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Experimental Studies on Modified Suction Caissons in Fine Sand Subject to Uplift Loading

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Transactions of Tianjin University 2017年第6期23卷 562-569页

作者： Hanbo Zhai dayong li College of Civil Engineering and Architecture Shandong University of Science and Technology School of Civil Engineering Tianjin University College of Civil Engineering Fuzhou University

A modified suction caisson (MSC), which was reported by the authors of this paper previously, comprises an external short-skirted structure that is added to a regular suction caisson (RSC). It has been proved that MSCs can improve the lateral bearing capacity and limit the deflection of the caisson compared with RSCs. A series of model tests were conducted to investigate responses of MSCs subject to uplift loading in saturated sand. The effects of external skirt dimensions on the uplift bearing capacity of MSCs were considered. In addition, the influences of the sealed top lid of the skirted structure on the uplift bearing capacity and the resulting passive suction of MSCs were also studied. It was found that the uplift bearing capacities of MSCs are 1.4–1.7 times that of RSCs. Moreover, test results in serviceable conditions show that the sealed external skirted structure of perspex-made suction caissons significantly contributed to the uplift bearing capacity as a result of passive suction. © 2017 Tianjin University and Springer-Verlag GmbH Germany

关键词： Bearing capacity Caissons Flowcharting Foundations Offshore wind turbines Pressure vessels Wind turbines

Genetic Relationships Among Five Basic Genomes St, E, A, B and D in Triticeae Revealed by Genomic Southern and in situ Hybridization

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Journal of Integrative Plant Biology 2007年第7期49卷 1080-1086页

作者： Zhao liu dayong li Xueyong Zhang Key Laboratory of Crop Germplasm and Biotechnology Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China Institute of Genetics and Developmental Biology the Chinese Academy of Sciences Beijing 100101 China.

The St and E are two important basic genomes in the perennial tribe Triticeae （Poaceae）. They exist in many perennial species and are very closely related to the A, B and D genomes of bread wheat （Triticum aestivum L.）. Genomic Southern hybridization and genomic in situ hybridization （GISH） were used to analyze the genomic relationships between the two genomes （St and E） and the three basic genomes （A, B and D） of T. aestivum. The semi-quantitative analysis of the Southern hybridization suggested that both St and E genomes are most closely related to the D genome, then the A genome, and relatively distant to the B genome. GISH analysis using St and E genomic DNA as probes further confirmed the conclusion. St and E are the two basic genomes of Thinopyrum ponticum （StStE^eE^bE^x） and Th. intermedium （StE^eE^b）, two perennial species successfully used in wheat improvement. Therefore, this paper provides a possible answer as to why most of the spontaneous wheat-Thinopyrum translocations and substitutions usually happen in the D genome, some in the A genome and rarely in the B genome. This would develop further use of alien species for wheat improvement, especially those containing St or E in their genome components.

关键词： E genome fluorescent in situ hybridization genomic in situ hybridization perennial Triticeae St genome wheat,

First evidence of prey capture and meat eating by wild Yunnan snub-nosed monkeys Rhinopithecus bieti in Yunnan,China

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Current Zoology 2010年第2期56卷 227-231页

作者： Baoping REN dayong li Zhijin liU Baoguo li Fuwen WEI Ming li Institute of Zoology Chinese Academy of Sciences Chaoyang District Beijing 100101 China College of life Sciences Northwest University Xi＇an 710069 China

Most extant nonhuman primates occasionally prey on fast-moving, warm-blooded animals; however, Indriidae, Lepilemuridae, and Colobinae either scavenged for meat or did not eat meat at all. Here we report six cases of animal consumption by the snub-nosed monkey Rhinopithecus bieti in a wild, habituated group between 2004 and 2009 in Yunnan, China. At present, only males in an all-male unit within the study group were involved in active hunting. Such a male-biased activity may be related to the group structure and spatial spread of R. bieti. Two females were observed eating freshly killed birds. The findings confirmed that R. bieti engaged in scavenging and, when hunting, employed a cranio-cervical bite to kill their prey. Meat eating is likely a nutrient maximization feeding strategy in R. bieti, especially in males. A begging behavior occurred after successful prey capture. Although begging was observed, no sharing of the meat was seen. The present findings illuminate the dietary diversity of R. bieti and their ability to expand their dietary spectrum.

