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Flexural behavior of high-strength,steel-reinforced,and prestressed concrete beams

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Frontiers of Structural and Civil Engineering 2021年第1期15卷 227-243页

作者： Qing JIANG Hanqin WANG Xun CHONG yulong feng Xianguo YE School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei 230009China Anhui Key Laboratory of Civil Engineering and Materials Hefei 230009China College of Water Conservancy and Civil Engineering Xinjiang Agricultural UniversityUrumqi 830052China

To study the flexural behavior of prestressed concrete beams with high-strength steel reinforcement and high-strength concrete and improve the crack width calculation method for flexural components with such reinforcement and concrete,12 specimens were tested under static *** failure modes,flexural strength,ductility,and crack width of the specimens were *** results show that the failure mode of the test beams was similar to that of the beams with normal reinforced concrete.A brittle failure did not occur in the *** further understand the working mechanism,the results of other experimental studies were collected and *** results show that the normalized reinforcement ratio has a greater effect on the ductility than the concrete *** cracking-and peak-moment formulas in the code for the design of concrete(GB 50010-2010)applied to the beams were both found to be ***,the calculation results of the maximum crack width following GB 50010-2010 and EN 1992-1-1:2004 were considerably *** the context of GB 50010-2010,a revised formula for the crack width is proposed with modifications to two major factors:the average crack spacing and an amplification coefficient of the maximum crack width to the average *** mean value of the ratio of the maximum crack width among the 12 test results and the relative calculation results from the revised formula is 1.017,which is better than the calculation result from GB ***,the new formula calculates the crack width more accurately in high-strength concrete and high-strength steel reinforcement ***,finite element models were established using ADINA software and validated based on the test *** study provides an important reference for the development of high-strength concrete and highstrength steel reinforcement structures.

关键词： high-strength steel reinforcement high-strength concrete flexural behavior crack width

Design and experiment of a Chinese chive harvester

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International Journal of Agricultural and Biological Engineering 2023年第2期16卷 125-131页

作者： yulong feng Xuchao Yin Hairong Jin Wenyu Tong Xiaofeng Ning College of Engineering Shenyang Agricultural UniversityShenyang 110866China Key Laboratory of Modern Horticultural Equipment Ministry of Agriculture and Rural AffairsShenyang 110866China

Recognizing the labor intensity of current domestic Chinese chive harvesting and the need for its mechanized harvesting,a self-propelled electric Chinese chive harvester is *** machine is composed of a control system,supporting mechanism,cutting parts,conveying and clamping mechanisms,frame,and collection *** can complete Chinese chive feeding,cutting,transmission,and binning operations at one *** has a cutting width of 0.25 m and wheelbases of 260 mm and 460 *** 12 V,42 Ah lead-acid batteries were used in series as the power *** mechanical properties of Chinese chive were analyzed,and shear and compression tests were carried out to determine that the average value of the maximum shear force on the chives is 129 *** to a compressive force of 225 N,Chinese chives are not *** to the physical characteristics of Chinese chives and the requirements of the harvesting operations,design and calculation of the key components of the harvester’s transmission mechanism and the strength of the whole machine frame were *** embedded control system and Cortex-M3 microprocessor were used to control the harvester and realize its functions of rolling and harvesting while regulating its speed and protecting its *** the Box-Behnken test design method,the machine’s operating speed,cutter speed,and cutter height were selected as influencing factors,and the lodging rate and loss rate were evaluated as a test.A mathematical regression model of influencing factors and evaluation indexes was established to analyze the influence of these factors and indexes and optimize test *** optimal parameter combination is determined to be:operating speed,1.1 km/h;cutter speed,220 r/min;cutter height 2.0 *** parameters were verified from field tests and the results showed that under the optimized parameter combination,the average lodging rate was 3.96% and the average loss rate was 3.23%,indicating that the Chinese chive harvester

关键词： harvester clamping mechanism test design lodging rate Chinese chive

Noxious invasive Eupatorium adenophorum may be a moving target:Implications of the finding of a native natural enemy,Dorylus orientalis

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Chinese Science Bulletin 2010年第33期55卷 3743-3745页

作者： NIU YanFen feng yulong XIE JianLei LUO FuCheng Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Kunming 650223 China Graduate University Chinese Academy of Sciences Beijing 100049 China College of Animal Science and Technology Yunnan Agricultural University Kunming 650201 China

Eupatorium adenophorum is a noxious invasive weed that is distributed throughout subtropical areas *** release may be at least one of the reasons underlying its success as an *** this study,we observed damage to the epidermis,cortex,phloem,cambium,and xylem tissues of roots and stems around the root collar of *** growing in an experimental field in Yunnan Province,southwest *** damage was caused by Dorylus orientalis,a polyphagous ant feeding on the weed and resulted in the death of the plants by interrupting nutrient exchange between shoots and *** ant showed selectivity for the invader to some *** finding of *** and other native enemies indicate that *** may gradually naturalize in introduced *** addition,this ant may have potential for use as a biocontrol agent against the invader.

