Localized corrosion of (lean) duplex stainless steels in immersion units of urban wastewater treatment plants

With lower alloying cost and higher mechanical properties, lean duplex stainless steels can be an alternative to the more commonly used austenitic stainless steels. However, these alloys are still not the preferred choice, probably due to a lack of field experience. A study was thus initiated in view of defining the limits of use of selected (lean) duplexes for urban wastewater treatment units. The present paper shows the localized corrosion performance of selected lean duplexes in chloride contaminated solutions. The results are compared with austenitic S30403 and S31603 and with the more standard duplexes S82441 and S32205. The effect of welding was also investigated. Exposures in field municipal wastewater plants were conducted for 1 year in low and high chloride content units. The results show that lean duplexes S32101 and S32202 can be used as alternatives to S30403 and S31603 in low chloride electrolytes. At 500 ppm of chloride content, duplex stainless steel S32304 showed better corrosion resistance than S30403 and S31603. For higher chloride contents (1000 ppm and above) the standard duplexes S82441 and S32205 shall be preferred.     

建筑陶瓷企业实施精益生产研究

分析了建筑陶瓷企业实施精益生产的条件和当前推行精益生产的主要障碍，对应用中存在的问题进行了分析并提出了相关建议。     

电机智能制造发展现状及推进策略

随着电机制造要求逐步提高、自动化逐渐普及,智能制造将成为未来主流的生产制造模式。基于对传统电机制造现状和发展趋势的分析,厘清智能制造优势及智能制造推进误区,概括智能制造推进内容及策略。以江苏大中电机股份有限公司相关项目为例,介绍智能制造的侧重内容、实施步骤、原则及实施成果。结果表明：总体生产效率提高了35.75%,生产运营成本降低了26.21%,产品不良率降低了75.84%。在此基础上概括电机行业智能制造推进参考战略,为中小型电机行业发展提供支持。     

The role of NO2 in the reduction of NO by hydrocarbon over Cu-ZrO2 and Cu-ZSM-5 catalysts

The reduction of NO _x with propene or propane in the presence of 1 or 4% O₂ was studied at low conversions over a 7.4 wt% Cu-ZrO₂ and a 3.2 wt% Cu-ZSM-5 catalyst. The rates of N₂ production were compared in experiments using only NO or a mixture of NO and NO₂ in the feed. They were also compared with the rates of NO₂ reduction to NO under the same conditions, and of NO oxidation to NO₂ in the absence of hydrocarbon. It was found that the reduction of NO₂ to NO was very fast, consistent with literature data. The data were best explained by a reaction scheme in which the hydrocarbon was activated primarily by reaction with adsorbed NO₂ to form an adsorbed oxidized N-containing hydrocarbon intermediate, the reaction of which with NO was the principal route to produce N₂ under lean NO _x conditions.On leave from State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.     

贫瘦煤替代瘦煤制备优质焦炭性能研究

根据瘦煤和贫瘦煤结焦机理、成焦显微结构和粒度变化特征,对贫瘦煤替代瘦煤的结焦显微结构、焦炭性能进行了研究。结果表明,瘦煤与贫瘦煤可以互相替代,并且在合理配比的情况下可改善焦炭质量;通过合理的粒度调整和配煤,在提高贫瘦煤或瘦煤比率的同时亦可得到优质焦炭。     

Efficient Reduction of NO x by H2 Under Oxygen-Rich Conditions over Pd/TiO2 Catalysts: An in situ DRIFTS Study

The H₂/NO/O₂ reaction under lean-burn conditions has been studied by means of in situ DRIFTS, reactor measurements and temperature-programmed desorption with the aim of understanding the very different behavior of Pd/TiO₂ and Pd/Al₂O₃ catalysts. The former deliver very high NO _x conversions (70-80%) with good N₂ selectivity whereas the latter show very low activity. In addition, PdTiO₂ exhibits two distinct NO _x reduction pathways, thus greatly extending the useful temperature range. It is shown that the PdTiO₂ low-temperature channel involves adsorption and subsequent dissociation of NO on reduced (Pd⁰) metal sites. The low activity of PdAl₂O₃ is a consequence of palladium remaining in an oxidized state under reaction conditions. The high-temperature NO reduction channel found with PdTiO₂ is associated with the generation and subsequent reaction of NH _x species.     

配贫瘦煤炼焦的探讨与实践

介绍了在生产性实验中配加不同比例的贫瘦煤炼焦对焦炭强度的影响 ,最经济合理的配煤比可使焦炭的强度有一定改善。     

战略网络形成动因之制造模式篇

本研究目的在于探究战略网络生成中制造模式的推动作用。文章首先分析了制造模式在技术经济范式变迁中扮演的角色,总结出制造模式与技术经济范式之间的关系,接着运用数学抽象和哲学思辨的方法,提炼出人类历史上三次制造模式对技术经济范式的价值实现函数。基于该函数研究发现:精益生产中目的在于充分调动人的主观能动性,以实现人的解放的复合机制——现场管理、劳工关系管理和知识管理等体系是制造模式未来的发展方向;战略网络的演进服务于制造模式的价值实现功能,它的生成是为了弥补制造模式柔性不足的缺陷。     

基于精益供应链的工程建设项目价值分析

结合精益供应链理论,以价值作为方案决策要点,对工程建设项目价值分析进行研究,通过案例说明价值分析在工程建设项目中的应用流程。采用模糊质量功能展开法综合评价各方案的价值,并进行对比分析,找出价值最优方案。基于精益供应链的工程建设项目价值分析是一种行之有效的方案决策方法。     

沥青路面贫混凝土基层应力计算

为分析贫混凝土基层沥青路面新型路面结构的基层应力情况,通过有限元分析方法计算贫混凝土基层的荷载应力,并利用弹性层状体系理论分析沥青面层厚度对其影响,由此推导出基层荷载应力的计算公式.根据不同自然区划的温度场和最大温度梯度,得出贫混凝土基层沥青路面中的基层温度应力的有限元解,于此提出了基层温度应力的计算公式.上述两公式为贫混凝土基层沥青路面结构中基层厚度设计的重要依据.