检索结果-南通市图书馆

Microstructure Variation and Hardness Diminution During Low Cycle Fatigue of 55NiCrMoV7 Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2007年第6期14卷 68-73页

作者： ZHANG zhan ping qi yu-hong DELAGNES Denis BERNHART Gerard Electro Mechanics and Materials College Dalian Maritime University Dalian 116026 Liaoning China Research Center on Tools Materials and Processes Ecole des Minesd＇Albi Carmaux 81013 Albi CT cedex 09 France

The influence of temperature and hardness level on the cyclic behavior of 55NiCrMoV7 steel, and the mierostrueture variation and hardness diminution during low cycle fatigue behavior were investigated. By means of SEM and XRD, the modality of carbides and the full width half-maximum （FWHM） of martensite （211） [M（211）] of Xray diffraction spectrum in fatigue specimen were studied. The results showed that the cyclic stress response behav ior generally showed an initial exponential softening for the first few cycles, followed by a gradual softening without cyclic softening saturation. The fatigue behavior of the steel is closely related to the hardness level. The hardness diminution and the variation of half-width M（211） are remarkably influenced by the interaction between the cyclic plastic deformation and the thermal loading when the fatigue temperature exceeds the tempering temperature of the steel.

关键词： low cycle fatigue 55NiCrMoV7 steel microstructure hardness half width

Comparison of Aerosol Single Scattering Albedo Derived from the Ozone Monitoring Instrument with Aerosol Robotic Network Observations

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2012年第3期5卷 264-269页

作者： LIU qi hong yu-Lan School of Earth and Space Sciences University of Seience and Technology of China Hefei 230026 China

The single-scattering albedo （SSA）, which quantifies radiative absorption capability, is an important optical property of aerosols. Ground-based methods have been extensively exploited to determine aerosol SSA but there were no satellite-based SSA measurements available until the advent of advanced remote sensing techniques, such as the Ozone Monitoring Instrument （OMI）. Although the overall accuracy of OMI SSA is estimated to approach 0.1, its regional availability is unclear. Four-year SSA daily measurements from three Aerosol Robotic Network （AERONET） sites in China （Xianghe, Taihu, and hong Kong） are chosen to determine the accuracy of OMI SSA in specific locations. The results show that on a global scale, the OMI SSA is systematically higher （with a mean relative bias of 3.5% and a RMS difference of ~0.06） and has poor correlation with the AERONET observations. In the Xianghe, Taihu, and hong Kong sites, the correlation coefficients are 0.16, 0.47, and 0.44, respectively, suggesting that the distinct qualities of OMI SSA depend on geographic locations and/or dominant aerosol environments. The two types of SSA data yield the best agreement in Taihu and the worst in hong Kong; the differing behavior is likely caused by varying levels of cloud contamination. The good consistency of the aerosol variation between the two SSA datasets on a seasonal scale is promising. These findings suggest that the current-version OMI SSA product can be applied to qualitatively characterize climatological variations of aerosol properties despite its limited accuracy as an instantaneous measurement.

关键词： aerosol single scatter albedo OMI AERONET

Identification and Characterization of 43 Microsatellite Markers Derived from Expressed Sequence Tags of the Sea Cucumber (Apostichopus japonicus)

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2011年第2期10卷 185-190页

作者： JIANG Qun LI qi yu hong KONG Lingfeng Fisheries College Ocean University of China Qingdao 266003 China

The sea cucumber Apostichopus japonicus is a commercially and ecologically important species in China. A total of 3056 potential unigenes were generated after assembling 7597 A. japonicus expressed sequence tags (ESTs) downloaded from Gen-Bank. Two hundred and fifty microsatellite-containing ESTs (8.18%) and 299 simple sequence repeats (SSRs) were detected. The average density of SSRs was 1 per 7.403 kb of EST after redundancy elimination. Di-nucleotide repeat motifs appeared to be the most abundant type with a percentage of 69.90%. Of the 126 primer pairs designed, 90 amplified the expected products and 43 showed polymorphism in 30 individuals tested. The number of alleles per locus ranged from 2 to 26 with an average of 7.0 alleles, and the observed and expected heterozygosities varied from 0.067 to 1.000 and from 0.066 to 0.959, respectively. These new EST-derived microsatellite markers would provide sufficient polymorphism for population genetic studies and genome mapping of this sea cucumber species.

