蒸汽过热器管断裂失效分析

某奥氏体不锈钢制蒸汽过热器管在加碱煮炉过程中发生断裂。采用力学性能测定、宏微观检验及能谱分析,对该断裂管进行了分析研究。结果表明,蒸汽过热管断裂失效是由碱脆造成的。     

多头注意力记忆网络的对象级情感分类

细粒度的情感分类任务需要识别文本当中与评论对象相关度最高的观点词并进行情感极性分类.文中利用多头注意力机制改进记忆网络,提取不同对象情感分类特征,实现对象级情感分类.将文本的词嵌入向量存储在记忆组件中,使用多头注意力机制在多个特征空间同时建模文本整体语义与对象相关语义.利用前馈网络层整合多个特征空间下的信息作为分类特征.在SemEval-2014数据集及扩充的数据集上实验表明,文中方法有利于缓解方法的选择性偏好.     

多条重叠与近间距盾构隧道施工控制及效果分析

本文以武汉地铁二号线及四号线洪中区间隧道为背景,针对多条重叠隧道小间距的特点,提出盾构隧道“先下后上”的总体施工原则,重点阐述了盾构掘进控制、夹层土注浆加固和洞内临时支撑隧道加固等关键措施,通过监测结果有效验证了其成功,可为今后的重叠隧道设计、施工管理提供经验借鉴。     

Nonlinear wave theory in reliability analysis of offshore structures

The reliability analysis of offshore structures under wave and wind actions is considered using second order random wave theory. To represent non-Gaussian properties of the resulting wave kinematics, the Hermite moment transformation is used. Further, the so-called sample-specific linearization method developed already (to be used in conjunction with the directional simulation method and the linear wave theory) will be extended to take into account both (1) non-Gaussianity of wave/wind load due to nonlinear load processes and also (2) the non-Gaussianity of wave kinematics due to the nonlinear wave theory. This allows an out-crossing approach to be used to assess the structural probability of failure and the involving out-crossing rate (which is not generally available for non-Gaussian processes) is required to be estimated. Using the proposed procedure, simple structures are analyzed in one- and multi-dimensional cases and the results for structural probability of failure are compared with those obtained using simple linear wave theory. Outcomes show that the use of nonlinear wave theory may affect the results considerably.     

高压汽包炉水冷壁爆管原因分析

通过爆口试件的金相分析、垢样扫描电镜及能谱分析和X射线衍射分析,结合对实际运行状况的调查,确定水冷壁爆管损坏的原因是由于排污不畅和停用腐蚀导致的介质浓缩下的碱腐蚀。针对碱腐蚀的主要原因,提出了相应的处理措施。     

利用六序分量复合序网法分析同杆双回线断线故障的新方法

本文结合双回线的特点，引入了六序故障分量，推导出同杆双回线各种断线故障的六序分量解析表达式，由此提出了六序复合序网分析双回线断线故障的新方法，此方法在分析双回线的断线时非常简单，并且六序故障分量之间的相位关系和幅值关系在复合序网中直观地表现出来，通过EMTP仿真计算证明了本文所提方法的正确性。     

Japanese Teaching Quality Satisfaction Analysis with Improved Apriori Algorithms under Cloud Computing Platform

In this paper, we use modern education concept and satisfaction theory to study the construction of a system used to evaluate Japanese teaching quality based on a satisfaction model. We use a cloud computing platform to mine the rules of Japanese teaching quality satisfaction by using an improved Apriori algorithm to explore the impact of measurement indicators of teaching objectives, processes and results on overall satisfaction with Japanese teaching practices, so as to improve Japanese teaching in the future. Scientific decision-making, improvement of teaching practices, transformation and innovation of students’ learning methods provide data reference and theoretical support.     

基于现有结构的空压机的改造设计

针对无法完全发挥效能的某厂二手空压机设备 ,结合厂方提出的改造目标 ,提出可在现有总体结构布置的情况下 ,采用通流能力好的三元叶轮、增加流道宽度等措施进行结构改造。经编制热力设计程序进行分析计算 ,结果表明这一方案切实可行     

蒸汽加热器弯头对焊焊缝开裂失效分析

利用光学显微镜、扫描电镜、电子能谱仪等测试手段,从材料成分、微观组织、断口形貌以及腐蚀产物成分等角度,分析了蒸汽加热器弯头对焊焊缝开裂失效的原因——系统操作过程中碱液进入蒸汽加热器所引起的应力腐蚀所致,同时提出了避免蒸汽加热器弯头对焊焊缝开裂失效的防护措施。     

GIS在公共气象服务网站的应用

给出以GIS分析为核心的公共气象服务网站框架。阐述GIS与多时空尺度气象要素间的相互关系,GIS在系统逻辑分层中的位置,一维、二维、三维分析图的网页功能。同时对GIS应用中所面对的一些关键技术进行了深入分析。如含权地理边界预剪裁气象要素插值算法、netCDF文件产生、二维和三维可视化技术等等。该套系统已经在中国天气网、四川气象网、成都公共气象服务网等网站中得到应用。