非标件压力管道加厚弯头凹坑腐蚀超声相控阵检测的应用

本文应用超声波相控阵技术,对非标件的压力管道加厚弯头凹坑腐蚀减薄进行了检测。检测发现,加厚弯头因其内部凹槽腐蚀特殊性,普通超声波测厚无法完成,而相控阵技术因其探头晶片聚焦功能可实现对加厚弯头腐蚀凹坑的识别,相控阵检测图像信号清晰完整,最后对检测有异常信号的弯头进行解剖,发现相控阵检测的缺陷信号与非标件弯头凹坑缺陷相符合,为今后检测非标件压力管道加厚弯头内部凹坑缺陷提供了有效的技术支持。     

Role of alloyed silicon and some inorganic inhibitors in the inhibition of meta-stable and stable pitting of Al in perchlorate solutions

The study of both meta-stable and stable pitting events on the surface of pure Al and three Al–Si alloys, namely (Al + 6%Si), (Al + 12%Si) and (Al + 18%Si) alloys, was carried out in deaerated neutral NaClO₄ solutions of various concentrations (10⁻⁴–10⁻² M). Measurements were carried out under the effect of various experimental conditions using potentiodynamic anodic polarization and potentiostatic techniques. The results presented below showed that meta-stable pits (appeared as oscillations in current) form at potentials close to the pitting potential (E _pit) and during the induction time for stable pit formation. Various factors affecting the rate of meta-stable and stable pits were studied. The presence of Si as an alloying element in Al reduces the rate of formation of meta-stable pits, corresponding to a reduction in the probability of developing stable pits, and an increase in the pitting potential results. The inhibitive effects of chromate, silicate, molybdate and tungstate on pitting corrosion in Al were also studied. Results obtained showed that these known inhibitors retard both meta-stable and stable pitting events. This makes attainment of stable pit growth more difficult in presence of these inhibitors.

Pitting mechanism on an austenite stainless steel nanocrystalline coating investigated by electrochemical noise and in-situ AFM analysis

The pitting corrosion behavior of an austenite stainless steel with polycrystalline (PC) and nanocrystalline (NC) microstructure in 3.5% NaCl solution was investigated by electrochemical noise (EN) and in-situ atomic force microscopy (AFM) under anodic potential. The power spectral density (PSD) and wavelet transform have been employed to analyze the EN data. The pitting corrosion resistance of the NC coating was much higher than that of the PC alloy, with different pitting mechanisms observed for both specimens; a slow metastable pit generation and healing for the PC alloy and a fast metastable pit initiation and death for the NC coating. There was good conformity between the EN and the in-situ AFM analysis. The pitting corrosion mechanism has been discussed according to the EN analysis and the in-situ AFM observations.     

End-point detection of copper super-filling in small features under a potentiostatic mode of operation

Copper filling of small features using a potential-controlled technique in electrolytic bath containing organic additives in a selected potential range is shown to be highly beneficial. End-points filling detection in features with width of less than 150 nm are observed in the current-time profile. This behavior is obtained once potential is applied in a selected potential range, capable of providing efficient copper deposition suppression on flat wafer surface sites. Thus, achieving a controlled feature filling with a clear end-point of copper super-filling with minimum copper overburden is feasible in a potentiostatic operation mode. Copper filling rate depends primarily on the selected potential value and the feature dimension characteristics (aspect ratio). Selective copper filling during potentiostatic deposition is favorable (over galvanostatic deposition) in high aspect ratio patterned wafers. Illustrations of i-t curve profiles during copper super-filling of complex wafer patterns in a potentiostatic mode are presented.     

动态设计及信息化施工在基坑支护中的应用

结合基坑支护的工程实例,简要介绍了基坑在土方开挖过程中进行动态设计、信息化施工的全过程,通过监测反馈的信息,分析了造成基坑变形的原因,并提出了相应的处理措施,以确保基坑支护工程的顺利进行。     

酒精活性干酵母与糖化酶在大曲酒压窖后转排生产中的应用

研究酒精活性干酵母、糖化酶在大曲酒压窖后转排生产中应用.实践证明,试验窖与对照窖相比,出窖酒醅的平均酸度、水分分别增加了1.31%和6.33%,淀粉浓度平均下降7.14%,酒精度平均达3.43%Vol,比对照窖高1.30%Vol;试验窖产出的基酒总酯、总酸及各微量成分含量较高,四大酯之间的比例较合理,复合香特征突出,香味正、口感好,酒质明显优于对照窖产酒,出酒率比对照窖平均提高6.09%;经济效益较好.(孙悟)     

应用VISUAL BASIC开发过程控制型专家系统工具

为适应现代工业生产过程自动化的需要,本文开发了一个结构简单、界面友好、用于过程控制的专家系统工具Visual Basic Expert System Tool(简称：VB-EST)。此工具用Visual Basic语言开发完成,它包括如下三个部分：1．知识库、2．推理机、3．跟踪及帮助。本文已用VB－EST工具成功地开发了均热炉群调度管理专家系统,其速度较高、效果良好。     

浓香型大曲酒窖池改造

浓香型大曲酒生产中,泥窖的优劣对酒质有重要的影响,本厂窖泥老化现象与窖型设计,建筑有密切的关系,对原窖进行改造,二窖合一,去掉中间的间壁,改原窖直立窖壁为斜窖壁,便于敷设窖泥,同时增加投粮量,提高窖帽高度,有利于保养窖泥,生产试验表明,新窖池产酒质量不亚于老窖池,产量产老窖池有所提高。（一平）     

董酒小窖发酵工艺参数变化分析

董酒生产工艺使用小曲小窖制酒醅,产酒工艺是董酒生产的重要组成部分,在小窖发酵工艺过程中,酒醅的水分、温度、酸度、淀粉、还原糖等工艺参数的变化至关重要,对董酒的品质、产量有着重要的影响。本研究对董酒小曲小窖酿酒工艺参数变化进行跟踪分析。     

High‐strength steel wires containing corrosion pits: stress analysis and critical distance based fatigue life estimation

The present paper deals with the problem of assessing the fatigue lifetime of high‐strength steel wires containing corrosion pits, with this investigation being based on a large number of experimental data selected from the technical literature. To evaluate the stress concentration phenomena characterising corroded metallic wires, according to the state‐of‐the‐art knowledge, pits were modelled either as semi‐ellipsoidal cavities or as hemispherical notches. The stress concentration factors, K_t, associated with these simplified pit geometries were calculated numerically by solving numerous three‐dimensional FE models. Subsequently, the K_t values being determined according to this standard numerical procedure were post‐processed systematically to derive simple analytical solutions suitable for estimating, in situations of engineering interest, the stress concentration factors associated with pitting corrosion. Finally, after making some assumptions to derive the necessary fatigue properties, the Theory of Critical Distances was used in the form of the Point Method and the Line Method to reanalyse the literature data being collected. This systematic validation exercise allowed us to prove that the Theory of Critical Distances is successful also in assessing the fatigue lifetime of high‐strength metallic cables containing corrosion pits, with the obtained estimates falling within an error factor of 3. Therefore, as far as wires weakened by corrosion pits are concerned, it was demonstrated that the Theory of Critical Distances can be used to post‐process the local linear‐elastic stress fields when they are not only determined numerically but also estimated by using those standard analytical solutions which are strictly valid solely for conventional notches.