关键词： sea cucumber Apostichopus japonicus microsatellite EST

Microstructures and Hardness of 8CrWMoV Steel with Multiple Types of Ultra Fine Carbides

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 279-283页

作者： DAIyu-mei ZHANGZhan-ping MAYong-qing qiyu-hong LIUYan-xia yuTao Instituteofmaterialsandtechnology DalianMaritimeUniversityDalian116026

The structure and hardness of 8CrWMoV steel with multiple types of ultra fine carbides are studied after annealing, quenching and tempering in this paper. The results show that multiple types of carbides M3C, M7C3, M23C6, M6C and MC were observed in the annealed steel. Nucleation and coalescence of new carbides, partial dissolution of original carbides in γ phase region during annealing at 800～840℃, result in ultra-fine carbides. Average size of the carbides is0.33～0.34μm in the steel annealed at 800～840℃. Because M3C and M23C6 dissolve easily in austenite, the high hardness HRC63～65 can be obtained by quenching at 840～860℃. Un-dissolved carbides M6C and MC (VC) can effectively prevent the coarsening of austenitic grain, and conduce to obtain very fine martensite. The retained austenite can be easy to decompose during tempering at low and middle temperature due to the precipitation of multiple types of carbides and the good tempering-resistance of the steel is obtained. The microstructure and property of the steel after heat treatment can be accurately explained by calculating based on phase equilibrium *** Words: 8CrWMoV steel, ultra-fine carbide, heat treatment, microstructure,

关键词：显微结构 8CrWMoV钢超细硬质合金硬度热处理

在线全文

学校读者我要写书评

暂无评论

论王安忆小说中的派生词

四川师范大学学报（社会科学版） 2011年第2期38卷 94-99页

作者：于启宏长沙理工大学中文系长沙410004

在王安忆小说中词性转换和词语派生是一个普遍现象。从三组统计数据可见:其一,48例句的句焦点在宾语位上;其二,48例句的句盲点在谓语的关系位上。综合所有数据得出的初步结论是:谓动词失重,句子的平衡点向句尾移动。依据文本系统表重新... 详细信息

在王安忆小说中词性转换和词语派生是一个普遍现象。从三组统计数据可见:其一,48例句的句焦点在宾语位上;其二,48例句的句盲点在谓语的关系位上。综合所有数据得出的初步结论是:谓动词失重,句子的平衡点向句尾移动。依据文本系统表重新整理这些派生词例句,叙述句与非叙述句各有48个。在非叙述句领域,叙述人不能完全控制被叙述人;后者可以在局域游离叙述人言筌,从而得以充分展露被叙述人的精神内涵。无论是少数的派生词句子还是多数的非派生词句子都源自同一叙述理念:降低文本中的叙述句数量。派生词的价值体现在语言的创新上,也体现在人物的创新上。

关键词：王安忆小说词性转换词语派生句型

在线全文

学校读者我要写书评

暂无评论

支气管哮喘和慢性阻塞性肺疾病的异同

中华结核和呼吸杂志 2006年第6期29卷 407-409页

作者：俞绮虹刘昌起天津市胸科医院胸内科 300051

支气管哮喘(简称哮喘)和慢性阻塞性肺疾病(COPD)的关系一直是呼吸科关注和探讨的话题,二者在基因、病理、生理和临床等众多方面拥有许多异同.