关键词： Yunnan snub-nosed monkeys Rhinopithecus bieti Colobinae Hunting behavior Meat consumption Male-biased activity

Experimental study on new method and automatic system for fast evaluating Al-Si alloy modification effect in front of furnace

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Science China(Technological Sciences) 2006年第5期49卷 569-575页

作者： SHI Dequan li dayong GAO Guili WANG lihua School of Material Science and Engineering Harbin University of Science and Technology Harbin 150040 China School of Material Science and Engineering Harbin University of Science and Technology Harbin 150040 China School of Material Science and Engineering Harbin University of Science and Technology Harbin 150040 China School of Material Science and Engineering Harbin University of Science and Technology Harbin 150040 China

A new method based on the surface tension measurement for fast evaluating modification effect of Al-Si alloy in front of furnace and an automatic system for fast measuring surface tension of molten Al-Si alloy are introduced. By theoretical analysis the relation between surface tension σe of molten Al-Si alloy and information parameters △P , N , φx and T has been established, namely, σ e = a △P + b . N + c . (φ x- φ0)+ d . T +e . By ex- periments the relationship between surface tension and modification level of Al-Si alloy has been also got that σ e > 530 mN/m, 400 ≤σe ≤530 mN/m and σ e < 400 mN/m are corresponding with AFS 1-2, AFS 3-4 and AFS 5-6 of Al-Si modification effect. Depending on the conclusions, modification effect can be recognized in a few seconds, which is of practical significance for real-time evaluating modification effect of Al-Si alloy in front of furnace.

关键词： surface tension, modification effect, new method, automatic testing system.

Substrate use and postural behavior in free-ranging snub-nosed monkeys(Rhinopithecus bieti)in Yunnan

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Integrative Zoology 2013年第4期8卷 335-345页

作者： Cyril C.GRUETER dayong li Baoping REN Ming li School of Anatomy Physiology and Human BiologyUniversity of Western AustraliaCrawleyAustralia College of life Sciences China West Normal UniversityNanchongSichuanChina Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijingChina

Extant colobines represent a predominantly arboreal primate radiation,but there are outliers such as some species of snub-nosed monkeys(Rhinopithecus spp.)that utilize both arboreal and terrestrial *** quantified the degree of terrestriality and the distribution of individuals across canopy levels,the extrinsic and intrinsic determinants and constraints of strata association as well as use of postures in relation to behavior and food sources in a wild population of Yunnan snub-nosed monkeys(Rhinopithecus bieti)in the Samage Forest,*** subjects spent 80.5%of the observation time in the trees and 19.5%on the *** use occurred most frequently in the context of travelling(61%)and less often in the context of feeding and resting(30%combined).Adult males frequented the ground significantly more often than other age-sex ***-sex differences were also apparent in substrate preferences,which likely reflect body weight *** males were significantly more associated with solid substrates and less with terminal branches than adult females and *** were seen more often on unstable ground(*** thin and oblique branches)and in the upper *** use also varied with behavior:feeding was much more common in the upper stratum,outer canopy,on highly inclined and thin branches,as compared to *** weather also influenced canopy use in that tree crowns were used less often during periods of *** most frequently exhibited resting and feeding postures was *** and suspensory postures were most often used in the context of feeding on lichens.

关键词： China colobine positional behavior posture terrestriality

Effects of dynamic recrystallization in extruded and compressed AZ31 magnesium alloy

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Acta Metallurgica Sinica(English Letters) 2010年第5期23卷 334-342页

作者： Xiaohui FAN Weiqin TANG Shaorui ZHANG dayong li Yinghong PENG School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China

Commercial AZ31 billets were extruded to round rods at three extrusion velocities of 0.8 m/min, 1.4 m/min and 2.2 m/min, at 643 K, 673 K and 703 K, respectively. The microstructure and texture evolution at different conditions were investigated by optical microscopy （OM） and electron backscattered diffraction （EBSD） techniques. The average grain size is reduced significantly after the hot extrusion, and the microstructure is obviously inhomogeneous due to dynamic recrystallization, which is confirmed by uni-axial compression experiments at elevated temperatures with different strain rates. The uni-axial compression leads to a fibre texture, and {110}010 texture is the major texture in extruded rods due to non-basal slip. As the extrusion temperature is elevated, the main texture becomes weak and other texture components appear.

