% of the identified associations belonging to Tulasnellaceae, and a smaller proportion involved members of the unknown Basidiomycota(9.67%). Community analyses revealed that phylogenetically related Dendrobium tended to interact with a similar set of Tulasnellaceae fungi. The interactions between Dendrobium and Tulasnellaceae fungi were significantly influenced by the phylogenetic relationships among the Dendrobium species. Our results provide evidence that the mycorrhizal specificity in the eight coexisting Dendrobium species was phylogenetically conserved.

关键词： orchid mycorrhiza mycorrhizal network fungal community composition phylogenetic conservatism

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