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Arc and Droplet Behaviors in Horizontal Short-Arc Pulsed Gas Metal Arc Welding of 9%Ni Steel with ERNiCrMo-3 Welding Wire

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Journal of Shanghai Jiaotong university(Science) 2024年第2期29卷 361-376页

作者：刘轶玮华学明吴东升李芳蔡艳王欢杨修荣 Shanghai Key Laboratory of Material Laser Processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Hudong-Zhonghua Shipbuilding(Group)Co. Ltd.Shanghai 200129China Zhuhai Cowin Welding Equipment&Consumables Co. Ltd.Zhuhai 519015GuangdongChina

Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding *** of short-circuit current was used to reduce *** length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to ***-arc P-GMAW with or without arc length stabilizer was *** droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld *** the arc length stabilizer was deactivated,the arc length was unstable and too *** droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit *** was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit *** arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray *** spray transfer had the largest droplet impact,no short circuit and no *** the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were *** provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.

关键词： droplet transfer arc behaviors weld bead formation short-arc pulsed gas metal arc welding(P-GMAW) high nickel alloy 9%Ni steel

巴布亚褶皱带中生界海相油气充注史及成藏动态演化

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海洋地质与第四纪地质 2024年第4期44卷 155-167页

作者：谢睿林小云刘建吴东胜长江大学南方复杂页岩油气地质与开发湖北省重点实验室武汉430100 长江大学地球科学学院武汉430100

巴布亚盆地是处于澳大利亚板块北移和太平洋板块西移的活动边缘的中、新生代前陆盆地,巴布亚褶皱带是盆地西北部的次级构造单元,中生界油气资源丰富,勘探潜力巨大,但由于构造活动频繁使得油气聚集-调整过程复杂,严重制约了该地区油气勘... 详细信息

巴布亚盆地是处于澳大利亚板块北移和太平洋板块西移的活动边缘的中、新生代前陆盆地,巴布亚褶皱带是盆地西北部的次级构造单元,中生界油气资源丰富,勘探潜力巨大,但由于构造活动频繁使得油气聚集-调整过程复杂,严重制约了该地区油气勘探工作。在油气地球化学特征及来源分析的基础上,利用多种古温标的联合反演模拟了单井埋藏史和热史,基于储层流体包裹体分析了充注史,恢复油气成藏动态演化过程。结果表明:①巴布亚褶皱带中生界油气主要分布于褶皱带西段和中段,呈“西气东油”式分布。②油气充注期次可划分为“2期4幕”,早期3幕油气充注时间为105~85、78~53和47~32 Ma,表现为低熟油、高熟油和天然气的连续充注过程,包裹体捕获的原油成熟度更高、规则甾烷ααα(20R)-C_(27)相对含量更为丰富,油气来源于侏罗系烃源岩;晚期1幕油气充注时间为4~0 Ma,油气表现为“高熟油-天然气”混合充注并有低熟油补充的特征,现今储层原油成熟度低于早期原油且富含奥利烷,油气来源于侏罗系—白垩系烃源岩。③油气成藏受多期构造运动影响的烃源岩类型及演化程度、大规模圈闭发育、高效垂向-侧向输导体系和保存条件的控制,通过以构造演化为线索建立的“双源垂向侧向短距供烃-聚集调整过程动态平衡”油气成藏动态演化模式,提出了位于挤压推覆构造带下盘的白垩系烃源岩对中生代含油气系统同样具有烃源贡献的认识,以期为该地区下一步的油气勘探提供参考。

关键词：油气地球化学特征油气充注史成藏动态演化中生界巴布亚褶皱带

基于分形维数的高速铁路地震预警系统地震P波震相识别方法

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铁道学报 2024年第1期46卷 164-171页

作者：杨长卫张凯文吴东升张志方张良瞿立明西南交通大学土木工程学院四川成都610031 中国铁路武汉局集团有限公司湖北武汉430071 西南交通大学地球科学与环境工程学院四川成都611756

为更好保障高速铁路的运营安全,高速铁路地震预警系统的实施十分必要。5级以下的小震事件占据地震事件的95%以上,提高高速铁路预警系统在小震震相识别的速度与精度能有效保障高铁安全运营。提出一种基于分形维数的地震震相识别算法,优... 详细信息