关键词： AZ31 Extrusion Dynamic recrystallization Microstructure Stress-strain Texture

Analysis and Suppression of End Flare in AHSS Roll‑Formed Seat Rail

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Automotive Innovation 2023年第3期6卷 404-413页

作者： Tianxia Zou Yang liu Weiqin Tang dayong li State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Roll forming has been widely used to manufacture long channels with complex *** flare,one of the typical shape errors,seriously affects the forming accuracy of roll-formed parts,especially using advanced high-strength *** this paper,the mechanism of end flare during the roll forming process of a high-strength automobile seat rail is *** roll forming process of an actual seat rail is *** finite element models of the roll forming process and cut-off springback are established to predict the deformation process and occurrence of end *** results indicate that the uneven distribution of longitudinal and shear residual stress along the length of the part is the main reason for the end *** on the simulation,two strategies are proposed to mitigate the end *** multiple bending processes in the transverse direction effectively balances the longitudinal and shear residual ***,the longitudinal bending process can make the longitudinal residual stress in the roll-formed parts more ***,verification experiments are carried out,and the forming accuracy of the seat rail is significantly improved.

关键词： Seat rail Roll forming End flare Residual stress Geometrical accuracy Finite element modelling

Sleeping site use of the white-headed langur Trachypithecus leucocephalus： The role of predation risk, territorial defense, and proximity to feeding sites

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Current Zoology 2011年第3期57卷 260-268页

作者： dayong li Qihai ZHOU Xiaoping TANG Henglian HUANG Chengming HUANG Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong Sichuan 637002 China College of life Science Guangxi Normal University Gulling Guangxi 541004 China Natiional Zoological Museum Istitute of Zoology Chinese Academy of Sciences Beijing 100101 China Institute of Zoology Chinese Academy of Sciences Beijing 100101 China

We collected data on sleeping site use from two groups of white-headed langurs Trachypithecus leucocephalus living in Fusui Nature Reserve, China between August 2007 and July 2008. This information was used to test several hypotheses regarding ultimate causes of sleeping site use in this primate. White-headed langurs slept either in caves （17 sites） or on a cliffledge （one site）. They used all sleeping sites repeatedly, and reused some of them on consecutive nights; three nights was the longest consecutive use of any one sleep site. We suggest that langurs use sleeping sites to make approach and attack by predators difficult, and to increase their own familiarity with a location so as to improve chances for escape. Langurs＇ cryptic behaviors with an increased level of vigilance before entering sleeping sites may also help in decreasing the possibility of detection by predators. Group 1 spent more sleeping nights in the central area of their territory than expected; in contrast, group 2 spent more sleeping nights in the periphery of their territory, which overlaps with that of another groups, than expected. The position of sleeping site relative to the last feeding site of the day and the first feeding site of the subsequent morning indicated a strategy closer to that of a multiple central place forager than of a central place forager. These results suggest that territory defense and food access may play an important role in sleeping site use of white-headed langurs [Current Zoology 57 （3）： 260-268, 2011].

关键词： White-headed langur Trachypithecus leucocephalus Sleeping site limestone habitat

Approximation approach to the SRM based on root decomposition in the simulation of spatially varying ground motions

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Earthquake Engineering and Engineering Vibration 2013年第3期12卷 363-372页

作者： Wu Yongxin Gao Yufeng li dayong Xu Changjie Ali H Mahfouz Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University Institute of Engineering Safety and Disaster Prevention Hohai University Geotechnical Research Institute Hohai University Department of Civil Engineering Shandong University of Science and Technology Research Center of Coastal and Urban Geotechnical Engineering Zhejiang University College of Engineering Jazan University

The spectral representation method （SRM） is widely used to simulate spatially varying ground motions. This study focuses on the approximation approach to the SRM based on root decomposition, which can improve the efficiency of the simulation. The accuracy of the approximation approach may be affected by three factors： matrix for decomposition, distribution of frequency interpolation nodes and elements for interpolation. The influence of these factors on the accuracy of this approach is examined and the following conclusions are drawn. The SRM based on the root decomposition of the lagged coherency matrix exhibits greater accuracy than the SRM based on the root decomposition of the cross spectral matrix. The equal energy distribution of frequency interpolation nodes proposed in this study is more effective than the counter pith with an equal spacing. Elements for interpolation do not have much of an effect on the accuracy, so interpolation of the elements of the decomposed matrix is recommended because it is less complicated from a computational efficiency perspective.

关键词： ground motions simulation spectral representation method spatially varying approximation root decomposition