关键词：慢性阻塞性肺疾病(COPD) 支气管哮喘异同呼吸科临床等

在线全文

学校读者我要写书评

暂无评论

一类非线性系统的执行器偏差故障诊断

系统工程与电子技术 2006年第10期28卷 1563-1565页

作者：夏扬曹松银于启宏邱宏扬州大学信息工程学院江苏扬州225009

针对一类具有系统建模误差,以及含传感器模型不确定项的非线性控制系统,提出了一种用于执行器故障诊断的观测器方法。观测器中引入自适应补偿项,当出现偏差后将对故障及建模不确定项进行补偿。自适应算法中采用了死区算子,增强了算法的... 详细信息

针对一类具有系统建模误差,以及含传感器模型不确定项的非线性控制系统,提出了一种用于执行器故障诊断的观测器方法。观测器中引入自适应补偿项,当出现偏差后将对故障及建模不确定项进行补偿。自适应算法中采用了死区算子,增强了算法的鲁棒性。同时利用自适应律进行偏差估计。理论分析证明观测器的观测误差收敛到零。仿真结果表明了方法的有效性。

关键词：执行器偏差故障检测故障诊断自适应补偿

在线全文

学校读者我要写书评

暂无评论

甲基硅油对有机硅防污涂层表界面特性的影响

材料工程 2015年第4期43卷 59-65页

作者：巴淼张占平齐育红大连海事大学船机修造工程实验室辽宁大连116026

以羟基封端的聚二甲基硅氧烷为主要成膜物,添加不同分子量和添加量的甲基硅油制备有机硅防污涂料。结果表明:甲基硅油的分子量越小、添加量越大,涂层的水接触角和二碘甲烷接触角越大,表面自由能越小;涂层的弹性模量随硅油分子量的减小... 详细信息

以羟基封端的聚二甲基硅氧烷为主要成膜物,添加不同分子量和添加量的甲基硅油制备有机硅防污涂料。结果表明:甲基硅油的分子量越小、添加量越大,涂层的水接触角和二碘甲烷接触角越大,表面自由能越小;涂层的弹性模量随硅油分子量的减小而降低,在A组分中,硅油添加量占13%(质量分数,下同)时,弹性模量最小;附着生物的相对结合力随着硅油分子量的增加而增大,随着硅油含量的增加而降低;海水浸泡期间,硅油中的甲基与水分子发生氢键作用,从而使得甲基的峰位变宽,涂层的疏水性降低;所有涂层在空气中静置一年,只有添加分子量为1750甲基硅油的未浸泡海水涂层表面观测到硅油的渗出,且硅油渗出量与添加量成正比。

关键词：有机硅甲基硅油涂层性能浸泡

在线全文

学校读者我要写书评

暂无评论

一种协同的FCPM模糊聚类算法

模式识别与人工智能 2010年第1期23卷 120-126页

作者：祁宏宇吴小俊王士同杨静宇江南大学信息工程学院无锡214122 南京理工大学计算机科学与技术学院南京210094

比重隶属度模糊聚类(FCPM)算法可从不同角度解决聚类问题,取得较好效果.协同聚类算法利用不同特征子集之间的协同关系,并与其它聚类算法相结合,可提高原有的聚类性能.文中在FCPM聚类算法的基础上进行改进,将其与协同聚类算法相结合,提... 详细信息

比重隶属度模糊聚类(FCPM)算法可从不同角度解决聚类问题,取得较好效果.协同聚类算法利用不同特征子集之间的协同关系,并与其它聚类算法相结合,可提高原有的聚类性能.文中在FCPM聚类算法的基础上进行改进,将其与协同聚类算法相结合,提出一种协同的FCPM聚类算法.该算法在原有FCPM聚类算法的基础上,提高对数据集的聚类效果.在对数据集Wine和Iris进行测试的结果表明,该方法优于FCPM算法,说明该方法的有效性.

关键词：比重隶属度模糊聚类(FCPM) 模糊C均值(FCM) 协同模糊聚类