关键词：紫茎泽兰入侵者天敌移动东方外来杂草亚热带地区生物防治剂

THE MECHANISM OF SEED DETERIORATION

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Journal of Northeast Forestry University 1993年第1期4卷 6-10页

作者： Liu Enju feng yulong Sun Hongzhi Northeast Forestry University 1. Northeast Forestry University China

Seed deterioration is an irresistible physiological phenomenon. The aim to study seed deterioration is to see if seed deterioration can be retarded artificially and the higher seed vigor of fine varieties be maintained. The change of seed deterioration occurs in almost every system, and affects many kinds of enzyme and almost all organcllc, as a result, the seed loses its vigor. The reason of seed deterioration and the lost of seed vigor are mainly studied and discussed in this paper. According to the external and internal two kinds of theory advanced by E. H. Roberts, Much deep discussions are made from the view of biochemistry.

关键词： Seed deterioration Deterioration Loses of vigor

Biology of Hippo signaling pathway:Skeletal muscle development and beyond

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Journal of Integrative Agriculture 2024年第6期23卷 1825-1838页

作者： Shuqi Qin Chaocheng Li Haiyan Lu yulong feng Tao Guo Yusong Han Yongsheng Zhang Zhonglin Tang Xinjiang Characteristic Livestock Breeding and Reproduction Team College of Animal Science and TechnologyShihezi UniversityShihezi 832003China Lanzhou Veterinary Research Institute Chinese Academy of Agricultural SciencesLanzhou 730046China Kunpeng Institute of Modern Agriculture at Foshan Foshan 528226China Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518124China

Global demand for farm animals and their meat products i.e.,pork,chicken and other livestock meat,is steadily *** the ongoing life science research and the rapid development of biotechnology,it is a great opportunity to develop advanced molecular breeding markers to efficiently improve animal meat production *** is an important study subject because of its crucial role in the regulation of organ *** recent years,with the increase of research on Hippo signaling pathway,the integrative application of multi-omics technologies such as genomics,transcriptomics,proteomics,and metabolomics can help promote the in-depth involvement of Hippo signaling pathway in skeletal muscle development *** Hippo signaling pathway plays a key role in many biological events,including cell division,cell migration,cell proliferation,cell differentiation,cell apoptosis,as well as cell adhesion,cell polarity,homeostasis,maintenance of the face of mechanical overload,*** influence on the development of skeletal muscle has important research value for enhancing the efficiency of animal husbandry *** this study,we traced the origin of the Hippo pathway,comprehensively sorted out all the functional factors found in the pathway,deeply analyzed the molecular mechanism of its function,and classified it from a novel perspective based on its main functional domain and mode of *** aim is to systematically explore its regulatory role throughout skeletal muscle *** specifically focus on the Hippo signaling pathway in embryonic stem cell development,muscle satellite cell fate determination,myogenesis,skeletal muscle meat production and organ size regulation,muscle hypertrophy and atrophy,muscle fiber formation and its transformation between different types,and *** roles in proliferation and regeneration are methodically summarized and analyzed *** summary and prospect of the Hippo signaling pathway within this a

关键词： Hippo skeletal muscle organ size myogenesis C2C12 livestock animals

Increased dependence on nitrogen-fixation of a native legume in competition with an invasive plant

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Plant Diversity 2024年第4期46卷 510-518页

作者： Meixu Han Haiyang Zhang Mingchao Liu Jinqi Tang Xiaocheng Guo Weizheng Ren Yong Zhao Qingpei Yang Binglin Guo Qinwen Han yulong feng Zhipei feng Honghui Wu Xitian Yang Deliang Kong College of Forestry Henan Agricultural UniversityZhengzhou 450002China College of Life Science Hebei UniversityBaoding 071002China Liaoning Key Laboratory for Biological Invasions and Global Changes College of Bioscience and BiotechnologyShenyang Agricultural UniversityShenyangLiaoning 110866China College of Horticulture China Agricultural UniversityBeijing 100193China State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Key Laboratory of Arable Land Quality Monitoring and Evaluation Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China

Suppression of roots and/or their symbiotic microorganisms,such as mycorrhizal fungi and rhizobia,is an effective way for alien plants to outcompete native ***,little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition *** a pot experiment was conducted with monoculture and mixed plantings of an invasive plant,Xanthium strumarium,and a common native legume,Glycine *** measured traits related to root and nodule quantity and activity and mycorrhizal *** to the monoculture,fine root quantity(biomass,surface area)and activity(root nitrogen(N)concentration,acid phosphatase activity)of *** decreased in mixed plantings;nodule quantity(biomass)decreased by 45%,while nodule activity in Nfixing via rhizobium increased by 106%;mycorrhizal colonization was *** of N fixation to leaf N content in *** increased in the mixed plantings,and this increase was attributed to a decrease in the rhizosphere soil N of *** in the mixed *** root quantity and activity,along with a higher mycorrhizal association was observed in *** in the mixed compared to ***,the invasive plant did not directly scavenge N from nodule-fixed N,but rather depleted the rhizosphere soil N of the legume,thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N *** quantity-activity framework holds promise for future studies on how native legumes respond to alien plant invasions.