为更好保障高速铁路的运营安全,高速铁路地震预警系统的实施十分必要。5级以下的小震事件占据地震事件的95%以上,提高高速铁路预警系统在小震震相识别的速度与精度能有效保障高铁安全运营。提出一种基于分形维数的地震震相识别算法,优化传统分形维数的计算方法,提高分形维数的计算速度。引入分形斜率曲线并划分为4个阶段,分析临界点的分形斜率特征,通过识别分形斜率极值时刻判断地震波精准到达时刻。提出的算法平均误差达到0.006 3 s,标准差达到0.043 8 s,满足高速铁路地震预警系统的时效性和准确度要求。

关键词：高速铁路地震预警 P波识别长时窗均值与短时窗均值之比赤池信息法则

Vulnerability of natural ecosystem in China under regional climate scenarios： An analysis based on eco-geographical regions

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Journal of Geographical Sciences 2014年第2期24卷 237-248页

作者： ZHAO dongsheng wu Shaohong Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

Assessment of vulnerability for natural ecosystem to climate change is a hot topic in climate change and ecology, and will support adapting and mitigating climate change. In this study, LPJ model modified according to features of China＇s natural ecosystems was em- ployed to simulate ecosystem dynamics under A2, B2 and A1B scenarios. Vulnerability of natural ecosystem to climate change was assessed according to the vulnerability assessment model. Based on eco-geographical regions, vulnerability of natural ecosystem to climate change was analyzed. Results suggest that vulnerability for China＇s natural ecosystems would strengthen in the east and weaken in the west, but the pattern of ecosystem vulner- ability would not be altered by climate change, which rises from southeast to northeast gradually. Increase in ecosystem vulnerable degree would mainly concentrate in temperate humid/sub-humid region and warm temperate humid/sub-humid region. Decrease in eco- system vulnerable degree may emerge in northwestern arid region and Qinghai-Tibet Plateau region. In the near-term scale, natural ecosystem in China would be slightly affected by cli- mate change. However, in mid-term and long-term scales, there would be severely adverse effect, particularly in the east with better water and thermal condition.

关键词： climate change natural ecosystem vulnerability regional climate scenarios

Uniform dimension results for Gaussian random fields

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Science China Mathematics 2009年第7期52卷 1478-1496页

作者： wu dongsheng XIAO YiMin Department of Mathematical Sciences University of Alabama in HuntsvilleHuntsvilleAL 35899USA Department of Statistics and Probability Michigan State UniversityEast LansingMI 48824USA College of Mathematics and Computer Science Anhui Normal UniversityWuhu 241000China

Let X = {X(t), t ∈ ? N } be a Gaussian random field with values in ? d defined by (1) $$ X(t) = (X_1 (t),...,X_d (t)),\forall t \in \mathbb{R}^N . $$ . The properties of space and time anisotropy of X and their connections to uniform Hausdorff dimension results are discussed. It is shown that in general the uniform Hausdorff dimension result does not hold for the image sets of a space-anisotropic Gaussian random field X.When X is an (N, d)-Gaussian random field as in (1), where X 1,...,X d are independent copies of a real valued, centered Gaussian random field X 0 which is anisotropic in the time variable. We establish uniform Hausdorff dimension results for the image sets of X. These results extend the corresponding results on one-dimensional Brownian motion, fractional Brownian motion and the Brownian sheet.

关键词： anisotropic Gaussian random fields sectorial local nondeterminism image Hausdorff dimension 60G15 60G17 60G60 42B10 43A46 28A80

基于LSTM-CNN的双路径滚动轴承故障诊断

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沈阳理工大学学报 2024年第1期43卷 44-49页

作者：景斯桐吴东升沈阳理工大学自动化与电气工程学院沈阳110159

针对轴承故障诊断中特征提取对人工依赖性强、特征提取不准确、对振动信号中的时间信息不敏感的问题,提出一种基于长短时记忆网络(LSTM)和卷积神经网络(CNN)结合的双路径递归神经网络方法,该方法对振动等原始信号进行处理,捕获时间序列... 详细信息

针对轴承故障诊断中特征提取对人工依赖性强、特征提取不准确、对振动信号中的时间信息不敏感的问题,提出一种基于长短时记忆网络(LSTM)和卷积神经网络(CNN)结合的双路径递归神经网络方法,该方法对振动等原始信号进行处理,捕获时间序列数据中的远距离依赖关系,并引入注意力机制,抑制输入信号的高频噪声,使模型关注关键信息,提高模型训练效率。在凯斯西储大学轴承故障数据集上的实验结果表明,该方法能有效提升轴承故障识别率,具有良好的故障分类能力。

