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Hot Deformation Behavior of a New 9%Cr Heat Resistant Steel G115

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Journal of Iron and Steel Research International 2013年第9期20卷 73-79页

作者： YAN Peng LIU Zheng-dong LIU Wei bao Han-sheng WENG Yu-qing Key Laboratory of Advanced Material of Ministry of Eclucation of China School of Materials Science and EngineeringTsinghua University Institute for Special Steels China Iron and Steel Research Institute

The hot deformation behavior of a new heat resistant steel Gl15 designed for 650 ℃ ultra-supercritical （USC） power plants was experimentally studied. Hot compression test was carried out in the temperature range of 900-1 200 ℃ and the strain rate range of 0.1-20 s i by using Gleeble 3800 thermal-mechanical simulator, and the corresponding flow curves were obtained. Experimental results show that the flow stress increases with the decrease of deformation temperature and the increase of strain rate. The hot deformation activation energy of G115 steel was determined to be 494 kJ/mol and the constitutive equation was also obtained. For convenience of the practical applica-tion, a good approximate equation was obtained for calculating the peak stress values of Gl15 steel under different deformation conditions. At the strain value of 0.9, natural logarithm of the critical Zener Hollomon parameter Zc of Gl15 steel was determined to be in the scope of 49.67 and 50.65, above which there will be no dynamic recrystalliza-tion （DRX）. And natural logarithm of the critical Zener-Hollomon parameter Zc of Gl15 steel was determined to be in the scopes of 45.58 and 46.27, below which full DRX may occur. Then, the status diagram of dynamic micro structures of G115 steel was established. In addition, the strain rate sensitivity of Gl15 steel is not constant during the test temperature range and it increases linearly from 900 to 1 200 ℃. Therefore, hot deformation at higher tem- peratures would obtain better workability.

关键词： heat resistant steel G115 hot deformation dynamic recrystallization constitutive equation Zener Hol-lomon parameter

New Sesquiterpenoids from Hedychium yunnanense gagnep

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Chinese Chemical Letters 2000年第11期11卷 1009-1012页

作者： Xiu Hua LIU dong bao ZHAO Chong Ren YANG Han qing WANG Chemistry and Chemical Engineering College of Henan University Kaifeng 475001 Phytochemistry Laboratory Kunming Instute of BotanyC.A.S.Kunming 650204 Lanzhou Institute of Chemical Physics C.A.SLanzhou 730000

Two new sesquiterpenoid trialcohol isomers named 1 beta, 4 alpha 11 alpha -trihydroxyeudesmane (1) and Yunnanensehedychetriol (2), were isolated from the fresh rhizomes of Hedychium Yunnanense gagnep. Their structures... 详细信息

关键词： Hedychium yunnanene Zingiberaceae sesquiterpenoid trialcohol isomers 1 beta,4 alpha,11 alpha-trihydroxyeudesmane Yunnanensehedychetriol

Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

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China Foundry 2024年第1期21卷 51-59页

作者： dong Pan qing-tao Guo Kai-lun Zhang Fu-zhi Yu Yu-ying Li Yu-bao Xiao State Key Laboratory of Metal Materials for Marine Equipment and Application Anshan 114009LiaoningChina Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting *** from conventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification *** this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding compared to traditional helical stirring *** a comprehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 *** higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of *** experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that compared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element *** SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.Consequently,SWHS holds great promise as a potential approach for improving the quality of continuous casting billets.

关键词： billet electromagnetic stirring helical solidification element segregation numerical simulation

Dynamic Mechanical Behavior and Hypervelocity Impact Performance of an Al-Based Nanocrystalline Alloy

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Acta Metallurgica Sinica(English Letters) 2017年第12期30卷 1169-1176页

作者： Shan-Shan Deng Gang Wang Run-qing Chi bao-Jun Pang dong-Jun Wang Jun Shen School of Materials Science and Engineering Harbin Institute of Technology Harbin China Laboratory for Microstructures Institute of MaterialsShanghai University Shanghai China National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin China Key Laboratory of Micro-Systems and Microstructures Manufacturing Ministry of Education Harbin China School of Materials Science and Engineering Tongji University Shanghai China

In a wide strain rate range from 10^-5 to 10^3s^-1, the deformation behavior of an Al-based nanocrystalline alloy was investigated. After fracture, the debris collected was used for statistical analysis, which is expected to reflect the profile of the fracture behavior of the alloy. The energy absorption of alloy at different strain rates was elucidated on account of mass distribution of debris. Based on the parameters obtained by the compression experiment at different strain rates, the numerical simulation experiment was carried out to evaluate the performance of Al-based nanocrystalline alloy as spacecraft shielding. The results suggest that Al-based nanocrystalline alloys have better shield performance than alu- minum alloy under the identical areal density at velocity of 1-7 km/s. The better shield performance is attributed to high fracture strength, high hardness and low toughness of Al-based nanocrystalline alloy as compared with those of aluminum alloy.

