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21.
Studies were made on the thermally stimulated discharge currents (TSDCs) in pure (undoped) and Fe-doped polystyrene films as a function of polarizing field, polarizing temperature and dopant concentration. While undoped films exhibited a single peak, doped films showed two peaks one at low temperatures and another at high temperatures. The low temperature peak, which exhibits a shift towards lower temperatures with increasing dopant concentration, is attributed to the relaxation of the main chain, while the high temperature peak, which shows a tendency to shift towards higher temperatures with dopant concentration, is due to space charge polarization. The TSDCs were higher for low dopant concentrations than their undoped counterparts, while for high concentrations of the dopant, the TSDCs decreased. Formation of charge transfer complexes at low dopant concentrations and molecular aggregates at higher dopant concentrations are suggested as the possible reasons for this behaviour.  相似文献   
22.
Material removal and surface damage of Ti3SiC2 ceramic during electrical discharge machining (EDM) were investigated. Melting and decomposition were found to be the main material removal mechanisms during the machining process. Material removal rate was enhanced acceleratively with increasing discharge current, ie, working voltage, ui, but increased deceleratively with pulse duration, te. Microcracks in the surface and loose grains in the subsurface resulted from thermal shock were confirmed, and the surface damage in Ti3SiC2 ceramic led to a degradation of both strength and reliability.  相似文献   
23.
BACKGROUND: Many industrial discharges, such as those generated from petrochemical refineries, contain large amounts of sulfurous, nitrogenous and organic contaminants. Denitrification has emerged as a suitable technology for the simultaneous removal of these pollutants in a single reactor unit; however, more evidence is demanded to clarify the limitations of denitrification on the simultaneous removal of sulfide and phenolic contaminants and to optimize the biological process. The aim of this study was to evaluate the capacity of a denitrifying sludge to simultaneously convert sulfide and p‐cresol via denitrification. RESULTS: Sulfide was the preferred electron donor over p‐cresol, imposing a 5 h lag phase (required for complete sulfide removal) on organotrophic denitrification. Addition of sulfide (20 mg S2? L?1) to p‐cresol‐amended denitrifying cultures also decreased the reduction rate of nitrate and nitrite, as well as the production rate of nitrogen gas. Nitrite reduction rate was the most affected step by sulfide, decreasing from 35 to 21 mg N (g VSS d)?1. A synergistic inhibitory effect of nitrate and sulfide was also observed on nitrite reduction. Despite the effects of sulfide on the respiratory rates monitored, complete removal of nitrate, sulfide and p‐cresol could be achieved after 48 h of incubation. CONCLUSION: Our results suggest that simultaneous removal of sulfide and p‐cresol could be achieved in denitrifying reactors, but a large hydraulic residence time may be required to sustain an efficient process due to inhibitory effects of sulfide. Copyright © 2008 Society of Chemical Industry  相似文献   
24.
为了保证进口精对苯二甲酸装置氧化反应器中钛制搅拌器的正常工作,对钛制搅拌器桨叶在运行中断裂脱落的原因进行了分析,并叙述了桨叶修理的方法和要求。经修理后的桨叶投入生产使用,达到了预期的目标。  相似文献   
25.
惠志林  高云  李明  崔舜  余成洲 《稀有金属》2003,27(6):734-737
介绍了一种复合金属多孔体的制备及其方法,首先以泡沫塑料为芯膜,经过导电化处理使其具有导电性,其次进行电沉积金属铁,再进行电沉积金属镍,经过热处理后可制备出复合金属多孔体。该复合金属多孔体用铁取代金属镍,其抗拉性能优于单质泡沫镍,同时可以降低制造成本,主要用于载体如电池电极。  相似文献   
26.
通过对五级旋风筒下料管、回转窑转速、配料方案、物料稳定等四方面进行改进,达到提产目的。  相似文献   
27.
The hydrogen fuel cell is a promising option as a future energy resource; however, the nature of the gas is such that the conversion process of other fuels to hydrogen on board is necessary. Among the raw fuel resources, methane could be the best candidate as it is plentiful. In this experiment, the possibility of producing hydrogen with less carbon formation from methane by a dielectric barrier discharge (DBD) was investigated. Without the addition of a catalyst, the formation of hydrogen reached between 30% and 35% at methane residence time of 0.22 min and supplied powers in the range of 60-130 W. The hydrogen selectivity increased at higher supplied power, but the process efficiency, defined as a ratio of the produced hydrogen to the supplied power, decreased slightly. In order to boost the hydrogen production with less carbon formation, a mixed oxide catalyst of zinc and chromium was added to the reactor. It was shown that the production of hydrogen was ca. 40% higher than the non-catalytic plasma process.  相似文献   
28.
29.
介绍了我国紫菜工业在工艺改进、资源开发、综合利用和深度加工等方面的情况,提出了提高产率、降低物耗、增进效益和增加品种的途径。  相似文献   
30.
含油废水处理   总被引:10,自引:0,他引:10  
赵亚乾  徐培 《水处理技术》1995,21(4):227-230
在水量水质调查的基础上,本文提出了以出水回用为目的的含油废水隔油调节沉淀-混凝沉淀-砂滤处理工艺,动态模型试验表明,废水中油和COD的去除率分别达到95%和90%,出水浊度低于2,此水质完全可回用于有关生产车间。  相似文献   
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