关键词：故障诊断注意力机制长短时记忆网络卷积神经网络

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基于ECAProNet模型的小样本变工况轴承故障诊断

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沈阳理工大学学报 2024年第1期43卷 22-27页

作者：王勉吴东升王笑臣沈阳理工大学自动化与电气工程学院沈阳110159

针对小样本变工况轴承故障诊断中易出现过拟合的问题,提出一种在原型网络(ProNet)中加入高效通道注意力机制(ECA)的轴承故障诊断方法(ECAProNet)。基于度量学习的思想,在改进原型网络框架下将通过特征提取模块的样本信号映射至特征度量... 详细信息

针对小样本变工况轴承故障诊断中易出现过拟合的问题,提出一种在原型网络(ProNet)中加入高效通道注意力机制(ECA)的轴承故障诊断方法(ECAProNet)。基于度量学习的思想,在改进原型网络框架下将通过特征提取模块的样本信号映射至特征度量空间,在该空间内确定查询样本与各类原型间的欧式距离,得到损失函数,进而优化特征提取网络框架;为达到元学习目的,采用基于episodes的训练策略,将算法泛化到不同工况的测试诊断中。在CWRU数据集上设置5-way 5-shot和5-way 1-shot验证实验,结果表明,ECAProNet在小样本变工况轴承故障诊断中表现出较好的性能。

关键词：故障诊断小样本学习变工况原型网络高效通道注意力机制

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基于地震P波初至2 s功率信息的高速铁路地震预警系统快速震级估算方法

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铁道学报 2024年第7期46卷 167-173页

作者：杨长卫张凯文吴东升张志方张良瞿立明西南交通大学土木工程学院四川成都610031 中国铁路武汉局集团有限公司湖北武汉430012 西南交通大学地球科学与环境工程学院四川成都611756

震级估算是高速铁路地震预警系统的关键技术参数,更加快速、准确的震级估算模型能够更好地保障人民的生命财产安全。利用日本K-net强震动数据,建立基于地震P波到达后携带功率信息的地震动衰减模型并用于震级估算,并将本文算法与传统算... 详细信息

震级估算是高速铁路地震预警系统的关键技术参数,更加快速、准确的震级估算模型能够更好地保障人民的生命财产安全。利用日本K-net强震动数据,建立基于地震P波到达后携带功率信息的地震动衰减模型并用于震级估算,并将本文算法与传统算法对比。结果表明,在1~5 s的时间窗下,模型的震级估算误差均明显小于传统的方法,且小震高估现象也明显改善;随着时窗长度的增加,模型的震级估算误差及标准差也逐渐降低,实现率也逐步提升,在1 s的时窗长度下,模型的单台震级估算实现率满足规范要求;对7级以下地震,模型的震级估算实现率可在地震P波到达1 s后满足规范要求;对7级以上地震,模型的震级估算实现率可以在地震P波到达2 s后满足规范要求。

关键词：高速铁路地震预警震级估算

Modeled effects of climate change on actual evapotranspiration in different eco-geographical regions in the Tibetan Plateau

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Journal of Geographical Sciences 2013年第2期23卷 195-207页

作者： YIN Yunhe wu Shaohong ZHAO dongsheng ZHENG Du PAN Tao Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

From 1981 to 2010, the effects of climate change on evapotranspiration of the alpine ecosystem and the regional difference of effects in the Tibetan Plateau （TP） were studied based on the Lund-Potsdam-Jena dynamic vegetation model and data from 80 meteorological stations. Changes in actual evapotranspiration （AET） and water balance in TP were analyzed. Over the last 30 years, climate change in TP was characterized by significantly increased temperature, slightly increased precipitation, and decreased potential evapotranspiration （PET）, which was significant before 2000. AET exhibited increasing trends in most parts of TP. The difference between precipitation and AET decreased in the southeastern plateau and increased in the northwestern plateau. A decrease in atmospheric water demand will lead to a decreased trend in AET. However, AET in most regions increased because of increased precipitation. Increased precipitation was observed in 86% of the areas with increased AET, whereas decreased precipitation was observed in 73% of the areas with decreased AET.

关键词： evapotranspiration LPJ model climate change Tibetan Plateau