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181.
182.
大系统分散鲁棒容错控制的进展及主要成果   总被引:1,自引:0,他引:1  
综述了近20年来关联大系统分散鲁棒容错控制的研究动态及取得的主要成果。说明了统一地研究分散鲁棒容错控制的必要性。在分散控制、鲁棒控制和容错控制研究领域内,分析了各种设计方法的主导思想及实质;指出了这些研究成果的意义与存在的问题。文中着重论述了分散、鲁棒、容错控制研究方法的发展途径。  相似文献   
183.
在聚乙二醇(PEO)存在下,CaCl2和Na2CO3反应生成了类似红鲍鱼壳的含有PEO的碳酸钙──高聚物复合材料。X-衍射和电镜照片显示,它有两种微观结构:外层为文石型和方解石型结构,内层为针状文石型结构。热重分析表明,该材料中含有3%左右PEO。结果说明,聚合物对碳酸钙晶核的形成和晶体的生长有很大影响,并对其形成机理进行了初步探讨。  相似文献   
184.
185.
液闪效率示踪法校正效果的评价   总被引:1,自引:0,他引:1  
本文评价了Aloka商品液闪仪效率示踪法dpm校正的效果。轻,中度猝灭校正效果理想,具有简便、实用和适用性广泛的特点。严重化学和颜色猝灭样品的校正结果分别随猝灭增加而向增大和减小的方向偏离,形成喇叭状曲线,文中对这一现象给出初步解释。  相似文献   
186.
Certain new sulfide-smelting processes and coal-gasification processes generate high-strength sulfur dioxide streams, for which a new process for converting sulfur dioxide to elemental sulfur needs to be developed because no process exists that is generally and economically applicable to the treatment of such streams. A thermodynamic and experimental investigation to develop a new process for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating secondary pollutants was carried out. In this process, the starting raw material, calcium sulfate, is reduced by a suitable reducing agent, such as hydrogen, to produce calcium sulfide, which is used to reduce sulfur dioxide to elemental sulfur vapor and calcium sulfate. The latter is, in turn, reduced to regenerate calcium sulfide. In this Part I, detailed experimental results are presented on the kinetics of the reaction between sulfur dioxide and calcium-sulfide pellets, which produces elemental sulfur and calcium sulfate. The experiments were carried out at temperatures between 1023 and 1088 K and sulfur-dioxide partial pressures between 9 and 60 kPa by the use of a thermogravimetric analysis (TGA) technique. The rate of this reaction was demonstrated by the conversion of 40 pct calcium-sulfide pellets obtained from the hydrogen reduction of fresh calcium sulfate in 10 minutes at 1073 K under a sulfur-dioxide partial pressure of 43 kPa. The reactivity decreased somewhat during the first three cycles but remained largely unchanged thereafter up to the tenth cycle. This characteristic of the pellets is important because the solids must be reusable for repeated cycles to avoid generating secondary pollutants. A pore-blocking model was found to fit the reaction rate. The reaction is first order with respect to sulfur-dioxide partial pressure and has an activation energy of 101 to 134 kJ/mol (24 to 32 kcal/mol) for calcium-sulfide pellets reacted and regenerated several different times. Sulfur dioxide-containing streams from certain sources, such as the regenerator off-gas from an integrated-gasification, combined-cycle, desulfurization unit and new sulfide-smelting plants, contain much higher partial pressures of SO2. In these cases, the rate of the first reaction is expected to be proportionally higher than in the test conditions reported in this article. The reduction kinetics of calcium-sulfate pellets with hydrogen gas is reported in the accompanying Part II.  相似文献   
187.
二氧化碳增油技术在孤岛油田的应用   总被引:1,自引:0,他引:1  
介绍了二氧化碳增油机理和二氧化碳增油技术在孤岛油田的应用情况。现场应用表明 ,二氧化碳非混相驱油是封闭小断块油田的有效增产措施 ,二氧化碳酸化 (压裂 )助排能起到缩短排液时间 ,保护油气层的作用  相似文献   
188.
Following up on recent studies of the Zn-rich corners of the Zn-Fe-Ni and Zn-Fe-Si ternary systems, a 450 °C isothermal section of the Zn-Fe-Ni-Si quaternary phase diagram with the Zn composition being fixed at 93 at.% was determined experimentally using optical microscopy, scanning electron microscopy (SEM) coupled with energy dispersive x-ray spectroscopy (EDS), and x-ray diffractometry (XRD). FeSi was found to be in equilibrium with almost all phases in the section, including the T, ζ, Ni-δ, NiSi2, and FeSi2 phases, as well as the liquid phase (L). Silicon solubilities in the T, ζ, and Ni-δ phases were rather limited. However, the solubilities of Fe and Zn in the NiSi2 phase, at 4.5 at.% and 7.2 at.%, respectively, were appreciable. The existence of the (L+NiSi2+Ni-δ) three-phase equilibrium state apparently prevents other Ni-Si compounds from entering equilibrium with the liquid at 450 °C. No true quaternary compound was found in the study.  相似文献   
189.
纺织服装工业是历史最悠久的产业,似乎天生就是劳动密集型的传统产业.然而,在技术高速发展的21世纪,纺织业正在发生着本质的变化,那就是从传统劳动密集型纺织向高技术纺织的转变,而且这种转变是全方位的,涉及到从原材料、纺织生产、最终产品到产品销售的方方面面.  相似文献   
190.
Microbiological denitrification of red beet juice   总被引:1,自引:0,他引:1  
The purpose of study was the determination of optimal conditions for red beet juice denitrification by Paracoccus denitrificans bacteria as well as the evaluation of the usefulness of microbiologically treated juice for the production of a natural colouring preparation for foods. Total reduction of nitrates was found during bacterial culturing at 25 and 30 °C, at an initial pH of 7.0-8.0 and juice osmotic pressure of 900-1100 mOsm/kg. Microbiological denitrification procedure affected colour, taste and aroma of the juice. However, the use of juice as food colouring and component was made feasible by acidification and partial evaporation of water together with volatile substances.  相似文献   
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