关键词： Nanostructure material Sintering Mechanical properties Computer simulation Spacecraft shielding

Human induced dryland degradation in Ordos Plateau,China,revealed by multilevel statistical modeling of normalized difference vegetation index and rainfall time-series

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Journal of Arid Land 2014年第2期6卷 219-229页

作者： Jing ZHANG JianMing NIU Tongliga bao Alexander BUYANTUYEV qing ZHANG JianJun dong XueFeng ZHANG College of Life Sciences Inner Mongolia University College of Environment and Resources Dalian Nationalities University Sino-US Center for Conservation Energyand Sustainability ScienceInner Mongolia University Faculty of Resources and Environment Baotou Teachers College Department of Botany and Plant Sciences University of California

Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index （NDVI） from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive （land restoration and re-vegetation） or negative （degradation） trends. Linear regressions were used to assess the accuracy of the multi- level statistical model. The results show that：（1） land restoration was the dominant process in the Ordos Plateau between 1998 and 2012; （2） the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man- agement in many parts of the Ordos; （3） compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi- nate some observed non-significant residual trends.

关键词： NDVl-rainfall relationship anthropogenic activities multilevel statistical modeling land degradation dryland Ordos Plateau

Two alternative modes for diffuse pollution control in Wuhan City Zoo

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Journal of Environmental Sciences 2007年第9期19卷 1067-1073页

作者： CHEN qing-feng SHAN bao-qing YIN Cheng-qing HU Cheng-xiao State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of Sciences Beijing 10085 China College of Resources and Environment Huazhong Agriculture University Wuhan 430050 China.

Pollution in urban zoos arises from diffuse and small point sources. However, its control has received little attention in past decades. Online and ofttine modes of ecological engineering technology were designed to control pollution from small point and diffuse sources in Wuhan City Zoo, China. Their characteristics and performances were investigated in sixteen runoff events from 2003 to 2005. The results showed that the two modes both improved runoff water quality and had high retention rates for water and pollutants. In the outflows, the event mean concentrations （EMCs） of total suspended solids （TSS）, chemical oxygen demand （COD）, total nitrogen （TN） and total phosphorus （TP） were reduced by 88%, 59%, 46% and 71% for the online mode, and those were 77%, 42%, 50% and 66% for the ofttine mode. The annual retention rates of pollutant loads for the online mode were 94.9%-98.5% in the three study years; those for the ofitine mode were 70.5%-86.4%. Based on calculation, the online mode was able to store the runoff of 66.7 mm rainfall completely, and the ofttine mode could store that of 31.3 mm rainfall. In addition, the online mode can provide an effective way for rainwater utilization and good habitats for aquatic wildlives, and has an excellent aesthetics value for recreationsal pastimes. The ofiline mode can save land resources and may be an effective and economical measure for diffuse pollution control in urban areas.

关键词： eutrophication runoff stormwater wetland zoo

Quantum Dissipative Threshold and Its Effect on Decay of Metastable State

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Communications in Theoretical Physics 2005年第4X期44卷 697-700页

作者： bao Jing-dong The Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal UniversityBeijing 100875 ChinaThe Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal UniversityBeijing 100875 China Department of Physics Beijing Normal University Beijing 100875 China

The coupling between system and reservoir is considered to be linear in the coordinates of the bath but nonlinear in the system's coordinate. A dissipative threshold is observed at finite temperatures due to nonlinear dissipation. The quantum decay rate of a metastable state including higher-order expanded terms of the coupling form function is proposed, which can be strongly decreased at finite temperatures when the quantum dissipative threshold is added to the saddle point of the potential.

关键词： threshold decay rate nonlinear dissipation quantum correction factor

安徽省高校《学生体质健康标准》实施网络管理的可行性研究

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四川体育科学 2004年第2期23卷 136-136,146页

作者：郜贻红钟晨张清鲍东毅芜湖师范专科学校体育系安徽芜湖241008

本文采用问卷调查、统计、INTERNET网络调查方法,通过对安徽省24所高校体育系部计算机情况、校园网络状况和实施《学生体质健康标准》等信息的研究,初步确定在安徽省高校实施《学生体质健康标准》网络化管理是可行,并提出相应的建议。

关键词：安徽高校《学生体质健康标准》网络化管理可行性研究教学模式教学管理

Pollutant loads of surface runoff in Wuhan City Zoo, an urban tourist area

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Journal of Environmental Sciences 2007年第4期19卷 464-468页

作者： ZHAO Jian-wei SHAN bao-qing YIN Cheng-qing State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The pollutant loads of surface runoff in an urban tourist area have been investigated for two years in the Wuhan City Zoo, China. Eight sampling sites, including two woodlands, three animal yards, two roofs and one road, were selected for sampling and study. The results indicate that pollutants ranked in a predictable order of decreasing load （e.g. animal yard〉roof〉woodland〉road）, with animal yards acting as the key pollution source in the zoo. Pollutants were transported mainly by particulate form in runoff. Particulate nitrogen and particulate phosphorous accounted on average for 61%, 78% of total pollutant, respectively, over 13 monitored rainfall events. These results indicate the treatment practices should be implemented to improve particulate nutrient removal. Analysis of the M（V） curve indicate that no first flush effect existed in the surface runoff from pervious areas （e.g. woodland, animal ground yard）, whereas a first flush effect was evident in runoff from impervious surfaces （e.g. animal cement yard, roof, road）.

关键词： surface runoff stormwater pollution urban tourist area impervious/pervious surface M(V) curve