关键词： Mycorrhizal strategy Nitrogen depletion Plant invasion Root nutrient acquisition strategy Symbiotic nitrogen fixation

Effects of T-S wave amplitude on the control of boundary layer transition by streaks

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Theoretical & Applied Mechanics Letters 2013年第4期3卷 35-39页

作者： Hui Guo yulong feng Haiwen Wang Ziteng Liu School of Aeronautic Science and Engineering Beihang University Key Laboratory of Fluid Mechanics of Ministry of Education Beihang University

The effects of streaks on boundary layer transition depend on the initial amplitude of T-S waves introduced to excite the transition. This problem was studied in a flat-plate boundary layer in water tunnel by using hydrogen bubble method. Three T-S wave initial amplitudes were tested. The results show that both narrow and wide-spacing streaks depress the transition excited by T-S waves with lower initial amplitude. However, when transition is excited by T-S waves of higher initial amplitude, the narrow-spacing streaks depress the transition, while the wide-spacing streaks promote the transition. Futrther the underlying mechanisms were also analyzed.

关键词： flow control boundary layer transition hydrogen bubble method streaks

西双版纳地区附生与非附生植物叶片对雾水的吸收

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应用生态学报 2006年第6期17卷 977-981页

作者：郑玉龙冯玉龙河北大学生命科学学院中国科学院西双版纳热带植物园昆明分部昆明650223

采用蒸馏水喷雾(模拟雾)法,测定了西双版纳地区干季中10种附生植物和非附生植物叶片水势(Φ)、相对含水量(RWC)和吸水量的变化,探讨了不同类型植物叶片的吸收雾水的能力.结果表明,随喷雾时间的延长,植物叶片Φ、RWC和吸水量均升高,说明... 详细信息

采用蒸馏水喷雾(模拟雾)法,测定了西双版纳地区干季中10种附生植物和非附生植物叶片水势(Φ)、相对含水量(RWC)和吸水量的变化,探讨了不同类型植物叶片的吸收雾水的能力.结果表明,随喷雾时间的延长,植物叶片Φ、RWC和吸水量均升高,说明附生植物和非附生植物叶片都能吸收雾水,但附生植物叶片吸水后Φ升高明显快于非附生植物.附生植物附着实蕨和爬树龙叶片吸水快、RWC变化大,表明其叶片吸收雾水的能力强;贝母兰和掌唇兰叶片吸水能力低于非附生植物中的穿鞘花和野靛稞,但高于其它4种非附生植物.傍晚雾生之前附生植物叶片Φ显著低于清晨,表明夜间附生植物叶片吸收了雾水;而非附生植物傍晚叶片Φ与清晨水势差异不显著,夜间几乎不吸收雾水.除贝母兰外,附生植物叶生物量分数高于非附生植物,利于其吸收雾水.由于西双版纳地区干季多雾,该区植物叶片最低水势均在-0·8MPa以上,水分胁迫不严重.

关键词：附生植物非附生植物雾叶片吸水水势相对含水量

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飞机草入侵种群与原产地种群生长性状的差异

生态学报 2014年第23期34卷 6890-6897页

作者：李委涛郑玉龙冯玉龙中国科学院西双版纳热带植物园勐腊666303 中国科学院大学北京100049 沈阳农业大学沈阳110866

飞机草(Chromolaena odorata)是我国热带地区危害严重的外来入侵植物,为揭示适应进化对其成功入侵的贡献,在同质种植园中,比较研究了飞机草10个入侵地种群与12个原产地种群生长性状的差异,为排除奠基者效应的可能影响,进一步比较了飞机... 详细信息

飞机草(Chromolaena odorata)是我国热带地区危害严重的外来入侵植物,为揭示适应进化对其成功入侵的贡献,在同质种植园中,比较研究了飞机草10个入侵地种群与12个原产地种群生长性状的差异,为排除奠基者效应的可能影响,进一步比较了飞机草10个入侵地种群与其原产地可能的祖先种群间的差异。结果表明,飞机草10个入侵地种群的基茎、株高、分枝数、生物量和比叶面积均显著高于12个原产地种群;与可能的祖先种群相比,飞机草10个入侵种群的生物量、分枝数和比叶面积仍更高。这些结果表明,在长期的入侵过程中飞机草通过进化提高了资源向生长的分配,支持增强竞争能力的进化假说。

关键词：飞机草同质种植园增强竞争能力的进化生长入侵